Polyphosphoinositide synthesis in platelets stimulated with low concentrations of thrombin is enhanced before the activation of phospholipase C

FEBS Letters

Lindberg, Uno¹  Lassing, Ingrid¹ 

[1] Department of Zoological Cell Biology, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden

关键词: Phosphoinositide turnover;    Phosphatidylinositol kinase;    Microfilament;    Profilin/actin;   

DOI  :  10.1016/0014-5793(90)80197-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When platelets, prelabelled with [³²P]orthophosphate, were stimulated with thrombin (0.5 U·ml⁻¹) there was an immediate increase in the radioactivity associated with the pools of polyphosphoinositides. Only subsequent to this increase, did the radioactivity of these phospholipid pools decrease as expected from a receptor-mediated activation of phospholipase C (phosphoinositidase). Phosphorylation of diacylglycerol (one of the second messengers formed in the hydrolysis of phosphatidylinositol-bisphosphate) to phosphatidic acid took place with a lag phase of about 3–5 s. Together these experiments suggest that stimulation of kinases phosphorylating phosphatidylinositol and phosphatidylinositol-phosphate may precede or occur in parallel with activation of receptor-linked phosphoinositidase.

【 授权许可】

Unknown