੕ହ૗৲खਢऐॊ໪঩ৎੑଢ଼஢भऊञठ௘৛ ఊಂ 叞‫؞‬ଽ౱ ஖಻ ‫؞‬਱৛ ௐ  ঽேఐ৾ଢ଼஢ਃଡ ী৕ఐ৾ଢ଼஢ਚ ੈསী৕३५ॸ঒ଢ଼஢७থॱ‫ش‬ ੕়ଢ଼஢প৾੹প৾ ੟৶ఐ৾ଢ଼஢ఐ ਃચଡୗী৕ఐ৾௧వ㐠ືࡢᩘࢆࡶࡗ࡚᫬㛫࡜࡞ࡍ̾̾࢔ࣜࢫࢺࢸࣞࢫࡢⴭ᭩ࠕ⮬↛Ꮫࠖ ࡟࠾ࡅࡿ᫬㛫࡟㛵ࡍࡿグ㏙࡛࠶ࡿࠋ᪥᫬ィࠊࢡ࢛࣮ࢶ᫬ィࠊࡑࡋ࡚ཎᏊ᫬ィࠊ኱ࡁࡉࡶ⢭ᗘࡶᵝࠎ࡛࠶ࡿࡀࠊ⚾ࡓࡕࡣ㐠ືࢆࡶ࡜࡟᫬㛫࡜࠸࠺ᴫᛕࢆసࡾฟࡋά⏝ࡋ࡚ࡁࡓࠋࡑࡋ࡚ࡇࡢ⪃࠼᪉ࡣᴫ᪥᫬ィ࡟ࡶᙜ࡚ࡣࡲࡾࡑ࠺࡛࠶ࡿࠋᢅࡗ࡚࠸ࡿ⣔ࡸᡭἲ࡟ࡼࡿᕪ␗ࡇࡑ࠶ࢀࠊಶయࡢ⾜ືࠊ⣽⬊ࡢ㐠ືࠊ࡜ࡁ࡟ࡣ⏕యศᏊࡢࣜࢬ࣑ࢵࢡ࡞≧ែኚ໬ࢆࡶ࡜࡟᫬㛫ࢆィࡗ࡚࠸ࡿࠋᮏ✏࡛ࡣࠊ᫬ࢆ้ࡴࢱࣥࣃࢡ㉁ࡀᏑᅾࡋ࡚࠸ࡿࡇ࡜ࠊࡑࡋ࡚ࡑࡢࢱࣥࣃࢡ㉁ࡢᵓ㐀ࡸ㐠ື࡟ᆅ⌫ࡢ⮬㌿࿘ᮇ㸦 ᫬㛫ࡢ᫬ᐃᩘ㸧ࡀ࢚ࣥࢥ࣮ࢻࡉࢀ࡚࠸ࡿࡇ࡜ࢆ⤂௓ࡋࠊ᭱ᚋ࡟ศ㔝ࡢᑗ᮶ᒎᮃ࡟ࡘ࠸࡚㏙࡭ࡓ࠸ࠋ
ࡸ㸯㸬ࡣࡌࡵ࡟ᗘ࡞࡝㸧ࡢ࿘ᮇⓗኚືࡀධຊ⣔ࢆ௓ࡋ࡚᣺ືయ࡬ᴫ᪥᫬ィࡢ◊✲ࡢṔྐࡣࠊಶయࡢ⾜ືࣜࢬ࣒ࢆつᐃ࡜ఏ࠼ࡽࢀࠊࡑࢀ࡟࿧ᛂࡍࡿࡼ࠺࡟᣺ືయࡣ఩┦ࢆ๓ࡍࡿ㑇ఏᏊ㸦᫬ィ㑇ఏᏊ㸧ࡢⓎぢ 2 ࡟➃ࢆⓎࡋࠊ᫬ィᚋ࡟ࢩࣇࢺࡉࡏ࡚ྠㄪࡍࡿ㸦ճྠㄪ⬟㸧ࠋࡇࢀࡽ㸱ࡘ㑇ఏᏊࡀࢥ࣮ࢻࡍࡿࢱࣥࣃࢡ㉁㸦᫬ィࢱࣥࣃࢡ㉁㸧ࡢ

ࡢᛶ㉁ࢆ㐣୙㊊࡞ࡃㄝ᫂ࡍࡿࣔࢹࣝࢆᥦၐࡍࡿࡇ࡜

Ᏻᐃᛶࡀ㌿෗࣭⩻ヂࢧ࢖ࢡࣝ࡟࠾࠸࡚㔜せ࡞ᙺ๭ࢆᢸ

ࡣࠊᴫ᪥᫬ィ◊✲࡟࠾࠸࡚┠ᣦࡍ࡭ࡁ฿㐩Ⅼࡢ୍ࡘ࡛࠺ࡇ࡜ࡀ♧ࡉࢀࠊࡑࡋ࡚௒ࡸࠊ᫬ィࢱࣥࣃࢡ㉁ࡢཎᏊ

࡞࠿ࢁ࠺࠿ 3ࠋᵓ㐀ࢆࡶ࡜࡟ィ᫬ᶵᵓࡀ㆟ㄽࡉࢀࡿࡲ࡛࡟⮳ࡗ࡚࠸ࡿࠋᑐ㇟࡜ࡍࡿ✵㛫ࢫࢣ࣮ࣝࡣಶయ࠿ࡽჾᐁࠊ⤌⧊ࠊ⣽⬊ࠊศᏊࢩࢫࢸ࣒ࠊศᏊࠊཎᏊ͐࡟ࡲ࡛ཬࡧ㸦ᅗ 1㸧ࠊࡑࡢ⤖ᯝ࡜ࡋ࡚ᢅ࠺᫬㛫ࢫࢣ࣮ࣝࡶ᪥࠿ࡽ᫬㛫ࠊศࠊ⛊ࠊࢧࣈ࣑ࣜ⛊͐࡬࡜ᗈࡀࡾࢆぢࡏࡘࡘ࠶ࡿࠋࡇࢀࡣࠊ⏕⌮Ꮫ࡟ࡼࡗ࡚ᣅ࠿ࢀࡓศ㔝ࡀศᏊ⏕≀Ꮫ࡟࡜࡝ࡲࡽࡎࠊ⏕໬Ꮫࠊ⏕≀≀⌮Ꮫࠊᵓ㐀⏕≀Ꮫࠊ⌮ㄽ⛉Ꮫ࡞࡝ࢆᕳࡁ㎸ࡳࡘࡘⓎᒎࡋ࡚ࡁࡓ⤒⦋ࢆ⾲ࡋ࡚࠸ࡿࠋ᫬✵㛫࣐ࣝࢳࢫࢣ࣮ࣝ໬ࡑࡋ࡚Ꮫ㝿໬ࡀ㐍ࡴ࡟ࡘࢀ࡚ࠊᴫ᪥᫬ィ◊✲ࡢ࠿ࡓࡕࡶከᵝ໬ࡋ࡚࠸ࡿࠋఱࢆࡶࡗ࡚ࠕᴫ᪥᫬ィࢆ⌮ゎࡋࡓࠖ࡜ゝ࠼ࡿ࡛࠶ࢁ࠺࠿ࠋࡇࡢၥ࠸࡟ᅇ⟅࡛ࡁࡿ࡜࠸࠺ࡇ࡜ࡣࠊ⌧≧࡜ࡋ࡚ィᡭἲࡀᮍᩚഛ࡛࠶ࡗࡓࡾᢏ⾡ⓗㄢ㢟ࡀṧࡉࢀ࡚࠸ࡓࡾࡍࡿ࡜ࡋ࡚ࡶࠊ◊✲ࡢ᭱⤊฿㐩Ⅼࡀ᫂☜࡟࢖࣓࣮ࢪ࡛ࡁ࡚࠸ࡿࡇ࡜࡟௚࡞ࡽ࡞࠸ࠋ➹⪅ࡽ⮬㌟࡟࡜ࡗ࡚ࡶ౫↛࡜ࡋ࡚㞴ࡋ࠸ၥ࠸࡛࠶ࡿࡀࠊᅔࡗࡓ࡜ࡁ࡟ࡣᴫ᪥᫬ィ࡟ඹ㏻ࡋ࡚ほᐹࡉࢀࡿ㸱ࡘࡢᛶ㉁㸦ᴫ᪥᫬ィࡢ㸱ᛶ㉁㸧࡟❧ࡕᡠࡿࡼ࠺ᚰ᥃ࡅ࡚࠸ࡿࠋᴫ᪥᫬ィࡢ᣺ືయࡣᜏᖖⓗ᮲௳ୗ࡛ࡶ⣙ 24 ᫬㛫ࡢ࿘ᮇ࡛Ⓨ᣺ࡋ㸦ձ⮬ᚊⓗⓎ᣺㸧ࠊ࠿ࡘ࿘ᮇ㛗ࡀ࡯࡜ࢇ࡝ᗘ౫Ꮡᛶࢆ♧ࡉ࡞࠸㸦ղᗘ⿵ൾᛶ㸧ࠋ⎔ቃ㸦ගᅗ  ࢱࣥࣃࢡ㉁ࡢ㝵ᒙᵓ㐀㸦ᕥഃ㸧࡜ゎᯒᡭἲ㸦ྑഃ㸧ࡢ㛵ಀ
;5'㸦㹖⥺⤖ᬗᵓ㐀ゎᯒ㸧ࠊ&U\R(0㸦ࢡࣛ࢖࢜㟁Ꮚ㢧ᚤ㙾࡟ࡼࡿ༢⢏Ꮚゎᯒ㸧
ࠊ6:$;6㸦⁐ᾮᩓ஘㸧
ࠊ105㸦᰾☢Ẽඹ㬆ἲ㸧࡞࡝ࠊᡭἲ࡟ࡼࡾ㐺⏝࡛ࡁࡿ✵㛫ࢫࢣ࣮ࣝ࡟≉ᚩࡀ࠶ࡿࠋ‫ݩ‬akiyamas@ims.ac.jp
時間生物学Vol. 24, No. 2 (2018)92㸰㸬ࢩ࢔ࣀࣂࢡࢸࣜ࢔ࡢᴫ᪥᫬ィࢩࢫࢸ࣒ࡣ඲ࡃ࡜ゝࡗ࡚ࡼ࠸࡯࡝ά⏝ࡉࢀ࡚࠸࡞࠸ࠋࡑࡢ◊✲ࡣࠊᴫ᪥᫬ィࡢ 3 ᛶ㉁ࡢⓎ⌧࡟㛵ࢃࡿ᭱ᑠࡢᵓᡂ༢఩㸦※᣺㸧ࢆ᥈⣴ࡋࠊࢩࢫࢸ࣒඲యࡢ⏕⌮Ꮫ㸱㸬⚾ࡓࡕࡀ┠ᣦࡍ࠿ࡓࡕⓗ࡞᣺ࡿ⯙࠸࡜※᣺࡜ࡢ㛵ಀᛶࢆ㏣ồࡍࡿ᪉ྥ࡟Ⓨࣜࣥ㓟໬㸭ATPase ࢧ࢖ࢡࣝࡢᏳᐃⓎ᣺࡟ࡣ KaiAᒎࡋ࡚ࡁࡓࠋ᫬ィ㑇ఏᏊ㸦kai㸧ࡀ᪥ᮏே◊✲⪅ࢆ୰࡜ KaiB ࡢඹᏑࡀᚲ㡲࡛࠶ࡿࡀࠊKaiC ༢⊂࡛ࡶᚰ࡜ࡋࡓ◊✲ࢢ࣮ࣝࣉ࡟ࡼࡗ࡚ 1998 ᖺ࡟ࢡ࣮ࣟࢽࣥATPase άᛶࡣῶ⾶᣺ືࡢࡼ࠺࡞⦆࿴ࢆ♧ࡋࠊࡲࡗࡓ

