文献库 文献相关信息
- 题目:
- RGS4 inhibits Gq-mediated activation of mitogen-activated protein kinase and phosphoinositide synthesis.
- 作者:
- Yan(Y),Chi(P P),Bourne(H R)
- 状态:
- 发布时间1997-06-02 , 更新时间 2013-11-21
- 期刊:
- J Biol Chem
- 摘要:
- Recombinant regulators of G protein-signaling (RGS) proteins stimulate hydrolysis of GTP by alpha subunits of the Gi family but have not been reported to regulate other G protein alpha subunits. Expression of recombinant RGS proteins in cultured cells inhibits Gi-mediated hormonal signals probably by acting as GTPase-activating proteins for Galphai subunits. To ask whether an RGS protein can also regulate cellular responses mediated by G proteins in the Gq/11 family, we compared activation of mitogen-activated protein kinase (MAPK) by a Gq/11-coupled receptor, the bombesin receptor (BR), and a Gi-coupled receptor, the D2 dopamine receptor, transiently co-expressed with or without recombinant RGS4 in COS-7 cells. Pertussis toxin, which uncouples Gi from receptors, blocked MAPK activation by the D2 dopamine receptor but not by the BR. Co-expression of RGS4, however, inhibited activation of MAPK by both receptors causing a rightward shift of the concentration-effect curve for both receptor agonists. RGS4 also inhibited BR-stimulated synthesis of inositol phosphates by an effector target of Gq/11, phospholipase C. Moreover, RGS4 inhibited inositol phosphate synthesis activated by addition of AlF4- to cells overexpressing recombinant alphaq, probably by binding to alphaq.GDP.AlF4-. These results demonstrate that RGS4 can regulate Gq/11-mediated cellular signals by competing for effector binding as well as by acting as a GTPase-activating protein.
- 语言:
- eng
- DOI:
DataTable pData
微信公众号
关注微信订阅号，实时查看信息，关注医学生物学动态。
版权所有 © 2025.Genelibs 济南弘晖生物技术有限公司 鲁ICP备13024435号-2
