Haga T, Haga K, Kameyama K, Nakata H
Institute for Brain Research, Faculty of Medicine, University of Tokyo, Japan.
Nihon Yakurigaku Zasshi. 1994 Sep;104(3):207-16. doi: 10.1254/fpj.104.207.
Recent progress on the activation of G protein-coupled receptor kinases is reviewed. beta-Adrenergic receptor kinase (beta ARK) is activated by G protein beta gamma -subunits, which interact with the carboxyl terminal portion of beta ARK. Muscarinic receptor m2-subtypes are phosphorylated by beta ARK1 in the central part of the third intracellular loop (I3). Phosphorylation of I3-GST fusion protein by beta ARK1 is synergistically stimulated by the beta gamma -subunits and mastoparan or a peptide corresponding to portions adjacent to the transmembrane segments of m2-receptors or by beta gamma -subunits and the agonist-bound I3-deleted m2 variant. These results indicate that agonist-bound receptors serve as both substrates and activators of beta ARK.
本文综述了G蛋白偶联受体激酶激活方面的最新进展。β-肾上腺素能受体激酶（βARK）由G蛋白βγ亚基激活，该亚基与βARK的羧基末端部分相互作用。毒蕈碱受体m2亚型在第三个细胞内环（I3）的中部被βARK1磷酸化。βγ亚基与马斯托帕兰或与m2受体跨膜段相邻部分对应的肽，或βγ亚基与激动剂结合的I3缺失m2变体协同刺激βARK1对I3-GST融合蛋白的磷酸化。这些结果表明，激动剂结合的受体既是βARK的底物又是其激活剂。
