title: The regulators of G protein signaling (RGS) domains of RGS4, RGS10, and GAIP retain GTPase activating protein activity in vitro.
abstract: Regulators of G protein signaling (RGS) proteins accelerate GTP hydrolysis by Gi but not by Gs class alpha-subunits. All RGS proteins share a conserved 120-amino acid sequence termed the RGS domain. We have demonstrated that the RGS domains of RGS4, RGS10, and GAIP retain GTPase accelerating activity with the Gi class substrates Gialpha1, Goalpha, and Gzalpha in vitro. No regulatory activity of the RGS domains was detected for Gsalpha. Short deletions within the RGS domain of RGS4 destroyed GTPase activating protein activity and Gialpha1 substrate binding. Comparable protein-protein interactions between Gialpha1-GDP-AlF4- and the RGS domain or full-length RGS4 were detected using surface plasmon resonance.
authors.affiliation: Pharmacology Department, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75235-9041, USA.
authors.forename: S
authors.initials: S
authors.lastname: Popov
authors.forename: K
authors.initials: K
authors.lastname: Yu
authors.forename: T
authors.initials: T
authors.lastname: Kozasa
authors.forename: T M
authors.initials: TM
authors.lastname: Wilkie
mesh_terms: D020558:GTP Phosphohydrolases / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006868:Hydrolysis; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D020710:RGS Proteins; D015398:Signal Transduction
chemical_list: D010750:Phosphoproteins; D011506:Proteins; D020710:RGS Proteins; C101113:RGS10 protein, human; C097187:regulator of G-protein signalling 19; C098799:RGS4 protein; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins