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PubMed · 1613976

[Small GTP-binding protein and platelet function].

M Kawata·Y Takai
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Abstract

In platelets, nearly ten small GTP-binding proteins (G proteins) are identified. Among these small G proteins, smg p21 is the most abundant. The C terminus of smg p21 is processed by three post-translational modifications: geranylgeranylation, removal of three amino acids and carboxyl methylation. There are two regulatory proteins for smg p21, smg p21 GTPase activating protein (GAP) and smg GDP dissociation stimulator (GDS). Moreover, smg p21 is phosphorylated by A-Kinase and this phosphorylation stimulates the action of smg GDS. C-Kinase and Ca2+ induce platelet activation, while A-Kinase antagonizes this activation. Since smg p21 is the substrate of A-Kinase, it is possible that smg p21 mediates the A-Kinase action and inhibits the platelet function, such as aggregation and secretion. The mode of action of and the possible function of smg p21 in platelets are discussed.

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Alkyl and Aryl TransferasesAnimalsBlood PlateletsCalciumGTP-Binding ProteinsGTPase-Activating ProteinsHumansMolecular WeightPhosphorylationPlatelet AggregationProtein Processing, Post-TranslationalProteinsSignal TransductionTransferasesEnglish AbstractJournal Article

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M Kawata, Y Takai. 1992. [Small GTP-binding protein and platelet function].. https://pubmed.ncbi.nlm.nih.gov/1613976/

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