Fraser C M
Section on Molecular Neurobiology, National Institute on Alcohol Abuse and Alcoholism, Rockville, Md.
Blood Vessels. 1991;28(1-3):93-103. doi: 10.1159/000158848.
Elucidation of the gene structure of several receptors known to mediate the signal of hormone or transmitter binding to intracellular effector systems through guanine-nucleotide-binding proteins (G proteins) has revealed that these receptors comprise a super-family of related proteins. The hallmark of all G-protein-linked receptors is a presumed topography of 7 membrane-spanning loops, analogous to the structure of bacteriorhodopsin. Members of this gene superfamily contain regions, particularly with the hydrophobic domains, of homologous sequence. The expression of G-protein-linked receptors in heterologous cell systems has allowed for the study of the pharmacological and biochemical properties of individual receptor subtypes in a manner not previously possible with intact tissues containing multiple receptors. Site-directed mutagenesis experiments have identified many conserved amino acids which are involved in ligand binding, receptor activation by agonists and receptor-G protein coupling, and suggest that the conservation of receptor structure throughout this gene family may reflect a conservation of important functional domains within these proteins.
对几种已知通过鸟嘌呤核苷酸结合蛋白（G蛋白）介导激素或递质与细胞内效应系统结合信号的受体的基因结构研究表明，这些受体构成了一个相关蛋白的超家族。所有与G蛋白相连的受体的标志是推测的7个跨膜环拓扑结构，类似于细菌视紫红质的结构。这个基因超家族的成员含有同源序列区域，特别是疏水结构域。在异源细胞系统中表达与G蛋白相连的受体，使得以完整组织中含有多种受体时无法实现的方式研究单个受体亚型的药理和生化特性成为可能。定点诱变实验已经确定了许多参与配体结合、激动剂激活受体以及受体与G蛋白偶联的保守氨基酸，并表明整个这个基因家族中受体结构的保守性可能反映了这些蛋白质中重要功能域的保守性。
