Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction. Plays a role in the regulation of adenylyl cyclase signaling in certain regions of the brain. Plays a role in the formation or stabilzation of a G protein heterotrimer (G(olf) subunit alpha-beta-gamma-7) that is required for adenylyl cyclase activity in the striatum (By similarity). G proteins are composed of 3 units, alpha, beta and gamma. Expressed in a variety of tissues. Down-regulated in pancreatic and esophageal cancer. Belongs to the G protein gamma family.