Plant Cell Advance Publication. Published on January 30, 2017, doi:10.1105/tpc.16.00768 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 LARGE-SCALE BIOLOGY ARTICLE Protein Degradation Rate in Arabidopsis thaliana Leaf Growth and Development Lei Li, Clark J. Nelson, Josua Trösch, Ian Castleden, Shaobai Huang, A. Harvey Millar* ARC Centre of Excellence in Plant Energy Biology, Bayliss Building M316, University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia, Australia *Corresponding author: [email protected] Short title: Protein turnover in leaf development One-sentence summary: The degradation rate of 1228 Arabidopsis proteins were measured, their variation assessed and the data used to calculate the protein turnover energy costs in different leaves of the rosette. The authors responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is Harvey Millar ([email protected]). ABSTRACT We have applied 15N labeling approaches to leaves of the Arabidopsis thaliana rosette to characterize their protein degradation rate and understand its determinants. The progressive labeling of new peptides with 15N and measuring the decrease in the abundance of >60,000 existing peptides over time allowed us to define the degradation rate of 1228 proteins in vivo. We show that Arabidopsis protein half-lives vary from several hours to several months based on the exponential constant of the decay rate for each protein. This rate was calculated from the relative isotope abundance of each peptide and the fold change in protein abundance during growth. Protein complex membership and specific protein domains were found to be strong predictors of degradation rate, while N-end amino acid, hydrophobicity or aggregation propensity of proteins were not. We discovered rapidly degrading subunits in a variety of protein complexes in plastids and identified the set of plant proteins whose degradation rate changed in different leaves of the rosette and correlated with leaf growth rate. From this information, we have calculated the protein turnover energy costs in different leaves and their key determinants within the proteome. 1 ©2017 American Society of Plant Biologists. All Rights Reserved 39 INTRODUCTION 40 41 For plants to respond to the daily requirements of cellular maintenance and for their organs 42 to progress through different developmental stages, new complements of proteins need to 43 be synthesized while existing ones are degraded. Protein synthesis occurs via ribosomes in 44 the cytosol, plastid and mitochondrion. Synthesis rate is defined by the abundance and 45 availability of different mRNA (Juntawong et al., 2014), the energetic status of cells to 46 provide the amino acids and ATP for catalysis (Edwards et al., 2012), and the post- 47 translational regulation of ribosomal function (Ren et al., 2011). Cellular protein degradation 48 is achieved by the coordinated action of the proteasome on ubiquitinated proteins in the 49 cytosol (Vierstra, 2009), autophagy of cytosolic complexes and organelles through vacuole- 50 based protein degradation machinery (Araujo et al., 2011) and a network of organelle- 51 localized proteases (Janska et al., 2013; van Wijk, 2015). The rates of synthesis and 52 degradation of individual proteins define the proteomes of plant tissues and their rate of 53 change. 54 55 The combination of protein synthesis and degradation is often termed protein turnover; 56 however, there are many different definitions and assumptions made in using this term and 57 in calculating it. Protein degradation rates and calculated turnover rates can be measured on 58 a total plant protein basis by combining all polypeptides as a group and measuring rates at 59 which ‘old protein’ disappears or ‘new protein’ replaces old. These types of calculation look 60 at the amount of original protein remaining and/or the proportion of new protein to old at 61 several time points and calculate a rate of renewal. This approach typically does not 62 consider the inherent rate of degradation of the newly synthesized material. Rates calculated 63 without considering degradation of new proteins are intrinsically linked to the growth rate of 64 the tissue which can dramatically alter the pool size of the new protein component over time. 65 Protein turnover of roots has been measured this way using pulse chase 66 labelling of fast and slow growing grass species (Scheurwater et al., 2000) to define 67 degradation rates of 0.12-0.16 d-1 and a total protein half-life of 4-6 days. Using Arabidopsis 68 thaliana rosettes and 13CO2 pulse-chase labelling (and a focus on the relative isotope ratio of 69 Ala residues) degradation rates of 0.03-0.04 d-1 and a leaf protein half-life of 3.5 d were 70 calculated by combining degradation and original protein dilution through new protein 71 synthesis (Ishihara et al., 2015). 14 C-Leucine 72 73 Protein degradation and turnover can also be measured for specific proteins of interest. This 74 requires a method to identify individual proteins and to differentiate between old and new 75 polypeptides for the same protein over the timeframe of measurement. Early studies used 2 76 antibodies and generic protein biosynthesis inhibitors to do this, but given the cellular 77 consequence of protein biosynthesis inhibition, there are many pleiotropic effects in such 78 measurements in all but very short timeframes (Vogtle et al., 2009; Armbruster et al., 2010). 79 The combination of stable isotopes and peptide mass spectrometry have recently allowed 80 old and new protein populations to be differentiated without the need for protein biosynthesis 81 inhibition and have become a method of choice in new studies. The experimental 82 measurement of protein degradation rate (KD) through isotopic labeling and mass 83 spectrometry (MS) has enabled datasets of hundreds of individual protein degradation rates 84 and half-lives to be assessed in yeast, mammalian cell culture and intact animals typically 85 using single labeled amino acids (SILAC) (Price et al., 2010; Schwanhausser et al., 2011; 86 Yip et al., 2011). Plants are typically not amenable to successful SILAC labelling due to their 87 synthesis and interconversion of all protein amino acids. As a result, studies have assessed 88 the utility of various metabolic labels (2H, 89 2010; Chen et al., 2011; Li et al., 2012). Recently, metabolic labelling with inorganic 90 been the most commonly used stable isotope incorporation technique to define degradation 91 or turnover rates of organelle proteins in Arabidopsis cell culture (Nelson et al., 2013), 92 protease targets in Arabidopsis leaf mitochondria (Huang et al., 2015; Li et al., 2016), ~500 93 proteins in barley (Hordeum vulgare) leaves (Nelson et al., 2014), ~200 membrane and 94 microsomal fraction proteins from Arabidopsis roots (Fan et al., 2016), and ~500 Medicago 95 leaf and root proteins during drought and recovery from drought (Lyon et al., 2016). One 96 study has also followed selected protein degradation rates using 13CO2 in Arabidopsis leaves 97 (Ishihara et al., 2015). While the primary data from labelling in each case represent relative 98 isotope abundance (RIA) for a given peptide, different methods have been used to calculate 99 protein degradation, synthesis, and turnover rates and protein half-lives. Some of these 100 calculations considered the growth rate of tissues, the degradation rate of newly synthesized 101 proteins and the relative abundance of different proteins during labelling, while others did 102 not. Depending on the method used, the KD reported can be highly dependent on tissue 103 growth rate and/or on relative abundance of the protein over time and may not represent a 104 property of the polypeptide per se. As a result, we still have limited data on the rate of 105 protein degradation for different classes of plant proteins and little clarity about whether 106 degradation rate is a variable or constant feature of the lifecycle of a specific plant 107 polypeptide type. 13 C, and 15 N) for the purpose in plants (Yang et al., 15 N has 108 109 Here, we aimed to define the key features of proteins that determine their experimental 110 degradation rate and measure changes in these rates for given protein sets at different 111 stages of Arabidopsis leaf growth through assembly of a larger and more precise data set 112 than used in previous studies. This approach provides a foundational dataset for protein 3 113 degradation rates in Arabidopsis and evidence of which proteins have variable degradation 114 rates as leaves grow. In the process, we have newly identified rapidly degrading subunits in 115 a variety of protein complexes in plastids, found the set of proteins for which degradation 116 rate positively or negatively correlates with leaf growth rate and considered the protein 117 turnover energy costs for total and specific proteins in different leaves of the Arabidopsis 118 rosette. 119 120 RESULTS 121 122 Changes in Arabidopsis leaf protein content at different stages of leaf development 123 When specific proteins remain in steady-state within the proteome over the time course of 124 15 125 the rate of tissue growth. To calculate this dilution effect, Arabidopsis thaliana seedlings were 126 grown in natural abundance hydroponic culture medium (99.6% 127 produced their tenth true leaf, a stage referred to as leaf production stage 1.10 (Boyes et al., 128 2001). To compare their total protein abundance, leaf number 3, 5 and 7 from a series of 129 rosettes were collected over a period of 5 days (Supplemental Figure 1A). Proteins were 130 extracted from these leaf samples for analysis of total leaf protein content (Figure 1). This 131 allowed an assessment of the growth rate of different leaves of the rosette on a protein 132 basis. We assessed protein content by protein extraction and amido black measurement 133 (Supplemental Data set 1) and by imaging gel-separated proteins from whole leaves 134 ground into sample buffer (Supplemental Figure 1B, Supplemental Data set 1). leaf 3 135 increased its total protein content by only 3% per day, in contrast to leaves 5 and 7, which 136 grew at three and five times this rate, respectively (Figure 1). As a consequence, leaf 7 137 nearly doubled in size and total protein content over five days while leaf 3 hardly grew at all. N progressive labelling, a single dilution effect can be calculated and applied to account for 14 N) for 21 days until they 138 139 Protein degradation rate of specific proteins in Arabidopsis leaves 140 Leaves in the Arabidopsis rosette were then sampled at the same time points as above, but 141 in this case the hydroponic medium was changed at T=0 from 99.6% 14N to 98% 15N to allow 142 progressive labelling of each leaf over the time course of 5 days. A flow diagram of the 143 experiment and the sample preparation for mass spectrometry are shown in Supplemental 144 Figure 2. Extensive LC-MS/MS analysis of these samples provided data from 61,196 145 independently quantified peptides for which we could acquire the ratio between natural 146 abundance (NA) and heavy (H) labelled peptides. Using the ratio of labelled to NA peptides 147 and fold change in protein (FCP) as each leaf grew (Figure 1), we estimated degradation 148 rate for 1228 non-redundant Arabidopsis proteins. Inclusion in this list required each protein 149 to be quantified in >=3 of 27 samples, the number of peptides quantified independently in 4 150 the 27 samples to be greater or equal to 5 and for the protein identification to be p>0.95 as 151 outlined in Methods (Supplemental Data set 2A, B). Sample calculations of Labeled Protein 152 Fraction [LPF, i.e. H/(H+NA)] are shown for a slow degrading peptide (Supplemental 153 Figure 3A) and a fast degrading peptide (Supplemental Figure 3B) in each of the three 154 leaves over the time course. The degradation rates (KD) of 1228 proteins were calculated as 155 explained in the Methods section and as shown in Supplemental Figure 3C for the example 156 of a fast and a slow degrading peptide. KD is the proportional decrease of the current protein 157 abundance per day; i.e. it is the exponential constant of the decay rate for each protein and 158 as such has units of d-1. These KD rates showed a wide distribution ranging from 0 to 2 d-1, 159 which is equivalent to half-lives for proteins of several hours to several months. These are 160 the average KD across all cell types in a leaf tissue examined and, like all quantitative 161 proteomics, any cell type-specific differences will be lost in this averaging. The median 162 relative standard error (RSE) was < 10% for measurement of KD of a specific protein 163 (Supplemental Data set 2B). In general, about 15% of the data (184 proteins) showed 164 degradation rates more than two times the KD median (~0.22 d-1), which we defined as 165 relatively fast degrading proteins; about 13% (161 proteins) showed degradation rates of 166 less than half the median (~0.055 d-1), which we defined as relatively slowly degrading 167 proteins; while the majority (72%) showed values in the four fold range between these KD 168 values (Supplemental Data set 2B). 169 170 Determination of the fraction of proteins that are labeled, represented by the LPF value, is a 171 binary differentiation between two populations of peptides. As the peptides measured 172 typically contained 8-30 Ns per peptide, only a few N atoms anywhere in the peptide would 173 place a peptide in the heavy-labelled pool. All such peptides were considered heavy-labelled 174 and the degree of 175 measurements of the incorporation of a specific amino acid within a peptide, which requires 176 a detailed knowledge of the peptide incorporation ratio in that AA and the free AA pool 177 incorporation ratio to calculate peptide synthesis levels (Ishihara et al., 2015). However, 178 despite these advantages, the LPF approach employed here can be affected by a lag before 179 new protein synthesis can be effectively distinguishable from previously present (NA) 180 proteins. The lag is overcome as soon as a 10-15% labelling level is reached in major AA 181 pools (Nelson et al., 2014). The three different leaves did show some differences in 182 labelling efficiency (Supplemental Figure 4). A regression method can be used to determine 183 the lag effect as the lag in the x-intercept value when graphing of all timepoints (Nelson et 184 al., 2014). Calculations based on this method showed leaves 3, 5 and 7 had a 5-6 h lag 185 before 186 represented 4-25% of the time interval for day 5, day 3 and day 1 data, respectively, which 15 N labelling formed no part of our calculations. This is distinct from 15 N 15 N reached this 10-15% threshold (L3 = 4.7 h; L5 = 5.9 h, L7 = 5.2 h). This 5 187 was similar to the relative standard error of our calculations for any one protein. To examine 188 if this calculable lag would systematically effect KD values, we selected 146 proteins that 189 were quantified in all samples at all timepoints and plotted their degradation rates together 190 across all three replicates, timepoints and leaf types. No significant trends were apparent to 191 indicate that this general effect would bias our data (Supplemental Figure 5). We are not 192 aware of literature that has divided leaves into cell types to show differences in 193 incorporation rate within leaves to justify the concern that lag averages are not a fair 194 reflection for an average leaf calculation. 15 N 195 196 Grouping proteins by their functional category (Figure 2A) showed that most protein groups 197 maintained the median degradation rate of about 0.11 d-1. Exceptions were proteins involved 198 in protein synthesis that degraded at closer to 0.03 d-1 and stress, secondary metabolism 199 and redox proteins that degraded at rates approaching 0.20 d-1. Individual proteins 200 degrading at very high rates were found in many functional categories and typically showed 201 rates from 0.6 up to 2.0 d-1, which was 6 to 20 times the median KD and 4 to 13 standard 202 deviations from the median (Figure 2A). The 20 fastest degrading proteins comprised a set 203 of 8 plastid proteins, 6 cytosolic proteins and 6 proteins localized elsewhere in the cell (Table 204 1). To look for evidence of differences in the rate of autophagy of cellular structures or the 205 role of intraorganellar proteases in changing the degradation rate inside specific organelles, 206 we arranged the dataset into the final subcellular location of proteins using the location 207 Bayesian classifier, SUBAcon (Tanz et al., 2013; Hooper et al., 2014). This showed a lower 208 median degradation rate of mitochondrial, plastidial and nuclear proteomes and a higher 209 median degradation rate for the proteomes of endoplasmic reticulum (ER) and the Golgi 210 apparatus. This is broadly consistent with the physical separation of organelle proteomes 211 from the cytosolic proteolysis system and the transient nature of the protein complement of 212 ER and Golgi (Figure 2B). Direct comparison of protein degradation rates in this dataset to 213 either orthologues in barley (Nelson et al., 2014) was possible because the same 214 measurement approach was used in both of these studies (Figure 2C). This comparison 215 showed that four ortholog pairs between the two species had consistently high degradation 216 rates, namely the thiamin synthesis enzymes THI1 and THIC, D1 of PSII and PTERIN 217 DEHYDRATASE (R=0.99). However, more broadly this comparison showed a relatively low 218 correlation between degradation rate of the majority of Arabidopsis and barley homologous 219 pairs (R=0.38). 220 221 Changes in Arabidopsis leaf proteomes at different stages of development and across 222 the diurnal cycle 223 To check if proteins remained in steady-state within leaf proteomes over the time course of 6 224 our measurements, the relative abundances of specific Arabidopsis proteins were assessed 225 in the samples from different timepoints by spiking natural abundance samples after protein 226 extraction with a 227 leaves kept as a reference standard. Mixed proteins were then in-solution digested by 228 trypsin for mass spectrometry analysis. A flow diagram of this experiment and the sample 229 preparation for mass spectrometry are also shown in Supplemental Figure 2. This provided 230 quantitation of 1697 non-redundant proteins. Proteins were included in this group if they 231 were quantified in >=3 of 36 samples, the number of peptides quantified independently in the 232 36 samples was greater than or equal to 5 and the protein identification had p>0.95 as 233 outlined in methods (Supplemental Data set 3A). In total, 955 proteins in this set of 1697 234 were also found in the set of 1228 proteins for which we calculated a KD value (Figure 3A, 235 Supplemental Data set 3B). Principal components analysis (PCA) of protein relative 236 abundance data from this mass spectrometry experiment showed that the three different 237 leaves in the rosette could be separated by a single principal component explaining 43% of 238 the variation (Figure 3B). Only minor variations were observed in the PCA between samples 239 of the same leaf number at different points in time. Changes in relative protein abundances 240 over time in the different leaf proteomes were compared and statistically evaluated by T- 241 tests and 1-way ANOVA (Figure 3C; Supplemental Data set 3C). This analysis indicated 242 that only a few percent of proteins significantly changed in abundance in leaf 3 across the 243 whole time course, which was close to expectation for random variation in the experiment 244 (p<0.01). Leaf 7 showed a similar pattern of percentage differences with only the samples 245 from the day 1 showing significant differences from day 5 samples. No specific proteins were 246 found to change in abundance between all timepoints in leaf 3 and leaf 7 (Figure 3C). By 247 contrast, leaf 5 showed 13-33% of the analyzed protein set differing in relative abundance by 248 day 5; however, only 0.4% (two proteins) showed consistent changes across the time course 249 (Supplemental Data set 3C). This revealed that relatively high abundance proteins of leaf 3 250 and leaf 7 were effectively in steady state during the experiment, albeit with different rates of 251 new tissue growth (Figure 1), and thus steady-state principles could be applied to establish 252 protein degradation rates for existing proteins in leaves 3 and 7 over a 5 day period. For leaf 253 5, some variation in abundance was evident but only at the day 5 timepoint. The majority of 254 data showed only 20-30% changes in abundance, for the proteins that differed at day 5, 255 which will not have a major effect on KD calculations. 