title: Angiotensin-II and MARCKS: a hydrogen peroxide- and RAC1-dependent signaling pathway in vascular endothelium.
abstract: MARCKS is an actin-binding protein that modulates vascular endothelial cell migration and cytoskeleton signaling (Kalwa, H., and Michel, T. (2011) J. Biol. Chem. 286, 2320-2330). Angiotensin-II is a vasoactive peptide implicated in vascular physiology as well as pathophysiology; the pathways connecting angiotensin-II and cytoskeletal remodeling are incompletely understood. Here we show that MARCKS is expressed in intact arterial preparations, with prominent staining of the endothelium. In endothelial cells, angiotensin-II-promoted MARCKS phosphorylation is abrogated by PEG-catalase, implicating endogenous H(2)O(2) in the angiotensin-II response. Studies using the H(2)O(2) biosensor HyPer2 reveal that angiotensin-II promotes increases in intracellular H(2)O(2). We used a Rac1 FRET biosensor to show that angiotensin-II promotes Rac1 activation that is attenuated by PEG-catalase. siRNA-mediated Rac1 knockdown blocks angiotensin-II-stimulated MARCKS phosphorylation. Cell imaging studies using a phosphoinositide 4,5-bisphosphate (PIP(2)) biosensor revealed that angiotensin-II PIP(2) regulation depends on MARCKS and H(2)O(2). siRNA-mediated knockdown of MARCKS or Rac1 attenuates receptor-mediated activation of the tyrosine kinase c-Abl and disrupts actin fiber formation. These studies establish a critical role for H(2)O(2) in angiotensin-II signaling to the endothelial cytoskeleton in a novel pathway that is critically dependent on MARCKS, Rac1, and c-Abl.
authors: Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Hermann
authors: H
authors: Kalwa
authors: Juliano L
authors: JL
authors: Sartoretto
authors: Simone M
authors: SM
authors: Sartoretto
authors: Thomas
authors: T
authors: Michel
mesh_terms: D000804:Angiotensin II / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D002374:Catalase / Q000494:pharmacology; D002417:Cattle; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000235:genetics / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C000619710:MARCKS protein, human; C000619711:Marcks protein, mouse; D008565:Membrane Proteins; D009479:Neuropeptides; D019269:Phosphatidylinositol 4,5-Diphosphate; C107953:RAC1 protein, human; C484602:Rac1 protein, mouse; C070295:catalase-polyethylene glycol; D000804:Angiotensin II; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D011092:Polyethylene Glycols; D006861:Hydrogen Peroxide; D002374:Catalase; D016315:Proto-Oncogene Proteins c-abl; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein