2001 Fiscal Year Final Research Report Summary
Checkpoint control of G2 phase in cell cycle.
Project/Area Number |
11670112
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
General medical chemistry
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Research Institution | The University of Tokyo |
Principal Investigator |
NAGATA Akihisa The University of Tokyo, Graduate school of Medicine, Lecture, 大学院・医学系研究科, 講師 (50155933)
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Co-Investigator(Kenkyū-buntansha) |
JINNO Shigeki The University of Tokyo, Graduate school of Medicine, Associate, 大学院・医学系研究科, 助手 (10251224)
OKAYAMA Hiroto The University of Tokyo, Graduate school of Medicine, Professor, 大学院・医学系研究科, 教授 (40111950)
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Project Period (FY) |
1999 – 2001
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Keywords | cell cycle / checkpoint / S.pombe / rdp1 / G2 phase |
Research Abstract |
In eukaryotes, the cdc2-cyclin B kinase complex plays a crucial role in controlling the start of mitosis. In the fission yeast S. pombe, soon after cell cycle start, the kinase complex transported to the nucleus is inactivated by phosphorylation on tyrosine 15 (Y15) of Cdc2 by Wee1 or Mik1 kinase. At the end of G2, the complex is activated by Cdc25 phosphatase-catalyzed dephosphorylation and triggers the onset of mitosis. This regulatory system is highly conserved throughout higher eukaryotes. Recently we isolated a new G2/M controlling element named rdo1^+ from S. pombe. The rdp1+cDNA is 1.0 Kb long and is capable of encoding a 203 amino-acid protein with an estimated relative molecular mass of 24,332. But rdp1 has no significant homology with any other known proteins. Cell deleted for rdp1^+ did not grow at 18℃ or lower temperature. This cold-sensitive growth phenotype was fully suppressed by the rdp1^+ gene itself. Analysis shows that rdp1^+ is required for dephosphorylation of Y15 at low temperature, yet inhibits the function of dephosphorylation Cdc2.
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