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Oxidative stress inhibits caveolin-1 palmitoylation and trafficking in endothelial cellsDuring normal and pathological conditions, endothelial cells (ECs) are subjected to locally generated reactive oxygen species, produced by themselves or by other vessel wall cells. In excess these molecules cause oxidative injury to the cell but at moderate levels they might modulate intracellular signalling pathways. We have investigated the effect of oxidative stress on the palmitoylation and trafficking of caveolin-1 in bovine aortic ECs. Exogenous H2O2 did not alter the intracellular localization of caveolin-1 in ECs. However, metabolic labelling experiments showed that H2O2 inhibited the trafficking of newly synthesized caveolin-1 to membrane raft domains. Several mechanisms potentially responsible for this inhibition were examined. Impairment of caveolin-1 synthesis by H2O2 was not responsible for diminished trafficking. Similarly, the inhibition was independent of H2O2-induced caveolin-1 phosphorylation as shown by the markedly different concentration dependences. We tested the effect of H2O2 on palmitoylation of caveolin-1 by the incorporation of [3H]palmitic acid. Exposure of ECs to H2O2 markedly inhibited the palmitoylation of caveolin-1. Comparable inhibition was observed after treatment of cells with H2O2 delivered either as a bolus or by continuous delivery with glucose and glucose oxidase. Kinetic studies showed that H2O2 did not alter the rate of caveolin-1 depalmitoylation but instead decreased the 'on-rate' of palmitoylation. Together these results show for the first time the modulation of protein palmitoylation by oxidative stress, and suggest a cellular mechanism by which stress might influence caveolin-1-dependent cell activities such as the concentration of signalling proteins and cholesterol trafficking.
Document ID
20040088510
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Parat, Marie-Odile
(The Lerner Research Institute, Cleveland Clinic Foundation 9500 Euclid Avenue, Cleveland, OH 44195, United States)
Stachowicz, Rafal Z.
Fox, Paul L.
Date Acquired
August 21, 2013
Publication Date
February 1, 2002
Publication Information
Publication: The Biochemical journal
Volume: 361
Issue: Pt 3
ISSN: 0264-6021
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: HL
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cell Biology
Non-NASA Center

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