15 N fully-labeled protein sample from a separate batch of Arabidopsis 256 257 One important factor that could explain the need for rapid degradation of some proteins is a 258 circadian or diurnal change in transcription and translation that would need to be matched by 259 the degradation rate to enable a daily rhythm in protein abundance. Expression profiling of 260 Arabidopsis leaves has previously shown that diurnal patterns of transcription can underlie 7 261 daily fluctuations in protein abundances in leaves (Mockler et al., 2007; Giraud et al., 2010; 262 Lee et al., 2010). To test if enhanced degradation rate correlates with diurnal gene 263 expression or protein abundance changes, we attempted to correlate the calculated KD with 264 the degree of change in transcript abundance of diurnally regulated genes (Mockler et al., 265 2007) or the degree of change in Arabidopsis protein abundance following 8 hours of 266 illumination (Liang et al., 2016); however we found no significant correlation of these with KD 267 (R=0.01 and R=0.02-0.08; n=917 and 1158, respectively). By contrast, when the 1228 KD 268 values were separated into slow (n=161), intermediate (n=883) and fast (n=184) groups, as 269 outlined above, and compared to light-induced, dark-induced and non-diurnal transcripts (as 270 defined by Mockler et al., 2007), non-parametric tests showed an enrichment (p< 0.01) of 271 light-induced transcripts in the fast KD group compared to the non-diurnal or dark-induced 272 transcripts. This apparent link between light-induced diurnal expression and fast KD was 273 observed in long-day or 12h-12h experiments in both Col-0 and Ler backgrounds (Smith et 274 al., 2004; Blasing et al., 2005; Mockler et al., 2007). 275 276 Intrinsic protein properties linked to degradation rate 277 The fact that protein degradation rate of individual proteins was quite reproducible between 278 leaf types over the time course indicated that some factors intrinsic to each protein’s 279 expression, protein properties or susceptibility to modification, unfolding or proteolysis could 280 be a central controller of protein degradation rate. The N-end rule proposes that the N- 281 terminal amino acid of a protein is a key driver for turnover rate. A series of stabilizing and 282 destabilizing N-terminal AAs having already been experimentally defined in yeast and 283 mammals (Bachmair et al., 1986; Gonda et al., 1989). However, we were unable to find any 284 statistical linkage between KD and either the N-end AA of mature proteins or sets of AAs 285 considered to be stable, unstable or of average stability based on yeast and mammalian 286 data (Figure 4A, Supplemental Data set 4A). AA residues within protein sequences can 287 promote ordered aggregation, which can be a precondition for altered rates of protein 288 degradation in mammals. The TANGO algorithm can predict this aggregation propensity 289 (Fernandez-Escamilla et al., 2004). In our set of 1228 proteins, the top 100 fastest degrading 290 proteins show significantly higher protein aggregation propensity (AGG; p<0.05) and longer 291 AA length (LEN; p<0.05), but no significant difference (p=0.70) in AGG/LEN when compared 292 to the 100 slowest turnover proteins (Figure 4B, Supplemental Data set 4B). This result 293 implies that the aggregation propensity of faster degradation proteins in Arabidopsis was 294 dependent on length and there was a tendency for proteins to be longer in the set of faster 295 degrading proteins. Integral membrane proteins require different machinery for degradation 296 than soluble proteins and have different accessibility to proteases (Fleig et al., 2012; Avci 297 and Lemberg, 2015). Neither grand average of hydrophobicity (GRAVY) nor transmembrane 8 298 domain number showed overall correlations with the KD of proteins, but beta barrel structure 299 proteins had very low KD values compared to other groups of proteins (Supplemental Data 300 set 4C). 301 302 Many proteins do not operate as independent monomers in vivo but are present in strict 303 stoichiometry in protein complexes. We tested the hypothesis that degradation rates of 304 members of a complex would be more consistent with other members of the same complex 305 than the wider set of cellular proteins. The members of seven major protein complexes 306 representing the cytosol ribosome, proteasome, plastid ATP synthase, plastid ribosome, 307 photosystem I (PSI), photosystem II (PSII) and mitochondrial electron transport chain (Mt 308 ETC) were extracted from the 1228 dataset, and all other proteins in the 1228 were 309 considered in one group, designated as ‘Others’. Outlier data for specific protein complexes 310 and from the ‘Others’ group were removed for the analysis. The standard deviation (σ) was 311 calculated for KD values for each protein complex (Figure 4C, red line) with N subunits and 312 this was compared to 100,000 randomly sampled sets of the same N from the ‘Others’ 313 category (blue distributions). Probability (p) values showed that in all cases, except the 314 cytosolic ribosome, the standard deviations were significantly smaller for the complexes than 315 for the random distribution sets of the same N. In a complementary approach, a pairwise 316 Silhouette (Si) clustering comparison (Rousseeuw, 1987) was performed between each 317 protein complex and ‘Others’. The ∆Si value (-2, 2) in each case showed the level of relative 318 tightness of the KD rates of the specific protein complexes compared with ‘Others’. Plastid 319 ATP synthase, PSI and proteasome had the highest ∆Si values and were thus the three 320 protein complexes with the tightest distribution in terms of the degradation rates of their 321 subunits (Supplemental Data set 4D). 322 323 A protein’s function or domain structure may also be a factor in defining its degradation rate. 324 The high degradation rate of proteins has previously been explained based on specific 325 features of a protein fold that enables rapid degradation in protein abundance, e.g. the auxin 326 degron (Nishimura et al., 2009), or the irreversible binding of inhibitors to a protein domain or 327 due to an enzymatic mechanism that damages an active site (e.g. self-hydrolyzing enzymes, 328 reactive oxygen species damage, co-substrate enzymes or catalysis with suicide substrates) 329 (Walsh, 1984; Chatterjee et al., 2011). To test systematically for domains in Arabidopsis 330 proteins linked to degradation rate, we searched for differences in protein degradation rate 331 distributions between protein sets with common protein domains. Fifty-eight non-redundant 332 protein domain sets were selected for non-parametric k-sample K-W (p<0.01) and C-I post- 333 hoc testing (Table 2, Supplemental Data set 4E). These protein domains can be divided 334 into 10 groups (A-J) based on degradation rates. The four proteins containing the SH3 9 335 domain involved in translation were the most stable proteins (median of 0.05 d-1) while the 336 four proteins (three E2 and one E1 ligases) containing the ubiquitin-conjugating enzyme 337 domain (median of 0.38 d-1) were the most unstable. 338 339 Differences in degradation rate and abundance of specific proteins in leaves of 340 varying ages 341 While overall protein degradation rates of individual proteins were relatively reproducible 342 (median RSE of all peptide data or a protein ~10%, and between leaf types in the rosette 343 RSE ~16%; Supplemental Data set 2B), there were specific proteins for which degradation 344 rate appeared to be significantly influenced by the leaf from which the protein was derived. 345 Analysis of these proteins allowed us to look for linkages between changes in protein 346 degradation rate and protein relative abundance in two very different growth scenarios. 347 Proteins in leaf 3 and leaf 7 were selected if they had significant differences in both protein 348 abundance (Figure 5A left; p<0.05; 502 pairs) and degradation rate (right; p<0.05; 433 349 pairs) and the set was separated into functional categories. Leaves 3 and 7 were chosen 350 because proteins in their proteomes best reflected a steady-state over time that could be 351 described by a simple dilution effect (Figure 3). The abundance and degradation differences 352 for these proteins were calculated as relative ∆Abundance and relative ∆KD (i.e. (Leaf 7-Leaf 353 3)/Average (Leaf 3, 7)) and are each presented as boxplots in Figure 5A. The dashed line 354 indicates the point of parity between leaf 3 and 7. Lower protein abundance in leaf 3 of 7 355 correlated with higher degradation rates for plastid proteins involved in cell organization, light 356 reactions, stress, Calvin cycle and photorespiration enzymes, while high protein abundances 357 in leaf 3 or 7 correlated with low protein degradation rate for plastid proteins involved in 358 tetrapyrrole synthesis, protein folding and protein synthesis. When we focused on 359 photosynthesis-associated proteins, and matched individual proteins across the data from 360 leaf 3, 7 and 5, we found that there was a consistent correlation between relative abundance 361 (Figure 5B) and protein degradation rate (Figure 5C) on a protein-by-protein basis across 362 different protein complexes and metabolic pathways. In these experiments, leaf 5 KD data 363 sat neatly between that of leaf 3 and leaf 7, despite some concerns about the steady-state 364 assumption rising from Figure 3. A set of KD values for 49 photosynthesis proteins were 365 also independently calculated by regression analysis across all time points, to ensure the 366 effect was not due to the method of calculation. This alternative analysis gave effectively the 367 same result i.e. degradation rates were higher in leaf 7 than leaf 3, with leaf 5 in between 368 (Supplemental Figure 6, Supplemental Data set 5A). A set of 179 unique proteins with 369 significant changes in both degradation rates and abundances between leaf 3 and 7 were 370 then analyzed using correlation analysis. Nearly 85% of these proteins showed patterns of 371 either increasing degradation rate and decreasing protein abundance, or decreasing 10 372 degradation rate and higher protein abundance (Supplemental Data set 5B). 373 374 Protein kinetic signatures of leaf growth 375 In hypertrophic mouse hearts, organ growth rate has been associated with disease and 376 differences in protein degradation rate has been used to propose the concept of ‘protein 377 kinetic signatures’ associated with cellular dysfunction (Lam et al., 2014). These kinetic 378 signatures have been defined as proteins for which a change in degradation rate correlated 379 with tissue growth rate. These rate-changing-proteins were regarded as a new type of 380 disease marker (Lam et al., 2014). We used the same principle here to determine if the 381 degradation rate of specific leaf proteins could be correlated to leaf growth rate. In our case, 382 these plant rate-changing-proteins would be biomarkers associated with plant leaf growth 383 rather than indicators of disease. By presenting protein degradation rates in different 384 functional categories as a function of the growth rates of leaves (Figure 6A-E; 385 Supplemental Data set 6A) we observed that the degradation rate of many photosynthesis- 386 related proteins positively correlated with leaf growth rate, with the exception of chaperonin 387 60 proteins (Figure 6A). The latter have their highest abundance in the fastest growing leaf 388 type, leaf number 7 (Figure 6F). For organelle ATP-dependent proteases, the degradation 389 rate of FtSH class proteases positively correlated with growth, while the degradation rate of 390 CLP, MAP and DEG classes negatively correlated with growth rate (Figure 6C). Amongst 391 the proteasome subunits and ubiquitination machinery, E3 ligases positively correlated with 392 leaf growth rate while the proteasome itself negatively correlated with leaf growth rate 393 (Figure 6E). Amongst the subunits of the plastid and cytosolic ribosomes, there was a 394 consistent negative correlation between protein degradation rate and leaf growth rate 395 (Figure 6B,D). 396 397 But what could these correlations mean? A key biochemical impact of changing degradation 398 rate as leaf growth rate changes is the alteration of the age profile of specific proteins in 399 different leaves. For example, increasing the degradation rate of ribosomal proteins as 400 leaves mature and slow their growth rate, increases the proportion of new ribosomes in the 401 mature leaf. Young growing leaves can achieve the same result by ribosome numbers 402 increasing through growth, rather than replacement. As a result, both leaves maintain similar 403 age profiles for ribosomes that are 0 to 8 days old (Supplemental Data set 6B). By contrast, 404 the slowing degradation rate of photosynthetic proteins as leaves slow their growth rate will 405 mean distinctly older age profiles for these photosynthetic enzymes in mature leaf tissues. 406 Our calculations of this effect show that ~90% of photosynthetic enzymes will be less than a 407 week old in leaf 7 compared to only ~55% of photosynthetic enzymes in leaf 3 408 (Supplemental Data set 6B). 11 409 410 Proportion of energy use in degradation and synthesis of specific protein classes in 411 different leaves 412 We also estimated total ATP costs from protein degradation and synthesis in the three leaf 413 types from the Arabidopsis rosette by summing up the costs for all the 1228 proteins in our 414 dataset. This used protein degradation rates, calculated protein synthesis rates, leaf growth 415 rate and the steady-state of the leaf proteome and coupled them with individual protein 416 lengths. We used a 5.25 ATP per AA residue cost of synthesis (including AA synthesis, 417 ribosome translation, and transport) and 1.25 ATP per AA residue cost of degradation 418 (unfolding), and estimated relative protein abundance based on modified estimates from 419 PaxDb (see Methods for details of calculations and references, see Supplemental Data set 420 7A for details). The set of 1228 proteins we have measured account for the bulk of protein 421 abundance in Arabidopsis leaves (nearly 90% of all Arabidopsis leaf protein based on ppm 422 counts from PaxDb and RBCL measurement). Assuming that cellular respiration is the 423 primary net ATP production source in leaves, the relative proportion of ATP used for protein 424 synthesis and degradation could also be determined by using leaf respiration rates of the 425 Arabidopsis rosette (Sew et al., 2013). In leaves that are not growing (e.g. leaf 3 in this 426 study), synthesis of new protein is simply replacing degraded protein and would cost 13% of 427 cellular ATP. By contrast, in leaf 7 that was rapidly growing, synthesis costs reached 38% of 428 total respiratory ATP (Figure 7A). This analysis also showed that the overall ATP cost of 429 protein degradation was ~4% of respiratory ATP synthesis across all leaf types. When the 430 protein abundance of plastids and relatively high number of higher turnover proteins in the 431 plastid were considered, nearly 70% of synthesis and degradation costs were attributable to 432 the plastid, with the cytosolic proteome representing 10% of costs and other organelles all 433 having relatively small percentage costs (Figure 7B, Supplemental Data set 7B). Within 434 functional categories, the Calvin cycle and light reactions alone represented nearly 50% of 435 all protein synthesis and degradation costs. We also used these data to highlight the set of 436 proteins in Arabidopsis that each account for more than 1% of total protein turnover costs in 437 leaves (Figure 7C-D, Table 3, Supplemental Data set 7C). The subunits of Rubisco 438 represented 13-18% of all protein costs, while representing ~17% of total cell protein 439 abundance. Some proteins were on this list largely owing to their rapid degradation rate 440 rather than their large abundance; for example, the PSII D1 subunit was expected to be a 441 high cost protein, while AOS and THI1 have not typically been considered as large energy 442 costs to the plant cell but each represented more than 1% of total ATP costs for protein 443 turnover (Figure 7C-D). 444 445 DISCUSSION 12 446 447 Key considerations in assessing plant protein degradation rates in growing leaves 448 Calculations of protein degradation require information on whether the proteome is in steady 449 state and how increases in protein abundance relate to organ or tissue growth rate. Most 450 historical studies in mammals have assumed steady-state to be the case in short timeframes 451 where no treatments were imposed (Price et al., 2010; Cambridge et al., 2011; 452 Schwanhausser et al., 2011). In plants, some reports have attempted to measure changes in 453 protein abundance of specific targets of interest (Li et al., 2012; Lyon et al., 2016), and 454 others have relied on linear regression across a time series to remove outliers and thus only 455 retain information when turnover rates have not changed (Yang et al., 2010; Nelson et al., 456 2014; Fan et al., 2016). However, these approaches have their limitations in plants and are 457 prone to both error and to the removal of interesting biological features of interest in the 458 data. Notably, regression analysis focuses on the increasing abundance of newly 459 synthesized protein which is mainly derived from growth in plant systems and masks the real 460 kinetics of the protein degradation process. In addition, plant protein turnover studies have 461 typically provided a list of protein degradation rates, without any comparative evaluation of 462 changes in degradation during growth and development. To address these issues, we have 463 taken a series of approaches. Firstly, we undertook a quantitative proteomics analysis within 464 and between different leaves within the Arabidopsis thaliana rosette after the 10th leaf had 465 appeared and followed changes in these leaf proteomes over the 5 days required for a 466 labelling strategy to yield a substantial list of protein degradation rates. This has shown that 467 in leaves 3 and 7, the relative abundance of 97-99% of relatively high abundance proteins 468 within each leaf type did not significantly change on a per unit protein basis, even though 469 total protein per leaf increased at different rates over 5 days. The apparent steady-state 470 evident in leaves 3 and 7 was less valid in leaf 5, in which only 80-90% of the proteome 471 remained unchanged in relative abundance over the 5 days of labelling. This illustrates that 472 while quasi-steady states of proteomes can be found during plant leaf growth, these need to 473 be experimentally measured and confirmed before an analysis strategy is implemented that 474 relies of this principle. That said, we observed that the changes that were measured in leaf 5 475 were not consistent across all timepoints and the scale of the fold changes did not typically 476 alter the nesting of KD values from leaf 5 in analysis of datasets (e.g. Figure 5 and 6). 