| Project/Area Number |
08660112
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
応用微生物学・応用生物化学
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| Research Institution | TOTTORI UNIVERSITY |
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Principal Investigator |
YAMANO Yoshiaki TOTTORI UNIVERSITY,FACULTY OF AGRICULTURE,ASSOCIATE PROFESSOR, 農学部, 助教授 (00182593)
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| Co-Investigator(Kenkyū-buntansha) |
MORISHIMA Isao TOTTORI UNIVERSITY,FACULTY OF AGRICULTURE,PROFESSOR, 農学部, 教授 (30032296)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | ANGIOTENSIN II / RECEPTOR / HYPERTENSION / G PROTEIN / SECOND MESSENGER / SITE-DIRECTED MUTAGENESIS / PCR-SSCP法 / 高血圧症 |
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| Research Abstract |
To delineate domains essential for G_q-protein coupling in the carboxyl-terminal tail of rat angiotensin II receptor type 1A (AT_<1A>), the receptor in the putative cytosolic regions was truncated by site-derected mutagenesis introducing stop codons in the cDNA and determined consequent changes in the effect of GTPgammaS on angiotensin II (Ang II) binding and in inositol trisphosphate (IP_3) production in response to Ang II.
To identify the domains responsible for the activation of G_q, we studied the effect of synthetic peptide (P-5) representing domains of carboxyl-terminal segment (residues 306-320) of AT_<1A> and its analog (substituting AAA for Y^<312>-F^<314>-L^<314> : Mut P-5) on the binding of the ^<35>S-labeled GTPgammaS to G_q. The effects of GTPgammaS on Ang II binding (shift of AT_<1A> from a high affinity state to a low affinity form) and IP_3 production in deletional mutant receptor 1-317 AT_<1A> were similar to wild type AT_<1A>, whereas those of mutants 1-309,1-311,1-312 and 1-313 AT_<1A> were markedly reduced. The binding of ^<35>S-labeled GTPgammaS to G_q was promoted by P-5, but not by Mut P-5. These results indicate that cytosolic carboxyl-terminal domains Tyr^<312>, Phe^<313> and Leu^<314> of rat AT_<1A> are essential for coupling and activation of G_q.
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