Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
Cell Signal. 2012 Jan;24(1):25-34. doi: 10.1016/j.cellsig.2011.08.014. Epub 2011 Sep 1.
Heterotrimeric G proteins typically transduce signals from G protein-coupled receptors (GPCRs) to effector proteins. In the conventional G protein signaling paradigm, the G protein is located at the cytoplasmic surface of the plasma membrane, where, after activation by an agonist-bound GPCR, the GTP-bound Gα and free Gβγ bind to and regulate a number of well-studied effectors, including adenylyl cyclase, phospholipase Cβ, RhoGEFs and ion channels. However, research over the past decade or more has established that G proteins serve non-canonical roles in the cell, whereby they regulate novel effectors, undergo activation independently of a GPCR, and/or function at subcellular locations other than the plasma membrane. This review will highlight some of these non-canonical aspects of G protein signaling, focusing on direct interactions of G protein subunits with cytoskeletal and cell adhesion proteins, the role of G proteins in cell division, and G protein signaling at diverse organelles.
三聚体 G 蛋白通常将信号从 G 蛋白偶联受体 (GPCR) 转导至效应蛋白。在传统的 G 蛋白信号传递范例中，G 蛋白位于质膜的细胞质表面，在激动剂结合的 GPCR 激活后，GTP 结合的 Gα 和游离的 Gβγ 结合并调节许多经过充分研究的效应蛋白，包括腺苷酸环化酶、磷脂酶 Cβ、RhoGEFs 和离子通道。然而，过去十年或更长时间的研究已经确立，G 蛋白在细胞中具有非典型作用，通过这种作用，它们调节新的效应蛋白，独立于 GPCR 进行激活，和/或在质膜以外的亚细胞位置发挥作用。这篇综述将重点介绍 G 蛋白信号传递的一些非典型方面，包括 G 蛋白亚基与细胞骨架和细胞黏附蛋白的直接相互作用、G 蛋白在细胞分裂中的作用以及不同细胞器中的 G 蛋白信号传递。