477 Secondly, we used paired data at different time points to calculate average protein 478 degradation rates rather than linear regression across all time points. This enabled more fast 479 and slow degradation rates to be measured and variable rates to be averaged across 480 timepoints and peptides, rather than these data being discarded (Li et al., 2012). Thirdly, we 481 observed that protein abundance per g FW varies in Arabidopsis leaves during development 482 (Supplemental Figure 1), hence it was important to focus our calculations of dilution of 13 15 N 14 N- 483 labelled peptides on the increase in leaf protein content rather than on size or weight of each 484 leaf. This observation is consistent with independent evidence that young leaf total protein 485 content changes over time in Arabidopsis as a proportion of leaf size (Ishihara et al., 2015). 486 487 Protein features linked to degradation rate 488 The >150-fold variation of protein degradation rates of the ~1000 relatively abundant 489 proteins 490 characteristics define the degradation kinetics of different protein types. The availability of 491 these degradation rates provided an opportunity to explore a range of possible hypotheses 492 and provide some statistical comparisons of degradation rates for different groups of 493 proteins. It is well established that the proteolysis machinery of the cell is spatially distributed 494 and the latency of proteins in different cellular locations varies, which means that not all 495 proteins will be acted upon by the same protease network or in the same timeframe (van 496 Wijk, 2015). Using subcellular location information as a basis for dissecting the dataset, we 497 observed lower protein degradation rates in metabolic organelles that are separated from the 498 cytosol by phospholipid membranes, and higher protein degradation rates in the 499 endomembrane system, which is directly involved in protein synthesis and traffics proteins to 500 the plasma membrane. This suggests that there are broad spatially-based groupings in the 501 proteome that set a median rate of degradation of proteins in different subcellular 502 compartments. However, quantitatively these patterns represent less than 2 fold of the 503 variation in median degradation rates. Diurnal fluctuation in transcription could be a marker 504 for a heightened turnover rate for specific proteins in the light or the dark. Our analysis of this 505 effect failed to see a significant correlation in the data as a whole, but we did observe that 506 proteins with light-induced transcriptional patterns were enriched in the set of proteins with 507 faster KD. This indicates that light-dependent transcriptional processes may be associated 508 with enhanced protein degradation of the proteins being synthesized, while dark-dependent 509 processes are relatively less connected. in Arabidopsis leaves raises significant questions about which protein 510 511 Although the N-terminal residue of a polypeptide has some reported influence on turnover 512 rate for subsets of plant proteins (Apel et al., 2010; Zhang et al., 2015), the N-terminal 513 residue alone appeared to have little predictive value in our dataset to define the turnover 514 rate of unknown sets of protein of different sequences (Figure 4A). Protein aggregation 515 propensity has been linked to protein degradation rate and has been shown in other 516 eukaryotic systems to be independent of protein size (De Baets et al., 2011). 517 Arabidopsis dataset, aggregation propensity and protein size both correlated with turnover 518 rate when the extremes of the fast and slow degradation distribution were compared, but 519 when the higher aggregation propensity of large proteins was accounted for, there was no 14 In our 520 longer a relationship with degradation rate (Figure 4B). This suggests that while aggregation 521 propensity could account for some differences in degradation rate, as shown in mammals, it 522 is mainly due to protein length rather than amino acid composition of proteins in Arabidopsis. 523 Subunits of protein complexes might be expected to turn over at similar rates, and this was 524 largely confirmed when six out of seven physical complexes or protein systems were found 525 to show significantly tighter distributions of degradation rates compared to random samplings 526 of proteins(Figure 4C). This means that co-membership of a complex could be a useful 527 predictive tool for predicting unknown protein degradation rates. 528 families and domain groups were shown by this analysis as the major factors that could be 529 used to predict degradation rates (Table 2). Nearly 40-fold differences in degradation rate 530 were observed for proteins in different domain classes. Specific protein fold 531 532 Protein stability and the correlations with protein function 533 One essential goal of protein degradation studies is to help elucidate the biological functions 534 of specific proteins based on their variable turnover rates, and to this end efforts have been 535 made in correlation analysis of protein turnover and protein biological functions across 536 different organisms (Schwanhausser et al., 2011; Christiano et al., 2014; Karunadharma et 537 al., 2015). Consistent with evidence in yeast (Christiano et al., 2014) ribosomal subunits are 538 some of the most stable and long-lived proteins in Arabidopsis (Figure 2A). This means 539 ribosomal proteins can be used for a long time period after their biogenesis, with their 540 abundance controlled post-translationally by protein degradation at late stages of 541 development. However, even in these long-lasting protein sets, the relative degradation rate 542 distribution for the cytosolic ribosome had a higher standard deviation than those of other 543 protein complexes (Figure 4C). These non-uniform degradation rates in the cytosolic 544 ribosome may be related to the specialized role of structural subunits in ribosome and 545 altered stages of assembly which has been proposed in a ribosome turnover study in human 546 cells (Doherty et al., 2009). 547 548 Within photosynthetic complexes (Figure 5C) it was evident that three proteins had high 549 degradation rates, well beyond the normal distribution for their complexes. While D1 550 (Atcg00020) is well known for its high degradation rate at the reaction center of PSII (Melis, 551 1999; Takahashi and Badger, 2011; Lambreva et al., 2014), the discovery that PetD 552 (Atcg00730) of the cytochrome b6f complex and PIFI (At3g15840) of the NDH complex had 553 comparable degradation rates was not anticipated. These three proteins are core 554 components required for electron transport functions of PSII, cytochrome b6f and NDH 555 complexes, respectively. Interestingly, PetD is subject to proteolysis in highly purified 556 cytochrome b6f complex in vitro even in the presence of protease inhibitors, by an unknown 15 557 mechanism (Zhang and Cramer, 2004). PIFI has been shown to be essential for NDH 558 complex-mediated chlororespiration in Arabidopsis and PIFI knockout mutants exhibit a 559 greater sensitivity to photoinhibition (Wang and Portis, 2007). Their fast degradation rate in 560 vivo might reveal some functional similarity of these proteins in their respective protein 561 complexes. D1 and PetD proteins are both chloroplast encoded. D1 is at the plastoquinone 562 binding site of PSII and is directly involved in coordinating and protecting the metal cluster 563 responsible for producing oxygen and protons from H2O (Umena et al., 2011; Lambreva et 564 al., 2014; Wei et al., 2016).Cyanobacterial PetD forms the p-side of the cytochrome b6f 565 complex which accepts protons from plastosemiquinone and defines a route for H+ transfer 566 in the complex (Hasan et al., 2013). Also, the transcripts for D1 and PetD proteins are both 567 found to be up-regulated in the adg1-1 tpt-2 double mutant, which shows rapid 568 photoinhibition under high light (Schmitz et al., 2014). D1 protein is widely recognized as a 569 major target in PSII in the photodamage and photoprotection cycle (Melis, 1999; Takahashi 570 and Badger, 2011). PetD and PIFI, like the D1 subunit, might represent new targets for light 571 or other active electron and proton transfer pathway-associated damage and repair 572 processes. 573 574 575 Protein abundance and turnover changes in young leaves with rapid chloroplast 576 division 577 We observed that plastid-localized light-reaction and Calvin cycle proteins showed lower 578 protein abundance coupled with lower protein stability in leaf 7 (Figure 5), while ribosomal 579 proteins showed higher stability and accumulated in the fast-growing leaf 7 (Figure 5A). This 580 supports the proposal that regulatory mechanisms for accumulation of ribosomal proteins in 581 fast-growing stages in plants is independent of transcript abundance but more likely due to 582 stabilization of the assembled ribosome complexes (Baerenfaller et al., 2012; Ponnala et al., 583 2014). Increased levels of synthesis, folding and degradation proteins could provide high 584 protein synthesis and degradation capability in younger leaves. This may in turn explain 585 faster turnover of a range of metabolic protein sets in younger leaves, such as Calvin cycle 586 and photorespiratory enzymes and light reaction complex subunits (Figure 5A,C). 587 588 Analysis of the relative protein degradation changes with leaf growth rate (Figure 6) 589 highlighted that while the degradation rate for the majority of the photosynthetic apparatus 590 components positively correlated with growth (Figure 6A), those of CPN60A and CPN60B 591 negatively correlated with growth. These chaperonins are needed for plastid division (Suzuki 592 et al., 2009), so their increased stabilization and abundance (Figure 6F) are consistent with 593 the more frequent chloroplast division events that occur in young leaves (Osteryoung and 16 594 Pyke, 2014). The selective degradation changes observed in younger leaves could also be 595 caused by specific changes in proteolysis and translational control when leaves are growing 596 at a faster rate. Analysis of relative protein degradation rates versus leaf growth rate (Figure 597 6) highlighted that while turnover of protein synthesis components negatively correlated with 598 growth (Figure 6B,D), there were specific classes of organelle proteases whose turnover 599 rate positively correlated with growth. The FtsH protein set highlighted in Figure 6 are the 600 same proteins that are highlighted in the protein domain set FtsH (IPR016135), which was 601 one of the fastest degrading domain groups in our analysis (Table 2). These proteases have 602 direct roles in the turnover of the photosynthetic apparatus and in plastid thylakoid formation 603 (Zaltsman et al., 2005; Kato et al., 2012; Rowland et al., 2015). It has been reported that 604 mRNA for FtsH1, FtsH2, FtsH5 and FtsH8 generally increases in young developing leaves 605 (Zaltsman et al., 2005). High mRNA levels for these proteases provides a fast synthesis 606 potential, which is consistent with our finding that FtsH1, FtsH2, FtsH5 and FtsH8 exhibit 607 rapid rates of degradation in younger leaves mostly without large changes in relative 608 abundance (Figure 6C, Supplemental Data set 8). 609 610 Plastid turnover is controlled, however, not only by internal proteases but also by the 611 proteasome and vacuolar quality control pathways mediated by E3 (Ling et al., 2012; 612 Woodson et al., 2015). Ubiquitination plays a role in control of plastids via a RING-type 613 ubiquitin E3 ligase, SP1, which mediates the ubiquitination and degradation of TOC 614 components that are required for developmental transition of plastids (Ling et al., 2012; 615 Huang et al., 2013). Most recently, the plant U-box E3 ligase PUB4 was found to mediate the 616 ubiquitination and selective degradation of damaged chloroplast through globular vacuoles 617 (Woodson et al., 2015). While the proteasome subunit degradation rate was low in young 618 leaves, the degradation rates of three E3 ligases we identified (one RING-type At1g57800, 619 two F-box At4g39756 and At5g01720) were higher in younger leaves (Figure 6E). Enhanced 620 degradation of selective E3 ligases in younger leaves could thus also help maintain fast 621 chloroplast biogenesis in younger leaves. However, it is still unclear whether this is achieved 622 by promotion of developmental transition and/or by selective breakdown of damaged 623 plastids. 624 625 Energy costs of leaf protein turnover 626 It has been widely accepted that active transport and protein turnover are the two highest 627 cost processes in cell biology (Scheurwater et al., 2000). Calculations of energy costs for 628 protein turnover depend on knowing the synthesis and degradation rates of proteins, as well 629 as the length and abundance of each protein. This study provided the rate data, length is 630 straightforward to determine, and abundance was estimated used the PaxDb estimates for 17 631 Arabidopsis leaves (pax-db.org/). Expressing this ATP demand for protein synthesis and 632 degradation as a proportion of available cellular ATP requires a cellular ATP synthesis rate 633 calculation. While mitochondria are the primary ATP source in all eukaryotes, chloroplasts 634 can also produce ATP through photophosphorylation in plants. Early studies showed that 635 isolated intact chloroplast protein synthesis could be driven by light or added ATP while 636 etioplast protein synthesis could be driven only by added ATP (Siddell and Ellis, 1975; Ellis, 637 1981). This demonstrated that photophosphorylation and ATP imported through transporters 638 could both be energy sources for chloroplast protein synthesis. However, several more 639 recent calculations concluded that in planta additional ATP needs to be imported into 640 chloroplast through translocators to meet the demands of CO2 assimilation and 641 photorespiration without even considering the energy cost of other biosynthetic processes 642 including protein synthesis (Flugge et al., 2011; Kramer and Evans, 2011). This leaves 643 chloroplasts dependent on import of respiration-derived ATP for most biosynthetic processes 644 including protein synthesis. The importance of ATP import for chloroplast maintenance is 645 also evident by reports that restriction of ATP import through NTT translocators can lead to 646 dwarf and necrotic leaf phenotypes (Reinhold et al., 2007) and can disrupt hormonal 647 signaling (Schmitz et al., 2010). Our calculations are based on the caveat that respiration is 648 the only net source of ATP available for protein synthesis in plants. The dominance of the 649 plastid proteome as a major energy cost through these calculations supports the importance 650 of ATP import into chloroplasts based on the insufficiency of ATP supply from 651 photophosphorylation. 652 653 Our data show that on a leaf basis the degradation costs were effectively static at ~4%, 654 while synthesis rates varied considerably with the rate of leaf growth. Protein synthesis and 655 degradation together cost ~16% of the total leaf oxidative phosphorylation-dependent ATP 656 production in developed leaves with slow growth rates and ~42% in developing leaves with 657 fast growth rates. This analysis suggests the protein turnover energy budget is one of the 658 highest maintenance costs in growing Arabidopsis leaves. The Calvin cycle and the protein 659 machinery of the light reactions are the highest cost functions in the growing Arabidopsis leaf 660 (Figure 7, Table 3). These categories also share the top five high energy cost individual 661 proteins. Interestingly, photorespiration proteins in plastids, mitochondria and peroxisomes 662 are all among the top 20 proteins in terms of energy cost (Supplemental Data set 7A). 663 Changes in the degradation rates or abundance of high energy cost proteins could cause 664 significant fluctuations of the total energy budget and alter the ability of cells to reach a new 665 balance between energy supply and consumption. The availability of a direct calculation of 666 energy cost for specific proteins under different growth rates in an individual leaf will help to 667 explain energy constraints in changing the abundance of specific proteins. 18 668 669 670 METHODS 671 672 Hydroponic growth of Arabidopsis 673 Arabidopsis thaliana accession Columbia-0 plants were grown under 16/8-h light/dark 674 conditions with cool white T8 tubular fluorescent lamps 4000K 3350 lm (Osram, Germany) 675 with intensity of 100–125 μmol m-2 s-1 at 22 °C. The hydroponic protocol was as described 676 previously (Waters et al., 2012) and used a modified Hoagland solution (2 mM CaCl2, 6 mM 677 KNO3, 0.5 mM NH4NO3, 0.5 mM MgSO4, 0.25 mM KH2PO4, 0.05 mM KCl and 0.04 mM Fe- 678 EDTA) supplemented with micro elements (25 μM H3BO3, 2 μM MnCl2, 2 μM ZnSO4, 0.5 μM 679 CuSO4, 0.15 μM CoCl2 and 0.25 μM (NH4)6Mo7O24) and 2.6 mM MES, and the pH was 680 adjusted to 5.8-6.0. Seeds were planted on the surface of stone wool stuffed in 1.5-ml black 681 tubes with the bottoms cut out to sit in 24-well floater tubes racks containing 160 ml growth 682 medium. The seeds were vernalized under 4 °C for 2-3 days before being transferred to the 683 growth chambers. Half-strength growth medium was used for the first week. A single plant 684 was placed in every tube and four tubes in each floater tube rack (Supplemental Figure 685 1A). The growth medium was changed every 7 days. 686 687 Unlabelled Arabidopsis plants were grown for 21 days until they reached leaf production 688 stage 1.10 (T0) (Boyes et al., 2001) in natural abundance medium as noted above. Leaves 689 3, 5 and 7 from three biological replicates were collected at T0 (21 days), T1 (22 days), T3 690 (24 days) and T5 (26 days). Thirty-six unlabelled leaf whole protein samples were extracted 691 and protein concentration from each leaf was determined by an amido black assay. 692 15 693 For progressive 694 production stage 1.10 (T0) (Boyes et al., 2001) in natural abundance medium. The growth 695 medium was then discarded and the growth racks rinsed four times with fresh medium 696 without nitrogen (no KNO3 or NH4NO3) to ensure the old solution was washed out. A total of 697 160 ml of 698 and the plants were grown for 1, 3 and 5 days (T1, 3 and 5) before collecting leaf number 3, 699 5 and 7 for total protein extraction (Supplemental Figure 1A). Four leaves numbered 3, 5 or 700 7 from plants in one rack were pooled as a biological replicate. Three biological replicates 701 were collected at each time point. Twenty-seven 702 unlabelled samples (T0) were collected and stored separately for later analysis. 