Morris A J, Malbon C C
Department of Molecular Pharmacology, Diabetes and Metabolic Diseases Research Center, University Medical Center, State University of New York/Stony Brook, Stony Brook, New York 11794-8651, USA.
Physiol Rev. 1999 Oct;79(4):1373-430. doi: 10.1152/physrev.1999.79.4.1373.
Heterotrimeric G proteins in vertebrates constitute a family molecular switches that transduce the activation of a populous group of cell-surface receptors to a group of diverse effector units. The receptors include the photopigments such as rhodopsin and prominent families such as the adrenergic, muscarinic acetylcholine, and chemokine receptors involved in regulating a broad spectrum of responses in humans. Signals from receptors are sensed by heterotrimeric G proteins and transduced to effectors such as adenylyl cyclases, phospholipases, and various ion channels. Physiological regulation of G protein-linked receptors allows for integration of signals that directly or indirectly effect the signaling from receptor-->G protein-->effector(s). Steroid hormones can regulate signaling via transcriptional control of the activities of the genes encoding members of G protein-linked pathways. Posttranscriptional mechanisms are under physiological control, altering the stability of preexisting mRNA and affording an additional level for regulation. Protein phosphorylation, protein prenylation, and proteolysis constitute major posttranslational mechanisms employed in the physiological regulation of G protein-linked signaling. Drawing upon mechanisms at all three levels, physiological regulation permits integration of demands placed on G protein-linked signaling.
脊椎动物中的异源三聚体G蛋白构成了一个分子开关家族，它将大量细胞表面受体的激活传递给一组不同的效应器单元。这些受体包括视色素，如视紫红质，以及重要的家族，如参与调节人类广泛反应的肾上腺素能、毒蕈碱型乙酰胆碱和趋化因子受体。受体发出的信号由异源三聚体G蛋白感知，并传递给效应器，如腺苷酸环化酶、磷脂酶和各种离子通道。G蛋白偶联受体的生理调节允许整合直接或间接影响从受体→G蛋白→效应器信号传导的信号。类固醇激素可以通过对编码G蛋白偶联途径成员的基因活性进行转录控制来调节信号传导。转录后机制受生理控制，改变已有mRNA的稳定性，并提供额外的调节水平。蛋白质磷酸化、蛋白质异戊二烯化和蛋白水解是G蛋白偶联信号传导生理调节中采用的主要翻译后机制。利用所有三个水平的机制，生理调节允许整合对G蛋白偶联信号传导的需求。
