Angiotensin-II and MARCKS: a hydrogen peroxide- and RAC1-dependent signaling pathway in vascular endothelium

• Published in: The Journal of biological chemistry Vol. 287; no. 34; pp. 29147 - 29158
• Main Authors: Kalwa, Hermann, Sartoretto, Juliano L, Sartoretto, Simone M, Michel, Thomas
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 17.08.2012
• Subjects: Angiotensin II - genetics; Angiotensin II - metabolism; Animals; Biosensing Techniques - methods; Catalase - pharmacology; Cattle; Cytoskeleton - genetics; Cytoskeleton - metabolism; Endothelium, Vascular - cytology; Endothelium, Vascular - metabolism; HEK293 Cells; Humans; Hydrogen Peroxide - metabolism; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mice; Mice, Knockout; Myristoylated Alanine-Rich C Kinase Substrate; Neuropeptides - genetics; Neuropeptides - metabolism; Phosphatidylinositol 4,5-Diphosphate - genetics; Phosphatidylinositol 4,5-Diphosphate - metabolism; Polyethylene Glycols - pharmacology; Proto-Oncogene Proteins c-abl - genetics; Proto-Oncogene Proteins c-abl - metabolism; rac GTP-Binding Proteins - genetics; rac GTP-Binding Proteins - metabolism; rac1 GTP-Binding Protein - genetics; rac1 GTP-Binding Protein - metabolism; Signal Transduction; Signal Transduction - drug effects; Signal Transduction - physiology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.381517

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.