ࢢࡉࢀࡿ࡜ 4ࠊࢃࡎ࠿㸴ᖺᚋࡢ 2004 ᖺࡲ࡛࡟ࠊ3 ✀ࡃⓎ᣺࡛ࡁ࡞࠸ࢃࡅ࡛ࡶ࡞࠸ࡇ࡜࡟⚾ࡓࡕࡣẼࡀ௜࠶ࡿ᫬ィࢱࣥࣃࢡ㉁㸦KaiAࠊKaiBࠊKaiC㸧ࡑࢀࡒࢀ࠸ࡓ㸦ᅗ 2㸧22ࠋῶ⾶ᆺࡢ᣺ືᡂศࢆᗄࡘ࠿ࡢ௬ᐃࡢࡢ༢⊂⤖ᬗᵓ㐀ࡀሗ࿌ࡉࢀࡓ 5-8ࠋࡑࡢᚋࠊ㸱✀ࡢ Kaiࡶ࡜࡛ゎᯒࡋࡓ࡜ࡇࢁࠊ࠾ࡼࡑ 0.91 d-1 ࡢᅛ᭷᣺ືᩘ

ࢱࣥࣃࢡ㉁࡜ ATP ࢆΰྜࡍࡿࡇ࡜࡟ࡼࡾࠊ2005 ᖺ࡟㸦ȰN㸧࡟ヱᙜࡍࡿࡇ࡜ࡀุ᫂ࡋࡓࠋKaiC ࡢ࿘ᮇኚKaiC ࡢࣜࣥ㓟໬ࢧ࢖ࢡࣝࡀヨ㦂⟶ෆ࡛෌ᵓᡂࡉࢀ 9ࠊ␗యࢆ౑ࡗ࡚ほᐹᑐ㇟ࢆᗈࡆࡓ࡜ࡇࢁࠊȰN ࡣ in vitro

ࡑࡋ࡚ 2007 ᖺ࡟ ATPase ࢧ࢖ࢡࣝ 10 ࡀぢฟࡉࢀࡓࠋࣜࣥ㓟໬ࢧ࢖ࢡࣝ㸦KaiA㸭KaiB ඹᏑୗ㸧ࡢ࿘Ἴᩘࡔ

෌ᵓᡂ⣔ࡢⓏሙ࡟࡜ࡶ࡞࠸ࠊ◊✲ࡢ⯙ྎࡣ Kai ࢱࡅ࡛࡞ࡃ㸦ᅗ 3D㸧
ࠊin vivo ㌿෗࣭⩻ヂࢧ࢖ࢡࣝࡢ࿘

ࣥࣃࢡ㉁ࡢศᏊ㛫┦஫స⏝࡬࡜⛣ࡉࢀࡓࠋᑐ㇟࡜࡞ࡿἼᩘ࡜ࡶ㧗࠸┦㛵ࢆ♧ࡋࡓ㸦ᅗ 3B㸧
ࠋࡸࡣࡾࠊKaiC

ࢱࣥࣃࢡ㉁ࡢ✀㢮ࡀ㝈ᐃࡉࢀࠊヨᩱࡢ౪⤥యไࡀᩚഛ

࡟ࡣᆅ⌫ࡢ⮬㌿㢖ᗘ㸦1 ᅇ㸭᪥㸧࡛㥑ືࡉࢀࡿ㐠ືࡀࡉࢀࡓ࡜ࡁࡢ⏕໬Ꮫࡢ✺◚ຊࡣ௚࡟㢮ࢆぢ࡞࠸ࡶࡢෆໟࡉࢀ࡚࠸ࡿࡢ࡛࠶ࡿࠋࡀ࠶ࡿࠋࢩ࢔ࣀࣂࢡࢸࣜ࢔ࡢ◊✲࡟࠾࠸࡚ࡶࡑࢀࡣ౛ȰN ࡣᐃᖖ≧ែ࡟࠾ࡅࡿ ATPase άᛶ࡜㧗࠸┦㛵ࢆእ࡛ࡣ࡞ࡃࠊKai ࢱࣥࣃࢡ㉁ࡢ┦஫స⏝࡟㛵ࡍࡿ㔜せ♧ࡋࡓࠋ౛࠼ࡤࠊ࢔࣑ࣀ㓟ኚ␗࡟ࡼࡗ࡚ KaiC ࡢㄢ㢟ࡢ኱㒊ศࢆඃ⚽࡞⏕໬Ꮫ⪅ࡀࢫࣆ࣮ࢻឤࢆࡶࡗ

ATPase άᛶࡀ㸰ಸ࡟ྥୖࡍࡿ࡜ࠊȰN ࡸ㌿෗᫬ィࡢ࡚ゎỴࡋ࡚࠸ࡿ 11-13ࠋࡑࢀࡽ࡟⥆ࡃࡼ࠺࡟ࠊNMR14,15ࠊ

᣺ືᩘࡶ㸰ಸ࡜࡞ࡗࡓ㸦ᅗ 3CEF㸧ࠋKaiC ࡣᐃᖖ≧ែ⁐ᾮᩓ஘ 16,17ࠊ㹖⥺⤖ᬗᵓ㐀ゎᯒࡸ㟁Ꮚ㢧ᚤ㙾 18,19 ࡞࡛⣙ 12 ಶࡢ ATP ࢆ㸯᪥࡟ຍỈศゎࡍࡿࡀࠊࡇࡢάᛶ

࡝ࢆ㥑౑ࡋࡓ◊✲ᡂᯝࡀⓎ⾲ࡉࢀࠊ⏕໬Ꮫࡢࡳ࡛ゎ᫂ࡣ᪤▱ࡢ࣮ࣔࢱ࣮ࢱࣥࣃࢡ㉁㸦103㹼107 d-1㸧࡟ẚ࡭࡛ࡁ࡞࠿ࡗࡓ㒊ศࢆ⏕≀≀⌮Ꮫࡸᵓ㐀⏕≀Ꮫࡀ⿵᏶࡚ⴭࡋࡃప࠸ࠋȰN ࢆつᐃࡍࡿ ATP ຍỈศゎ཯ᛂࢆࡋ࡚ࡁࡓࠋ2017 ᖺ࡟ࡣ KaiABC 」ྜయࡢ㒊ศᵓ㐀ࡀཎᏊࢫࢣ࣮࡛ࣝ⌮ゎࡋࠊ➨㸯ࡢᛶ㉁࡟࠶ࡓࡿ 24 ᫬㛫ࢡࣛ࢖࢜㟁Ꮚ㢧ᚤ㙾 20 ࠾ࡼࡧ㹖⥺⤖ᬗᵓ㐀ゎᯒ 21 ࡟㸦⤯ᑐⓗ࡞㐜ࡉ㸧ࡢ㉳※ࢆゎ᫂ࡋࡓ࠸̾̾ࡇࢀࡀ⚾ࡓࡕࡼࡾྠᐃࡉࢀࠊ࠸ࡲ࡛ࡣࠊ※᣺㸦KaiABC ⣔㸧࡜ධฟࡢ┠ᣦࡍᴫ᪥᫬ィ◊✲ࡢ࠿ࡓࡕ࡛࠶ࡗࡓࠋຊ⣔ࡢ┦஫స⏝࡟ࡘ࠸࡚ࡶᵓ㐀⏕≀Ꮫⓗ࡟◊✲ࡉࢀ࡚࠸ࡿ 21ࠋATP ຍỈศゎ࡜ࡣࠊỈศᏊ㸦W1㸧ࢆ ATP ࡢᮎ➃ࣜࣥ㓟㸦PȚ㸧࡟స⏝ࡉࡏ࡚࢔ࢹࣀࢩࣥ஧ࣜࣥ㓟㸦ADP㸧ࡇࢀࡽࡢ◊✲࡟ࡼࡾࠊKai ࢱࣥࣃࢡ㉁ࡀ࡝ࡢࡼ࠺࡞

