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. Guanine nucleotide binding proteins are heterotrimeric signal-transducing molecules consisting of alpha, beta, and gamma subunits. The gamma subunit determines the specificity of which signaling pathways will be affected by this particular complex. The protein encoded by this gene represents the gamma subunit of both inhibitory and stimulatory complexes.