Phosphatidylinositol turnover in platelet activation; Calcium mobilization and protein phosphorylation

Kozo Kaibuchi, Kimihiko Sano, Masahiko Hoshijima, Yoshimi Takai, Yasutomi Nishizuka

Research output: Contribution to journalArticlepeer-review

121 Citations (Scopus)


Ca2+-activated, phospholipid-dependent protein kinase (C-kinase) in platelets is normally activated by diacylglycerol, which is derived from phosphatidylinositol through its receptor-linked breakdown. Under appropriate conditions this enzyme can also be activated by synthetic diacylglycerol which is directly added to intact platelets. C-Kinase thus activated preferentially phosphorylates an endogenous platelet protein having a molecular weight of approximately 40,000. This protein phosphorylation is merely a prerequisite but not a sufficient requirement for the release of serotonin. Evidence is presented suggesting that Ca2+ mobilization and C-kinase activation are synergistically involved in the physiological response of platelets to extracellular messengers, such as thrombin, collagen and platelet-activating factor.

Original languageEnglish
Pages (from-to)323-335
Number of pages13
JournalCell Calcium
Issue number4-5
Publication statusPublished - 10-1982
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physiology
  • Molecular Biology
  • Cell Biology


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