期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1997
卷号：94
期号：2
页码：428-432
DOI：10.1073/pnas.94.2.428
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：RGS proteins constitute a newly appreciated and large group of negative regulators of G protein signaling. Four members of the RGS family act as GTPase-activating proteins (GAPs) with apparent specificity for members of the Gi subfamily of G protein subunits. We demonstrate here that two RGS proteins, RGS4 and GAIP, also act as GAPs for Gq, the G protein responsible for activation of phospholipase C{beta}. Furthermore, these RGS proteins block activation of phospholipase C{beta} by guanosine 5'-(3-O-thio)triphosphate-Gq. GAP activity does not explain this effect, which apparently results from occlusion of the binding site on G for effector. Inhibitory effects of RGS proteins on G protein-mediated signaling pathways can be demonstrated by simple mixture of RGS4 or GAIP with plasma membranes.
