| Project/Area Number |
06454653
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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 |
Functional biochemistry
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
ITOH Hiroshi TOKYO INST.OF TECHNOL,DEPT.BIOSCI.& BIOTECH., ASSOC.PROF., 生命理工学部・寄附講座客員助教授 (10183005)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUNO Norikazu TOKYO INST.OF TECHNOL,DEPT.BIOSCI.& BIOTECH., RES.ASSOC., 生命理工学部, 寄附講座教員 (90212232)
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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 |
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | Cell Growth / Signal Transduction / G Protein / MAP Kinase / βγサブユニット |
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| Research Abstract |
Heterotrimeric GTP-binding proteins (G proteins) are composed of alpha, beta, and gamma subunits, and transduce a variety of signals from seven transmembrane receptors to effector molecules. Although it was known that cell growth is regulated by the G protein-mediated signals, the molecular mechanism of the intracellular signal transduction remains unclear. In this study, we attempted to clarify the relationship of the G protein-mediated signaling and the Ras・MAP kinase cascade using transient transfection of G protein subunits into HEK 293 cells. By measuring MAP kinase activity, we found that G protein betagamma subunit function as a signal transducer in the signaling from receptors, and the betagamma subunit activates Ras. Moreover, mutation analysis suggested that the C-terminal 2 amino acids of G protein beta subunit are required for association with G protein gamma subunit, and the C-terminal region of the beta subunit participates differentially in the signaling for MAPK/ERK and JNK/SAPK activations in the cells. Further biological studies using the mutants of G protein beta subunit should throw more light on the role of G proteins in the signaling for cell growth regulation.
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