RGS4 and GAIP are GTPase-activating proteins for G(q alpha) and block activation of phospholipase C beta by gamma-thio-GTP-G(q alpha)
RGS4 and GAIP are GTPase-activating proteins for G(q alpha) and block activation of phospholipase C beta by gamma-thio-GTP-G(q alpha)
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DOI：
10.1073/pnas.94.2.428
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发表时间：
1997-01-21
影响因子：
11.1
通讯作者：
Kozasa, T
中科院分区：
文献类型：
--
作者：
Hepler, JR;Berman, DM;Kozasa, T
RGS蛋白是新近发现的一大类G蛋白信号负调控蛋白。RGS家族的4个成员作为gtpase激活蛋白（gap），对G蛋白亚基的G（i α）亚家族成员具有明显的特异性。我们在这里证明了两个RGS蛋白，RGS4和GAIP，也作为G（q α）的gap， G（α）蛋白负责磷脂酶C β的激活。此外，这些RGS蛋白阻断了鸟苷5'-（3- o -硫）三磷酸- g （q α）对磷脂酶C β的激活。GAP活性不能解释这种效应，这显然是由于效应物的G（α）结合位点被阻断所致。RGS蛋白对G蛋白介导的信号通路的抑制作用可以通过RGS4或GAIP与质膜的简单混合来证明。
RGS proteins constitute a newly appreciated and large group of negative regulators of G protein signaling. Pour members of the RGS family act as GTPase-activating proteins (GAPs) with apparent specificity for members of the G(i alpha) subfamily of G protein subunits. We demonstrate here that two RGS proteins, RGS4 and GAIP, also act as GAPs for G(q alpha), the G(alpha) 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-G(q alpha). GAP activity does not explain this effect, which apparently results from occlusion of the binding site on G(alpha) 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.