࡜ࣜࣥ㓟㸦Pi㸧࡟ศゎࡍࡿ཯ᛂ࡛࠶ࡿ㸦ᅗ 4㸧ࠋࡶ࠺໬Ꮫ㔞ㄽẚࡸ✵㛫㓄⨨࡛」ྜయࢆᙧᡂࡋࠊࡑࢀࡽࡀ᫬

ᑡࡋ໬Ꮫⓗ࡟ㄝ᫂ࡍࡿ࡜ࠊỈศᏊ㸦H-O-H㸧ࡢ㓟⣲ཎィࡢ఩┦࡜㐃ືࡋ࡚࡝ࡢࡼ࠺࡟᫬㛫ኚ໬ࡍࡿࡢ࠿ࡀᏊࡀಖ᭷ࡍࡿ㟁Ꮚᑐࢆ PȚ࡟᥋㏆㸦ồ᰾ᨷᧁ㸧ࡉࡏ࡚ゎ᫂ࡉࢀࡓࠋ✵㛫ศゎ⬟ࡸ⤖ྜẚࡢほⅬ࠿ࡽࡣ༑ศ࡞

Pi ࢆษࡾ㞳ࡍ㐣⛬㸦SN2 ཯ᛂ㸧࡛࠶ࡾࠊ཯ᛂᛶࢆ㆟⌮ゎ࡟㐩ࡋ࡚࠸࡞࠸ࢣ࣮ࢫࡶᩓぢࡍࡿࡀࠊ※᣺ࡢศᏊ㛫┦஫స⏝࡟㛵ࡍࡿㄢ㢟ࡣ࡯ࡰఱ࠿ࡋࡽࡢ᪉ἲ࡛◊✲ࡉࢀࠊ୍ᐃࡢᡂᯝࡀᣲࡆࡽࢀࡓ࡜ゝ࠼ࡿࠋᚤຊ࡞ࡀࡽ➹⪅ࡽࡶࡑࡢ୍㒊࡟㛵ࢃࡗ࡚ࡁࡓࡢࡔࡀࠊ࡛ࡣࡇࢀ࡛ᴫ᪥᫬ィࡢ㸱ᛶ㉁ࡣ㐣୙㊊࡞ࡃㄝ᫂ࡉࢀࡓࡢ࡛࠶ࢁ࠺࠿㸽」ྜయࡢᵓ㐀ࡀ᫂ࡽ࠿࡟࡞ࡿ࡜ࠊ⤖ྜ┦ᡭࡸ⤖ྜẚࡢኚ໬ࢆ⧊ࡾ㎸ࢇࡔ཯ᛂࣔࢹࣝࢆᵓ⠏ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࠋศᏊࢆグྕ࡛␎グࡋࠊࡑࢀࡽࡢ㞳ྜ㞟ᩓࢧ࢖ࢡࣝࡀほᐹ⤖ᯝ࡟ἢ࠺ࡼ࠺࡟཯ᛂ㏿ᗘࡸྛ✀ࣃ࣓࣮ࣛࢱࢆ᭱㐺໬ࡍࡿࡇ࡜ࡣࠊከᵝ໬ࡋࡘࡘ࠶ࡿᴫ᪥᫬ィ◊✲ࡢ࠿ࡓࡕ㸦฿㐩Ⅼ㸧ࡢࡦ࡜ࡘ࡛࠶ࡿࠋࡓࡔṧᛕ࡞ࡀࡽࡇࡢሙྜࠊᵓ㐀ࢹ࣮ࢱࡣᑓࡽ⤖ྜᵝᘧࡸ⤖ྜẚࡢྠᐃࡢࡓࡵ࡟ࡔࡅ⏝࠸ࡽࢀࠊཎᏊࢫࢣ࣮ࣝࡢ᝟ሗ㸦ᗙᶆ㸧

時間生物学
9Vol. 24, No. 2 (2018)ᅗ  .DL& ࡢ $73DVH άᛶࡢࢲ࢖ࢼ࣑ࢡࢫ
.DL& ༢⊂࡛࠶ࡗ࡚ࡶࠊ$73DVH άᛶࡢ⦆࿴㐣⛬࡟ῶ⾶ᆺࡢ᣺ືᡂศࡀほᐹࡉࢀࡿࠋᅗ  ࢩ࢔ࣀࣂࢡࢸࣜ࢔⏕≀᫬ィࢩࢫࢸ࣒ࡢ㝵ᒙ┦㛵ࣉࣟࢵࢺ
.DL& ࿘ᮇኚ␗య㸦ᰴ㸧ࡢࠗ㐠ື࠘ࡢ㢖ᗘࢆ࿘Ἴᩘࡶࡋࡃࡣάᛶ࡜ࡋ
࡚ホ౯ࡋࠊࡑࢀࡽࢆ✵㛫ࢫࢣ࣮ࣝࡈ࡜࡟ࣉࣟࢵࢺࡋ࡚㝵ᒙ㛫ࡢ┦㛵ࢆ᳨ドࡋࡓࠋ౛࠼ࡤࠊࣃࢿࣝ ' ࡢ
⦪㍈ࡣ .DL& ࣜࣥ㓟໬ࢧ࢖ࢡࣝࡢ࿘
Ἴᩘ㸦.DL$ ࡜ .DL% ඹᏑୗ㸧ࠊࡑࡋ࡚ᶓ㍈ࡣ $73DVH άᛶࡢῶ⾶᣺ືᡂศࡢ࿘Ἴᩘ㸦.DL& ༢⊂㸧࡟ᑐᛂࡍࡿࠋࡢ␗ᛶ໬ࡣࢱࣥࣃࢡ㉁ศᏊࡢ㐠ືࡢ୰࡛ࡶ࠿࡞ࡾ㐜࠸㒊㢮࡟࠶ࡓࡾࠊ
௒ᅇࡢࢣ࣮ࢫ࡛ࡶ 14㹼16 kcal mol-1ࡢάᛶ໬࢚ࢿࣝࢠ࣮ࢆせࡍࡿࡇ࡜ࢆぢฟࡋࡓࠋPȚ࿘㎶ࡢ❧య㞀ᐖࠊࡑࢀࢆゎᾘࡍࡿࡓࡵࡢ኱つᶍ࡞ᵓ㐀ኚ໬ࠊ࣌ࣉࢳࢻ⤖ྜࡢ␗ᛶ໬࡟ࡼࡿ࢖ࣥࢱ࣮ࣟࢵࢡࠊࡇ
ࢀࡽ 3 ࡘࡢᢚไⓗไᚚࢆཷࡅ࡚ KaiC ࡢ ATPase ࡣపάᛶ໬ࡋࠊࡑࢀ࡟ࡼࡗ࡚ 24 ᫬㛫࡜࠸࠺㐜࠸᫬㛫ࢫࢣ࣮ࣝࢆᐇ⌧ࡋ࡚࠸ࡿࡼ࠺࡛࠶ࡿࠋ
KaiC ෆ㒊࡛⏕ࡳฟࡉࢀࡓ㐜࠸᫬㛫ࢫࢣ࣮ࣝࡢ㐠ືࡣࠊ୍య࡝ࡢࡼ࠺࡟ࡋ࡚ศᏊ㛫┦஫స⏝ࡢ㝵ᒙ㸦ᅗ
3D㸧࡬࡜ఏᦙࡉࢀࡿࡢ࡛࠶ࢁ࠺࠿㸽ࢱࣥࣃࢡ㉁࡜ࣜ
࢞ࣥࢻ㸦ࢱࣥࣃࢡ㉁ࢆྵࡴ㸧ࡢ┦஫స⏝ࡀ≉␗ⓗ࡛࠶ࡿሙྜࠊ୧⪅ࡢ❧యᵓ㐀ࡀ⤖ྜ཯ᛂࡢ๓ᚋ࡛୙ኚ࡛࠶ࡿࡇ࡜ࡣ⛥࡛ࠊ᪂ࡓ࡟ᙧᡂࡉࢀࡓỈ⣲⤖ྜࡸࣇ࢓ࣥࢹᅗ  .DL& ࡢ $73DVH ࢆᢚไࡍࡿ㸱ࡘ௙᥃ࡅ
3Ț࿘㎶ࡢ❧య㞀ᐖࠊ኱つᶍ࡞ᵓ㐀ኚ໬㸦㯤Ѝࢩ࢔ࣥ㸧ࠊ࣌ࣉࢳࢻ⤖ྜࡢ␗ᛶ໬㸦FLVWUDQV㸧ࠊࡇࢀࡽ㸱ࡘࡢᢚไⓗไᚚࢆཷࡅ࡚.DL& ࡢ $73DVH ࡣపάᛶ໬ࡍࡿࠋ

࣮ࣝ࣡ࣝࢫ┦஫స⏝࡞࡝࡟కࡗ࡚❧యᵓ㐀ࢆ෌ᵓ⠏ࡍࡿࠋࡇࡇ࡛㔜せ࡞ࡢࡣ࡛ࡁ࠶ࡀࡗࡓ」ྜయࡢᵓ㐀ࢆほᐹࡍࡿࡤ࠿ࡾ࡛ࡣ࡞ࡃࠊ」ྜయᙧᡂࡢ㏵ୖẁ㝵࡟╔┠ࡋ࡚ࡣࡌࡵ࡚᫂ࡽ࠿࡟࡞ࡿࡇ࡜ࡶ࠶ࡿ࡜࠸࠺Ⅼ࡛ㄽࡍࡿ࠺࠼࡛ ATP ࡟ᑐࡍࡿ W1 ࡢ㓄⨨ࡀ㔜せ࡜࡞ࡿࠋ࠶ࡿࠋᵓ㐀ኚ໬ࡢࢱ࢖࣑ࣥࢢࡀ⤖ྜ࢖࣋ࣥࢺࡢ๓࠿ᚋ⚾ࡓࡕࡀ㛗࠸ᖺ᭶ࢆ࠿ࡅ࡚ゎ࠸ࡓཎᏊᗙᶆࢆࡶ࡜࡟࠿࡟ࡼࡗ࡚ࠊ཯ᛂࡣ኱ࡁࡃ㐪ࡗࡓᵝ┦ࢆぢࡏࡿࠋ⌮ㄽ໬Ꮫⓗ࡞ィ⟬ࢆᐇ᪋ࡋࡓ࡜ࡇࢁࠊPȚ࿘㎶࡟ W1

