RGS proteins that are GAPs for G alpha (z) ACTIVATION Pubmed12223533 Pubmed20374713 Reactome Database ID Release 43921141 Reactome, http://www.reactome.org ReactomeREACT_24903 Regulators of G protein signaling (RGS) proteins all contain a 120 amino acid RGS domain that defines the family and enable the protein to bind to active G alpha:GTP. RGS binding greatly increases the intrinsic GTPase activity of G alpha subunits; RGS proteins are GTPase-activating proteins (GAPs) for G alpha. In vitro there is often little or no selectivity for GPCR or G alpha subtype, but in vitro there are marked preferences. Some RGS proteins contain many additional domains and have diverse functions, not limited to modulating GPCR signaling (McCoy & Hepler 2009). RGS proteins active for G alpha (z) G alpha (z) auto-inactivates by hydrolysing GTP to GDP