Slupe Andrew M, Merrill Ronald A, Strack Stefan
Department of Pharmacology, University of Iowa, 2-432 BSB, Iowa City, IA 52242, USA.
Enzyme Res. 2011;2011:398751. doi: 10.4061/2011/398751. Epub 2011 Jul 2.
Protein phosphatase 2A- (PP2A-) catalyzed dephosphorylation of target substrate proteins is widespread and critical for cellular function. PP2A is predominantly found as a heterotrimeric complex of a catalytic subunit (C), a scaffolding subunit (A), and one member of 4 families of regulatory subunits (B). Substrate specificity of the holoenzyme complex is determined by the subcellular locale the complex is confined to, selective incorporation of the B subunit, interactions with endogenous inhibitory proteins, and specific intermolecular interactions between PP2A and target substrates. Here, we discuss recent studies that have advanced our understanding of the molecular determinants for PP2A substrate specificity.
蛋白磷酸酶2A（PP2A）催化的靶底物蛋白去磷酸化作用广泛存在，对细胞功能至关重要。PP2A主要以催化亚基（C）、支架亚基（A）和4个调节亚基家族（B）之一的成员组成的异源三聚体复合物形式存在。全酶复合物的底物特异性由复合物所处的亚细胞区域、B亚基的选择性掺入、与内源性抑制蛋白的相互作用以及PP2A与靶底物之间的特定分子间相互作用决定。在此，我们讨论了最近的研究，这些研究加深了我们对PP2A底物特异性分子决定因素的理解。
