Regulator of G protein signaling (RGS) domain found in the R12 subfamily of proteins
The RGS (Regulator of G-protein Signaling) domain is an essential part of the R12 (Neuronal RGS) protein subfamily of the RGS protein family, a diverse group of multifunctional proteins that regulate cellular signaling events downstream of G-protein coupled receptors (GPCRs). RGS proteins play a critical regulatory role as GTPase activating proteins (GAPs) of the heterotrimeric G-protein G-alpha-subunits. Deactivation of G-protein signaling, controlled by RGS domain, accelerates GTPase activity of the alpha subunit by hydrolysis of GTP to GDP that results in reassociation of the alpha-subunit with the beta-gamma-dimer and thereby inhibition of downstream activity. As a major G-protein regulator, RGS domain containing proteins are involved in many crucial cellular processes such as regulation of intracellular trafficking, glial differentiation, embryonic axis formation, skeletal and muscle development, and cell migration during early embryogenesis. The R12 RGS subfamily includes RGS10, RGS12 and RGS14 all of which are highly selective for G-alpha-i1 over G-alpha-q.