Conformational Selection ࡜࿧ࡤࢀࡿศᏊㄆ㆑ᶵᵓ

ࡢᨷᧁࢆጉࡆࡿ❧య㞀ᐖ㸦➨㸯ࡢ௙᥃ࡅ㸧ࡀタࡅࡽࢀ㸦CS ᶵᵓࠊᅗ 5A㸧ࡣࠊᵓ㐀ኚ໬ࡀ⤖ྜࡼࡾࡶඛ࡟㉳࡚࠸ࡿࡇ࡜ࡀࢃ࠿ࡗࡓࠋࡇࡢ❧య㞀ᐖࢆྲྀࡾ㝖ࡃࡓࡵࡇࡿ࡜ࡍࡿ཯ᛂࣔࢹ࡛ࣝࠊ౛࠼ࡤࠊKaiB ࡀ⤖ྜ࡟㐺࡟ KaiC ࡣ኱つᶍ࡞ᵓ㐀ኚ໬㸦➨㸰ࡢ௙᥃ࡅ㸧ࢆవ൤ࡋࡓ KaiC ࡢ࠶ࡿ≧ែࢆ㑅ᢥⓗ࡟ㄆ㆑ࡋ࡚⤖ྜࡍࡿ࡜࡞ࡃࡉࢀࡿࡀࠊࡑࢀࡀᐜ᫆ࡃ㉳ࡇࡽ࡞࠸ࡼ࠺࡟ࠊ࠸ࡗࡓ࢖࣓࣮ࢪࢆᥥࡃࡇ࡜ࡀ࡛ࡁࡿࠋࡇࡢ࡜ࡁAsp145-Ser146 㛫ࡢ࣌ࣉࢳࢻ⤖ྜ࡟➨㸱ࡢ௙᥃ࡅ

KaiBC 」ྜయࡢ⤖ྜ࢖࣋ࣥࢺࡣ KaiC ࡢ≧ែ/ᵓ㐀࡟㸦cis-trans ␗ᛶ໬㸧ࡀ᪋ࡉࢀ࡚࠸ࡿࠋ࣌ࣉࢳࢻ⤖ྜ౫Ꮡࡋࡓᙧ࡛グ㏙࡛ࡁࡿࠋ௚᪉ࠊInduced Fit ᶵᵓ㸦IF

時間生物学

Vol. 24, No. 2 (2018)94

ABᅗ  ศᏊㄆ㆑࡟࠾ࡅࡿ⤖ྜ࡜ᵓ㐀ኚ໬ࡢࢱ࢖࣑ࣥࢢ$ &6 ᶵᵓ࡜ ,) ᶵᵓࡢᑐẚࠋࣜ࢞ࣥࢻ .DL% ⃰ᗘࡀ㣬࿴ࡋࡓ࡜ࡁࡢ」ྜయ⏕ᡂ㏿ᗘࡣࠊ&6 ᶵᵓ࡛࠶ࢀࡤ NI ࡟ࠊࡑࡋ࡚ ,) ᶵᵓ࡛࠶ࢀࡤ㸦NINE㸧࡟࡞ࡿࠋ % 」ྜయ⏕ᡂ㏿ᗘࡢ .DL% ⃰ᗘ౫Ꮡᛶࠋ.DL& ࣜࣥ㓟໬ࢧ࢖ࢡࣝࡀᏳᐃࡋ࡚ほᐹࡉࢀࡿ .DL% ⃰ᗘ㡿ᇦ㸦ᅗୖ㒊ࡢ⅊Ⰽ㒊ศ㸧࡛ࡣࠊ.DL& ࡟ᑐࡋ࡚ .DL% ࡀ㣬࿴ࡋ࡚࠾ࡾࠊࡑࡢ㏿ᗘࡣᐃᖖ≧ែ࡟࠾ࡅࡿ .DL& ࡢ $73DVH άᛶ K G ࡟㏆࠸ࠋᶵᵓࠊᅗ 5A㸧ࡣ⤖ྜࡀᵓ㐀ኚ໬࡟ඛ⾜ࡍࡿ཯ᛂࣔࢹศᏊ✀࡟ఏᦙࡋࠊ᭱⤊ⓗ࡟ࢩࢫࢸ࣒඲య࡬࡜Ἴཬࡉࡏ࡛ࣝ࠶ࡾࠊ౛࠼ࡤࠊࡲࡎ KaiB ࡜ KaiC ࡀ㐼㐝ࡋ࡚஫࡚࠸ࡃ௙⤌ࡳࡀഛࢃࡗ࡚࠸ࡿࠋ࠸ࡢᵓ㐀ࢆಖᣢࡋࡓࡲࡲ」ྜ໬ࡋࠊḟࡢẁ㝵࡛ KaiCࡇࡢࡼ࠺࡟ࠊ➨㸯ࡢᛶ㉁࡟࠶ࡓࡿ㐜ࡉࡢ㉳※࡟ࡘ࠸㸦ሙྜ࡟ࡼࡗ࡚ࡣ KaiB ࡶ㸧ࡀࡼࡾᏳᐃ࡞」ྜయࡢ≧࡚ࡣ◊✲ࡢぢ㏻ࡋࡀ❧ࡕࡘࡘ࠶ࡿࠋ࡛ࡣࠊ➨㸰ࡢᛶ㉁ែࢆồࡵ࡚ᵓ㐀ࢆኚ໬ࡉࡏࡿࠋࡣ࡝࠺࡛࠶ࢁ࠺࠿ࠋ ᗘ⿵ൾᛶࡣᴫ᪥᫬ィ࡟ඹ㏻ࡋ࡚࡝ࡕࡽࡢࣔࢹࣝ࡟࠾࠸࡚ࡶࠊ⤖ྜࢆక࠺㐣⛬ࡀ⃰ᗘほᐹࡉࢀࡿ≉ᚩ࡛࠶ࡾࠊᴫ᪥᫬ィࡀ୍⯡ⓗ࡞໬Ꮫ᣺ື౫Ꮡⓗ࡟࡞ࡿࡇ࡜ࡣඹ㏻ࡋ࡚࠾ࡾࠊμM ⛬ᗘࡢ⃰ᗘᇦᏊ࡜༊ูࡋ࡚ᢅࢃࢀࡿ⌮⏤ࡢ୍ࡘ࡛࠶ࡿࠋ㐜࠸໬Ꮫ཯࡛࠶ࢀࡤၥ㢟࡞ࡃ⛊௨ୗࡢ࣮࢜ࢲ࣮࡛᏶⤖ࡍࡿࠋࡔࡀ

ᛂ࡯࡝ྠࡌ㏿ᗘᐃᩘࢆ⏝࠸ࡓ࡜ࡋ࡚ࡶ(ᅗ 5)ࠊᵓ㐀ኚ໬㐣⛬ࡉࠖ࡜ࠕ࡜⤖ྜ㐣⛬ࡀ๓ᚋࡍࡿࡔࡅ࡛」ྜయᙧᡂ㏿ᗘࡢ KaiB௚᪉ࠊKaiC ࡢ ATP ຍỈศゎ཯ᛂࡣᴟ➃࡟㐜ࡃ㸦12 d-1㸧ᗘ౫Ꮡⓗ࡟࡞ࡿࡓࡵࠊ໬Ꮫࡢୡ⏺࡛ࡣࠊࠕ㐜ᗘ⿵ൾᛶࠖࡣ㏻ᖖ┦ᐜࢀ࡞࠸⌧㇟࡛࠶ࡿࠋ

ᗘ⿵ൾไᚚୗ࡟࠶ࡿ㸦Q10 = 1.0 㹼 1.1)ࠋࡇࡢ

⃰ᗘ౫Ꮡᛶ࡟ᕪࡀ⏕ࡌࡿࠋKaiB ⃰ᗘࡀ㣬࿴ࡋ࡚࠸ࡿ

࠿ࡘ᮲௳࡛ࡣࠊIF ᶵᵓᐤࡾࡢሙྜࡣ㸦kf + kb㸧ࡢ㏿ᗘ࡛ࠊ㠀ซ࡞≉ᛶࡢ⫼ᬒ࡟ࠕᴫ᪥᫬ィ࡜ࡋ࡚ࡢ≉ู࡞ఱ࠿ࠖ

ࡑࡋ࡚ CS ᶵᵓᐤࡾ࡛࠶ࢀࡤ kf ࡢ㏿ᗘ࡛」ྜయࡀᙧᡂ

ࡀᏑᅾࡍࡿ࡜࠸࠺᝿ᐃࡢࡶ࡜ࠊᡃࠎࡣࡉࢀࡿࠋkf ࡀ㐜࠸ ATP ຍỈศゎ཯ᛂ࡜ඹᙺࡋࡓ KaiCࡢ⥙⨶ⓗࢫࢡ࣮ࣜࢽࣥࢢࡸᵓ㐀࣮࣋ࢫ࡛ࡢタィ㸦ᅗࡢᵓ㐀ኚ໬㸦ᅗ 4㸧࡟࠶ࡓࡿ࡜ࡍࡿ࡜ࠊ࡝ࡕࡽࡢ཯ᛂ

6㸧ࠊࡑࡋ࡚ࡑࢀࡽࡢᵓ㐀ゎᯒ࡟᪥ࠎྲྀࡾ⤌ࢇ࡛࠸ࡿࠋ

ᶵᵓࢆ㑅ᢥࡍࡿ࠿࡟ࡼࡗ࡚ୗὶ࡟ఏᦙࡉࢀࡿ཯ᛂ㏿ḟ࡟┠ᣦࡍ฿㐩ⅬࡣࠊཎᏊࢫࢣ࣮ࣝࡢ᝟ሗࢆࡶ࡜࡟➨ᗘ࡟ᕪࡀ⏕ࡌࡿࠋ㸯࡜➨㸰ࡢᛶ㉁ࢆ஫࠸࡟▩┪࡞ࡃㄝ᫂ࡍࡿࡇ࡜࡛࠶KaiB ࡜ KaiC ࡢ┦஫స⏝ࢆ⺯ගศගἲ࡛ヲࡋࡃㄪᗘ౫Ꮡኚ␗యࡿࠋ࡭ࡓ࡜ࡇࢁࠊࡸࡣࡾ CS ᶵᵓࡀỴᐃⓗ࡞ᙺ๭ࢆᯝࡓࡋ࡚࠸ࡿࡇ࡜ࡀࢃ࠿ࡗࡓ 23ࠋᐇ㦂ࡢヲ⣽ࡣ┬␎ࡍࡿࡀࠊ㸲㸬ࢩࣙ࢘ࢪࣙ࢘ࣂ࢚ࡸ࣐࢘ࢫࡢᴫ᪥᫬ィࢩࢫࢸ࣒

