Hu Guang, Wensel Theodore G
Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):9755-60. doi: 10.1073/pnas.152094799. Epub 2002 Jul 15.
The regulator of G protein signaling (RGS)-9-1.G(beta 5) complex forms the GTPase accelerating protein for G(alpha t) in vertebrate photoreceptors. Although the complex is soluble when expressed in vitro, extraction of the endogenous protein from membranes requires detergents. The detergent extracts contain a complex of RGS9-1, G(beta 5), G(alpha t), and a 25-kDa phosphoprotein, R9AP (RGS9-1-Anchor Protein). R9AP is encoded by one intronless gene in both human and mouse. Full or partial cDNA or genomic clones were obtained from mice, cattle, human, zebrafish, and Xenopus laevis. R9AP mRNA was detected only in the retina, and the protein only in photoreceptors. R9AP binds to the N-terminal domain of RGS9-1, and anchors it to the disk membrane via a C-terminal transmembrane helix.
G蛋白信号调节因子(RGS)-9-1.G(β5)复合物在脊椎动物光感受器中形成G(αt)的GTP酶加速蛋白。尽管该复合物在体外表达时是可溶的,但从膜中提取内源性蛋白需要去污剂。去污剂提取物中含有RGS9-1、G(β5)、G(αt)和一种25 kDa的磷蛋白R9AP(RGS9-1锚定蛋白)的复合物。R9AP在人和小鼠中均由一个无内含子基因编码。从小鼠、牛、人、斑马鱼和非洲爪蟾中获得了全长或部分cDNA或基因组克隆。仅在视网膜中检测到R9AP mRNA,而在光感受器中仅检测到该蛋白。R9AP与RGS9-1的N端结构域结合,并通过C端跨膜螺旋将其锚定到盘膜上。