ฦᏄ࣓࣭ࢰ࣭ࠉ࣐࢛ࢨࣤ㹋 ࡡṄ ࡂᵕᏄࢅ├᥃ふᐳ
᪡⛼⏛ኬᏕ⌦ᕝᏕ⾙㝌ࡡᇖཾග஄ㅦᖅ࡛ᮄୖୌᙢᩅ᤭ࡢࠉ⣵⬂හ࡚࢓ࢠࢲࣤ⥲⥌㸟࡞
Ἒࡖ࡙͆Ⲭ∸͇ࢅ㐘ࡩᩐ༎ࢻࢿ࣒࣭ࢹࣜࡡ࣓࣭ࢰ࣭⺦Ⓣ㈻ࠉ࣐࢛ࢨࣤ㹋ࡡ͆Ṅࡂ͇௘
⤄ࡲࢅ᪺ࡼ࠾࡞ࡊࡱࡊࡒࠊ࣐࢛ࢨࣤ㹋ࡢ஦ᮇࡡ͂㊂̓ࢅᣚࡔࠉࡐࡿࢅ౐ࡖ࡙⛛ິࡊࡱ
ࡌ࠿ࠉ∞᪁ࡡ⬦࡞┘༰࡛ࡊ࡙᚜ᑚ⟮㸝⣵⬂හ࡞࠵ࡾ⦼⥌≟ࡡ⺦Ⓣ㈻㸞ࢅ⤎ྙࡈࡎࡾᡥ
Ἢࢅ㛜Ⓠࡊࠉ⛛ິࡊ࡙࠷ࡾ᫤ࡡ⬦ࡡິࡀ㸝みᗐን໩ࡷ⛛ິ㸞ࢅකᏕ㢟᚜㙶࡚├᥃ふᐳ
ࡌࡾࡆ࡛࡞ิࡴ࡙ᠺຉࡊࡱࡊࡒࠊ஦ᮇࡡ㊂ࢅᣚࡗெ㛣ࡢ㔔ງࡷៈᛮ㸝ເ࠷㸞ࢅฺ⏕ࡊ
࡙Ṅ࠷࡙࠷ࡱࡌ࠿ࠉ࣐࢛ࢨࣤ㹋ࡢ࣐ࢠࣞࡡୠ⏲≁᭯ࡡࣇࣚࢗࣤ㐘ິࢅฺ⏕ࡊ࡙࠷ࡾࡆ
࡛࠿ฦ࠾ࡽࡱࡊࡒࠊࡆࡡ௘⤄ࡲࡡよ᪺ࡢࠉ௙ࡡ࣓࣭ࢰ࣭⺦Ⓣ㈻ࡡິష࣒࢜ࢼࢫ࣑ࡡ⌦
よ࡞ࡗ࡝࠿ࡾ࡛࡛ࡵ࡞ࠉெᕝ㍲㏞ࢻࢿ࣏ࢨࣤࡡスゝ࡝࡜࡫ࡡ㈁⊡ࡵ᭿ᙽࡈࡿࡱࡌࠊࡆ
ࡡᠺᯕࡢࠉ㸪᭮㸧㸪᪝Ⓠ⾔ࡡ⡷ᅗࡡ⛁Ꮥ㞟ヽࠔࢦ࢕࢙ࣤࢪࠕ࡞᥎㍍ࡈࡿࡱࡌࠊ
ࢦ࢕࢙ࣤࢪ᥎㍍ㄵᩝ
ㄵᩝ㢗┘㸯Myosin V Walks by Lever Action and Brownian Motion
ࠔ࣐࢛ࢨࣤ㹋ࡢᱫᏄࡡິష࡛ࣇࣚࢗࣤ㐘ິ࡞ࡻࡽṄࡂࠕ
ⴥ⩽ 㸯ᇖཾග஄㸝᪡⛼⏛ኬᏕ⌦ᕝᏕ⾙㝌∸⌦Ꮥ⛁ㅦᖅ㸞
ᮄୖୌᙢ㸝᪡⛼⏛ኬᏕ⌦ᕝᏕ⾙㝌∸⌦Ꮥ⛁ᩅ᤭㸞