15 N labelling, plants were also grown for 21 days until they reached leaf N medium (6 mM K15NO3, 0.5 mM 15 NH415NO3) was added for every four plants 15 N labelled (T1, 3 and 5) and nine 703 704 To obtain a fully labeled 15 N protein reference standard, 19 15 N medium (with 6 mM K15NO3, 0.5 15 NH415NO3) was used to replace the natural abundance nitrogen in the medium and 705 mM 706 plants were grown from seed in this medium for 26 days (T5). 707 number 3, 5 and 7 was analyzed separately and each showed 98% 708 (determined from median of 1500-2000 peptides). Fully 709 5 and 7 samples were pooled and used as 710 subsequent experiments. 15 N labelling efficiency in leaf 15 N incorporation 15 N labeled total proteins from leaf 3, 15 N fully labelled proteins reference for 711 712 Fold change in protein abundance (FCP) following leaf production stage 1.10 713 Aliquots of the thirty-six unlabelled leaf samples (T0, 1, 3 and 5) noted above were also used 714 for fresh weight (FW) and protein content measurements (Supplemental Figure 1). Liquid 715 nitrogen snap frozen samples (0.1 g) were vortexed with Qiagen tissue lysis beads (5 mm) 716 and boiled in 1×Sample buffer (2% [w/v] SDS, 62.5 mM Tris-HCl, 10% [v/v] glycerol, 5% [v/v] 717 mercaptoethanol, bromophenol blue) for 5 minutes and then centrifuged at 10, 000 x g for 10 718 minutes. The supernatant was collected and separated with SDS-PAGE on Bio-Rad 719 Criterion precast gels (10–20% [w/v] acrylamide, Tris-HCl, 1 mm, 18-well comb gels). 720 Electrophoresis was performed at 300 V for 15-20 min. Proteins were visualized by colloidal 721 Coomassie Brilliant Blue G250 staining. ImageJ was used to quantify protein content in each 722 sample (Supplemental Figure 1B). FCP was determined by combining fresh weight and 723 protein content changes (Supplemental Data set 1). 724 725 Determining changes in specific protein abundance over 5 days using a fully labeled 726 15 727 A total of 50 µg of each the thirty-six unlabeled leaf protein samples noted above was mixed 728 individually with 50 µg of the fully 729 Each sample was separated into 96 fractions by high pH HPLC separation and further 730 pooled into 12 fractions. A total of 432 fractions from thirty-six samples were analyzed by 731 mass spectrometry. Filtered samples (5 µl each) were loaded onto a C18 high-capacity nano 732 LC chip (Agilent Technologies) using a 1200 series capillary pump (Agilent Technologies) as 733 described previously. Following loading, samples were eluted from the C18 column directly 734 into a 6550 series quadrupole time-of-flight mass spectrometer (Agilent Technologies) with a 735 1200 series nano pump using the following buffer B (0.1% FA in acetonitrile) gradient: 5-35% 736 in 35 min, 35-95% in 2 min and 95-5% in 1 min. Parameter settings in the mass 737 spectrometer were as described previously (Nelson et al., 2014). N protein reference standard 15 N-labelled reference and digested in solution by trypsin. 738 739 740 741 Agilent .d files were processed by an in-house script written in Mathematica for partial 15 labelling quantification (Nelson et al., 2014) modified to calculate the ratio between 14 peptide (L) and fully 15 N N N-labelled reference peptide (H). L and H formed two separate 20 742 populations by a non-negative least square (NNLS) approach as described previously (Guan 743 et al., 2011; Nelson et al., 2014). All filters used for partial 744 al., 2014) and two more filters were applied: firstly, a minimum 80% 745 required to disregard quantifications with high noise level between L and H; secondly, a 746 minimum signal-to-noise ratio of 5 was used to disregard high neighboring noise contribution 747 to L and H. 432 Agilent .d files were further processed by TPP to get protein probabilities for 748 identification. Only proteins with p>0.95 (FDR less than 0.6%) were further reported. 749 Examples for CPN60A (At2g28000), HPT108 (At3g63190) and PGK1 (phosphoglycerate 750 kinase 1, At3g12780) in leaf 3, 5 and 7 are shown in Supplemental Figure 7. 15 N labelling were kept (Nelson et 15 N enrichment was 751 752 Protein abundance was represented as ratio to reference. Protein abundance comparison of 753 the same protein from leaves 3 and 7 was presented as relative ∆Abundance (i.e. (leaf 7 754 abundance–leaf 3 abundance)/Average (leaf 3 and leaf 7 abundance)). The processed 755 quantification data in provided in Supplemental Data set 9 and the peptide identification 756 data for each timepoint in Supplemental Data sets 10-13. 757 758 Protein Separation, Digestion, Mass Spectrometry Analysis and Determination of 759 Peptide 15N Incorporation Ratio 760 The twenty-seven 15N progressively labeled and three unlabelled leaf samples (0.1-0.2 g) 761 were snap frozen in liquid nitrogen and homogenized using Qiagen tissue lysis beads (5 762 mm) by vortex. A total plant protein extraction kit (PE0230-1KT, Sigma Chemicals) was used 763 to extract total proteins. The final pellet of total protein was dissolved in Solution 4 and then 764 reduced and alkylated by tributylphosphine (TBP) and iodoacetamide (IAA) as described in 765 the Sigma manual. The suspension was centrifuged at 16,000 g for 30 min and the 766 supernatant was assay for protein concentration by amido black quantification as described 767 previously (Li et al., 2012). Protein (100 µg) in solution from each sample was then mixed 768 with equal volume of 2×sample buffer (4% SDS, 125 mM Tris, 20% glycerol, 0.005% 769 Bromophenol blue and 10% mercaptoethanol, pH6.8) before being separated on a Biorad 770 protean II electrophoresis system with a 4% (v/v) polyacrylamide stacking gel and 12% (v/v) 771 polyacrylamide separation gel. Proteins were visualized by colloidal Coomassie Brilliant Blue 772 G250 staining. 773 774 The SDS-PAGE gel lane for each sample was cut into 12 fractions. The resulting 360 gel 775 pieces were twice decolorized by de-stain solution (10 mM NH4NO3, 50% Acetonitrile) for 45 776 min. Dried gel pieces from one fraction were digested with 375 ng trypsin at 37 °C overnight 777 and then extracted as described previously (Nelson et al., 2014). The digested peptide 778 solutions were dried by vacuum centrifugation at 30 °C, re-suspended in 20 µl loading buffer 21 779 (5% Acetonitrile, 0.1% Formic Acid) and filtered by Millipore 0.22 micron filters before being 780 loaded for HPLC separation. A total of 5 µl of filtered samples were loaded onto a C18 high- 781 capacity nano LC chip (Agilent Technologies) using a 1200 series capillary pump (Agilent 782 Technologies) as described previously. Following loading, samples were eluted from the C18 783 column directly into a 6550 series quadrupole time-of-flight mass spectrometer (Agilent 784 Technologies) with a 1200 series nano pump using the following buffer B (0.1% FA in 785 Acetonitrile) gradient: 5-35% in 35 min, 35-95% in 2 min and 95-5% in 1 min. Parameter 786 settings in the mass spectrometer were as described previously (Nelson et al., 2014). 787 788 Agilent .d files were converted to mzML using the Msconvert package (version 2.2.2973) 789 from the Proteowizard project, and mzML files were subsequently converted to Mascot 790 generic files using the mzxml2 search tool from the TPPL version 4.6.2. Mascot generic file 791 peak lists were searched against an in-house Arabidopsis database comprising ATH1.pep 792 (release 10) from The Arabidopsis Information Resource (TAIR) and the Arabidopsis 793 mitochondrial and plastid protein sets (33621 sequences; 13487170 residues) (Lamesch et 794 al., 2012), using the Mascot search engine version 2.3 and utilizing error tolerances of 100 795 ppm for MS and 0.5 Da for MS/MS; “Max Missed Cleavages” set to 1; variable modifications 796 of oxidation (Met) and carbamidomethyl (Cys). We used iProphet and ProteinProphet from 797 the Trans Proteomic Pipeline (TPP) to analyze peptide and protein probability and global 798 false discovery rate (FDR) (Nesvizhskii et al., 2003; Deutsch et al., 2010; Shteynberg et al., 799 2011). The reported peptide lists with p=0.8 have FDRs of <3% and protein lists with p=0.95 800 have FDRs of <0.5%. Quantification of LPFs (labeled protein fraction) were accomplished by 801 an in-house script written in Mathematica as described previously (Nelson et al., 2014). The 802 data for determination of LPF for peptides by 803 Supplemental Data set 14 and the peptide identification data in Supplemental Data set 804 15. 15 N progressive labelling are provided in 805 806 Calculation of KD and KS 807 Protein degradation is a first order and stochastic process, and an exponential rate (KD) is 808 used to represent the proportional decrease of current protein abundance per day. Protein 809 synthesis is a zero order process, and is thus described as a proportional increase of its 810 starting pool (KS/A) per day (Claydon and Beynon, 2012; Li et al., 2012). ‘A’ is the starting 811 abundance for a specific protein at the beginning of the labelling period (T0). Because of the 812 stochastic nature of degradation, newly synthesized proteins experience the same 813 proportional decrease as existing proteins. As a result, calculation of gross synthesis rates 814 requires the measurement of newly synthesized proteins and the addition of the proportion 815 of newly synthesized proteins lost by degradation. Protein degradation rate KD and synthesis 22 816 rate KS/A for specific proteins were calculated from the progressive labeling data using a 817 combination of Fold Change in Protein (FCP) and the labeled peptide fraction (LPF) 818 following a method described previously (Li et al., 2012). 819 820 KD calculation: =− 821 ln ∙ (1 − ) KS calculation: = − 1− ∙ ∙ ∙ 822 823 The fresh weight of leaves with a protein content correction was first used as an approximate 824 value of Fold Change in Protein Abundance (Measured FCP) and this was applied to 825 calculate degradation rates (KD). However, it is challenging to measure FCP and protein 826 turnover simultaneously from the same samples, and sample-to-sample variation in 827 measuring them separately affects the calculation of protein degradation rates. In addition, 828 different leaves were found to show different nitrogen uptake and assimilation capability 829 (Masclaux-Daubresse et al., 2010) and could thus lead to different lag effects in 830 labelling. Younger leaves appeared to show faster nitrogen assimilation rates into amino acid 831 pools compared to relatively older leaves, which is evidenced by the higher 832 in the same peptide of younger leaves. To avoid these effects on degradation rate 833 calculation and comparisons across leaves, a median polish strategy, which has been widely 834 used for multiple experiment normalization (Lim et al., 2007), was employed to pre-process 835 the data. The median LPF value in each sample is a good indicator of FCP for each 836 experimental replicate. Based on a time point to time point protein turnover rate calculation 837 (Li et al., 2012), a calculated FCP for each sample can be deduced (Calculated FCP). 15 N 15 N enrichment ∙ = 1− ( ) 838 The comparison of calculated FCP and measured FCP showed a strong correlation (k=1.00, 839 R=0.95), but calculated FCP recognizes subtle growth changes in individual samples and 840 gives more precise calculations of KD and KS values. Calculated FCP was applied for further 841 calculations. Protein degradation comparison of the same protein from Leaves 3 and 7 is 842 presented as a relative ∆KD value (i.e. (L7 KD–L3 KD)/Average (L3 and 7 KD)). 843 844 Defining protein orthologues in barley 845 Protein sequences were obtained from MIPS PlantsDB (Nussbaumer et al., 2013) for barley 846 and orthologues for those proteins with quantified degradation rates in barley (Nelson et al., 23 847 2014) were then acquired through BLASTP provided by The Arabidopsis Information 848 Resource (TAIR) release 10. The highest scoring Arabidopsis orthologue was selected for 849 each protein in barley given its E-value was below 10-5. Correlation of protein degradation 850 rates between Arabidopsis and barley was assessed by parametric (Pearson) and 851 nonparametric (Spearman and Kendal) tests. 852 853 Energy cost and production for protein turnover 854 For a specific protein, energy cost for turnover was calculated to depend upon absolute 855 protein abundance (PA), amino acid length (AAL); protein degradation rate (KD) and 856 synthesis rate (KS). Protein degradation cost was based on 1-1.5 ATP per residue in the 857 proteasome degradation pathway (Peth et al., 2013). Protein synthesis cost was based on 5- 858 5.5 ATP per residue in ribosome translation, protein transport and amino acid biosynthesis 859 (Piques et al., 2009; Kaleta et al., 2013). The energy cost in ATP for degradation and new 860 synthesis of a specific protein was calculated by 1.25∙PA∙AAL∙KD/5.25 PA∙AAL∙KS (µmol∙d-1). 861 Whole protein content was measured as fresh weight of leaf tissues (~2% protein per FW). 862 Whole amino acid absolute abundance can be calculated based on whole protein content 863 and average amino acid molecular weight. The gross AA residue content of proteins of each 864 leaf number was calculated by averaged values from T0-5: leaf 3 (9.59 µmol), leaf 5 (18.69 865 µmol), leaf 7 (18.97 µmol) and overall (47.24 µmol). Relative protein abundances for the 866 1228 proteins in ppm were acquired from the Arabidopsis leaves abundance datasets 867 aggregated in the PaxDb database (Piques et al., 2009; Gfeller et al., 2011; Baerenfaller et 868 al., 2012; Wang et al., 2012) with the exception that the numbers for the Rubisco large 869 subunit (RBCL), which is well outside the normal distribution of values in PaxDb, were 870 replaced by a number from experimental evidence, based on the fact that 40% of total 871 soluble protein in Arabidopsis is Rubisco (Eckardt et al., 1997) and that only 50-60% of leaf 872 protein is soluble. This means RBCL represents 23.2% of total leaf protein by mass or 873 16.5% by molar ratio in Arabidopsis, replacing PaxDb numbers for RBCL of 8.8% by mass 874 and 6.6% by molar ratio. 875 876 The ATP production rate of respiration is based on experimentally determined respiration 877 rates presented as oxygen consumption 100 nmol.min-1.g-1 in different Arabidopsis leaves 878 (Sew et al., 2013). ATP production rates in different leaves can be deduced based on 1 O2- 879 4.5 ATP: leaf 3 (34.20 µmol·d-1), leaf 5 (67.05 µmol·d-1), leaf 7 (69.86 µmol·d-1) and overall 880 (171.11 µmol·d-1). Calculations of energy cost and production for protein turnover are 881 detailed in (Supplemental Data set 7A). 882 24 883 Accession Numbers 884 All accession numbers used are from the TAIR10 annotation of the Arabidopsis genome 885 (www.arabidopsis.org). 886 887 888 Supplemental data sets 1-15 can be accessed in the Dryad repository: Protein degradation rate in Arabidopsis thaliana leaf growth and development, doi:10.5061/dryad.q3h85 889 Raw MS data for 890 PXD004550. 891 Raw MS data for the relative abundance of proteins between leaves and time points can be 892 downloaded via ProteomeXchange: PXD004549. 15 N progressive labelling can be downloaded via ProteomeXchange: 893 894 Supplemental Data 895 Supplemental Figure 1. Arabidopsis leaf growth rates and leaf protein content. 896 897 Supplemental Figure 2. A flow diagram of tissue sampling and mass spectrometry for 898 progressive labelling and 899 5 and 7 of the Arabidopsis rosette over time. 15 N 15 N spiked analysis of protein abundance experiments in leaves 3, 900 901 Supplemental Figure 3. Determination of the labeled protein fraction (LPF) for peptide and 902 protein degradation rate measurements. 903 15 904 Supplemental Figure 4. The N enrichment level in the heavy labelled 905 population in each leaf at each timepoint. 15 N peptide 906 907 Supplemental Figure 5. The protein degradation (KD) rates of the 146 proteins that were 908 present in all 27 samples analyzed, before and after the median-polish normalization. 909 910 Supplemental Figure 6. A set of 49 degradation rates (KD) for photosynthesis proteins 911 involved in different protein complexes and functional categories calculated by regression in 912 leaf 3, 5 and 7. 913 914 Supplemental Figure 7. The relative protein abundance of CPN60A (At2g28000), HPT108 915 (At3g63190) and PGK1 (PHOSPHOGLYCERATE KINASE 1, At3g12780) in leaves 3, 5 and 916 7. 917 918 Supplemental Data set 1. Growth rates of Arabidopsis leaf 3, leaf 5 and leaf 7. 919 25 920 Supplemental Data set 2. Protein degradation rates of 1228 proteins and statistical analysis 921 across samples. 922 923 Supplemental Data set 3. Ratios of specific protein abundances relative to a 924 labelled reference. fully15N 925 926 Supplemental Data set 4. The correlation of intrinsic properties of proteins with their protein 927 degradation rates. 928 929 Supplemental Data set 5. Comparison of protein degradation rate (KD) and protein 930 abundance between selected proteins in leaf 3 and leaf 7. 931 932 Supplemental Data set 6. Comparison of protein degradation rate (KD) and leaf growth 933 rates in leaf 3, leaf 5 and leaf 7. 934 935 Supplemental Data set 7. Calculation of ATP costs for protein synthesis and degradation in 936 leaf 3, leaf 5 and leaf 7. 937 938 Supplemental Data set 8. Comparison of protein degradation rate and protein abundance 939 for selected proteins of interest. 940 941 Supplemental Data set 9. Determination of protein abundance fold change relative to a 942 reference in 36 individual leaf samples. 15 N 943 944 Supplemental Data sets 10-13. The peptide identification data for each time point for 945 peptides at T=0,1,3 and 5 days in the spiked in 15N reference experiment. 946 947 Supplemental Data set 14. Determination of LPF for peptides by 948 in 27 individual leaf samples. 15 N progressive labelling 949 950 Supplemental Data set 15. The peptide identification data for 951 peptides at all time points. 15 N progressively labelled 952 953 Acknowledgements: 954 This work was supported by the facilities of the Australian Research Council Centre of 955 Excellence Program (CE140100008). AHM was funded by an ARC Future Fellowship 956 (FT110100242). The authors declare that they have no conflict of interest. 26 957 958 Author contributions: 959 LL performed most of the experiments and data analysis. CJN helped design experiments, 960 and advised on and performed some of the mass spectrometry and data analysis. JT and IC 961 provided computational support, scripts and aided analysis of the data. AHM, LL and SH 962 designing experiments, analyzed and discussed results. AHM and LL wrote the manuscript. 963 All authors commented on the results and the manuscript. 964 27 965 Figure Legends 966 967 Figure 1. Individual growth rates of leaves in the Arabidopsis rosette and the 968 consequent fold change in protein over time. Leaves 3, 5 and 7 from Arabidopsis plants 969 grown in hydroponic culture were collected over a time course (T0, 1, 3 and 5 days) 970 beginning with 21-day-old plants that had developed 10 leaves (leaf production stage 1.10). 