Phosphoinositide 3-kinase activity is implicated in assorted cellular responses activated by mammalian cell surface receptors and the regulation of protein sorting in yeast. The p110(gamma) (PIK3CG) enzyme is activated in vitro by both the (alpha) and (beta)(gamma) subunits of heterotrimeric GTP-binding proteins (G proteins) and does not associate with a p85 adaptor molecule. PI 3-kinase C2(gamma), also designated p110(gamma), may link signaling through G protein-coupled receptors to the generation of phosphoinositide second messengers that are phosphorylated in the D-3 position. The PI 3-kinase C2(gamma) gene encodes a 1,050 amino acid polypeptide with 36% identity to human PI 3-kinase C2(alpha). Research indicates that PI 3-kinase C2(gamma) can block the growth of human colon cancer cells.