MYPT1/PP1‐Mediated EZH2 Dephosphorylation at S21 Promotes Epithelial–Mesenchymal Transition in Fibrosis through Control of Multiple Families of Genes
Lan Zhang, Ling Wang, Xuebin Hu, Min Hou, Yuan Xiao, Jia‐Wen Xiang, Jie Xie, Zhi‐Gang Chen, Tian‐Heng Yang, Qian Nie, Jialing Fu, Yan Wang, Shuyu Zheng, Yun‐Fei Liu, Yuwen Gan, Qian Gao, Yue‐Yue Bai, Jing‐Miao Wang, Ruili Qi, Ming Zou, Qin Ke, Xing‐Fei Zhu, Lili Gong, Yizhi Liu, David Wan‐Cheng Li
Abstract
The methyltransferase EZH2 plays an important role in regulating chromatin conformation and gene transcription. Phosphorylation of EZH2 at S21 by AKT kinase suppresses its function. However, protein phosphatases responsible for the dephosphorylation of EZH2-S21 remain elusive. Here, it is demonstrated that EZH2 is highly expressed in the ocular lens, and AKT-EZH2 axis is important in TGFβ-induced epithelial-mesenchymal transition (EMT). More importantly, it is identified that MYPT1/PP1 dephosphorylates EZH2-S21 and thus modulates its functions. MYPT1 knockout accelerates EMT, but expression of the EZH2-S21A mutant suppresses EMT through control of multiple families of genes. Furthermore, the phosphorylation status and gene expression modulation of EZH2 are implicated in control of anterior subcapsular cataracts (ASC) in human and mouse eyes. Together, the results identify the specific phosphatase for EZH2-S21 and reveal EZH2 dephosphorylation control of several families of genes implicated in lens EMT and ASC pathogenesis. These results provide important novel information in EZH2 function and regulation.