Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. This protein may be involved in the determination of the cAMP level according to nutritional conditions, most probably as a regulator of adenylyl cyclase. G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. Belongs to the G-alpha family. Truncated N-terminus.