Phosphatidylinositol 3-Kinases

Abstract

Phosphatidylinositol 3-kinase (PI 3-kinase), which is responsible for phosphorylating phosphatidylinositol (PI), PI(4)P, and PI(4, 5)P₂, is a crucial signaling intermediate in the regulation of various biological functions. The site of the lipid kinase action has not been well defined. However, recent reports suggest that the products of PI 3-kinase regulate the activities of several protein kinases including some subtypes of protein kinase C. The evidence has also been obtained for the role of PI 3-kinase as regulator of small GTP-binding proteins including the members of Rac and Rab families.