?cl02565: RGS Superfamily (this model, PSSM-Id:413378 is obsolete and has been replaced by 470619)
Regulator of G protein signaling (RGS) domain superfamily The RGS domain is an essential part of the Regulator of G-protein Signaling (RGS) protein family, a diverse group of multifunctional proteins that regulate cellular signaling events downstream of G-protein coupled receptors (GPCRs). RGS proteins play critical regulatory roles as GTPase activating proteins (GAPs) of the heterotrimeric G-protein G-alpha-subunits. While inactive, G-alpha-subunits bind GDP, which is released and replaced by GTP upon agonist activation. GTP binding leads to dissociation of the alpha-subunit and the beta-gamma-dimer, allowing them to interact with effectors molecules and propagate signaling cascades associated with cellular growth, survival, migration, and invasion. Deactivation of the G-protein signaling controlled by the RGS domain accelerates GTPase activity of the alpha subunit by hydrolysis of GTP to GDP, which results in the 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. RGS proteins are also involved in apoptosis and cell proliferation, as well as modulation of cardiac development. Several RGS proteins can fine-tune immune responses, while others play important roles in neuronal signals modulation. Some RGS proteins are principal elements needed for proper vision.
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