971 Typical images of leaves 3 to 8 from these plants at the beginning of the experiment are 972 shown. The growth of leaves over the subsequent 5 days were determined by following the 973 fold change in protein per leaf at each time point compared to T0 for leaf 3 (green), leaf 5, 974 (yellow) and leaf 7 (red). An average relative growth rate (d-1) was determined from both 975 changes in fresh weight and protein content by scanning images of gels (see Supplemental 976 Figure 1, Supplemental Data set 1). 977 978 Figure 2. Degradation rates of 1228 Arabidopsis proteins reported as averages based 979 on functional categories or localization inside cells, and in comparison to barley 980 orthologues. 981 (A) Average Arabidopsis leaf protein degradation rates box-plotted by functional categories 982 and their localization in cells. Functional categories were acquired from MapCave and 983 localization information from SUBAIII. Only major functional categories and localization 984 groups (n>10) are shown. Median, quartiles and standard deviations are shown. Outliers are 985 shown as hollow dots and extreme outliers are highlighted as solid squares and annotated. 986 The five major localizations are highlighted with colors: Cytosol (Cyt-Blue), Nucleus (Nc- 987 Red), Extracellular (Et-Cyan), Mitochondrion (Mt-Yellow) and Plastid (Pt-Green). (B) Protein 988 degradation rates of the 1228 proteins box-plotted based on localization within the cell. 989 Abbreviations as in (A), and dual targeting proteins (DUAL), Vacuole (Vc), plasma 990 membrane (PM), endoplasmic reticulum (ER), peroxisomal (Px) and Golgi. (C) Protein 991 degradation rates of a subset of 288 Arabidopsis proteins for which orthologues in barley 992 had published rates. One spot represents a protein turnover rate in barley (x-axis) and 993 Arabidopsis (y-axis). Four outliers (2SD above median, in red dashed line rectangle) are 994 shown (Pearson correlation, R=0.99). The remaining 284 proteins (pointed out by black 995 dashed line rectangle) are shown by black dots (Pearson correlation, R=0.38). 996 997 Figure 3 Changes in relative abundance estimates for individual proteins in leaves of 998 the Arabidopsis rosette during 5 days of leaf growth. (A) The intersection of the number 999 of specific proteins with a measured KD value and a protein relative abundance assessment. 1000 (B) Principle components analysis of specific protein abundances from mass spectrometry 1001 analysis. Abundance data for 955 proteins (KD values recorded in Figure 2) were used for 28 1002 the analysis. The clustering of leaf 3 (green), leaf 5 (yellow) and leaf 7 (green) is shown in 1003 the grey shading. The full data are provided in Supplemental Data set 3A and B. (C) A 1004 matrix of paired statistical comparisons of protein abundance between day 0, day 1, day 3 1005 and day 5 time points for each leaf is presented with the percentage of the proteins from (B) 1006 that significantly changed in abundance (t-test p<0.01) reported (full data in Supplemental 1007 Data set 3C). Outside the matrix is the percentage of proteins measured that were found to 1008 change in abundance (t-test P<0.01) across the entire time course in each leaf. 1009 1010 Figure 4. Intrinsic properties of Arabidopsis proteins that correlate with protein 1011 degradation rate. (A) Comparison of protein degradation rate with experimental evidence 1012 of the mature N-terminal amino acid residue. Only protein sets in which more than 5 1013 members had the same N-terminal amino acid residue were examined, a set of 376 1014 proteins in total. A non-parametric Kruskal-Wallis k-samples test showed no significant 1015 difference among the 12 N-terminal groups. However, the K, S and D groups showed 1016 significantly different degradation rate distributions from T by a Conover-Iman post-hoc test. 1017 No statistically significant differences were found when degradation rates of stable AAs (A, 1018 V, M, G, T, P), unstable AAs (K, F, D, R, Q) and average stability AAs (all others AAs) were 1019 compared (Supplemental Data set 4A). These groups were defined based on the 1020 consensus of yeast and mammal N-end rules. 1021 distribution graph of protein aggregation propensity (AGG) of each protein, the AA length of 1022 each protein (LEN), and the ratio of AGG/AA length between the top 100 most stable and 1023 bottom 100 most unstable proteins from the set of 1228 proteins with degradation rates. 1024 Statistical significance was estimated by the Kolmogorov-Smirnov test. (C) The standard 1025 deviation (σ) of the protein degradation rates of the protein subunits of 7 major protein 1026 complexes compared to randomly sampled distributions of σ for the same sized group of 1027 proteins from the set of 1228. 1028 Proteasome, Pt ATP synthase, Pt Ribosome, PSI, PSII and Mt ETC; all other proteins were 1029 considered to be one group ‘Others’. The standard deviation (σ) was calculated for each 1030 specific protein complexes with N subunits and then compared to the distribution of 100,000 1031 random samplings of groups of size N from ‘Others’. The red line shows the σ value of a 1032 specific protein complex while the blue distribution shows a histogram of σ values from the 1033 100,000 random samplings of each value of N. The probability (p) value is the proportion of 1034 100,000 random samplings of N that show a smaller σ than the specific protein complex. (B) A Cumulative Relative Frequency The protein complexes were: Cytosol Ribosome, 1035 1036 Figure 5. Comparisons of the relative protein abundance and degradation rate of 1037 specific proteins that differed in their measurements between leaf 3 and leaf 7. (A) 1038 Proteins with significant changes (T-test, p<0.05) in abundance (502 pairs, left) or 29 1039 degradation rate (433 pairs, right) between leaf 3 and leaf 7 are presented. The changes in 1040 relative abundance and degradation rate are shown as relative ∆Abundance and ∆KD by 1041 comparing leaf 7 to leaf 3 data. Major functional categories (as in Figure 2) that comprised 1042 at least 5 proteins for abundance or degradation data are displayed. All remaining proteins 1043 were combined in the group ‘Others’. Outliers are presented as hollow dots. The dashed line 1044 shows the boundary for no change in abundance and degradation between leaf 3 and leaf 7. 1045 (B) Relative ∆Abundance was compared for leaf 3, 5 and 7 for photosynthesis protein 1046 complexes and functional categories (110 proteins). The proteins on the X-axis are in the 1047 same order for each leaf comparison. Error bars show standard errors of relative 1048 ∆Abundance from each leaf separately, all comparisons are relative to leaf 3. (C) Protein 1049 degradation rates (KD) was compared for leaves 3, 5 and 7 for photosynthesis protein 1050 complexes and functional categories (116 proteins). The proteins on the X-axis are in the 1051 same order for each leaf comparison. Average KD and standard errors calculated from data 1052 for each leaf separately are shown. The proteins in (B) and (C) are not in the same order but 1053 are shown in rank order within each complex to show the consistent trend in relative 1054 ∆Abundance and protein degradation rates (KD) across the three leaves. 1055 1056 1057 Figure 6. Correlation of Arabidopsis protein degradation rates with leaf growth rate. 1058 Protein degradation rates (KD) in leaves 5 and 7 were normalized to corresponding values 1059 for the same proteins in leaf 3. Ratios of KD to leaf 3 KD values for (A) 92 photosynthesis 1060 proteins; (B) 11 plastid ribosome proteins; (C) plastid proteases including CLPs (CLPP2, 1061 CLPP5, CLPP6, CLPC, CLPR1, CLPR2, CLPR4, CLPR 6, Clp), DEG (DEGP1, DEGP 2) 1062 and MAP, and FTSHs (FTSH1, FTSH2, FTSH5, FTSH8); (D) 12 cytosol ribosome proteins 1063 and 10 initiation and elongation proteins; and (E) Proteasome E2 and E3 ligase proteins, 1064 are shown plotted against the leaf growth rates of leaves 3, 5 and 7. All proteins shown had 1065 positive or negative Pearson correlations between the ratio of KD and leaf growth rate of 1066 R>0.9 or R<-0.9, respectively. The red dashed line is a boundary for negative and positive 1067 correlations. 1068 compared with leaf 3 (*p<0.05). Error bars are SE of all data from each leaf separately. (F) The relative protein abundance of CPN60 A&B in leaves 5 and 7 is 1069 1070 1071 Figure 7. ATP energy budgets for protein degradation and synthesis in Arabidopsis 1072 leaves. (A) The proportion of cellular ATP used for protein degradation (blue), protein 1073 synthesis (yellow) and other aspects of cell maintenance (grey). Energy budgets are 1074 presented as the averages across leaves 3, 5 and 7, and in each leaf individually. (B) The 1075 proportion of ATP used for protein degradation (blue) and synthesis (yellow) in maintaining 30 1076 the proteomes of major cellular organelles and structures (when ATP cost >1% of total ATP 1077 use). 1078 functional categories of proteins (when ATP cost >2% of total ATP use). (D) The fifteen 1079 individual proteins with the highest ATP cost to maintain in the Arabidopsis proteome; only 1080 four of these were from the two highest cost functional categories (dotted lines). Subcellular 1081 location, functional categories and specific high cost proteins were sorted by the proportion 1082 of energy cost for protein synthesis (yellow). Respiration was presumed to be the primary 1083 net ATP production source for protein synthesis and its value is based on experimental data 1084 from the Arabidopsis rosette. (C) ATP used for protein degradation (blue) and synthesis (yellow) by major 1085 1086 1087 1088 1089 31 1090 1091 1092 1093 1094 Table 1 The twenty most-rapidly degrading proteins in Arabidopsis leaves. Protein accession number, short name, location in the cell and functional category are shown for each protein. The protein’s degradation rate (KD) and its standard error (SE) are shown along with the number of biological samples in which it was observed (Brep No.), the number of peptide spectra used to calculate the KD and the calculated half-life of the protein. Protein Location Functional Category KD -1 (d ) SE Brep No. Pep No. Halflife (d) 31 0.36 At5g54770 THI1 Plastid co-factor and vitamin metabolism 1.93 0.16 12 At1g79930 HSP91 Cytosol stress 1.88 0.49 6 6 0.37 0.11 7 12 0.43 At4g17090 BAM3 Plastid major CHO metabolism 1.62 At3g19710 BCAT4 Cytosol AA synthesis 1.15 0.09 5 8 0.60 0.31 4 5 0.64 At3g22200 POP2 Mito AA synthesis 1.09 AtCg00020 D1 Plastid light reaction 1.08 0.15 11 36 0.64 0.05 7 8 0.66 At5g19140 AILP1 Plastid metal handling 1.05 At1g23290 RPL27A Cytosol protein synthesis 0.97 0.05 5 5 0.72 0.09 10 28 0.78 At2g29630 THIC Plastid co-factor and vitamin metabolism 0.89 At3g15840 PIFI Plastid light reaction 0.87 0.10 8 8 0.80 0.14 7 11 0.82 At1g72930 TIR Cytosol stress 0.84 At1g11910 APA1 Vacuole protein degradation 0.78 0.06 12 13 0.89 At3g20050 TCP-1 Cytosol protein folding 0.77 0.34 5 7 0.90 0.03 9 9 0.91 At5g19940 PAP Plastid cell organisation 0.76 At4g14030 SBP1 Cytosol metal handling 0.76 0.14 6 8 0.91 0.32 7 7 0.92 At1g22930 TCP-11 Nucleus not assigned 0.75 At3g02110 SCPL25 Extracellular protein degradation 0.73 0.02 9 9 0.94 0.31 4 5 0.95 At4g15545 NA Nucleus not assigned 0.73 At1g42960 NA Plastid not assigned 0.69 0.38 6 7 1.00 misc 0.69 0.05 11 15 1.00 At5g62350 Invertase Extracellular 1095 1096 1097 32 1098 Table 2 Average degradation rates (KD) of groups of proteins containing the same protein 1099 domain. Shown are 58 protein domains (with at least 4 protein members per domain) that 1100 each had a tight average KD distribution (Median/SD>2). Non-parametric k-sample K-W 1101 analysis (p<0.01) and a C-I post-hoc test was used to divide the protein domains into groups 1102 A-J. Domains are listed by increasing degradation rates (all data in Supplemental Data set 1103 4E). The number of protein members (No.), KD minimum, maximum and median for each 1104 protein domain are shown. -1 Protein Domains Translation protein SH3-like domain -1 -1 PD Code No. KD (d ) Min KD (d ) Max KD (d ) Median IPR008991 4 0.024 0.070 0.047 A 0.076 0.069 A-B Group Glyceraldehyde-3-phosphate dehydrogenase, type I IPR006424 4 0.051 Ribosomal protein L12 family IPR027534 4 0.041 0.086 0.068 A-B 0.093 0.064 A-B Bifunctional inhibitor/plant lipid transfer helical domain IPR016140 4 0.054 PsbQ-like domain IPR023222 4 0.050 0.095 0.070 A-B 0.096 0.076 A-B NB-ARC IPR002182 4 0.055 Zinc finger, PHD-type IPR001965 4 0.060 0.093 0.080 A-B 0.104 0.084 A-B Zinc finger, RING/FYVE/PHD-type IPR013083 6 0.016 Serine/threonine-protein kinase, active site IPR008271 4 0.025 0.104 0.080 A-B 0.116 0.084 A-B Mitochondrial substrate/solute carrier IPR018108 5 0.044 PsbP family IPR002683 11 0.046 0.140 0.086 A-B 0.173 0.079 A-C Chlorophyll a/b binding protein domain IPR023329 14 0.040 Tetratricopeptide repeat IPR019734 4 0.067 0.104 0.087 A-D 0.115 0.088 A-D Protein kinase, ATP binding site IPR017441 5 0.025 Transketolase-like, pyrimidine-binding domain IPR005475 4 0.069 0.117 0.081 A-D 0.137 0.080 A-D Riboflavin synthase-like beta-barrel IPR017938 4 0.064 Protein kinase-like domain IPR011009 8 0.025 0.124 0.096 A-D ATPase, alpha/beta subunit, nucleotide-binding domain IPR000194 5 0.050 0.112 0.102 A-E 0.151 0.084 A-E Galactose mutarotase-like domain IPR011013 5 0.069 Aminoacyl-tRNA synthetase, class II (G/ P/ S/T) IPR002314 6 0.068 0.135 0.093 B-E 0.135 0.107 B-E Isocitrate/isopropylmalate dehydrogenase domain IPR019818 4 0.037 Proteasome, subunit alpha/beta IPR001353 10 0.072 0.136 0.093 B-E 0.151 0.091 B-E Glycoside hydrolase-type carbohydrate-binding, subgroup IPR014718 4 0.084 Malate dehydrogenase, active site IPR001252 5 0.025 0.181 0.123 B-E 0.178 0.103 B-E Ribosomal protein S5 domain 2-type fold IPR020568 8 0.034 HAD hydrolase, subfamily IA IPR006439 4 0.069 0.152 0.101 B-F 0.135 0.115 B-F Isopropylmalate dehydrogenase-like domain IPR024084 5 0.037 Short-chain dehydrogenase/reductase, conserved site IPR020904 4 0.058 0.148 0.116 B-G 0.202 0.129 C-G PDZ domain IPR001478 5 0.047 D-isomer specific 2-hydroxyacid dehydrogenase domain IPR029752 5 0.005 0.176 0.160 D-G 0.179 0.132 D-G Aminotransferase, class I/classII IPR004839 8 0.055 Threonyl/alanyl tRNA synthetase, SAD IPR012947 4 0.097 0.168 0.119 D-H 0.204 0.128 D-H Dehydrogenase, E1 component IPR001017 4 0.071 Calycin IPR012674 4 0.082 0.210 0.128 D-H 6 0.093 0.224 0.114 D-H Fructose-bisphosphate aldolase, class-I IPR000741 33 Glutathione S-transferase, C-terminal IPR004046 6 0.062 0.230 0.159 E-H 0.219 0.160 E-H Clp, N-terminal IPR004176 4 0.065 AMP-dependent synthetase/ligase IPR000873 4 0.070 0.222 0.146 E-H 0.271 0.160 E-H ATP-grasp fold, subdomain 1 IPR013815 7 0.063 14-3-3 protein, conserved site IPR023409 7 0.096 0.185 0.129 E-H Aldo/keto reductase IPR001395 4 0.100 0.172 0.135 E-I 0.220 0.131 F-I Thioredoxin domain IPR013766 12 0.094 Immunoglobulin-like fold IPR013783 5 0.103 0.171 0.152 F-I 0.227 0.153 F-I Glutaredoxin IPR002109 6 0.076 Pyridine nucleotide FAD/NAD(P)-binding domain IPR023753 11 0.070 0.296 0.170 F-I 0.220 0.169 G-I Thioredoxin IPR005746 9 0.103 Alpha-D-phosphohexomutase superfamily IPR005841 5 0.101 0.298 0.153 G-I 0.261 0.161 G-I ATPase, AAA-type, conserved site IPR003960 8 0.056 Tubulin/FtsZ, C-terminal IPR008280 4 0.061 0.276 0.208 G-I 0.266 0.164 G-I Alcohol dehydrogenase superfamily, zinc-type IPR002085 8 0.097 Rossmann-like alpha/beta/alpha sandwich fold IPR014729 13 0.077 0.376 0.201 H-I 0.196 0.179 H-J Immunoglobulin E-set IPR014756 5 0.141 Ferredoxin [2Fe-2S], plant IPR010241 4 0.130 0.267 0.194 H-J 0.292 0.198 H-J Aconitase/3-isopropylmalate dehydratase domain IPR001030 4 0.134 Pyruvate/Phosphoenolpyruvate kinase-like domain IPR015813 6 0.172 0.271 0.197 I-J 0.221 0.218 I-J UspA IPR006016 5 0.192 Peptidase, FtsH IPR005936 4 0.162 0.261 0.238 I-J 4 0.351 0.388 0.377 J Ubiquitin-conjugating enzyme/RWD-like IPR016135 1105 1106 34 1107 Table 3 ATP cost of protein degradation and synthesis for major functional categories of leaf 1108 proteins. Major functional categories were divided into seven groups. Minor functional 1109 categories and non-assigned proteins were grouped together as ‘Other’. Functional 1110 categories were sorted by the proportional cost of protein synthesis. The number of proteins 1111 in each group, KD mean and standard deviation (SD) are shown. -1 -1 No. KD (d ) Mean KD (d ) SD Deg Cost (%) Syn Cost (%) Calvin cycle 27 0.11 0.09 25.2 30.1 light reaction 84 0.13 0.15 16.5 16.3 photorespiration 11 0.12 0.05 2.7 2.4 AA synthesis 50 0.19 0.22 3.6 3.2 secondary metabolism 33 0.18 0.13 1.8 2.0 TCA 31 0.12 0.05 2.1 2.0 hormone metabolism 15 0.25 0.18 2.5 2.0 glycolysis 24 0.14 0.05 2.0 1.9 co-factor and vitamin metabolism 10 0.38 0.60 2.3 1.6 major CHO metabolism 17 0.25 0.36 1.3 1.1 lipid metabolism 29 0.13 0.09 1.1 1.1 tetrapyrrole synthesis 16 0.12 0.07 1.1 1.0 nucleotide metabolism 26 0.13 0.11 1.0 1.0 C1-metabolism 12 0.14 0.04 1.1 0.9 ETC 21 0.12 0.08 0.3 0.3 minor CHO metabolism 10 0.15 0.07 0.2 0.2 protein synthesis 76 0.08 0.14 4.0 4.2 protein degradation 81 0.17 0.14 3.3 2.8 protein folding 24 0.12 0.17 0.7 0.8 protein targeting 18 0.13 0.08 0.5 0.5 protein AA activation 20 0.15 0.12 0.5 0.4 protein PTMs 16 0.15 0.08 0.2 0.2 redox 52 0.15 0.08 3.3 3.1 misc. 53 0.16 0.11 2.8 2.5 stress 43 0.19 0.30 2.1 2.1 signalling 26 0.14 0.08 0.7 0.6 cell organisation 22 0.19 0.16 1.5 1.3 cell cycle 14 0.14 0.10 0.9 1.0 Functional Categories Photosynthesis (48.9%) Metabolism (18.4%) Protein (8.9%) Stress and Signalling (8.3%) Cell (2.6%) 35 20 0.17 0.10 0.4 0.3 RNA binding 13 0.15 0.10 1.3 1.2 RNA regulation 33 0.12 0.07 1.0 1.0 DNA 11 0.13 0.10 0.1 0.1 transport 31 0.12 0.06 1.4 1.3 metal handling 11 0.33 0.31 0.5 0.3 Other (9.1%) 248 0.15 0.12 9.7 9.1 cell wall RNA and DNA (2.2%) Transport and Metal Handling (1.6%) 1112 1113 1114 36 1115 Reference 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 Apel, W., Schulze, W.X., and Bock, R. (2010). Identification of protein stability determinants in chloroplasts. Plant J 63, 636-650. Araujo, W.L., Tohge, T., Ishizaki, K., Leaver, C.J., and Fernie, A.R. (2011). Protein degradation - an alternative respiratory substrate for stressed plants. Trends Plant Sci 16, 489498. Armbruster, U., Zuhlke, J., Rengstl, B., Kreller, R., Makarenko, E., Ruhle, T., Schunemann, D., Jahns, P., Weisshaar, B., Nickelsen, J., and Leister, D. (2010). The Arabidopsis thylakoid protein PAM68 is required for efficient D1 biogenesis and photosystem II assembly. Plant Cell 22, 3439-3460. Avci, D., and Lemberg, M.K. (2015). Clipping or Extracting: Two Ways to Membrane Protein Degradation. Trends in cell biology 25, 611-622. Bachmair, A., Finley, D., and Varshavsky, A. (1986). In vivo half-life of a protein is a function of its amino-terminal residue. Science 234, 179-186. Baerenfaller, K., Massonnet, C., Walsh, S., Baginsky, S., Buhlmann, P., Hennig, L., HirschHoffmann, M., Howell, K.A., Kahlau, S., Radziejwoski, A., Russenberger, D., Rutishauser, D., Small, I., Stekhoven, D., Sulpice, R., Svozil, J., Wuyts, N., Stitt, M., Hilson, P., Granier, C., and Gruissem, W. (2012). Systems-based analysis of Arabidopsis leaf growth reveals adaptation to water deficit. Mol Syst Biol 8, 606. Blasing, O.E., Gibon, Y., Gunther, M., Hohne, M., Morcuende, R., Osuna, D., Thimm, O., Usadel, B., Scheible, W.R., and Stitt, M. (2005). Sugars and circadian regulation make major contributions to the global