HSP70 decreases receptor-dependent phosphorylation of Smad2 and blocks TGF-β-induced epithelial-mesenchymal transition  

作　　者：Yihao Li Xianjiang Kang Qiang Wang 

机构地区：[1]College of Life Sciences, Hebei University, Baoding 071002, China [2]State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China

出　　处：《Journal of Genetics and Genomics》2011年第3期111-116,共6页遗传学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(No.90919058);the National Basic Research Program of China(Nos. 2011 CB943904 and 2011 CB943800)

摘　　要：Smad2 and Smad3, the intracellular mediators of transforming growth factor β （TGF-β） signaling, are directly phosphorylated by the activated type I receptor kinase, and then shuttle from the cytoplasm into the nucleus to regulate target gene expression. Here, we report that the 70-kDa heat-shock protein （HSP70） interacts with Smad2 and decreases TGF-β signal transduction. Ectopic expression of HSPT0 prevents receptor-dependent phosphorylation and nuclear translocation of Smad2, and blocks TGF-β-induced epithelial-mesenchymal transition （EMT） in HaCat cells. Our findings reveal an essential role of HSP70 in TGF-β-induced epithelial-mesenchymal transition （EMT） by impeding Smad2 phosphorylation.Smad2 and Smad3, the intracellular mediators of transforming growth factor β （TGF-β） signaling, are directly phosphorylated by the activated type I receptor kinase, and then shuttle from the cytoplasm into the nucleus to regulate target gene expression. Here, we report that the 70-kDa heat-shock protein （HSP70） interacts with Smad2 and decreases TGF-β signal transduction. Ectopic expression of HSPT0 prevents receptor-dependent phosphorylation and nuclear translocation of Smad2, and blocks TGF-β-induced epithelial-mesenchymal transition （EMT） in HaCat cells. Our findings reveal an essential role of HSP70 in TGF-β-induced epithelial-mesenchymal transition （EMT） by impeding Smad2 phosphorylation.

关 键 词：TGF-Β HSP70 SMAD2 EMT 

分 类 号：Q516[生物学—生物化学] Q959.837