| Project/Area Number |
06454177
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Pathological medical chemistry
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| Research Institution | Nara Institute of Science and Technology |
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Principal Investigator |
KAIBUCHI Kozo Nara Institute of Science and Technology, Division of Signal Transduction, Professor, バイオサイエンス研究科, 教授 (00169377)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAFUKU Masato Nara Institute of Science and Technology, Division of Signal Transduction, Assis, バイオサイエンス研究科, 助教授 (80202216)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1995: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1994: ¥4,600,000 (Direct Cost: ¥4,600,000)
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| Keywords | Small GTPase / Protein kinase / Cytoskeleton / Cell Adhesion / シグナル伝達 / G蛋白質 |
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| Research Abstract |
The small GTPase Ras is implicated in the regulation of various cell functions such as gene expression and cell proliferation. Here, we purified a Ras-interacting protein and identified it as AF-6. AF-6 has a GLGF/Dlg homology repeat (DHR) motif and shows a high degree of sequence similarity with Drosophila Canoe. The recombinant AF-6 and Canoe specifically interacted with GTP・Ras. The known Ras target c-Raf-l inhibited the interaction of AF-6 with GTP・Ras. These results indicate that AF-6 and Canoe are putative targets for Ras.
The small GTPase Rho has been implicated in cytoskeletal responses to extracellular signals such as lysophosphatidic acid (LPA) to form stress fibers and focal contacts. Upon stimulation, GDP・Rho is believed to be converted to GTP・Rho then binds specific targets to mediate downstream signaling. Here we found that GTP・Rho. GTP・Rho directly bound and activated two types of serine/threonine kinases. One is protein kinase N (PKN), of which C-terminal catalytic domain is homologous to that of protein kinase C.PKN was autophosphorylated in Swiss 3T3 cells upon stimulation by LPA and this autophosphorylation was blocked by treatment with Botulinum C3 exoenzyme. The other is novel protein kinase with Mr of about 164 kDa, which we have molecular cloned and designated as Rho-kinase. These finding indicates that upon stimulation GTP・Rho seems to interact with unique subsets of protein kinases.
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