Abstract
Angiotensin II (AII) increases production of reactive oxygen species from NAD(P)H oxidase, a response that contributes to vascular hypertrophy. Here we show in cultured vascular smooth muscle cells that S-glutathiolation of the redox-sensitive Cys(118) on the small GTPase, Ras, plays a critical role in AII-induced hypertrophic signaling. AII simultaneously increased the Ras activity and the S-glutathiolation of Ras (GSS-Ras) detected by biotin-labeled GSH or mass spectrometry. Both the increase in activity and GSS-Ras was labile under reducing conditions, suggesting the essential nature of this thiol modification to Ras activation. Overexpression of catalase, a dominant-negative p47(phox), or glutaredoxin-1 decreased GSS-Ras, Ras activation, p38, and Akt phosphorylation and the induction of protein synthesis by AII. Furthermore, expression of a Cys(118) mutant Ras decreased AII-mediated p38 and Akt phosphorylation as well as protein synthesis. These results show that H(2)O(2) from NAD(P)H oxidase forms GSS-Ras on Cys(118) and increases its activity leading to p38 and Akt phosphorylation, which contributes to the induction of protein synthesis. This study suggests that GSS-Ras is a redox-sensitive signaling switch that participates in the cellular response to AII.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Angiotensin II / metabolism*
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Animals
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Cells, Cultured
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Enzyme Activation
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ErbB Receptors / metabolism
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Glutaredoxins
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Glutathione / chemistry
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Glutathione / metabolism*
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Humans
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Hydrogen Peroxide / metabolism
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Mitogen-Activated Protein Kinases / metabolism
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Muscle, Smooth, Vascular / cytology*
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Myocytes, Smooth Muscle / cytology
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Myocytes, Smooth Muscle / metabolism*
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NADH, NADPH Oxidoreductases / metabolism
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NADPH Oxidases
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Oxidants / metabolism
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Oxidation-Reduction
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Oxidoreductases / genetics
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Oxidoreductases / metabolism
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Protein Serine-Threonine Kinases / metabolism
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins c-akt
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Rats
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Reactive Oxygen Species / metabolism
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Signal Transduction / physiology*
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Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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p38 Mitogen-Activated Protein Kinases
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ras Proteins / chemistry
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ras Proteins / genetics
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ras Proteins / metabolism*
Substances
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Glrx protein, rat
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Glrx2 protein, rat
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Glutaredoxins
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Oxidants
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Proto-Oncogene Proteins
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Reactive Oxygen Species
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Angiotensin II
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Hydrogen Peroxide
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Oxidoreductases
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NADH, NADPH Oxidoreductases
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NADPH Oxidases
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ErbB Receptors
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AKT1 protein, human
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Akt1 protein, rat
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Protein Serine-Threonine Kinases
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Proto-Oncogene Proteins c-akt
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Mitogen-Activated Protein Kinases
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p38 Mitogen-Activated Protein Kinases
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ras Proteins
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Glutathione