Project/Area Number |
05680615
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
Cell biology
|
Research Institution | KYUSHU UINVERSITY |
Principal Investigator |
HAYASHI Naoyuki (1994-1995) Graduate School of Medical Science, Research Associate, 大学院・医学系研究科, 助手 (50253456)
関口 猛 (1993) 九州大学, 大学院医学系研究科, 助手 (60187846)
|
Project Period (FY) |
1993 – 1995
|
Project Status |
Completed (Fiscal Year 1995)
|
Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1993: ¥1,300,000 (Direct Cost: ¥1,300,000)
|
Keywords | RCC1 / G protein / protein-protein interaction / 2-hybrid method / nucleopore / guanine nucleotide exchange / chromosomal condensation / cell cycle / 2ハイブリッド法 / phosphorylation / cdc2 Kinase / alternative splicing |
Research Abstract |
The tsBN2 cell, which has a mutation in the RCC1 gene, causes condensation of prematurely replicated chromosomes by the temperature-shift to 39.5゚C after synchronization at S phase. RCC1 encodes a guanine nucleotide exchanging factor for the nuclear small G protein, Ran. We tried to isolate the factors interacting with RCC1 to investigate the mechanisms of RCC1 function to control the chromosomal condensation. By 2-hybrid screening, 5 cDNAs from RanBP1 and RanBP2 genes were obtained. RanBP1 formed complex with RCC1 depending upon presence of Ran and inhibited release of the guanine nucleotide from Ran by RCC1 in vitro. On the other hand, we found that RanBP1 localized cytosole in vivo by indirect immunofluorescence observation. RanBP2 encoded the 358 kDa nucleopore-protein, and it had the leucine-rich region in N-terminus, the region homologous to cyclophilin in C-terminus, and 8 times repeated Zn-finger in the middle region. We found that this protein localized at cytosolic filaments of the nucleopores by immunofluorescence and immuno-electron microscope observations. The polyclonal antibody against RanBP2 inhibited protein import of the nuclear protein, indicating that this was essential for the nuclear transport system.
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