| Project/Area Number |
05808066
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Cell biology
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
HOSOYA Hiroshi Hirosima Univ, Dept.Biol, Sci., Assoc, Prof., 理学部, 助教授 (90183102)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1993: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Cell cycle / MLCK / Myosin / myonin regulatory light chaiu, phoshorylation / myosir light chain kinase / ミオシン調節軽鎖 / ミオシン軽鎮キナーゼ / Cell cycle / 細胞分裂 / ミオシン軽鎖 / 細胞周期 / cdc2キナーゼ / アクチン / 細胞骨格 |
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| Research Abstract |
We have analyzed myosin light chain kinase (MLCK) activities in unfertilized and fertilized egg extracts from sea urchin, Hemicentrotus pulcherrimus. Total kinase activities that phosphorylates regulatory light chain of mysion-II (MLC) are higher in unfertilized egg extracts than in fertilized egg extracts in vitro. Phosphopeptide mapping analysis shows that the kinase activities in unfertilized eggs phosphorylate MLC both at the sites which MLCK purified from chicken gizzard (cgMLCK) and protein kinase C (PKC) phosphorylate, respectively. In metaphase, the kinase activity that phosphorylates MLC at cgMLCK sites is decreased, but the kinase activity that phosphorylates MLC at PKC sites is increased. Fractionation of undfertilized egg extracts using a gel filtration chromatography resulted in two peaks (termed fraction I and fraction II) of sea urchin MLCK activities. Prosphopeptide mapping analsis shows that both kinases phosphorylate MLC at cgMLCK sites but one is calciumcalmodulin dependent MLCK and the other is calciumcalmodulin independent MLCK,respectively.
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