title: Caveolin-1 is transiently dephosphorylated by shear stress-activated protein tyrosine phosphatase mu.
abstract: Endothelial cells are subjected to hemodynamic shear stress, which regulates multiple vascular functions partially by the caveolin-1-dependent mechanisms. Caveolin-1 is a principal protein in the plasma membrane microdomains called caveolae and interacts with various signaling molecules. Recently, caveolin-1 was elucidated to be phosphorylated on tyrosine 14. However, it is not known how phosphorylation of caveolin-1 is controlled in endothelium. In this study, we found that caveolin-1 is phosphorylated by p38 mitogen-activated protein kinase (MAPK) under a static condition. When endothelial cells were exposed to shear stress, caveolin-1 was transiently dephosphorylated. Since the activity of p38 MAPK was not affected by shear stress, the shear-dependent dephosphorylation of caveolin-1 was not mediated by p38 MAPK. Of interest, sodium orthovanadate, an inhibitor for phosphatases, blocked the shear-dependent dephosphorylation of caveolin-1. We also observed that protein tyrosine phosphatase mu was transiently activated by shear stress, suggesting its role in the dephosphorylation of caveolin-1.
authors.affiliation: Department of Molecular Biology and Institute of Nanosensor and Biotechnology, Dankook University, San 8, Hannam-dong, Yongsan-ku, Seoul 140-714, Republic of Korea.
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Shin
authors.forename: Hanjoong
authors.initials: H
authors.lastname: Jo
authors.forename: Heonyong
authors.initials: H
authors.lastname: Park
mesh_terms: D000818:Animals; D002417:Cattle; D051242:Caveolin 1 / Q000378:metabolism*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D007700:Kinetics; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D033081:Shear Strength; D013314:Stress, Mechanical; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D051242:Caveolin 1; D048051:p38 Mitogen-Activated Protein Kinases; D017027:Protein Tyrosine Phosphatases; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2