The core domain of RGS16 retains G-protein binding and GAP activity in vitro, but is not functional in vivo.
The regulators of G-protein signaling (RGS) family members contain a conserved region, the RGS domain, and are GTPase-activating proteins for many members of G-protein alpha-subunits. We report here that the core domain of RGS16 is sufficient for in vitro biochemical functions as assayed by its G-protein binding affinity and its ability to stimulate GTP hydrolysis by G alpha(o) protein. RGS16 also requires, in addition to the RGS domain, the divergent N-terminus for its biological function in the attenuation of pheromone signaling in yeast, whereas its C-terminus region is dispensable. Together with other evidence, these data support the notion that RGS proteins interact with other cellular factors and may serve to link specific G-proteins to different downstream effectors in G-protein-mediated signaling pathways.
Chen
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Regulatory Biology Laboratory, Institute of Molecular and Cell Biology, National University of Singapore, Singapore.
Lin
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SC
D001665:Binding Sites; D019204:GTP-Binding Proteins / Q000378:metabolism*; D020690:GTPase-Activating Proteins; D016296:Mutagenesis; D010675:Pheromones / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D020710:RGS Proteins; D012441:Saccharomyces cerevisiae
D020690:GTPase-Activating Proteins; D010675:Pheromones; D011506:Proteins; D020710:RGS Proteins; C107413:RGS16 protein; D019204:GTP-Binding Proteins