Phosphoinositide-3-Kinase Regulatory Subunit 5 (PIK3R5)

Receptor-regulated class I phosphoinositide 3-kinases (PI3Ks) phosphorylate the membrane lipid phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) to PtdIns(3,4,5)P3, which in turn recruits and activates cytosolic effectors involved in proliferation, survival, or chemotaxis.

PIK3R5 is a PI3K regulatory subunit .fluorescence-tagged porcine p101 and human p110-gamma (PIK3CG) interacted in transfected human embryonic kidney cells and retained the essential functions of wildtype heterodimeric PI3K-gamma. G protein-beta-gamma recruited PI3K-gamma from the cytosol to the membrane through interaction with the p101 subunit. Accordingly, p101 was required for G protein-mediated activation of PI3K-gamma.