Phosphoinositide 3-kinase gamma is a lipid kinase that produces the lipid second messenger phosphatidylinositol 3,4,5-trisphosphate. The kinase is composed of a catalytic subunit and one of several regulatory subunits, and is chiefly activated by G protein-coupled receptors. This gene encodes a regulatory subunit, and is distantly related to the phosphoinositide-3-kinase, regulatory subunit 5 gene which is located adjacent to this gene on chromosome 7. The orthologous protein in the mouse binds to both the catalytic subunit and to G(beta/gamma), and mediates activation of the kinase subunit downstream of G protein-coupled receptors. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2014].