Phosphoinositide 3-kinases (PI3Ks) phosphorylate inositol lipids and are involved in the immune response. The protein encoded by this gene is a class I catalytic subunit of PI3K. Like other class I catalytic subunits (p110-alpha p110-beta, and p110-delta), the encoded protein binds a p85 regulatory subunit to form PI3K. This gene is located in a commonly deleted segment of chromosome 7 previously identified in myeloid leukemias. Several transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jun 2015],catalytic activity:ATP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = ADP + 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate.,enzyme regulation:Activated by both the alpha and the beta-gamma G proteins.,function:3-phosphorylates the cellular phosphoinositide PtdIns-4,5-biphosphate (PtdIns(4,5)P2) to produce PtdIns-3, 4,5-triiphosphate (PtdIns(3,4,5)P3). Links G-protein coupled receptor activation to the secondary messenger PtdIns(3,4,5)P3 production.,pathway:Phospholipid metabolism, phosphatidylinositol phosphate biosynthesis.,similarity:Belongs to the PI3/PI4-kinase family.,similarity:Contains 1 PI3K/PI4K domain.,subunit:Heterodimer of a catalytic subunit (PIK3CG/p120) and a regulatory (PIK3R5a/p101) subunit.,tissue specificity:Pancreas, skeletal muscle, liver and heart.,
