| Project/Area Number |
02807202
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Kyoto University |
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Principal Investigator |
YATSUNAMI Kimio Kyoto University, Pharmacology, Assistant, 薬学部, 助手 (30191141)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIKAWA Atsushi Kyoto University, Pharmacology, Professor, 薬学部, 教授 (10025695)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Prostaglandin E / prostacyclin / desensitization / receptor / GTP binding protein / GTP / Mastocytoma cells |
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| Research Abstract |
We have investigated the mechanism of desensitization of receptors for prostaglandin E_1 and for l_2 (prostacyclin). When the membranes were preincubated with[ ^3H] PGE_1 for 60 min at 37ﾟC. the dissociation of the ligand form the receptor was remarkably decreased, even in the presence of GTPgammaS. The stable[ ^3H]PGE_1-bound receptor complex was solubilized with 6% digitonin. The solubilized[ ^3H]PGE_1 receptor was eluted with[ ^<35>S]GTPgammaS binding activity from an Ultrogel AcA44 column. The fractions containing activities of both[ ^3H]PGE_1 and[ ^<35>S]GTPgammaS bindings were further purified by column chromatographies on wheat germ agglutinin(WGA)-agarose and phenyl-Sepharose CL-4B. The partially purified[ ^3H]PGE_1-bound receptor was affinity-labeled with [ ^<14>C]5'-P-fluorosulfonylbenzoylguanosine and a protein with a molecular mass of 60 kDa was detected.
Iloprost, a stable prostacyclin analogue, transiently stimulated adenylate cyclase activity. floprost also induced the translocation of alpha subunits(42- and 45-kDa)of stimulatory guanine nucleotide-binding proteins(Gsalpha)from the membrane to the cytosol. These results taken together demonstrate the the desensitization of prostaglandin receptors, 'are caused by distinct mechanisms between those of prostaglandin E_1 and prostacyclin.
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