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 (By similarity). G proteins are composed of 3 units, alpha, beta and gamma (By similarity). In this context, interacts with GNB2 (By similarity). The heterodimer formed by GNB1 and GNG2 interacts with ARHGEF5 (By similarity). The heterodimer formed by GNB1 and GNG2 interacts with GRK2 (By similarity). Belongs to the G protein gamma family.