ฦᏄ࣓࣭ࢰ࣭ࡢࠉ⏍మහࡡ࢙ࢾ࣭ࣜ࢟፳మ࡚࠵ࡾ㸶㹉㹅㸝࢓ࢸࢿࢨࣤ୔⇝㓗㸞ࡡຊ
Ềฦよ࢙ࢾ࣭ࣜ࢟ࢅฺ⏕ࡊ࡙ࠉ⛛ິࡷᅂ㌹㐘ິࢅࡌࡾ⺦Ⓣ㈻ฦᏄ࡚ࡌࠊິࡀࡡふᐳࡢ
ິష࣒࢜ࢼࢫ࣑ࡡ⌦よ࡞ࡗ࡝࠿ࡽࡱࡌ࠿ࠉฦᏄࡢᑚࡈ࠷ࡒࡴ࡞ࡐࡡࡱࡱ࡚ࡢິࡀࢅᤂ
࠻ࡾࡆ࡛ࡢᅏ㞬࡚ࡌࠊ௑ᅂࡡ◂✪࡚ࡢࠉ࣐࢛ࢨࣤ㹋ࡡẒ㍉Ⓩ◫࠷Ფ≟ࡡ㒂ฦ㸝⬦㸞࡞ࠉ
ࡐࡡ㸦㸥㸥ಶ⛤ᗐࡡ㛏ࡈࡡᲤ≟ࡡ⺦Ⓣ㈻ࢅ┘༰࡛ࡊ࡙⤎ྙࡈࡎࠉ⬦ࡡみᗐን໩ࢅ┘༰
ࡡኬࡀ࡝ິࡀ࡞ቌᖕࡊࡱࡊࡒࠊெ㛣ࡡࡻ࠹࡝ኬࡀ࡝⏍∸࡛ࡢ഼ࡂງࡡᛮ㈻࠿␏࡝ࡾࡒ
ࡴࠉ࣐ࢠࣞࡡୠ⏲ࡡິࡀࡢࡗ࠾ࡲ࡞ࡂ࠷ࡡ࡚ࡌ࠿ࠉ௑ᅂࡢࡐࡡິࡀࢅິ⏤࡛ࡊ࡙ᚋࡾ
ࡆ࡛࡞ᠺຉࡊࡱࡊࡒࠊࡆࡡᡥἪࡢฦᏄ࣓࣭ࢰ࣭ࡓࡄ࡚࡝ࡂࠉみᗐን໩ࢅఔࡖ࡙ᶭ⬗ࡌ
ࡾ࡛⩻࠻ࡼࡿࡾኣࡂࡡ⺦Ⓣ㈻ฦᏄࡡິࡀࡡ᳠ฝ࡞᭯ຝ࡚࠵ࡽࠉࡐࡿࡼ࡫ࡡᚺ⏕࠿᭿ᙽ
ࡈࡿࡱࡌࠊ
࡝࠽ࠉࡆࡡ◂✪ࡢᩝ㒂⛁Ꮥ┤⛁Ꮥ◂✪㈕୩ࡦ࡞ྜྷ㸧㸦ୠ⣎㸸㹄㸺ࣈࣞࢡ࣑ࣚ࡞ᇱࡘ
ࡀᐁ᪃ࡊࡱࡊࡒࠊ
᥎㍍ㄵᩝࡡᴣさ
ㄵᩝ㢗┘㸯Myosin V Walks by Lever Action and Brownian Motion
࿰ゼ㸝௫㢗㸞࣐࢛ࠖࢨࣤ㹋ࡢᱫᏄࡡິష࡛ࣇࣚࢗࣤ㐘ິ࡞ࡻࡽṄࡂࠗ
ⴥ⩽ 㸯Katsuyuki Shiroguchi and Kazuhiko Kinosita Jr.
