The role of protein kinase C in the human platelet.

Protein kinase C is a key enzyme in signal transduction systems that involve the breakdown of phospholipids. In the platelet, protein kinase C plays an important role in the induction of the aggregatory and secretory responses as well as in preventing a continuous activation of the platelet excitatory signal transducing system. Furthermore, elevation of platelet cAMP that leads to inhibition of platelet activation appears to interact with the excitatory pathway at the level of protein kinase C. A pivotal role for protein kinase C in platelet activation is proposed.