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 (PubMed:28219978). The heterodimer formed by GNB1 and GNG2 interacts with ARHGEF5 (PubMed:19713215). The heterodimer formed by GNB1 and GNG2 interacts with GRK2 (By similarity). Expressed in fetal tissues, including testis, adrenal gland, brain, white blood cells and brain. Belongs to the G protein gamma family.