ᇖཾග஄㸝᪡⛼⏛ኬᏕ⌦ᕝᏕ⾙㝌∸⌦Ꮥ⛁ㅦᖅ㸞
ᮄୖୌᙢ㸝᪡⛼⏛ኬᏕ⌦ᕝᏕ⾙㝌∸⌦Ꮥ⛁ᩅ᤭㸞
᥎㍍㞟ヽ㸯Science㸝⡷ᅗ⛁Ꮥ㞟ヽ㸞ࠉ㸪᭮㸧㸪᪝Ⓠ⾔
◂✪⫴ᬊ࡛ㄵᩝහᐖ㸯
㎾ᖳࠉ⏍మහ࡚ᶭ⬗ࡌࡾ⺦Ⓣ㈻ࡷ㹇㹃㸶ࢅฦᏄᶭ᲌࡛࡛ࡼ࠻ࠉࡐࡡິష࣒࢜ࢼࢫ࣑ࢅㄢ࡬
ࡾ◂✪࠿᛬㏷࡞㐅ࡲࡗࡗ࠵ࡾࠊฦᏄ࣓࣭ࢰ࣭ࡢࡐࡡ௥⾪᰹࡚ࠉ⏍మහࡡ࢙ࢾ࣭ࣜ࢟㏳㈄࡚࠵
ࡾ㸶㹉㹅㸝࢓ࢸࢿࢨࣤ୔⇝㓗㸞ࡡຊỀฦよ࢙ࢾ࣭ࣜ࢟ࢅฺ⏕ࡊ࡙ࠉ⛛ິࡷᅂ㌹㐘ິࢅࡌࡾ⺦
Ⓣ㈻࡚࠵ࡾࠊୌ᪁ྡྷ࡞୩㐅㐘ິࡌࡾ࣓࣭ࢰ࣭ࡡິష࣒࢜ࢼࢫ࣑ࡡよ᪺࡞࠽࠷࡙ࡢࠉ࣐࢛ࢨࣤ
㹋ࡡ◂✪࠿ࡵࡖ࡛ࡵ㐅ࢆ࡚࠷ࡾࠊ࣐࢛ࢨࣤ㹋ࡢ㸶㹉㹅ࢅຊỀฦよࡌࡾ஦ᮇࡡ͂㊂̓ࢅᣚࡔ㸝ᅒ㸞ࠉ
⣵⬂හ࡚࢓ࢠࢲࣤ⥲⥌㸟࡞Ἒࡖ࡙Ⲭ∸ࢅ㐘ࢆ࡚࠷ࡾࠊࡆࡿࡱ࡚ࡡ◂✪࠾ࡼࠉᚃ㊂࠿๑㊂ࢅ㏛
࠷㉲ࡊ࡙๑᪁ࡡ࢓ࢠࢲࣤ⥲⥌࡞╌ᆀࡌࡾ࣓ࢸࣜ࠿ᗀࡂᨥᣚࡈࡿ࡙࠽ࡽࠉࡆࡡⅤ࡚ࡢெ㛣ࡡṄ
⾔࡛ࡻࡂజ࡙࠷ࡾࠊࡊ࠾ࡊ࡝࠿ࡼฦᏄᶭ᲌࠿ᶭ⬗ࡌࡾࢻࢿ࣒࣭ࢰ࣭ࡡୠ⏲࡚ࡢࠉ㔔ງࡷៈᛮ
㸝ເ࠷㸞ࡢ↋っ࡚ࡀࡾ࡮࡜ᑚࡈࡂࠉࡱࡒࣇࣚࢗࣤ㐘ິ࠿ᏋᅹࡌࡾࡒࡴࠉṄ⾔࣒࢜ࢼࢫ࣑ࡢெ
㛣ࡡࡐࡿ࡛ࡢᮇ㈻Ⓩ࡞␏࡝ࡾ࡛⩻࠻ࡼࡿ࡙࠷ࡾࠊࡆࡿࡱ࡚ࠉ࣐࢛ࢨࣤ㹋ࡡິష࣒࢜ࢼࢫ࣑ࢅ
⌦よࡌࡾ୕࡚㔔さ࡝さ⣪࡚࠵ࡾࠉ࢓ࢠࢲࣤ⥲⥌࠾ࡼ㞫ࡿࡒᚃ㊂࠿๑᪁࡞╌ᆀࡌࡾࡱ࡚ࡡິࡀ