KaiBC 」ྜయࡢᙧᡂࡣ KaiC ࡢ㐜࠸ ATPase ࡜ࣜࣥࢩࣙ࢘ࢪࣙ࢘ࣂ࢚ࡸ࣐࢘ࢫ࡜࠸ࡗࡓ᫬㛫⏕≀Ꮫ࡟㓟໬≧ែ࡟ࡼࡾࢤ࣮ࢸ࢕ࣥࢢࡉࢀ࡚࠾ࡾࠊKaiB ࡣຍ࠾ࡅࡿ㧗➼ࣔࢹࣝ⏕≀ࡣ➹⪅ࡽࡀ┤᥋ᢅࡗ࡚࠸ࡿ◊Ỉศゎ⏘≀࡛࠶ࡿ ADP ࢆ⤖ྜࡋࡓࣜࣥ㓟໬ᆺ KaiC✲ᑐ㇟࡛ࡣ࡞࠸ࡀࠊKai ࢱࣥࣃࢡ㉁◊✲⪅ࡢ┠⥺࠿ࡽࢆ㑅ᢥࡋ࡚⤖ྜࡍࡿࠋࣜࣥ㓟໬㸭ATPase ࢧ࢖ࢡࣝࡀᙜヱศ㔝ࡀ࡝ࡢࡼ࠺࡟ぢ࠼࡚࠸ࡿࡢ࠿ࢆࠊ⏕≀≀⌮ᏛᏳᐃⓎ᣺ࡍࡿ⃰ᗘᇦ࡛ࡣࠊ」ྜ໬཯ᛂࡢᚊ㏿ẁ㝵ࡀࡸᵓ㐀⏕≀ᏛࡢどⅬࢆ஺࠼ࡘࡘ⤂௓ࡋࡓ࠸ࠋ㌿෗᫬ィ

KaiC ࡢ ATP ຍỈศゎ཯ᛂ㸦ᅗ 5B㸧࡜࡞ࡿࡇ࡜ࡶ☜ࢆぢᤣ࠼ࡿࡢ࡛࠶ࢀࡤࠊ㌿෗࠿ࡽ⮬ᕫᢚไࡲ࡛ࡢ᫬㛫ㄆࡉࢀࡓࠋKaiC ࡟ࡣ㐜࠸᫬㛫ࢫࢣ࣮ࣝࡢ⦆࿴ࢆ⏕ࡳ㐜ࢀ㸦㐜ࡉ㸧ࢆ⏕ࡳฟࡍᵓ㐀ᇶ┙ࡸ཯ᛂᶵᵓࡀᶆⓗ࡜ฟࡍࡔࡅ࡛࡞ࡃࠊࡑࢀࢆ≉ู࡞┦஫స⏝ࢆ௓ࡋ࡚௚ࡢ࡞ࡿࡔࢁ࠺ࠋᐇ㝿ࠊ㌿෗࣭⩻ヂࢧ࢖ࢡࣝ࡟⤌ࡳ㎸ࡲࢀ

時間生物学
9Vol. 24, No. 2 (2018)ᅗ  ᵓ㐀᝟ሗࢆࡶ࡜࡟ࡋࡓ .DL&ᗘ౫Ꮡኚ␗యࡢタィᴫᛕᅗࡓ᫬ィࢱࣥࣃࢡ㉁ࢆ୰ᚰ࡟◊✲ࡀ㐍ࡵࡽࢀ࡚࠾ࡾࠊࡇ

ࡢඹ⤖ᬗ໬࡟ᡂຌࡋࡓ౛ࡀ࠶ࡿ 32,33ࠋKL001 ࡣࣉࣟࢀࡲ࡛࡟ࢩࣙ࢘ࢪࣙ࢘ࣂ࢚㸦Drosophila㸧ࡢ PERIODࢸ࢔ࢯ࣮࣒࡟ࡼࡿ mCRY ࡢศゎࢆᢚไࡍࡿຠᯝࡀ࠶

ࢱࣥࣃࢡ㉁㸦dPER㸧24ࠊ࣐࢘ࢫࡢ PERIOD ࢱࣥࣃࢡࡾࠊ⤖ᯝ࡜ࡋ࡚ᴫ᪥᫬ィࢆ㛗࿘ᮇ໬ࡍࡿࠋ⣽⬊ෆࡢ

mPER3 㸧 25,26 ࠊ ࡑ ࡋ ࡚mCRY ࡣ㢮ఝࡋࡓ F ࣎ࢵࢡࢫᆺࣘࣅ࢟ࢳ࣮ࣥࣜ࢞ࢮ

CLOCK/BMAL1 」ྜయ 27 ࡞࡝ࡢ❧యᵓ㐀ࡀゎ᫂ࡉࢀࡢ FBXL3 ࡟ࡼࡾ୙Ᏻᐃ໬ࡉࢀࠊࡑࡋ࡚ FBXL21 ࡟࡚ ࠸ ࡿ ࠋ ࡇ ࢀ ࡽ ࡢ ࢱ ࣥ ࣃ ࢡ ㉁ ࡟ ࡣ bHLH 㸦 basicࡼࡾᏳᐃ໬ࡉࢀࡿࡇ࡜ࡀ▱ࡽࢀ࡚࠾ࡾ 34ࠊKL001 ࡀ

helix-loop-helix㸧ࣔࢳ࣮ࣇࡸ PAS㸦Per-Ahr/Arnt-Sim㸧୧⪅ࡢࣂࣛࣥࢫ࡟ኚㄪࢆ୚࠼ࡓࡢࡔ࡜ࡍࡿ࡜⯆࿡῝ࢻ࣓࢖ࣥ࡜࠸ࡗࡓ㌿෗ㄪ⠇ᅉᏊࢆ≉ᚩ࡙ࡅࡿᵓ㐀ࣘ࠸౛࡛࠶ࡿ࡜ゝ࠼ࡼ࠺ࠋ㉁ 㸦 mPER1, mPER2,ࢽࢵࢺࡀಖᏑࡉࢀ࡚࠸ࡿࠋPAS ࢻ࣓࢖ࣥࢆ௓ࡋࡓ஧࡯ࡰ᫬ࢆྠࡌࡃࡋ࡚ࠊ኱ฟࡽࡣ CRY ࡢࣜࣥ㓟໬ಟ㔞య⏺㠃ࡢ┦஫స⏝ࡀ㢮ఝࢱࣥࣃࢡ㉁㸦mPER1-3㸧㣭㒊఩ࢆ⥙⨶ⓗ࡟ྠᐃࡋࠊࡑࡇ࡟࢔࣑ࣀ㓟ኚ␗ࢆᑟධ

࡛␗࡞ࡿࡇ࡜ 25,26ࠊ࿘ᮇኚ␗ࡀ஧㔞య⏺㠃௜㏆࡟఩⨨ࡋ࡚࿘ᮇ㛗࡬ࡢᙳ㡪ࢆㄪ࡭࡚࠸ࡿ 35ࠋ࿘ᮇ㛗ࢆኚ໬ࡉࡍࡿࡇ࡜ 24,27 ࡞࡝ࠊᵓ㐀᝟ሗࢆ᫬ィࢱࣥࣃࢡ㉁ࡢᏳᐃ

ࡏࡓ࢔࣑ࣀ㓟ኚ␗ࢆ mCRY ࡢ⤖ᬗᵓ㐀࡟࣐ࢵࣆࣥࢢᛶ࡜㛵㐃ࡉࡏࡘࡘゎ㔘ࡀ࡞ࡉࢀ࡚࠸ࡿࠋࡋࡓ⤖ᯝࡣ⨾ࡋࡃࠊࢱࣥࣃࢡ㉁ᵓ㐀࡟័ࢀᾐࡋࢇࡔⴭ

bHLH-PAS ࣇ࢓࣑࣮ࣜ࡟ᒓࡉ࡞࠸ Cryptochrome⪅࡟࡜ࡗ࡚ࡣᛮࢃࡎࡓࡵᜥࡀ₃ࢀࡿ࡯࡝࡛࠶ࡿࠋ࢔࣑

㸦CRY㸧ࡣࠊࢩࣙ࢘ࢪࣙ࢘ࣂ࢚㸦dCRY㸧࡜࣐࢘ࢫࣀ㓟ኚ␗ࡣ P-loop ࡜ C-lid ࡜࿧ࡤࢀࡿ㡿ᇦ࡟ᒁᅾࡋ

㸦mCRY㸧ࡢ⣔࡛ᶵ⬟࡟㐪࠸ࡀ࠶ࡿࠋdCRY ࡣ㟷Ⰽග࡚࠾ࡾࠊࡉࡽ࡟ඛ㏙ࡢ KL001 ࡢ⤖ྜ㒊఩࡜ࡶ㏆᥋ࡋࢆཷᐜࡋ࡚ࣜࢬ࣒ࡢ఩┦ኚ໬ࢆಁࡍࠋdCRY ࡢ㹖⥺⤖࡚࠸ࡿࡢࡔ㸟ࡇࢀࡽࡢ㡿ᇦ࡟㈇㟁Ⲵࡀ⣼✚ࡍࡿࡇ࡜ᬗᵓ㐀ࡢ✵㛫ศゎ⬟ࡣ 2.3ύ ࡛࠶ࡾ 28,29ࠊࡇࢀࡣ࢔࣑

