Phosphoinositide 3-kinases (PI 3-Ks) phosphorylate the 3’- OH position of the inositol ring of inositol lipids. They act as participants in signaling pathways that regulate cell growth by virtue of their activation in response to various mitogenic stimuli. PI 3-Ks are composed of a catalytic subunit, such as PI 3-kinase C2∫ (PIK3CB) and an adaptor subunit. PI 3-kinase C2∫ , also known as p110-∫, is a 1,070 amino acid protein that shares 42% identity with p110 of cow origin. It is expressed in several human and rodent cell lines. Studies predict that PI 3-kinase C2∫ has a role in modulating the formation and stability of å2B (ITGA2B)/∫3 (ITGB3) Integrin adhesion bonds, which are essential in shear force-induced platelet activation.
Phosphorylates PtdIns, PtdIns4P and PtdIns(4,5)P2 with a preference for PtdIns(4,5)P2.