regulation of diurnal gene expression in Arabidopsis. The Plant cell 17, 3257-3281. Boyes, D.C., Zayed, A.M., Ascenzi, R., McCaskill, A.J., Hoffman, N.E., Davis, K.R., and Gorlach, J. (2001). Growth stage-based phenotypic analysis of Arabidopsis: a model for high throughput functional genomics in plants. Plant Cell 13, 1499-1510. Cambridge, S.B., Gnad, F., Nguyen, C., Bermejo, J.L., Kruger, M., and Mann, M. (2011). Systems-wide proteomic analysis in mammalian cells reveals conserved, functional protein turnover. J Proteome Res 10, 5275-5284. Chatterjee, A., Abeydeera, N.D., Bale, S., Pai, P.J., Dorrestein, P.C., Russell, D.H., Ealick, S.E., and Begley, T.P. (2011). Saccharomyces cerevisiae THI4p is a suicide thiamine thiazole synthase. Nature 478, 542-546. Chen, W.P., Yang, X.Y., Harms, G.L., Gray, W.M., Hegeman, A.D., and Cohen, J.D. (2011). An automated growth enclosure for metabolic labeling of Arabidopsis thaliana with 13Ccarbon dioxide - an in vivo labeling system for proteomics and metabolomics research. Proteome Sci 9, 9. Christiano, R., Nagaraj, N., Frohlich, F., and Walther, T.C. (2014). Global proteome turnover analyses of the Yeasts S. cerevisiae and S. pombe. Cell Rep 9, 1959-1965. Claydon, A.J., and Beynon, R. (2012). Proteome dynamics: revisiting turnover with a global perspective. Mol Cell Proteomics 11, 1551-1565. De Baets, G., Reumers, J., Delgado Blanco, J., Dopazo, J., Schymkowitz, J., and Rousseau, F. (2011). An evolutionary trade-off between protein turnover rate and protein aggregation favors a higher aggregation propensity in fast degrading proteins. PLoS Comput Biol 7, e1002090. Deutsch, E.W., Mendoza, L., Shteynberg, D., Farrah, T., Lam, H., Tasman, N., Sun, Z., Nilsson, E., Pratt, B., Prazen, B., Eng, J.K., Martin, D.B., Nesvizhskii, A.I., and Aebersold, R. (2010). A guided tour of the Trans-Proteomic Pipeline. Proteomics 10, 37 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1150-1159. Doherty, M.K., Hammond, D.E., Clague, M.J., Gaskell, S.J., and Beynon, R.J. (2009). Turnover of the human proteome: determination of protein intracellular stability by dynamic SILAC. J Proteome Res 8, 104-112. Eckardt, N.A., Snyder, G.W., Portis, A.R., Jr., and Orgen, W.L. (1997). Growth and photosynthesis under high and low irradiance of Arabidopsis thaliana antisense mutants with reduced ribulose-1,5-bisphosphate carboxylase/oxygenase activase content. Plant physiology 113, 575-586. Edwards, J.M., Roberts, T.H., and Atwell, B.J. (2012). Quantifying ATP turnover in anoxic coleoptiles of rice (Oryza sativa) demonstrates preferential allocation of energy to protein synthesis. J Exp Bot 63, 4389-4402. Ellis, R.J. (1981). Chloroplast Proteins - Synthesis, Transport, and Assembly. Annual Review of Plant Physiology and Plant Molecular Biology 32, 111-137. Fan, K.T., Rendahl, A.K., Chen, W.P., Freund, D.M., Gray, W.M., Cohen, J.D., and Hegeman, A.D. (2016). Proteome Scale-Protein Turnover Analysis Using High Resolution Mass Spectrometric Data from Stable-Isotope Labeled Plants. J Proteome Res. Fernandez-Escamilla, A.M., Rousseau, F., Schymkowitz, J., and Serrano, L. (2004). Prediction of sequence-dependent and mutational effects on the aggregation of peptides and proteins. Nat Biotechnol 22, 1302-1306. Fleig, L., Bergbold, N., Sahasrabudhe, P., Geiger, B., Kaltak, L., and Lemberg, M.K. (2012). Ubiquitin-dependent intramembrane rhomboid protease promotes ERAD of membrane proteins. Molecular Cell 47, 558-569. Flugge, U.I., Hausler, R.E., Ludewig, F., and Gierth, M. (2011). The role of transporters in supplying energy to plant plastids. J Exp Bot 62, 2381-2392. Gfeller, A., Baerenfaller, K., Loscos, J., Chetelat, A., Baginsky, S., and Farmer, E.E. (2011). Jasmonate controls polypeptide patterning in undamaged tissue in wounded Arabidopsis leaves. Plant Physiol 156, 1797-1807. Giraud, E., Ng, S., Carrie, C., Duncan, O., Low, J., Lee, C.P., Van Aken, O., Millar, A.H., Murcha, M., and Whelan, J. (2010). TCP transcription factors link the regulation of genes encoding mitochondrial proteins with the circadian clock in Arabidopsis thaliana. Plant Cell 22, 3921-3934. Gonda, D.K., Bachmair, A., Wunning, I., Tobias, J.W., Lane, W.S., and Varshavsky, A. (1989). Universality and structure of the N-end rule. J Biol Chem 264, 16700-16712. Guan, S.H., Price, J.C., Prusiner, S.B., Ghaemmaghami, S., and Burlingame, A.L. (2011). A Data Processing Pipeline for Mammalian Proteome Dynamics Studies Using Stable Isotope Metabolic Labeling. Molecular & Cellular Proteomics 10. M111.010728 Hasan, S.S., Yamashita, E., Baniulis, D., and Cramer, W.A. (2013). Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex. Proc Natl Acad Sci U S A 110, 4297-4302. Hooper, C.M., Tanz, S.K., Castleden, I.R., Vacher, M.A., Small, I.D., and Millar, A.H. (2014). SUBAcon: a consensus algorithm for unifying the subcellular localization data of the Arabidopsis proteome. Bioinformatics 30, 3356-3364. Huang, S., Nelson, C.J., Li, L., Taylor, N.L., Stroher, E., Peteriet, J., and Millar, A.H. (2015). INTERMEDIATE CLEAVAGE PEPTIDASE55 Modifies Enzyme Amino Termini and Alters Protein Stability in Arabidopsis Mitochondria. Plant Physiol 168, 415-427. Huang, W., Ling, Q., and Jarvis, P. (2013). The ubiquitin-proteasome system regulates chloroplast biogenesis. Commun Integr Biol 6, e23001. 38 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 Ishihara, H., Obata, T., Sulpice, R., Fernie, A.R., and Stitt, M. (2015). Quantifying protein synthesis and degradation in Arabidopsis by dynamic 13CO2 labeling and analysis of enrichment in individual amino acids in their free pools and in protein. Plant Physiol 168, 74-93. Janska, H., Kwasniak, M., and Szczepanowska, J. (2013). Protein quality control in organelles - AAA/FtsH story. Biochim Biophys Acta 1833, 381-387. Jayapal, K.P., Sui, S., Philp, R.J., Kok, Y.J., Yap, M.G., Griffin, T.J., and Hu, W.S. (2010). Multitagging proteomic strategy to estimate protein turnover rates in dynamic systems. J Proteome Res 9, 2087-2097. Juntawong, P., Girke, T., Bazin, J., and Bailey-Serres, J. (2014). Translational dynamics revealed by genome-wide profiling of ribosome footprints in Arabidopsis. Proc Natl Acad Sci U S A 111, E203-212. Kaleta, C., Schauble, S., Rinas, U., and Schuster, S. (2013). Metabolic costs of amino acid and protein production in Escherichia coli. Biotechnol J 8, 1105-1114. Karunadharma, P.P., Basisty, N., Chiao, Y.A., Dai, D.F., Drake, R., Levy, N., Koh, W.J., Emond, M.J., Kruse, S., Marcinek, D., Maccoss, M.J., and Rabinovitch, P.S. (2015). Respiratory chain protein turnover rates in mice are highly heterogeneous but strikingly conserved across tissues, ages, and treatments. FASEB J 29, 3582-3592. Kato, Y., Sun, X., Zhang, L., and Sakamoto, W. (2012). Cooperative D1 Degradation in the Photosystem II Repair Mediated by Chloroplastic Proteases in Arabidopsis. Plant Physiol. 159:1428-39 Kramer, D.M., and Evans, J.R. (2011). The importance of energy balance in improving photosynthetic productivity. Plant Physiol 155, 70-78. Lam, M.P., Wang, D., Lau, E., Liem, D.A., Kim, A.K., Ng, D.C., Liang, X., Bleakley, B.J., Liu, C., Tabaraki, J.D., Cadeiras, M., Wang, Y., Deng, M.C., and Ping, P. (2014). Protein kinetic signatures of the remodeling heart following isoproterenol stimulation. J Clin Invest 124, 1734-1744. Lambreva, M.D., Russo, D., Polticelli, F., Scognamiglio, V., Antonacci, A., Zobnina, V., Campi, G., and Rea, G. (2014). Structure/function/dynamics of photosystem II plastoquinone binding sites. Curr Protein Pept Sci 15, 285-295. Lamesch, P., Berardini, T.Z., Li, D., Swarbreck, D., Wilks, C., Sasidharan, R., Muller, R., Dreher, K., Alexander, D.L., Garcia-Hernandez, M., Karthikeyan, A.S., Lee, C.H., Nelson, W.D., Ploetz, L., Singh, S., Wensel, A., and Huala, E. (2012). The Arabidopsis Information Resource (TAIR): improved gene annotation and new tools. Nucleic Acids Research 40, D1202-1210. Lee, C.P., Eubel, H., and Millar, A.H. (2010). Diurnal changes in mitochondrial function reveal daily optimization of light and dark respiratory metabolism in Arabidopsis. Molecular & Cellular Proteomics 9, 2125-2139. Li, L., Nelson, C.J., Solheim, C., Whelan, J., and Millar, A.H. (2012). Determining degradation and synthesis rates of arabidopsis proteins using the kinetics of progressive 15N labeling of two-dimensional gel-separated protein spots. Mol Cell Proteomics 11, M111 010025. Li, L., Nelson, C., Fenske, R., Trösch, J., Pružinská, A., Millar, A.H., and Huang, S. (2016). Changes in specific protein degradation rates in Arabidopsis thaliana reveal multiple roles of Lon1 in mitochondrial protein homeostasis. Plant J. (in press, 10.1111/tpj.13392) Liang, C., Cheng, S., Zhang, Y., Sun, Y., Fernie, A.R., Kang, K., Panagiotou, G., Lo, C., and Lim, 39 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 B.L. (2016). Transcriptomic, proteomic and metabolic changes in Arabidopsis thaliana leaves after the onset of illumination. BMC plant biology 16, 43. Lim, W.K., Wang, K., Lefebvre, C., and Califano, A. (2007). Comparative analysis of microarray normalization procedures: effects on reverse engineering gene networks. Bioinformatics 23, i282-288. Ling, Q., Huang, W., Baldwin, A., and Jarvis, P. (2012). Chloroplast biogenesis is regulated by direct action of the ubiquitin-proteasome system. Science 338, 655-659. Lyon, D., Castillejo, M.A., Mehmeti-Tershani, V., Staudinger, C., Kleemaier, C., and Wienkoop, S. (2016). Drought and recovery: independently regulated processes highlighting the importance of protein turnover dynamics and translational regulation in Medicago truncatula. Mol Cell Proteomics. 15:1921-37 Masclaux-Daubresse, C., Daniel-Vedele, F., Dechorgnat, J., Chardon, F., Gaufichon, L., and Suzuki, A. (2010). Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. Ann Bot 105, 1141-1157. Melis, A. (1999). Photosystem-II damage and repair cycle in chloroplasts: what modulates the rate of photodamage ? Trends Plant Sci 4, 130-135. Mockler, T.C., Michael, T.P., Priest, H.D., Shen, R., Sullivan, C.M., Givan, S.A., McEntee, C., Kay, S.A., and Chory, J. (2007). The DIURNAL project: DIURNAL and circadian expression profiling, model-based pattern matching, and promoter analysis. Cold Spring Harbor symposia on quantitative biology 72, 353-363. Nelson, C.J., Li, L., Jacoby, R.P., and Millar, A.H. (2013). Degradation rate of mitochondrial proteins in Arabidopsis thaliana cells. J Proteome Res 12, 3449-3459. Nelson, C.J., Alexova, R., Jacoby, R.P., and Millar, A.H. (2014). Proteins with high turnover rate in barley leaves estimated by proteome analysis combined with in planta isotope labeling. Plant Physiol 166, 91-108. Nesvizhskii, A.I., Keller, A., Kolker, E., and Aebersold, R. (2003). A statistical model for identifying proteins by tandem mass spectrometry. Anal Chem 75, 4646-4658. Nishimura, K., Fukagawa, T., Takisawa, H., Kakimoto, T., and Kanemaki, M. (2009). An auxin-based degron system for the rapid depletion of proteins in nonplant cells. Nat Methods 6, 917-922. Nussbaumer, T., Martis, M.M., Roessner, S.K., Pfeifer, M., Bader, K.C., Sharma, S., Gundlach, H., and Spannagl, M. (2013). MIPS PlantsDB: a database framework for comparative plant genome research. Nucleic acids research 41, D1144-1151. Osteryoung, K.W., and Pyke, K.A. (2014). Division and dynamic morphology of plastids. Annu Rev Plant Biol 65, 443-472. Peth, A., Nathan, J.A., and Goldberg, A.L. (2013). The ATP costs and time required to degrade ubiquitinated proteins by the 26 S proteasome. J Biol Chem 288, 2921529222. Piques, M., Schulze, W.X., Hohne, M., Usadel, B., Gibon, Y., Rohwer, J., and Stitt, M. (2009). Ribosome and transcript copy numbers, polysome occupancy and enzyme dynamics in Arabidopsis. Mol Syst Biol 5, 314. Ponnala, L., Wang, Y., Sun, Q., and van Wijk, K.J. (2014). Correlation of mRNA and protein abundance in the developing maize leaf. The Plant journal : for cell and molecular biology 78, 424-440. Price, J.C., Guan, S., Burlingame, A., Prusiner, S.B., and Ghaemmaghami, S. (2010). Analysis of proteome dynamics in the mouse brain. Proc Natl Acad Sci U S A 107, 1450814513. 40 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 Reinhold, T., Alawady, A., Grimm, B., Beran, K.C., Jahns, P., Conrath, U., Bauer, J., Reiser, J., Melzer, M., Jeblick, W., and Neuhaus, H.E. (2007). Limitation of nocturnal import of ATP into Arabidopsis chloroplasts leads to photooxidative damage. Plant J 50, 293304. Ren, M., Qiu, S., Venglat, P., Xiang, D., Feng, L., Selvaraj, G., and Datla, R. (2011). Target of rapamycin regulates development and ribosomal RNA expression through kinase domain in Arabidopsis. Plant Physiol 155, 1367-1382. Rousseeuw, P.J. (1987). Silhouettes - a Graphical Aid to the Interpretation and Validation of Cluster-Analysis. Journal of Computational and Applied Mathematics 20, 53-65. Rowland, E., Kim, J., Bhuiyan, N.H., and van Wijk, K.J. (2015). The Arabidopsis Chloroplast Stromal N-Terminome: Complexities of Amino-Terminal Protein Maturation and Stability. Plant Physiol 169, 1881-1896. Scheurwater, I., Dunnebacke, M., Eising, R., and Lambers, H. (2000). Respiratory costs and rate of protein turnover in the roots of a fast-growing (Dactylis glomerata L.) and a slow-growing (Festuca ovina L.) grass species. J Exp Bot 51, 1089-1097. Schmitz, G., Reinhold, T., Gobel, C., Feussner, I., Neuhaus, H.E., and Conrath, U. (2010). Limitation of nocturnal ATP import into chloroplasts seems to affect hormonal crosstalk, prime defense, and enhance disease resistance in Arabidopsis thaliana. Mol Plant Microbe Interact 23, 1584-1591. Schmitz, J., Heinrichs, L., Scossa, F., Fernie, A.R., Oelze, M.L., Dietz, K.J., Rothbart, M., Grimm, B., Flugge, U.I., and Hausler, R.E. (2014). The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities. J Exp Bot 65, 1619-1636. Schwanhausser, B., Busse, D., Li, N., Dittmar, G., Schuchhardt, J., Wolf, J., Chen, W., and Selbach, M. (2011). Global quantification of mammalian gene expression control. Nature 473, 337-342. Sew, Y.S., Stroher, E., Holzmann, C., Huang, S., Taylor, N.L., Jordana, X., and Millar, A.H. (2013). Multiplex micro-respiratory measurements of Arabidopsis tissues. New Phytol 200, 922-932. Shteynberg, D., Deutsch, E.W., Lam, H., Eng, J.K., Sun, Z., Tasman, N., Mendoza, L., Moritz, R.L., Aebersold, R., and Nesvizhskii, A.I. (2011). iProphet: multi-level integrative analysis of shotgun proteomic data improves peptide and protein identification rates and error estimates. Molecular & cellular proteomics : MCP 10, M111 007690. Siddell, S.G., and Ellis, R.J. (1975). Protein synthesis in chloroplasts. Characteristics and products of protein synthesis in vitro in etioplasts and developing chloroplasts from pea leaves. Biochem J 146, 675-685. Smith, S.M., Fulton, D.C., Chia, T., Thorneycroft, D., Chapple, A., Dunstan, H., Hylton, C., Zeeman, S.C., and Smith, A.M. (2004). Diurnal changes in the transcriptome encoding enzymes of starch metabolism provide evidence for both transcriptional and posttranscriptional regulation of starch metabolism in Arabidopsis leaves. Plant physiology 136, 2687-2699. Suzuki, K., Nakanishi, H., Bower, J., Yoder, D.W., Osteryoung, K.W., and Miyagishima, S.Y. (2009). Plastid chaperonin proteins Cpn60 alpha and Cpn60 beta are required for plastid division in Arabidopsis thaliana. BMC Plant Biol 9, 38. Takahashi, S., and Badger, M.R. (2011). Photoprotection in plants: a new light on photosystem II damage. Trends Plant Sci 16, 53-60. Tanz, S.K., Castleden, I., Hooper, C.M., Vacher, M., Small, I., and Millar, H.A. (2013). SUBA3: 41 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 a database for integrating experimentation and prediction to define the SUBcellular location of proteins in Arabidopsis. Nucleic Acids Res 41, D1185-1191. Umena, Y., Kawakami, K., Shen, J.R., and Kamiya, N. (2011). Crystal structure of oxygenevolving photosystem II at a resolution of 1.9 A. Nature 473, 55-60. van Wijk, K.J. (2015). Protein maturation and proteolysis in plant plastids, mitochondria, and peroxisomes. Annu Rev Plant Biol 66, 75-111. Vierstra, R.D. (2009). The ubiquitin-26S proteasome system at the nexus of plant biology. Nat Rev Mol Cell Biol 10, 385-397. Vogtle, F.N., Wortelkamp, S., Zahedi, R.P., Becker, D., Leidhold, C., Gevaert, K., Kellermann, J., Voos, W., Sickmann, A., Pfanner, N., and Meisinger, C. (2009). Global Analysis of the Mitochondrial N-Proteome Identifies a Processing Peptidase Critical for Protein Stability. Cell 139, 428-439. Walsh, C.T. (1984). Suicide substrates, mechanism-based enzyme inactivators: recent developments. Annu Rev Biochem 53, 493-535. Wang, D., and Portis, A.R., Jr. (2007). A novel nucleus-encoded chloroplast protein, PIFI, is involved in NAD(P)H dehydrogenase complex-mediated chlororespiratory electron transport in Arabidopsis. Plant Physiol 144, 1742-1752. Wang, M., Weiss, M., Simonovic, M., Haertinger, G., Schrimpf, S.P., Hengartner, M.O., and von Mering, C. (2012). PaxDb, a database of protein abundance averages across all three domains of life. Mol Cell Proteomics 11, 492-500. Waters, M.T., Nelson, D.C., Scaffidi, A., Flematti, G.R., Sun, Y.K., Dixon, K.W., and Smith, S.M. (2012). Specialisation within the DWARF14 protein family confers distinct responses to karrikins and strigolactones in Arabidopsis. Development 139, 12851295. Wei, X., Su, X., Cao, P., Liu, X., Chang, W., Li, M., Zhang, X., and Liu, Z. (2016). Structure of spinach photosystem II-LHCII supercomplex at 3.2 A resolution. Nature 534, 69-74. Woodson, J.D., Joens, M.S., Sinson, A.B., Gilkerson, J., Salome, P.A., Weigel, D., Fitzpatrick, J.A., and Chory, J. (2015). Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts. Science 350, 450-454. Yang, X.Y., Chen, W.P., Rendahl, A.K., Hegeman, A.D., Gray, W.M., and Cohen, J.D. (2010). Measuring the turnover rates of Arabidopsis proteins using deuterium oxide: an auxin signaling case study. Plant J 63, 680-695. Yip, C.Y., Harbour, M.E., Jayawardena, K., Fearnley, I.M., and Sazanov, L.A. (2011). Evolution of respiratory complex I: "supernumerary" subunits are present in the alphaproteobacterial enzyme. J Biol Chem 286, 5023-5033. Zaltsman, A., Feder, A., and Adam, Z. (2005). Developmental and light effects on the accumulation of FtsH protease in Arabidopsis chloroplasts--implications for thylakoid formation and photosystem II maintenance. Plant J 42, 609-617. Zhang, H., and Cramer, W.A. (2004). Purification and crystallization of the cytochrome b6f complex in oxygenic photosynthesis. Methods Mol Biol 274, 67-78. Zhang, H., Deery, M.J., Gannon, L., Powers, S.J., Lilley, K.S., and Theodoulou, F.L. (2015). Quantitative proteomics analysis of the Arg/N-end rule pathway of targeted degradation in Arabidopsis roots. Proteomics 15, 2447-2457. 