࡛ຠᯝࡀ㢧ⴭ࡟࡞ࡿࡇ࡜ࡶ㆟ㄽࡉࢀ࡚࠾ࡾࠊཎᏊࢫࢣࣀ㓟ഃ㙐ࡢ఩⨨/㓄ྥࡸỈ⣲⤖ྜ࡞࡝ࢆ㧗⢭ᗘ࡛㆟ㄽ࣮ࣝࡢᵓ㐀᝟ሗࡀ᭷ຠά⏝ࡉࢀࡓ◊✲౛࡛࠶ࡿࠋ

ࡍࡿ࡟㊊ࡿ✵㛫ศゎ⬟࡛࠶ࡿࠋບ㉳ࡉࢀࡓ FAD ࠿ࡽࡶ࠺୍ࡘࡢ୺ᡓሙࠊࣜࣥ㓟໬㓝⣲࢝ࢮ࢖ࣥ࢟ࢼ࣮ࢮࡢ㟁Ꮚ⛣ື㐣⛬ࡸ FAD ග㑏ඖ࡞࡝ࠊᵓ㐀᝟ሗࢆࡶ࡜

㸦Ck1 㸧࠿ࡽࡶ┠ࡀ㞳ࡏ࡞࠸ࠋCk1 ࡣ mPER2 ࢆࣜ࡟ࡋࡓ◊✲ࡀᒎ㛤ࡉࢀ࡚࠸ࡿࠋdCRY ࡢᶵ⬟ࢆ⪃࠼ࡿࣥ㓟໬ࡋ࡚Ᏻᐃ໬ࡋࠊศゎࢆᢚไࡍࡿࡇ࡜࡛࿘ᮇࢆ㛗࡜ࠊ➨㸱ࡢᛶ㉁࡟࠶ࡓࡿྠㄪ⬟࡜ཎᏊࢫࢣ࣮ࣝࡢ᝟ሗࡃࡍࡿᶵ⬟ࢆ᭷ࡍࡿࠋmPER2 ࡣ Ck1 ࡟ࡼࡗ࡚ࣜࣥࢆ࡝ࡢࡼ࠺࡟⤖ࡧ௜ࡅࡿ࠿ࡀ௒ᚋࡢ࣏࢖ࣥࢺ࡟࡞ࡿ㓟໬ಟ㣭ࢆཷࡅࡿ㒊఩ࢆ」ᩘ᭷ࡍࡿࡀࠊ᭱ࡶ N ᮎ➃࡛࠶ࢁ࠺ࠋ࡟఩⨨ࡍࡿ Ser659 ࡢಟ㣭ࡀ᭱ึ࡟㉳ࡇࡾࠊ࠿ࡘࡑࢀ௚ ᪉ ࠊ mCRY ࡣ mPER ࡜ ࣊ ࢸ ࣟ 」 ྜ యࡀ௚ࡢࣜࣥ㓟໬㒊఩ࢆྵࡵࡓ཯ᛂ඲యࡢᚊ㏿ẁ㝵࡟㸦mCRY1/mPER2㸧ࢆᙧᡂࡋ࡚㈇ࡢ㌿෗ไᚚࢆ⾜࠺ࠋ࡞ࡿࡇ࡜ࡀᐇ᫬㛫 NMR ゎᯒ࡛♧ࡉࢀ࡚࠸ࡿ 36ࠋ᭱㏆

mCRY1/mPER2 ࡢ X ⥺⤖ᬗᵓ㐀ࡣ 2.45ύࡢ✵㛫ศゎࡢ◊✲ᡂᯝ࡟ࡼࡿ࡜ࠊCk1 ࡟ࡣ㹁ᮎ➃ 16 ṧᇶࡢ㓄⬟࡛ゎ࠿ࢀ 30,31ࠊ஧㔞య⏺㠃࡟఩⨨ࡍࡿள㖄࢖࢜ࣥࡸࠊ

ิࡀ␗࡞ࡿ࢔࢖ࢯࣇ࢛࣮࣒ࡀᏑᅾࡋࠊ␗࡞ࡿࣜࣥ㓟໬ࡑࡢ㏆ഐ࡛ mCRY1 ෆ࡟ᙧᡂࡉࢀࡓࢪࢫࣝࣇ࢕ࢻ⤖άᛶࢆ♧ࡍ 37ࠋࣜࣥ㓟໬άᛶࡢࡼࡾప࠸ Ck1 1 ࡀྜ࡞࡝ࠊཎᏊࢫࢣ࣮ࣝࡢᵓ㐀ゎᯒࢆࡶ࡜࡟⣽⬊ෆࣞࢻPER2 ࢆࡼࡾ୙Ᏻᐃ໬ࠊࡑࡋ࡚ࣜࣥ㓟໬άᛶࡢ㧗࠸ࢵࢡࢫ࡜ࡢ㛵ಀᛶࡀ♧၀ࡉࢀ࡚࠸ࡿࠋ

Ck1 2 ࡀ PER2 ࢆࡼࡾᏳᐃ໬ࡍࡿࡇ࡜࡛࿘ᮇ㛗ࢆㄪࡉࡽ࡟ࠊmCRY ༢య࡟ࡘ࠸࡚ࡢ◊✲ࡶάⓎ࡛࠶ࡿࠋᩚࡋ࡚࠸ࡿࡼ࠺ࡔࠋCk1 ࡢ㹁ᮎ➃ࡣࠊࡑࢀ༢⊂࡛Ᏻ㏆ᖺ࡛ࡣᴫ᪥᫬ィ࡟ᙳ㡪ࢆཬࡰࡍ⸆๣㸦KL001㸧ࢆࢫᐃ࡞❧యᵓ㐀㸦Ș࣊ࣜࢵࢡࢫࡸșࢩ࣮ࢺ࠿ࡽ࡞ࡿ⌫≧ࢡ࣮ࣜࢽࣥࢢࡋࠊmCRY ࡜ KL001 ࡀ⤖ྜࡋࡓ≧ែ࡛ࢻ࣓࢖ࣥ㸧ࢆᙧᡂࡋ࡞࠸ኳ↛ኚᛶ㡿ᇦ࡛࠶ࡿ࡜♧၀ࡉ

時間生物学Vol. 24, No. 2 (2018)9ࢀ࡚࠾ࡾࠊmPER2 ࢆྵࡴ௚ࡢ᫬ィࢱࣥࣃࢡ㉁࡜ࡢ」ࡢᵓ㐀ࢆ᭱ึ࡟ゎ࠸࡚ࠊࡑࢀࢆ୺せ࡞ᅜ㝿Ꮫ⾡ㄅ࡟ㄽྜ໬᫬࡟┦ᡭࡢᙧ≧࡟ྜࢃࡏࡓᵓ㐀ࢆᙧᡂࡍࡿࡢ࠿

ᩥᥖ㍕ࡋࡓ࠸࡜⪃࠼ࡿࡶࡢ࡛࠶ࡿࠋ≉ู࡞ᛮ࠸ධࢀࡸ

ࡶࡋࢀ࡞࠸ࠋCk1 ࡀὀ┠ࢆᾎࡧࡿูࡢ⌮⏤ࡣࠊࡑࡢᏛ⾡ⓗ⯆࿡ࡀ࡞࠸㝈ࡾࠊ᪤࡟ᵓ㐀ࡀゎ࠿ࢀ࡚࠸ࡿ⣔࡟ࣜࣥ㓟໬άᛶࡀᗘ⿵ൾࡉࢀ࡚࠸ࡿࡓࡵ࡛࠶ࡿࠋ⠛ཎከ኱࡞ປຊࢆὀࡄࡇ࡜ࡣ⛥࡛࠶ࡿࠋKaiC ࡢሙྜࠊࡑୗ࡛ࡣ ATP ⤖ྜᆺ Ck1ࡢ඲యᵓ㐀ࡣ 2004 ᖺࡢ Molecular Cell ㄅ࡟ሗࡌࡽࢀࡽࡢ◊✲ᡂᯝ࡟ࡼࡿ࡜ࠊ㧗

࡜ᇶ㉁ࡢ┦஫స⏝ࡀ୙Ᏻᐃ໬ࡍࡿࡢ࡜ྠ᫬࡟ ADP ⤖7ࠊࡑࡢᚋࠊࣜࣥ㓟໬ኚ␗యࡸ」ྜయᵓ㐀࡟ࡘ࠸࡚ࡢ

ྜᆺ Ck1 ࡜⏕ᡂ≀ࡢ┦஫స⏝ࡀᏳᐃ໬ࡋࠊࡇࢀࡽࡀ

ሗ࿌ࡀ⥆࠸ࡓࠋᵓ㐀ࡸືែ࡟㛵ࡍࡿ◊✲ࢆ⥅⥆ࡋ࡚࠸ᗘୖ᪼࡟క࠺ຍ㏿ศࢆ┦ẅࡍࡿࡼ࠺࡟స⏝ࡋ࡚⿵ࡿࡢࡣࠊᡃࠎࢆྵࡵ࡚ࠊ࠸ࡎࢀࡶࢩ࢔ࣀࣂࢡࢸࣜ࢔ࡢ

ൾไᚚࢆᐇ⌧ࡋ࡚࠸ࡿ 38ࠋin vitro ࣔࢹࣝ⣔࡟࠾ࡅࡿᴫ᪥᫬ィ࡟୪ࠎ࡞ࡽࡠ㛵ᚰࢆᣢࡘ◊✲ࢢ࣮ࣝࣉ࡛࠶

Ck1 ࡢ཯ᛂࡣศ࣮࢜ࢲ࣮࡛࠶ࡾࠊKaiC ࡼࡾࡶ㸯㹼ࡿࠋᴫ᪥᫬ィࡢ◊✲ࡣ௚࡟ẚ࡭࡚᫬㛫ࡀ࠿࠿ࡿഴྥࡀ㸰᱆ࡃࡽ࠸㏿࠸ࡓࡵࠊ୧⪅ࡢ࠶ࡿࡢ࡛ࠊዲࡁࡌࡷ࡞࠸࡜⥆࠿࡞࠸㠃ࡶ࠶ࡿࡔࢁ࠺ࠋᗘ⿵ൾไᚚ࡟࡝ࢀࡃࡽ࠸㢮ఝⅬࡀ࠶ࡿࡢ࠿ὀព῝ࡃ᳨ドࡋ࡚࠸ࡁࡓ࠸ࠋ

