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 regulating dopamine-mediated locomotion behavior (PubMed:15378064). G proteins are composed of 3 units, alpha, beta and gamma (By similarity). Interacts with G protein gamma subunits gpc-1 and gpc-2 and with egl-10 and eat-16 (PubMed:11333232). Belongs to the WD repeat G protein beta family.