MAGI3促进E-cadherin翻译修饰并影响β-catenin亚细胞定位

MAGI3 Promotes the Post-Translational Modification of E-cadherin and Regulates the Intracellular Localization of β-Catenin

目的：研究MAGI3对细胞黏附连接关键蛋白E-cadherin翻译后修饰及其对β-catenin在细胞内分布的影响，为探讨MAGI3通过调控细胞黏附连接影响肿瘤侵袭、转移的可能机制提供线索。方法首先采用Western印迹方法检测过表达MAGI3后E-cadherin蛋白表达条带的迁移变化，研究其翻译后修饰的变化；然后应用RT-PCR方法检测E-cadherin的表达在mRNA水平的变化，研究MAGI3对其转录水平的影响；进一步利用核质膜分离实验检测MAGI3对β-catenin胞内定位的影响。结果过表达MAGI3使E-cadherin蛋白翻译后修饰发生变化（ P＜0.05），但在mRNA水平没有明显变化。同时，过表达MAGI3后分布到细胞质膜上的β-catenin明显增多（P＜0.05）。结论 MAGI3可能通过促进E-cadherin的翻译后修饰，并促进β-catenin在细胞膜上的分布。

Objective To investigate the effect of MAGI3 on the post-translational modification of E-cadherin protein and the intracellular localization of β-catenin, and to provide a clue for the underlying mechanisms by which MAGI3 influences tumor invasion and metastasis through regulating adherens junction.Methods The post-translational modification of E-cadherin protein upon MAGI3 overexpression was detected by using Western blotting.RT-PCR assay was used to detect the change of E-cadherin expression at mRNA level.Nuclear cytosol membrane separation experiment was fur-ther conducted to detect intracellular distribution of β-catenin after MAGI3 overexpression in HEK293 T cells.Results Overexpression of MAGI3 regulated the post-translational modification of E-cadherin protein but not its mRNA level.MAGI3 overexpression increased the membranous locali-zation of β-catenin.Conclusion MAGI3 may regulate the post-translational modification of E-cad-herin, and promote the redistribution ofβ-catenin on the cell membrane.