㏆࠸ᑗ᮶ࠊᴫ᪥᫬ィࡢㄽᩥࢆฟ∧ࡍࡿ࠺࠼࡛ࠊ᫬ィ
ࢱࣥࣃࢡ㉁ࡢᵓ㐀ࡸືែ࡟㛵ࡍࡿᐇ㦂ࢹ࣮ࢱࡀồࡵࡽࢀࡿࢣ࣮ࢫࡀቑ࠼࡚ࡃࡿ࠿ࡶࡋࢀ࡞࠸ࠋ့ங㢮ࡢ⣔㸲㸬࠾ࢃࡾ࡟ㄽᩥ➼࡟ᥖ㍕ࡉࢀࡓ᫬ィࢱࣥࣃࢡ㉁ࡢᵓ㐀ࡀ㒊ศࡣࡑࡢഴྥࡀᙉࡲࡿࡼ࠺࡞Ẽࡀࡍࡿࠋᵓ㐀᪤▱ࡢ⣔࡟ⓗ࡟ࡋ࠿᫂ࡽ࠿࡟࡞ࡗ࡚࠸࡞࠸ࡇ࡜ࡀ࠶ࡾࠊ␲ၥࢆឤᑓ㛛ᐙࢆᘬࡁ㎸ࡴࡢࡣᐜ࡛᫆࡞࠸ࡓࡵࠊ௒ᚋࡢᒎ㛤ࡢࡌࡓࡇ࡜ࡀ࠶ࡿࡢ࡛ࡣ࡞࠸ࡔࢁ࠺࠿ࠋ࡜ࡃ࡟့ங㢮ࡢ㏿ࡉ࡟ࡶࡼࢁ࠺ࡀࠊᴫ᪥᫬ィ࡟⯆࿡ࡢ࠶ࡿ◊✲⪅⮬㌟⣔࡟ᩓぢࡍࡿࡀࠊࡇࢀࡣ඲㛗ヨᩱࡢࣜࢥࣥࣅࢼࣥࢺⓎࡀᑓ㛛ᐙࡢᣦᑟࡢࡶ࡜࡟ờࢆ࠿ࡃ࠿ࠊ௒࠿ࡽⱝᡭࢆᣦ⌧⣔ࡀ☜❧ࡉࢀ࡚࠸࡞࠸࠿ࠊࡉࢀ࡚࠸࡚ࡶ඲㛗ヨᩱࡢᑟࡋ࡚⫱ᡂࡍࡿࡋ࠿࡞࠸ࠋࠕ඲㛗ヨᩱࡢᏳᐃ౪⤥ࡀᩚ⢭〇ࡸ⤖ᬗ໬࡟ᢏ⾡ⓗ࡞ไ⣙ࡀ࠶ࡿࡓࡵ࡛࠶ࡿࠋ⤖ᬗഛࡉࢀ࡚࠿ࡽࠖࡸࠕKaiC ࡢ࢝࢘ࣥࢱ࣮ࣃ࣮ࢺࡀぢࡘᵓ㐀ゎᯒ࡟㝈ࡽࡎᵓ㐀ゎᯒ࡟ࡣᗄࡘ࠿ࡢ࣎ࢺࣝࢿࢵ࠿ࡗ࡚࠿ࡽࠖࡢࡼ࠺࡞ᑐᛂ࡛ࡣୡ⏺࡟຾ࡘࡇ࡜ࡣ㞴ࡋࢡࡀ࠶ࡿࠋᵝࠎ࡞ᢏ⾡㠉᪂ࡀ࡞ࡉࢀ࡚ࡁࡓ௒᪥࡟࠾࠸࠸ࠋᡃࠎࡢ◊✲ࢢ࣮ࣝࣉ࡛ࡣࠊ㹖⥺⤖ᬗᵓ㐀ゎᯒࡸ⁐࡚ࡶ࡞࠾ࠊศᏊࡀ⤖ᬗ໬ࡍࡿ㐣⛬ࢆ㐣ཤࡢ⤒㦂࠿ࡽணᾮᩓ஘࡞࡝ࡢㅮ⩦఍ࢆᐃᮇⓗ࡟⾜ࡗ࡚࠸ࡿࠋࢫ࢟ࣝ࢔ࡍࡿࡇ࡜ࡣᅔ㞴࡛࠶ࡾࠊ⤖ᬗ໬᮲௳ࡢ⥙⨶ⓗࢫࢡࣜࢵࣉࢆ┠ᣦࡍᏛ⏕ࡸ࣏ࢫࢻࢡࠊࢧࣥࣉࣝᣢࡕ㎸ࡳࠊ࠸࣮ࢽࣥࢢ࡟㢗ࡽࡊࡿࢆᚓ࡞࠸ࠋࡲࡓ୍⯡ⓗ࡟ࠊ࣮ࣝࣉࡘ࡛ࡶḼ㏄࡛࠶ࡿࠋ≧ࡢᰂ㌾࡞ᵓ㐀ࢆከศ࡟ಖᣢࡍࡿࢱࣥࣃࢡ㉁ศᏊࡣࠊ

௨ୖᮏ✏࡛ࡣࠊ⏕≀≀⌮Ꮫࡸᵓ㐀⏕≀ᏛࡢほⅬ࠿ࡽ⌫≧࡟ᢡࡾ␚ࡲࡗࡓࡶࡢࡼࡾࡶ⤖ᬗ໬ࡀᐜ࡛᫆࡞ࡃᴫ᪥᫬ィࢆ◊✲ࡍࡿព⩏࡟ࡘ࠸࡚ⴭ⪅ࡢぢゎࢆ⧊ࡾ࡞ࡿࠋㄽᩥ࡟ᥖ㍕ࡉࢀ࡚࠸ࡿ㒊ศᵓ㐀ࡣࠊ඲㛗࠿ࡽษ஺ࡐࡘࡘࠊࢩ࢔ࣀࣂࢡࢸࣜ࢔ࡢᴫ᪥᫬ィࡢ◊✲ࡢ᪉ྥࡾฟࡍ㡿ᇦࢆᚤㄪᩚࡋ࡞ࡀࡽ⤖ᬗ໬ࢫࢡ࣮ࣜࢽࣥࢢ

ᛶ࡟ࡘ࠸࡚ᴫㄝࡋࡓࠋ๓㏙ࡢ࡜࠾ࡾࠊ⚾ࡓࡕࡢḟࡢ┠ࢆࡋࡓⱞປࡢ⤖ᯝ࡛࠶ࡿ࡜ཷࡅṆࡵ࡚ࡼ࠸ࠋே㢮ࡣࡇᶆࡣ➨㸯࡜➨㸰ࡢᛶ㉁ࢆ஫࠸࡟▩┪࡞ࡃཎᏊࢫࢣ࣮ࢀ௨እࡢ᪉ἲ࡛ศᏊࢆύࡢ⢭ᗘ࡛ᩚิࡉࡏࡿ⾡ࢆᣢ࡛ࣝㄝ᫂ࡍࡿࡇ࡜࡛࠶ࡿࠋ့ங㢮ࡢ⣔࡟࠾࠸࡚ࡶࠊࡕྜࢃࡏ࡚࠾ࡽࡎࠊᑡ࡞ࡃ࡜ࡶ⌧≧࡛ࡣࠊ⮬↛ࡢཿᬛCRY ࡸ PER ࡢᏳᐃᛶࠊ࣊ࢸࣟ」ྜయ࡟ࡼࡿ㈇ࡢไᚚ

࡟ࡍࡀࡿ࡯࠿࡞࠸ࡢ࡛࠶ࡿࠋ࡜ࡑࢀࢆゎ㝖ࡍࡿ௙⤌ࡳࠊCk1 ࡢࣜࣥ㓟໬άᛶ͐࡞ࢩ࢔ࣀࣂࢡࢸࣜ࢔ࡢ⣔࡟ẚ࡭ࡿ࡜ࠊ့ங㢮ࡢ᫬ィࢱ࡝ࠊ➨㸯ࡑࡋ࡚➨㸰ࡢᛶ㉁ࡢゎ᫂࡟ྥࡅ࡚᫬ィࢱࣥࣃ

ࣥࣃࢡ㉁ࡣ㛗㙐࡛㸦mCLOCK ࡣ 855 ࢔࣑ࣀ㓟ࠊ

ࢡ㉁ࡢᵓ㐀࡜ືែ࡟㛵ࡍࡿ◊✲ࡀᅜෆእ࡛άⓎ໬ࡋ

mCRY1 ࡣ 606 ࢔࣑ࣀ㓟㸪mPER2 ࡣ 1,257 ࢔࣑ࣀ㓟㸧࡚࠸ࡿࠋ஫࠸࡟ษ☩⌶☻ࡋࡘࡘࠊࡇࢀࡽࡢ㔜せ࡞ㄢ㢟࠿ࡘኳ↛ኚᛶ㡿ᇦ㸦Ck1 ࡢ C ᮎ➃࡞࡝㸧ࢆከศ࡟ྵ࡟ࢥ࣑ࣗࢽࢸ࢕඲య࡜ࡋ࡚࡝ࡇࡲ࡛㏕ࡾษࢀࡿࡢ࠿