42 5 6 7 15 2.5 2.0 1.5 8 d -1 4 0. Fold Change in Protein 3 -1 0.03 d-1 d .08 0 1.0 0.5 0.0 0 1 3 5 0 1 3 5 0 1 3 5 Time Course (d) Figure 1. Individual growth rates of leaves in the Arabidopsis rosette and the consequent fold change in protein over time. Leaves 3, 5 and 7 from Arabidopsis plants grown in hydroponic culture were collected over a time course (T0, 1, 3 and 5 days) beginning with 21-day-old plants that had developed 10 leaves (leaf production stage 1.10). Typical images of leaves 3 to 8 from these plants at the beginning of the experiment are shown. The growth of leaves over the subsequent 5 days were determined by following the fold change in protein per leaf at each time point com-pared to T0 for leaf 3 (green), leaf 5, (yellow) and leaf 7 (red). An average relative growth rate (d-1) was determined from both changes in fresh weight and protein content by scan-ning images of gels (see Supplemental Fig 1, Supplemental Data set 1). A Functional Category No. At1g23290 RPL27A Cyt protein synthesis 33 Cyt glycolysis 17 Cyt secondary metabolism 14 Cyt stress 17 Cyt misc 15 Cyt protein degradation 12 Cyt redox 11 Cyt /Nc protein degradation 16 Et misc 14 Mt ETC 20 Mt TCA 20 Nc RNA regulation 16 Pt protein synthesis 37 Pt protein folding 14 Pt lipid metabolism 16 Pt calvin cycle 27 Pt nucleotide metabolism 13 Pt lightreaction 84 Pt protein targeting 11 Pt AA synthesis 34 Pt tetrapyrrole synthesis 15 24 Pt redox Pt misc 11 Pt protein degradation 25 Pt major CHO metabolism 13 Pt secondary metabolism 13 Others 686 At1g79930 HSP91 At5g62350 Invertase At5g13650 elongation factor Atcg00020 D1 A3g48560 CSR1 At4g17090 BAM3 At5g54770 THI1 0.0 0.5 1.0 KD (d-1) 1.5 2.0 C B Mt 128 2.0 Pt 557 Nc 82 1.8 Et 65 Vc 10 R=0.99 THI1 Arabidopsis KD (d-1) 1.6 DUAL 59 1.4 1.2 1.0 Cyt 245 PM 31 ER 13 Px 35 0.4 Golgi 3 0.2 0.0 0.5 KD (d-1) 1.0 0.8 0.6 D1 THIC pterin dehydratase R=0.38 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 Barley KD (d-1) Figure 2. Degradation rates of 1228 Arabidopsis proteins based on averages in functional categories or localization inside cells, and in comparison to barley orthologues. (A) Average Arabidopsis leaf protein degradation rates box-plotted by functional categories and their localization in cells. Functioal categories were acquired from MapCave and localization information from SUBAIII. Only major functional categories and localization groups (n>10) are shown. Median, quartiles and standard deviations are shown. Outliers are shown as hollow dots and extreme outliers are highlighted as solid squares and annotated. The five major localizations are highlighted with colors: Cytosol (Cyt-Blue), Nucleus (Nc-Red), Extracellular (Et-Cyan), Mitochondrion (MtYellow) and Plastid (Pt-Green). (B) Protein degradation rates of the 1228 proteins box-plotted based on localization within the cell. Abbreviations as in (A), and dual targeting proteins (DUAL), Vacuole (Vc), plasma membrane (PM), endoplasmic reticulum (ER), peroxisomal (Px) and Golgi. (C) Protein degradation rates of a subset of 288 Arabidopsis proteins for which orthologues in barley had published rates. One spot represents a protein turnover rate in Barley (xaxis) and Arabidopsis (y-axis). Four outliers (2SD above median, in red dashed line rectangle) are shown (Pearson correlation, R=0.99). The remaining 284 proteins (pointed out by black dashed line rectangle) are shown by black dots (Pearson correlation, R=0.38). A Relative Abundance Set y axis 300 PC 2 16.8% 200 B Degradation Rate (KD) Set 955 5 1228 5 3 -100 3 0 1 Leaf 5 100 Leaf 3 1697 5 100 200 0 1 x axis PC1 3 42.7% -100 Leaf 7 -200 0 300 1 C Leaf 3 Leaf 5 Leaf 7 Days 0 0.0 1 2.8 3 1.5 2.8 5 1.7 3.2 0.0 0 1 3 0.4 0.2 5 2.1 1.7 29.0 33.2 12.7 0 1 3 0.0 0.2 5 0.6 0.2 1.8 14.1 0.4 0 1 3 5 Days Figure 3. Changes in relative abundance estimates for individual proteins in leaves of the Arabidopsis rosette during 5 days of leaf growth. (A) The intersection of the number of specific proteins with a measured KD value and a protein relative abundance assessment. (B) Principle components analysis of specific protein abundances from mass spectrometry analysis. Abundance data for 955 proteins (KD values recorded in Figure 2) were used for the analysis. The clustering of leaf 3 (green), leaf 5 (yellow) and leaf 7 (green) is shown in the grey shading. The full data are provided in Supplemental Data set 3A and B. (C) A matrix of paired statistical comparisons of protein abundance between day 0, day 1, day 3 and day 5 time points for each leaf is presented with the percentage of the proteins from (B) that significantly changed in abundance (t-test p<0.01) reported (full data in Supplemental Data set 3C). Outside the matrix is the percentage of proteins measured that were found to change in abundance (t-test P<0.01) across the entire time course in each leaf. A KD (d-1) 1.0 0.5 0.0 10 64 26 12 152 34 5 5 8 28 8 24 K Q P L G R T S V D A E 119 39 Average Unstable 239 Stable Cumulative Relative Freq B C 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 p<0.05 2000 4000 6000 8000 Aggregation Propensity 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.00 Stable Unstable p<0.05 500 1000 1500 2000 2500 Length 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 p=0.70 0 5 10 15 AGG/LEN 20 No.of Samples PS I PS II Mt ETC Cyt Ribosome Proteasome Pt ATP synthase Pt Ribosome 6000 p<0.01 p<0.01 p=0.20 p<0.01 p<0.01 p=0.05 p<0.05 5000 4000 3000 2000 1000 0 0.0 0.1 0.2 0.0 0.1 0.2 0.0 0.1 0.2 0.0 0.1 0.2 0.0 0.1 0.2 0.0 0.1 0.2 0.0 0.1 0.2 σ (N=24) σ (N=16) σ (N=7) σ (N=31) σ (N=17) σ (N=33) σ (N=20) Figure 4. Intrinsic properties of Arabidopsis proteins that correlate with protein degradation rate. (A) Comparison of protein degradation rate with experimental evidence of the mature N-terminal amino acid residue. Only protein sets in which more than 5 members had the same N-terminal amino acid residue were examined, a set of 376 proteins in total. A non-parametric Kruskal-Wallis k-samples test showed no significant difference among the 12 N-terminal groups. However, the K, S and D groups showed significantly different degradation rate distributions from T by a Conover-Iman post-hoc test. No statistically significant differences were found when degradation rates of stable AAs (A, V, M, G, T, P), unstable AAs (K, F, D, R, Q) and average stability AAs (all others AAs) were compared (Supplemental Data set 4A). These groups were defined based on the consensus of yeast and mammal N-end rules. (B) A Cumulative Relative Frequency distribution graph of protein aggregation propensity (AGG) of each protein, the AA length of each protein (LEN), and the ratio of AGG/AA length between the top 100 most stable and bottom 100 most unstable proteins from the set of 1228 proteins with degradation rates. Statistical significance was estimated by the Kolmogorov-Smirnov test. (C) The standard deviation (σ) of the protein degradation rates of the protein subunits of 7 major protein complexes compared to randomly sampled distributions of σ for the same sized group of proteins from the set of 1228. The protein complexes were: Cytosol Ribosome, Proteasome, Pt ATP synthase, Pt Ribosome, PSI, PSII and Mt ETC; all other proteins were considered to be one group ‘Others’. The standard deviation (σ) was calculated for each specific protein complexes with N subunits and then compared to the distribution of 100,000 random samplings of groups of size N from ‘Others’. The red line shows the σ value of a specific protein complex while the blue distribution shows a histogram of σ values from the 100,000 random samplings of each value of N. The probability (p) value is the proportion of 100,000 random samplings of N that show a smaller σ than the specific protein complex. Leaf 7 vs Leaf 3 More Less A Leaf 7 vs Leaf 3 Functional Category Stable Unstable Pt cell organisation Pt lightreaction Cyt stress Pt calvin cycle Pt protein targeting Pt major CHO metabolism Others Pt misc Pt protein degradation Pt redox Pt AA synthesis Pt protein folding Pt protein synthesis Cyt protein synthesis Pt tetrapyrrole synthesis -2 B -1 0 1 Relative ΔAbundance 2 -2 -1 0 1 Relative ΔKD 2 2.0 Relative ΔAbundance 1.5 PS II PS I Cyt b6f Chlororespiration 1.0 Photorespiration Calvin Cycle 0.5 0.0 -0.5 -1.0 ATP synthase -1.5 Electron NADH Carrier DH -2.0 Leaf 3 C 1.6 Leaf 5 Atcg00020 D1 1.2 Atcg00730 PetD 1.0 KD (d-1) Chlororespiration Cyt b6f 1.4 0.8 Leaf 7 PS II At3g15840 PIFI Photorespiration PS I 0.6 ATP synthase Calvin Cycle Electron NADH Carrier DH 0.4 0.2 STN7 0.0 Figure 5. Comparisons of the relative protein abundance and degradation rate of specific proteins that differed in their measurements between leaf 3 and leaf 7. (A) Proteins with significant changes (T-test, p<0.05) in abundance (502 pairs, left) or degradation rate (433 pairs, right) between leaf 3 and leaf 7 are presented. The changes in relative abundance and degradation rate are shown as relative ∆Abundance and ∆KD by comparing leaf 7 to leaf 3 data. Major functional categories (as in Figure 2) that comprised at least 5 proteins for abundance or degradation data are displayed. All remaining proteins were combined in the group ‘Others’. Outliers are presented as hollow dots. The dashed line shows the boundary for no change in abundance and degradation between leaf 3 and leaf 7. (B) Relative ∆Abundance was compared for leaves 3, 5 and 7 for photosynthesis protein complexes and functional categories (110 proteins). The proteins on the X-axis are in the same order for each leaf comparison. Error bars show standard errors of relative ∆Abundance from each leaf separately, all comparisons are relative to leaf 3. (C) Protein degradation rates (KD) was compared for leaves 3, 5 and 7 for photosynthesis protein complexes and functional categories (116 proteins). The proteins on the X-axis are in the same order for each leaf comparison. Average KD and standard errors calculated from data for each leaf separately are shown. The proteins in (B) and (C) are not in the same order but are shown in rank order within each complex to show the consistent trend in relative ∆Abundance and Protein degradation rates (KD) across the three leaves. B A 4.0 PSBF 3.0 2.0 1.0 0.0 CPN60A&B 0.03 0.08 Growth Rates (d-1) C FTSH1,2 5&8 1.0 0.0 CLPs MAP&DEGs 0.03 0.6 0.4 0.2 0.0 0.03 0.08 Growth Rates (d-1) 1.0 0.08 Growth Rates (d-1) 0.15 Cyt Ribosome, Initiation & Elongation 0.8 0.6 0.4 0.2 0.0 0.03 0.15 E 0.08 Growth Rates (d-1) 0.15 F Proteasome, E2 and E3 2.8 E3 2.2 1.6 1.0 0.4 0.03 0.08 0.15 Growth Rates (d ) -1 Ratio of protein abundance to reference Ratio of KD to Leaf 3 0.8 D 1.5 0.5 Pt Risosome 1.0 0.15 Pt Proteases 2.0 Ratio of KD to Leaf 3 Ferredoxin 1 Ratio of KD to Leaf 3 Photosynthesis Ratio of KD to Leaf 3 Ratio of KD to Leaf 3 5.0 2.5 CPN60 A CPN60 B 2.0 1.5 * * 1.0 0.5 0.0 Leaf 3 Leaf 5 Leaf 7 Figure 6. Correlation of Arabidopsis protein degradation rates with leaf growth rate. Protein degradation rates (KD) in leaves 5 and 7 were normalized to corresponding values for the same proteins in Leaf 3. Ratios of KD to leaf 3 KD values for (A) 92 photosynthesis proteins; (B) 11 plastid ribosome proteins; (C) plastid proteases including CLPs (CLPP2, 5&6; CLPC, CLPR1, 2, 4&6 and Clp), DEG (DEGP1&2) and MAP, and FTSHs (FTSH1, 2, 5&8); (D) 12 cytosol ribosome proteins and 10 initiation and elongation proteins; and (E) Proteasome E2 and E3 ligase proteins, are shown plotted against the leaf growth rates of leaves 3, 5 and 7. All proteins shown had positive or negative Pearson correlations between the ratio of KD and leaf growth rate of R>0.9 or R<-0.9, respectively. The red dashed line is a boundary for negative and positive correlations. (F) The relative protein abundance of CPN60 A&B in leaves 5 and 7 is compared with leaf 3 (*p<0.05). Error bars are SE of all data from each leaf separately. A Overall 71% 35 4% 4% 13% Leaf 3 Degradation Synthesis Others 25% 3% C B 4% Leaf 5 84% 19% 77% Leaf 7 58% 38% Plastid Cytosol Mitochondrion Peroxisome Extracellular PM Nucleus Vacuole ATP use by Functional Categories (%) 30 25 20 15 10 5 ATP use for Subcellular Proteome Maintenance (%) 0 10 20 30 40 50 60 70 80 0 calvin cycle lightreaction protein synthesis AA synthesis redox protein degradation misc photorespiration stress secondary metabolism TCA hormone metabolism glycolysis N-metabolism Co-factor and vitamine metabolism D Highest ATP Cost Individual Proteins (%) 0 RBCL RCA ATPB ATPA THI1 DRT112 LOX2 RABE1b GLU1 PMDH2 FBA2 D1 GLDP1 AOS PSBP-1 5 10 15 Figure 7. ATP energy budgets for protein degradation and synthesis in Arabidopsis leaves. (A) The proportion of cellular ATP used for protein degradation (blue), protein synthesis (yellow) and other aspects of cell maintenance (grey). Energy budgets are presented as the averages across leaves 3, 5 and 7, and also in each leaf individually. (B) The proportion of ATP used for protein degradation (blue) and synthesis (yellow) in maintaining the proteomes of major cellular organelles and structures (when ATP cost >1% of total ATP use). (C) ATP used for protein degradation (blue) and synthesis (yellow) by major functional categories of proteins (when ATP cost >2% of total ATP use). (D) The fifteen individual proteins with the highest ATP cost to maintain in the Arabidopsis proteome; only four of these were from the two highest cost functional categories (dotted lines). Subcellular location, functional categories and specific high cost proteins were sorted by the proportion of energy cost for protein synthesis (yellow). Respiration was presumed to be the primary net ATP production source for protein synthesis and its value is based on experimental data from the Arabidopsis rosette. 20 Parsed Citations Apel, W., Schulze, W.X., and Bock, R. (2010). Identification of protein stability determinants in chloroplasts. Plant J 63, 636-650. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Araujo, W.L., Tohge, T., Ishizaki, K., Leaver, C.J., and Fernie, A.R. (2011). Protein degradation - an alternative respiratory substrate for stressed plants. Trends Plant Sci 16, 489-498. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Armbruster, U., Zuhlke, J., Rengstl, B., Kreller, R., Makarenko, E., Ruhle, T., Schunemann, D., Jahns, P., Weisshaar, B., Nickelsen, J., and Leister, D. (2010). The Arabidopsis thylakoid protein PAM68 is required for efficient D1 biogenesis and photosystem II assembly. Plant Cell 22, 3439-3460. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Avci, D., and Lemberg, M.K. (2015). Clipping or Extracting: Two Ways to Membrane Protein Degradation. Trends in cell biology 25, 611-622. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Bachmair, A., Finley, D., and Varshavsky, A. (1986). In vivo half-life of a protein is a function of its amino-terminal residue. Science 234, 179-186. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Baerenfaller, K., Massonnet, C., Walsh, S., Baginsky, S., Buhlmann, P., Hennig, L., Hirsch-Hoffmann, M., Howell, K.A., Kahlau, S., Radziejwoski, A., Russenberger, D., Rutishauser, D., Small, I., Stekhoven, D., Sulpice, R., Svozil, J., Wuyts, N., Stitt, M., Hilson, P., Granier, C., and Gruissem, W. (2012). Systems-based analysis of Arabidopsis leaf growth reveals adaptation to water deficit. Mol Syst Biol 8, 606. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Blasing, O.E., Gibon, Y., Gunther, M., Hohne, M., Morcuende, R., Osuna, D., Thimm, O., Usadel, B., Scheible, W.R., and Stitt, M. (2005). Sugars and circadian regulation make major contributions to the global regulation of diurnal gene expression in Arabidopsis. The Plant cell 17, 3257-3281. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Boyes, D.C., Zayed, A.M., Ascenzi, R., McCaskill, A.J., Hoffman, N.E., Davis, K.R., and Gorlach, J. (2001). Growth stage-based phenotypic analysis of Arabidopsis: a model for high throughput functional genomics in plants. Plant Cell 13, 1499-1510. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Cambridge, S.B., Gnad, F., Nguyen, C., Bermejo, J.L., Kruger, M., and Mann, M. (2011). Systems-wide proteomic analysis in mammalian cells reveals conserved, functional protein turnover. J Proteome Res 10, 5275-5284. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Chatterjee, A., Abeydeera, N.D., Bale, S., Pai, P.J., Dorrestein, P.C., Russell, D.H., Ealick, S.E., and Begley, T.P. (2011). Saccharomyces cerevisiae THI4p is a suicide thiamine thiazole synthase. Nature 478, 542-546. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Chen, W.P., Yang, X.Y., Harms, G.L., Gray, W.M., Hegeman, A.D., and Cohen, J.D. (2011). An automated growth enclosure for metabolic labeling of Arabidopsis thaliana with 13C-carbon dioxide - an in vivo labeling system for proteomics and metabolomics research. Proteome Sci 9, 9. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Christiano, R., Nagaraj, N., Frohlich, F., and Walther, T.C. (2014). Global proteome turnover analyses of the Yeasts S. cerevisiae and S. pombe. Cell Rep 9, 1959-1965. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Claydon, A.J., and Beynon, R. (2012). Proteome dynamics: revisiting turnover with a global perspective. Mol Cell Proteomics 11, 1551-1565. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title De Baets, G., Reumers, J., Delgado Blanco, J., Dopazo, J., Schymkowitz, J., and Rousseau, F. (2011). An evolutionary trade-off between protein turnover rate and protein aggregation favors a higher aggregation propensity in fast degrading proteins. PLoS Comput Biol 7, e1002090. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Deutsch, E.W., Mendoza, L., Shteynberg, D., Farrah, T., Lam, H., Tasman, N., Sun, Z., Nilsson, E., Pratt, B., Prazen, B., Eng, J.K., Martin, D.B., Nesvizhskii, A.I., and Aebersold, R. (2010). A guided tour of the Trans-Proteomic Pipeline. Proteomics 10, 1150-1159. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Doherty, M.K., Hammond, D.E., Clague, M.J., Gaskell, S.J., and Beynon, R.J. (2009). Turnover of the human proteome: determination of protein intracellular stability by dynamic SILAC. J Proteome Res 8, 104-112. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Eckardt, N.A., Snyder, G.W., Portis, A.R., Jr., and Orgen, W.L. (1997). Growth and photosynthesis under high and low irradiance of Arabidopsis thaliana antisense mutants with reduced ribulose-1,5-bisphosphate carboxylase/oxygenase activase content. Plant physiology 113, 575-586. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Edwards, J.M., Roberts, T.H., and Atwell, B.J. (2012). Quantifying ATP turnover in anoxic coleoptiles of rice (Oryza sativa) demonstrates preferential allocation of energy to protein synthesis. J Exp Bot 63, 4389-4402. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Ellis, R.J. (1981). Chloroplast Proteins - Synthesis, Transport, and Assembly. Annual Review of Plant Physiology and Plant Molecular Biology 32, 111-137. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Fan, K.T., Rendahl, A.K., Chen, W.P., Freund, D.M., Gray, W.M., Cohen, J.D., and Hegeman, A.D. (2016). Proteome Scale-Protein Turnover Analysis Using High Resolution Mass Spectrometric Data from Stable-Isotope Labeled Plants. J Proteome Res. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Fernandez-Escamilla, A.M., Rousseau, F., Schymkowitz, J., and Serrano, L. (2004). Prediction of sequence-dependent and mutational effects on the aggregation of peptides and proteins. Nat Biotechnol 22, 1302-1306. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Fleig, L., Bergbold, N., Sahasrabudhe, P., Geiger, B., Kaltak, L., and Lemberg, M.K. (2012). Ubiquitin-dependent intramembrane rhomboid protease promotes ERAD of membrane proteins. Molecular Cell 47, 558-569. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Flugge, U.I., Hausler, R.E., Ludewig, F., and Gierth, M. (2011). The role of transporters in supplying energy to plant plastids. J Exp Bot 62, 2381-2392. