title: ACE as a mechanosensor to shear stress influences the control of its own regulation via phosphorylation of cytoplasmic Ser(1270).
abstract: OBJECTIVE
  We tested whether angiotensin converting enzyme (ACE) and phosphorylation of Ser(1270) are involved in shear-stress (SS)-induced downregulation of the enzyme.
  
  
  RESULTS
  Western blotting analysis showed that SS (18 h, 15 dyn/cm(2)) decreases ACE expression and phosphorylation as well as p-JNK inhibition in human primary endothelial cells (EC). CHO cells expressing wild-type ACE (wt-ACE) also displayed SS-induced decrease in ACE and p-JNK. Moreover, SS decreased ACE promoter activity in wt-ACE, but had no effect in wild type CHO or CHO expressing ACE without either the extra- or the intracellular domains, and decreased less in CHO expressing a mutated ACE at Ser(1270) compared to wt-ACE (13 vs. 40%, respectively). The JNK inhibitor (SP600125, 18 h), in absence of SS, also decreased ACE promoter activity in wt-ACE. Finally, SS-induced inhibition of ACE expression and phosphorylation in EC was counteracted by simultaneous exposure to an ACE inhibitor.
  
  
  CONCLUSIONS
  ACE displays a key role on its own downregulation in response to SS. This response requires both the extra- and the intracellular domains and ACE Ser(1270), consistent with the idea that the extracellular domain behaves as a mechanosensor while the cytoplasmic domain elicits the downstream intracellular signaling by phosphorylation on Ser(1270).
authors: Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Sao Paulo, Brazil.
authors: Valerio Garrone
authors: VG
authors: Barauna
authors: Luciene Cristina Gastalho
authors: LC
authors: Campos
authors: Ayumi Aurea
authors: AA
authors: Miyakawa
authors: Jose Eduardo
authors: JE
authors: Krieger
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D004591:Electrophoresis, Polyacrylamide Gel; D042783:Endothelial Cells / Q000201:enzymology; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000235:genetics / Q000502:physiology*; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical
chemical_list: D007703:Peptidyl-Dipeptidase A