ࢇ࡛࠸ࡿࠋ᫬㛫㐜ࢀ㸦㐜ࡉ㸧ࡸ௒ᚋࡢᒎ㛤࡟ᮇᚅࡀ㧗ࡲࡿࠋᗘ⿵ൾࡢ᰾ᚰ࡟㏕ࡿࡓࡵ࡟ࡣࠊࡇࢀࡽࡢᕧ኱ࢱࣥࣃࢡ㉁ࡀᰂ㌾ᛶࢆಖࡕࡘ
ࡘ⤡ࡳྜࡗࡓ㉸ศᏊ」ྜయࢆㄪ〇ࡋࠊࡑࡢ༢㞳ࢆ⤒࡚ㅰ㎡ᵓ㐀ゎᯒࡍࡿࡇ࡜ࡀồࡵࡽࢀࡿࠋ௒᪥ࠊ㟁Ꮚ㢧ᚤ㙾ࢆḢ㝧ᮾᙪ༤ኈࠊ㜿㒊῟༤ኈࢆࡣࡌࡵ࡜ࡍࡿ◊✲ࢢࣝ⏝࠸ࡓ༢⢏Ꮚゎᯒࡢᢏ⾡㠉᪂ࡣ┠ぬࡲࡋ࠸ࡶࡢࡀ࠶࣮ࣉࡢྠ൉ࠊࡑࡋ࡚㏆⸨Ꮥ⏨༤ኈ㸦ྡྂᒇ኱Ꮫ㸧ࠊᒣࡿࡀࠊᰂ㌾࡛࣊ࢸࣟ࡞⣔࡬ࡢᑐᛂࡣࠊࢺࣔࢢࣛࣇ࢕࣮ୗᰤᶞ༤ኈ㸦኱㜰኱Ꮫ㸧ࠊᩪ⸨┿ྖ༤ኈ㸦ศᏊ⛉Ꮫ◊ᢏ⾡ࡢ᭦࡞ࡿⓎᒎࢆᚅࡘᚲせࡀ࠶ࡿࡔࢁ࠺ࠋᜥࡢ㛗࠸✲ᡤ㸧ࠊ᳃ಇᩥ༤ኈ㸦ศᏊ⛉Ꮫ◊✲ᡤ㸧ࠊ⏥⏣ಙ୍༤ኈ኱ኚ࡞௙஦ࡔࡀ┠ᶆࡣ᫂☜࡛࠶ࡿࠋ㸦ศᏊ⛉Ꮫ◊✲ᡤ㸧ࢆࡣࡌࡵ࡜ࡍࡿከࡃࡢඹྠ◊✲⪅࠶ࡃࡲ࡛ࡶ୍⯡ㄽࡔࡀࠊᵓ㐀⏕≀Ꮫ⪅ࡣ᪂ࡋ࠸ᮍ▱時間生物学
9Vol. 24, No. 2 (2018)࡟ᚚ♩⏦ࡋୖࡆࡲࡍࠋㄞࡳ᫆ࡉࢆඃඛࡍࡿពᅗ࠿ࡽ⛉Ꮫⓗ࡞ㄝ᫂ࢆ୍㒊┬␎ࡋ࡚グ㏙ࡋࡲࡋࡓࠋヲ⣽࡟ࡘ࠸dual phosphorylation of KaiC as a basis for࡚ࡣ௚ࡢ⥲ㄝ 39 ࡞࡝ࢆཧ↷ࡋ࡚㡬ࡅࢀࡤᖾ࠸࡛ࡍࠋcircadian rhythm in cyanobacteria. EMBO J.

26, 4029-4037 (2007).
12. Rust, M. J., Markson, J. S., Lane, W. S., Fisher,

ཧ⪃ᩥ⊩
1.

2.

࢔ࣜࢫࢺࢸࣞࢫ(ⴭ), ฟ㝯 (⩻ヂ), ᒾᓮඔ⬍(⩻D.

ヂ). ࢔ࣜࢫࢺࢸࣞࢫ඲㞟㸱 ⮬↛Ꮫ . ᒾἼ᭩ᗑphosphorylation(1968).

three-protein circadian clock. Science 318,Konopka, R. J. & Benzer S. Clock mutants ofDrosophila melanogaster. Proc. Natl. Acad. Sci.

3.

4.

5.

7.

8.

9.

&O'Shea,E.

governs

K.

Orderedoscillationofa809-812 (2007).
13. Nishiwaki, T., Kitayama, Y., Ochiai, E. &USA 68, 2112-2116 (1971).

Kondo, T. Exchange of ADP with ATP in theAkiyama, S. Structural and dynamic aspects

CIIof protein clocks: How can they be so slow andautophosphorylation of cyanobacterial clock

stable? Cell. Mol. Life Sci. 69, 2147-2160

protein KaiC. Proc. Natl. Acad. Sci. USA 111,

(2012).

4455-4460 (2014).

ATPasedomain

promotes

Ishiura, M. et al. Expression of a gene cluster

14. Chang, Y. G., Kuo, N. W., Tseng, R. & LiWang,kaiABC as a circadian feedback process in

A. Flexibility of the C-terminal, or CII, ring ofcyanobacteria. Science 281, 1519-1523 (1998).

KaiC governs the rhythm of the circadianYe, S., Vakonakis, I., Ioerger, T. R., LiWang, A.

clock of cyanobacteria. Proc. Natl. Acad. Sci.

C. & Sacchettini, J. C. Crystal structure ofUSA 108, 14431-14436 (2011).

circadian

6.

S.

from

15. Chang, Y. G., Tseng, R., Kuo, N. W., & LiWang,Synechococcus elongatus. J. Biol. Chem. 279,clockprotein

KaiA

A. Rhythmic ring-ring stacking drives the20511–20518 (2004).

circadian oscillator clockwise. Proc. Natl. Acad.

Garces, R. G., Wu, N., Gillon, W., & Pai, E. F.

Sci. USA 109, 16847-16851 (2012).

Anabaena circadian clock proteins KaiA and16. Akiyama, S., Nohara, A., Ito, K. & Maéda, Y.

KaiB reveal a potential common binding site

Assembly and disassembly dynamics of theto their partner KaiC. EMBO J. 23, 1688–cyanobacterial periodosome. Mol. Cell 29,1698 (2004).

703–716 (2008).

Pattanayek, R. et al. M. Visualizing a

17. Murayama, Y. et al. Tracking and visualizing

circadian clock protein: crystal structure of

the circadian ticking of the cyanobacterial

KaiC and functional insights. Mol. Cell 15,

clock protein KaiC in solution. EMBO J. 30,375–388 (2004).

68-78 (2011).

Hitomi, K., Oyama, T., Han, S. G., Arvai, A. S.,

18. Hayashi, F. et al. ATP-induced hexameric ring& Getzoff, E. D. Tetrameric architecture of thestructure of the cyanobacterial circadian clock

circadianprotein KaiC. Genes Cells 8, 287–296 (2003).

clock

protein

KaiB—Anovel

interface for intermolecular interactions and19. Pattanayek, R. et al. Analysis of KaiA-KaiC

its impact on the circadian rhythm. J. Biol.

protein interactions in the cyano-bacterialChem. 280, 19127–19135 (2005).

circadian

Nakajima,M.

etal.

Reconstitutionofcircadian oscillation of cyanobacterial KaiC

clock

using

hybridstructural

methods. EMBO J. 25, 2017–2028 (2006).
20. Snijder,J.

etal.

Structuresofthephosphorylation in vitro. Science 308, 414-415

cyanobacterial circadian oscillator frozen in a(2005).

fully assembled state. Science 355, 1181-1184

10. Terauchi, K. et al. ATPase activity of KaiC

(2017).

determines the basic timing for circadian clock

21. Tseng, R. et al. Structural basis of theof cyanobacteria. Proc. Natl. Acad. Sci. USA

day-night transition in a bacterial circadian104, 16377-16381 (2007).

clock. Science 355, 1174-1180 (2017).

11. Nishiwaki, T. et al. A sequential program of時間生物学

22. Abe, J. et al. Atomic-scale origins of slowness

Vol. 24, No. 2 (2018)98

in the cyanobacterial circadian clock. Science

32. Oshima, T. et al. C-H activation generates

349, 312-316 (2015).
23. Mukaiyama,A.

repressor complex. eLife 3, e03674 (2014).

etal.

Conformational

period-shortening

molecules

thattargetrearrangements of the C1 ring in KaiC

cryptochrome in the mammalian circadianmeasure the timing of assembly with KaiB.

clock. Angew. Chem. Int. Ed. 54, 7193–7197

Sci. Rep. 8, 8803 (2018).

(2015).

24. Yildiz, O. et al. Crystal structure and33. Lee,J.

W.

etal.

Development

interactions of the PAS repeat region of thesmall-molecule

Drosophila clock protein PERIOD. Mol. Cellderivatives as modulators of the circadian17, 69–82 (2005).

clock. Chem. Med. Chem. 10, 1489–1497

25. Kucera, N. et al. Unwinding the differences ofcryptochromeofstabilizer(2015).

the mammalian PERIOD clock proteins from

34. Hirano, A. et al. FBXL21 regulates oscillation

crystal structure to cellular function. Proc.

of the circadian clock through ubiquitination

Natl. Acad. Sci. USA 109, 3311-3316 (2012).

and stabilization of cryptochromes. Cell 152,

26. Hennig, S. et al. Structural and functional

1106–1118 (2013).

analyses of PAS domain interactions of the35. Ode, K. L. et al. Knockout-rescue embryonicclock proteins Drosophila PERIOD and mousestem cell-derived mouse reveals circadian-PERIOD2. PLoS Biol. 7, e1000094 (2009).

period control by quality and quantity of

27. Huang, N. et al. Crystal structure of theCRY1. Mol. Cell 65, 176–190 (2017).

heterodimeric CLOCK:BMAL1 transcriptional

36. Narasimamurthya, R. et al. CK1 /activatorcomplex.

Science337,189-194

primesthePER2

proteincircadianphosphoswitch. Proc. Natl. Acad. Sci. USA 115,(2012).
28. Zoltowski, B. D. et al. Structure of full-length

Drosophila cryptochrome. Nature 480, 396–399 (2011).
cryptochrome

5986-5991 (2018).
37. Fustin, J. M. et al. Two Ck1

transcripts

regulated by m6A methylation code for two

29. Czarna, A. et al. Structures of Drosophila
andmouse

cryptochrome1

provide insight into circadian function. Cell153, 1394–1405 (2013).
30. Schmalen, I. et al. Interaction of circadianclock proteins CRY1 and PER2 is modulated
by zinc binding and disulfide bond formation.

Cell 157, 1203–1215 (2014).
31. Nangle, S. N. et al. Molecular assembly of theperiod-cryptochrome circadian transcriptional

時間生物学
99

kinaseVol. 24, No. 2 (2018)

antagonistic kinases in the control of thecircadian clock. Proc. Natl. Acad. Sci. USA 115,5980-5985 (2018).
38. Shinohara, Y. et al. Temperature-sensitivesubstrateandproductbindingunderlietemperature-compensated phosphorylation inthe clock. Mol. Cell 67, 783–798 (2017).
39. ⛅ᒣಟᚿ. ᫬㛫⏕≀Ꮫ࡜ᨺᑕග⛉Ꮫࡢ᥋Ⅼ. ᨺᑕග 29, 56-63 (2016).