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Gfeller, A., Baerenfaller, K., Loscos, J., Chetelat, A., Baginsky, S., and Farmer, E.E. (2011). Jasmonate controls polypeptide patterning in undamaged tissue in wounded Arabidopsis leaves. Plant Physiol 156, 1797-1807. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Giraud, E., Ng, S., Carrie, C., Duncan, O., Low, J., Lee, C.P., Van Aken, O., Millar, A.H., Murcha, M., and Whelan, J. (2010). TCP transcription factors link the regulation of genes encoding mitochondrial proteins with the circadian clock in Arabidopsis thaliana. Plant Cell 22, 3921-3934. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Gonda, D.K., Bachmair, A., Wunning, I., Tobias, J.W., Lane, W.S., and Varshavsky, A. (1989). Universality and structure of the N-end rule. J Biol Chem 264, 16700-16712. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Guan, S.H., Price, J.C., Prusiner, S.B., Ghaemmaghami, S., and Burlingame, A.L. (2011). A Data Processing Pipeline for Mammalian Proteome Dynamics Studies Using Stable Isotope Metabolic Labeling. Molecular & Cellular Proteomics 10. M111.010728 Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Hasan, S.S., Yamashita, E., Baniulis, D., and Cramer, W.A. (2013). Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex. Proc Natl Acad Sci U S A 110, 4297-4302. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Hooper, C.M., Tanz, S.K., Castleden, I.R., Vacher, M.A., Small, I.D., and Millar, A.H. (2014). SUBAcon: a consensus algorithm for unifying the subcellular localization data of the Arabidopsis proteome. Bioinformatics 30, 3356-3364. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Huang, S., Nelson, C.J., Li, L., Taylor, N.L., Stroher, E., Peteriet, J., and Millar, A.H. (2015). INTERMEDIATE CLEAVAGE PEPTIDASE55 Modifies Enzyme Amino Termini and Alters Protein Stability in Arabidopsis Mitochondria. Plant Physiol 168, 415-427. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Huang, W., Ling, Q., and Jarvis, P. (2013). The ubiquitin-proteasome system regulates chloroplast biogenesis. Commun Integr Biol 6, e23001. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Ishihara, H., Obata, T., Sulpice, R., Fernie, A.R., and Stitt, M. (2015). Quantifying protein synthesis and degradation in Arabidopsis by dynamic 13CO2 labeling and analysis of enrichment in individual amino acids in their free pools and in protein. Plant Physiol 168, 74-93. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Janska, H., Kwasniak, M., and Szczepanowska, J. (2013). Protein quality control in organelles - AAA/FtsH story. Biochim Biophys Acta 1833, 381-387. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Jayapal, K.P., Sui, S., Philp, R.J., Kok, Y.J., Yap, M.G., Griffin, T.J., and Hu, W.S. (2010). Multitagging proteomic strategy to estimate protein turnover rates in dynamic systems. J Proteome Res 9, 2087-2097. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Juntawong, P., Girke, T., Bazin, J., and Bailey-Serres, J. (2014). Translational dynamics revealed by genome-wide profiling of ribosome footprints in Arabidopsis. Proc Natl Acad Sci U S A 111, E203-212. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Kaleta, C., Schauble, S., Rinas, U., and Schuster, S. (2013). Metabolic costs of amino acid and protein production in Escherichia coli. Biotechnol J 8, 1105-1114. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Karunadharma, P.P., Basisty, N., Chiao, Y.A., Dai, D.F., Drake, R., Levy, N., Koh, W.J., Emond, M.J., Kruse, S., Marcinek, D., Maccoss, M.J., and Rabinovitch, P.S. (2015). Respiratory chain protein turnover rates in mice are highly heterogeneous but strikingly conserved across tissues, ages, and treatments. FASEB J 29, 3582-3592. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Kato, Y., Sun, X., Zhang, L., and Sakamoto, W. (2012). Cooperative D1 Degradation in the Photosystem II Repair Mediated by Chloroplastic Proteases in Arabidopsis. Plant Physiol. 159:1428-39 Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Kramer, D.M., and Evans, J.R. (2011). The importance of energy balance in improving photosynthetic productivity. Plant Physiol 155, 70-78. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lam, M.P., Wang, D., Lau, E., Liem, D.A., Kim, A.K., Ng, D.C., Liang, X., Bleakley, B.J., Liu, C., Tabaraki, J.D., Cadeiras, M., Wang, Y., Deng, M.C., and Ping, P. (2014). Protein kinetic signatures of the remodeling heart following isoproterenol stimulation. J Clin Invest 124, 1734-1744. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lambreva, M.D., Russo, D., Polticelli, F., Scognamiglio, V., Antonacci, A., Zobnina, V., Campi, G., and Rea, G. (2014). Structure/function/dynamics of photosystem II plastoquinone binding sites. Curr Protein Pept Sci 15, 285-295. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lamesch, P., Berardini, T.Z., Li, D., Swarbreck, D., Wilks, C., Sasidharan, R., Muller, R., Dreher, K., Alexander, D.L., GarciaHernandez, M., Karthikeyan, A.S., Lee, C.H., Nelson, W.D., Ploetz, L., Singh, S., Wensel, A., and Huala, E. (2012). The Arabidopsis Information Resource (TAIR): improved gene annotation and new tools. Nucleic Acids Research 40, D1202-1210. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lee, C.P., Eubel, H., and Millar, A.H. (2010). Diurnal changes in mitochondrial function reveal daily optimization of light and dark respiratory metabolism in Arabidopsis. Molecular & Cellular Proteomics 9, 2125-2139. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Li, L., Nelson, C.J., Solheim, C., Whelan, J., and Millar, A.H. (2012). Determining degradation and synthesis rates of arabidopsis proteins using the kinetics of progressive 15N labeling of two-dimensional gel-separated protein spots. Mol Cell Proteomics 11, M111 010025. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Li, L., Nelson, C., Fenske, R., Trösch, J., Pružinská, A., Millar, A.H., and Huang, S. (2016). Changes in specific protein degradation rates in Arabidopsis thaliana reveal multiple roles of Lon1 in mitochondrial protein homeostasis. Plant J. (in press, 10.1111/tpj.13392) Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Liang, C., Cheng, S., Zhang, Y., Sun, Y., Fernie, A.R., Kang, K., Panagiotou, G., Lo, C., and Lim, B.L. (2016). Transcriptomic, proteomic and metabolic changes in Arabidopsis thaliana leaves after the onset of illumination. BMC plant biology 16, 43. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lim, W.K., Wang, K., Lefebvre, C., and Califano, A. (2007). Comparative analysis of microarray normalization procedures: effects on reverse engineering gene networks. Bioinformatics 23, i282-288. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Ling, Q., Huang, W., Baldwin, A., and Jarvis, P. (2012). Chloroplast biogenesis is regulated by direct action of the ubiquitinproteasome system. Science 338, 655-659. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Lyon, D., Castillejo, M.A., Mehmeti-Tershani, V., Staudinger, C., Kleemaier, C., and Wienkoop, S. (2016). Drought and recovery: independently regulated processes highlighting the importance of protein turnover dynamics and translational regulation in Medicago truncatula. Mol Cell Proteomics. 15:1921-37 Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Masclaux-Daubresse, C., Daniel-Vedele, F., Dechorgnat, J., Chardon, F., Gaufichon, L., and Suzuki, A. (2010). Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. Ann Bot 105, 1141-1157. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Melis, A. (1999). Photosystem-II damage and repair cycle in chloroplasts: what modulates the rate of photodamage ? Trends Plant Sci 4, 130-135. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Mockler, T.C., Michael, T.P., Priest, H.D., Shen, R., Sullivan, C.M., Givan, S.A., McEntee, C., Kay, S.A., and Chory, J. (2007). The DIURNAL project: DIURNAL and circadian expression profiling, model-based pattern matching, and promoter analysis. Cold Spring Harbor symposia on quantitative biology 72, 353-363. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Nelson, C.J., Li, L., Jacoby, R.P., and Millar, A.H. (2013). Degradation rate of mitochondrial proteins in Arabidopsis thaliana cells. J Proteome Res 12, 3449-3459. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Nelson, C.J., Alexova, R., Jacoby, R.P., and Millar, A.H. (2014). Proteins with high turnover rate in barley leaves estimated by proteome analysis combined with in planta isotope labeling. Plant Physiol 166, 91-108. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Nesvizhskii, A.I., Keller, A., Kolker, E., and Aebersold, R. (2003). A statistical model for identifying proteins by tandem mass spectrometry. Anal Chem 75, 4646-4658. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Nishimura, K., Fukagawa, T., Takisawa, H., Kakimoto, T., and Kanemaki, M. (2009). An auxin-based degron system for the rapid depletion of proteins in nonplant cells. Nat Methods 6, 917-922. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Nussbaumer, T., Martis, M.M., Roessner, S.K., Pfeifer, M., Bader, K.C., Sharma, S., Gundlach, H., and Spannagl, M. (2013). MIPS PlantsDB: a database framework for comparative plant genome research. Nucleic acids research 41, D1144-1151. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Osteryoung, K.W., and Pyke, K.A. (2014). Division and dynamic morphology of plastids. Annu Rev Plant Biol 65, 443-472. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Peth, A., Nathan, J.A., and Goldberg, A.L. (2013). The ATP costs and time required to degrade ubiquitinated proteins by the 26 S proteasome. J Biol Chem 288, 29215-29222. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Piques, M., Schulze, W.X., Hohne, M., Usadel, B., Gibon, Y., Rohwer, J., and Stitt, M. (2009). Ribosome and transcript copy numbers, polysome occupancy and enzyme dynamics in Arabidopsis. Mol Syst Biol 5, 314. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Ponnala, L., Wang, Y., Sun, Q., and van Wijk, K.J. (2014). Correlation of mRNA and protein abundance in the developing maize leaf. The Plant journal : for cell and molecular biology 78, 424-440. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Price, J.C., Guan, S., Burlingame, A., Prusiner, S.B., and Ghaemmaghami, S. (2010). Analysis of proteome dynamics in the mouse brain. Proc Natl Acad Sci U S A 107, 14508-14513. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Reinhold, T., Alawady, A., Grimm, B., Beran, K.C., Jahns, P., Conrath, U., Bauer, J., Reiser, J., Melzer, M., Jeblick, W., and Neuhaus, H.E. (2007). Limitation of nocturnal import of ATP into Arabidopsis chloroplasts leads to photooxidative damage. Plant J 50, 293304. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Ren, M., Qiu, S., Venglat, P., Xiang, D., Feng, L., Selvaraj, G., and Datla, R. (2011). Target of rapamycin regulates development and ribosomal RNA expression through kinase domain in Arabidopsis. Plant Physiol 155, 1367-1382. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Rousseeuw, P.J. (1987). Silhouettes - a Graphical Aid to the Interpretation and Validation of Cluster-Analysis. Journal of Computational and Applied Mathematics 20, 53-65. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Rowland, E., Kim, J., Bhuiyan, N.H., and van Wijk, K.J. (2015). The Arabidopsis Chloroplast Stromal N-Terminome: Complexities of Amino-Terminal Protein Maturation and Stability. Plant Physiol 169, 1881-1896. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Scheurwater, I., Dunnebacke, M., Eising, R., and Lambers, H. (2000). Respiratory costs and rate of protein turnover in the roots of a fast-growing (Dactylis glomerata L.) and a slow-growing (Festuca ovina L.) grass species. J Exp Bot 51, 1089-1097. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Schmitz, G., Reinhold, T., Gobel, C., Feussner, I., Neuhaus, H.E., and Conrath, U. (2010). Limitation of nocturnal ATP import into chloroplasts seems to affect hormonal crosstalk, prime defense, and enhance disease resistance in Arabidopsis thaliana. Mol Plant Microbe Interact 23, 1584-1591. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Schmitz, J., Heinrichs, L., Scossa, F., Fernie, A.R., Oelze, M.L., Dietz, K.J., Rothbart, M., Grimm, B., Flugge, U.I., and Hausler, R.E. (2014). The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities. J Exp Bot 65, 1619-1636. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Schwanhausser, B., Busse, D., Li, N., Dittmar, G., Schuchhardt, J., Wolf, J., Chen, W., and Selbach, M. (2011). Global quantification of mammalian gene expression control. Nature 473, 337-342. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Sew, Y.S., Stroher, E., Holzmann, C., Huang, S., Taylor, N.L., Jordana, X., and Millar, A.H. (2013). Multiplex micro-respiratory measurements of Arabidopsis tissues. New Phytol 200, 922-932. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Shteynberg, D., Deutsch, E.W., Lam, H., Eng, J.K., Sun, Z., Tasman, N., Mendoza, L., Moritz, R.L., Aebersold, R., and Nesvizhskii, A.I. (2011). iProphet: multi-level integrative analysis of shotgun proteomic data improves peptide and protein identification rates and error estimates. Molecular & cellular proteomics : MCP 10, M111 007690. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Siddell, S.G., and Ellis, R.J. (1975). Protein synthesis in chloroplasts. Characteristics and products of protein synthesis in vitro in etioplasts and developing chloroplasts from pea leaves. Biochem J 146, 675-685. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Smith, S.M., Fulton, D.C., Chia, T., Thorneycroft, D., Chapple, A., Dunstan, H., Hylton, C., Zeeman, S.C., and Smith, A.M. (2004). Diurnal changes in the transcriptome encoding enzymes of starch metabolism provide evidence for both transcriptional and posttranscriptional regulation of starch metabolism in Arabidopsis leaves. Plant physiology 136, 2687-2699. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Suzuki, K., Nakanishi, H., Bower, J., Yoder, D.W., Osteryoung, K.W., and Miyagishima, S.Y. (2009). Plastid chaperonin proteins Cpn60 alpha and Cpn60 beta are required for plastid division in Arabidopsis thaliana. BMC Plant Biol 9, 38. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Takahashi, S., and Badger, M.R. (2011). Photoprotection in plants: a new light on photosystem II damage. Trends Plant Sci 16, 5360. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Tanz, S.K., Castleden, I., Hooper, C.M., Vacher, M., Small, I., and Millar, H.A. (2013). SUBA3: a database for integrating experimentation and prediction to define the SUBcellular location of proteins in Arabidopsis. Nucleic Acids Res 41, D1185-1191. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Umena, Y., Kawakami, K., Shen, J.R., and Kamiya, N. (2011). Crystal structure of oxygen-evolving photosystem II at a resolution of 1.9 A. Nature 473, 55-60. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title van Wijk, K.J. (2015). Protein maturation and proteolysis in plant plastids, mitochondria, and peroxisomes. Annu Rev Plant Biol 66, 75-111. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Vierstra, R.D. (2009). The ubiquitin-26S proteasome system at the nexus of plant biology. Nat Rev Mol Cell Biol 10, 385-397. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Vogtle, F.N., Wortelkamp, S., Zahedi, R.P., Becker, D., Leidhold, C., Gevaert, K., Kellermann, J., Voos, W., Sickmann, A., Pfanner, N., and Meisinger, C. (2009). Global Analysis of the Mitochondrial N-Proteome Identifies a Processing Peptidase Critical for Protein Stability. Cell 139, 428-439. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Walsh, C.T. (1984). Suicide substrates, mechanism-based enzyme inactivators: recent developments. Annu Rev Biochem 53, 493535. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Wang, D., and Portis, A.R., Jr. (2007). A novel nucleus-encoded chloroplast protein, PIFI, is involved in NAD(P)H dehydrogenase complex-mediated chlororespiratory electron transport in Arabidopsis. Plant Physiol 144, 1742-1752. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Wang, M., Weiss, M., Simonovic, M., Haertinger, G., Schrimpf, S.P., Hengartner, M.O., and von Mering, C. (2012). PaxDb, a database of protein abundance averages across all three domains of life. Mol Cell Proteomics 11, 492-500. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Waters, M.T., Nelson, D.C., Scaffidi, A., Flematti, G.R., Sun, Y.K., Dixon, K.W., and Smith, S.M. (2012). Specialisation within the DWARF14 protein family confers distinct responses to karrikins and strigolactones in Arabidopsis. Development 139, 1285-1295. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Wei, X., Su, X., Cao, P., Liu, X., Chang, W., Li, M., Zhang, X., and Liu, Z. (2016). Structure of spinach photosystem II-LHCII supercomplex at 3.2 A resolution. Nature 534, 69-74. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Woodson, J.D., Joens, M.S., Sinson, A.B., Gilkerson, J., Salome, P.A., Weigel, D., Fitzpatrick, J.A., and Chory, J. (2015). Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts. Science 350, 450-454. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Yang, X.Y., Chen, W.P., Rendahl, A.K., Hegeman, A.D., Gray, W.M., and Cohen, J.D. (2010). Measuring the turnover rates of Arabidopsis proteins using deuterium oxide: an auxin signaling case study. Plant J 63, 680-695. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Yip, C.Y., Harbour, M.E., Jayawardena, K., Fearnley, I.M., and Sazanov, L.A. (2011). Evolution of respiratory complex I: "supernumerary" subunits are present in the alpha-proteobacterial enzyme. J Biol Chem 286, 5023-5033. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Zaltsman, A., Feder, A., and Adam, Z. (2005). Developmental and light effects on the accumulation of FtsH protease in Arabidopsis chloroplasts--implications for thylakoid formation and photosystem II maintenance. Plant J 42, 609-617. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Zhang, H., and Cramer, W.A. (2004). Purification and crystallization of the cytochrome b6f complex in oxygenic photosynthesis. Methods Mol Biol 274, 67-78. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Zhang, H., Deery, M.J., Gannon, L., Powers, S.J., Lilley, K.S., and Theodoulou, F.L. (2015). Quantitative proteomics analysis of the Arg/N-end rule pathway of targeted degradation in Arabidopsis roots. Proteomics 15, 2447-2457. Pubmed: Author and Title CrossRef: Author and Title Google Scholar: Author Only Title Only Author and Title Protein Degradation Rate in Arabidopsis thaliana Leaf Growth and Development Lei Li, Clark J Nelson, Josua Trösch, Ian Castleden, Shaobai Huang and A. Harvey Millar Plant Cell; originally published online January 30, 2017; DOI 10.1105/tpc.16.00768 This information is current as of June 13, 2017 Supplemental Data /content/suppl/2017/02/23/tpc.16.00768.DC2.html /content/suppl/2017/01/30/tpc.16.00768.DC1.html Permissions https://www.copyright.com/ccc/openurl.do?sid=pd_hw1532298X&issn=1532298X&WT.mc_id=pd_hw1532298X eTOCs Sign up for eTOCs at: http://www.plantcell.org/cgi/alerts/ctmain CiteTrack Alerts Sign up for CiteTrack Alerts at: http://www.plantcell.org/cgi/alerts/ctmain Subscription Information Subscription Information for The Plant Cell and Plant Physiology is available at: http://www.aspb.org/publications/subscriptions.cfm © American Society of Plant Biologists ADVANCING THE SCIENCE OF PLANT BIOLOGY
© Copyright 2026 Paperzz