| Project/Area Number |
09470031
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General medical chemistry
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| Research Institution | Kobe University |
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Principal Investigator |
KATAOKA Tohru Kobe Univ.Sch.Med., Dept.Physiology II,Professor, 医学部, 教授 (40144472)
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| Co-Investigator(Kenkyū-buntansha) |
HU Chang-Deng Kobe Univ.Sch.Med., Dept.Physiology II,Instructor, 医学部, 助手 (70294204)
OKADA Tomoyo Kobe Univ.Sch.Med., Dept.Physiology II,Instructor, 医学部, 助手 (80294205)
KATAOKA Yuriko Kobe Univ.Sch.Med., Dept.Physiology II,Instructor, 医学部, 助手 (50233739)
KARIYA Ken-ichi Kobe Univ.Sch.Med., Dept.Physiology II,Associate Prof., 医学部, 助教授 (40263371)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥13,200,000 (Direct Cost: ¥13,200,000)
Fiscal Year 1998: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1997: ¥9,500,000 (Direct Cost: ¥9,500,000)
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| Keywords | ras Oncogene / Posttranslational Modification / Farnesylation / Phospholipase C / Adenylyl Cyclase / Adenylyl Cyclase-Associated Protein / raf Oncogene / rap1A Anti-Oncogene / ホスホリバーゼC / raplA癌抑制遺伝子 / Ras癌遺伝子 / GTP結合蛋白質 |
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| Research Abstract |
1. We analysed the molecular mechanism and the physiological significance of interaction between the cysteine-rich region (CRR) of Raf-1 and the activator region of Ras, which is dependent on posttranslational modification (farnesylation) of Ras. By employing the fluorescence polarization method to measure binding of a synthetic peptide corresponding to the Ras C-terminus, which was chemically attached with famesyl group, we showed that the famesyl moiety of Ras is a critical determinant of the Ras-Raf interaction. We also elucitated the molecular mechanisms by which Ras and RaplA exert differential regulatory activities towards Raf-1 and B-Raf and by which phosphorylation of RaplA by protein kinase A results in inhibition of its activity to antagonize the Ras function. Based on these results, we proposed that the strength of interaction between Ras/RaplA and Raf-CRR must stand on an adequate level to cause Raf activation.
2. We elucidated the molecular mechanism by which farnesylation of Ras is required for activation of yeast adenylyl cyclase. We discovered a novel interaction between the farnesylated Ras and a complex between the N-terminal 36-residue region of the adenylyl cyclase-associated protein CAP and the C-terminus of adenylyl cyclase, and showed that this second interaction is responsible for the stimulatory effect of farnesylation on Ras-dependent adenylyl cyclase activation. This result taken together with the data with Raf suggested that the farnesylation-dependent second interaction may be generally required for activation of the effector molecules by Ras.
3. We discovered a novel Ras-effector candidate PLC210, which encodes a new form of phosphoinositide-specific phospholipase C, in the nematode C.elegans, and also isolated a cDNA encoding its human homologue. Both the nematode amid human PLC210 exhibited GTP-dependent binding to Ras/RaplA and had phospholipase C activity'. The mode of regulation by Ras is now under investigation.
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