ࡷࡐࡡິࡀࢅ⏍ࡲฝࡌງࡡᛮ㈻ࡢ୘᪺࡚࠵ࡖࡒࠊ
ᠻࠍࡢࡆࡡᮅよ᪺࡚࠵ࡖࡒ㊂ࡡິࡀࢅ᪺ࡼ࠾࡞ࡊࡒࠊࡱࡍࠉ┘༰࡛࡝ࡾᲤ≟ࡡ⺦Ⓣ㈻㸝᚜
ᑚ⟮㸟㸞ࢅ⬦㸝ᅒ㸞࡞⤎ྙࡈࡎࡾ᪁Ἢࢅ㛜Ⓠࡊࡒࠊࡐࡊ࡙ࠉṄ⾔୯ࡡ⬦ࡡິࡀࢅකᏕ㢟᚜㙶
࡚㏻⤾Ⓩ࡞ふᐳࡌࡾࡆ࡛࡞ᠺຉࡊࡒࠊࡐࡡ⤎ᯕࠉ࢓ࢠࢲࣤ⥲⥌࠾ࡼ㞫ࡿࡒᚃ㊂㸝ᅒࡡ⥫㸞࠿
᯺ࡼ࠾࠷͂⫝̸㛭⟿̓ࢅᨥⅤ࡞ࣚࣤࢱ࣑࡞ᅂ㌹ࡊ㸝ࣇࣚࢗࣤ㐘ິ㸞ࠉ࢓ࢠࢲࣤ⥲⥌࡞╌ᆀࡊ࡙
࠷ࡾ㊂㸝ᅒࡡ㟯㸞ࡢງ㸝ࢹࣜࢠ㸞Ⓠ⏍࡞ࡻࡽ͂㊂㤫̓ࡡみᗐࢅን࠻࡙⫝̸㛭⟿ࢅ๑᪁࡞ᢪࡊฝ
ࡌ㸝ࣝࣁ࣭ິష㸞ࡆ࡛࠿᪺ࡼ࠾࡞࡝ࡖࡒࠊࡆࡿࡢࠉ
࢙ࢾ࣭ࣜ࢟ࢅฺ⏕ࡊࡒ᪁ྡྷᛮࡡ࠵ࡾ⬗ິⓏ࡝ࣝࣁ
࣭ິష࡛ࠉུິⓏ࡝ࣇࣚࢗࣤ㐘ິࢅᕟዼ࡞⤄ࡲྙࢂ
ࡎࠉ࢓ࢠࢲࣤ⥲⥌࠾ࡼ㞫ࡿࡒᚃ㊂ࡡ๑᪁╌ᆀࢅྊ⬗
࡞ࡊ࡙ୌ᪁ྡྷᛮṄ⾔ࢅᐁ⌟ࡊ࡙࠷ࡾࡆ࡛ࢅណ࿝ࡌ
ࡾࠊ
ࡆࡡࡻ࠹࡝ࢻࢿ࣒࣭ࢰ࣭ࡡୠ⏲≁᭯ࡡṄ⾔࣒࢜
ࢼࢫ࣑ࡡよ᪺ࡢࠉ௙ࡡ⏍మฦᏄᶭ᲌ࡡິష࣒࢜ࢼࢫ
࣑ࡡ⌦よ࡞ኬࡀࡂᐞ୙ࡌࡾ࡛࡛ࡵ࡞ࠉெᕝ㍲㏞ࢻࢿ
࣏ࢨࣤࡡスゝ࡝࡜࡫ࡡ㈁⊡ࡵ᭿ᙽࡈࡿࡾࠊ
㸱◂✪㈕㸳 ᩝ㒂⛁Ꮥ┤⛁Ꮥ◂✪㈕⿭ຐ㔘≁ื᥆㐅◂✪㸝௥⾪⩽㸯ᮄୖୌᙢ㸞
ᩝ㒂⛁Ꮥ┤⛁Ꮥ◂✪㈕⿭ຐ㔘≁ื◂✪ဤዜທ㈕㸝௥⾪⩽㸯ᇖཾග஄㸞
ᩝ㒂⛁Ꮥ┤ ୠ⣎ (4* ࣈࣞࢡ࣑ࣚ㸝ᣈⅤ࣭ࣛࢱ࣭㸯▴ῳಘୌ㸝᪡⛼⏛ኬᏕᩅ᤭㸞㸞