CaVγ subunits inhibit CaV channel activity and modulate its activation and inactivation kinetics. CaVγ subunits have little effect on CaV channel trafficking. The γ subunit is an integral membrane protein. The γ subunit family consists of at least 8 members, which share a number of common structural features. Each member is predicted to possess four transmembrane domains, with intracellular N- and C-termini. The first extracellular loop contains a highly conserved N-glycosylation site and a pair of conserved cysteine residues.n The CaVγ5 subunit is highly expressed in the liver, kidney, heart, lung, skeletal muscles, and, with a lower abundance, in testes. The close association of epilepsy and ataxia with mutations in other neuronal voltage-dependent Ca2+ channels suggests these are potential candidate phenotypes for defects in the CaVγ5 (CACNG5) gene.