Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
Cell Signal. 2012 Aug;24(8):1541-7. doi: 10.1016/j.cellsig.2012.03.013. Epub 2012 Mar 28.
The Ciona intestinalis voltage sensitive phosphatase (Ci-VSP) was the first proven enzyme to be under direct control of the membrane potential. Ci-VSP belongs to a family of proteins known as Protein Tyrosine Phosphatases (PTP), which are a group of enzymes that catalyze the removal of phosphate groups from phosphatidylinositides and phosphorylated tyrosine residues on proteins. What makes Ci-VSP and similar phosphatases unique is the presence of a Voltage Sensing Domain (VSD) in their N-terminus. The VSD of Ci-VSP shares high homology with those from voltage-gated channels and confers voltage sensitivity to these enzymes. The catalytic domain of Ci-VSP displays extraordinary structural and functional similarities to PTEN. This latter protein is encoded by the Phosphatase and Tensin homolog deleted from chromosome 10 gene, thus its name, and it is known as a tumor suppressor. The resemblance between these proteins has prompted the use of PTEN as a template for the study of Ci-VSP and produced a rapid advance in our understanding of the mechanism of activity of Ci-VSP. This review will be focused on discussing recent advances in the understanding of the activation mechanism for these molecules known as electrochemical coupling.
秀丽隐杆线虫电压敏感磷酸酶（Ci-VSP）是第一个被证实受膜电位直接调控的酶。Ci-VSP 属于蛋白酪氨酸磷酸酶（PTP）家族，是一组能够催化从磷脂酰肌醇和蛋白质上磷酸化的酪氨酸残基上去除磷酸基团的酶。使 Ci-VSP 和类似的磷酸酶与众不同的是它们的 N 端存在电压感应结构域（VSD）。Ci-VSP 的 VSD 与电压门控通道的 VSD 具有高度同源性，赋予这些酶电压敏感性。Ci-VSP 的催化结构域与 PTEN 显示出非凡的结构和功能相似性。后者由 10 号染色体缺失的磷酸酶和张力蛋白同源物基因编码，因此得名，被认为是一种肿瘤抑制因子。这些蛋白质之间的相似性促使人们使用 PTEN 作为 Ci-VSP 研究的模板，并极大地促进了我们对 Ci-VSP 活性机制的理解。这篇综述将集中讨论在理解这些被称为电化学偶联的分子的激活机制方面的最新进展。
