Proteomics Analysis of Cellular Response to Oxidative Stress

Abstract

The proteomics analysis reported here shows that a major cellular response to oxidative stress is the modification of several peroxiredoxins. An acidic form of the peroxiredoxins appeared to be systematically increased under oxidative stress conditions. Peroxiredoxins are enzymes catalyzing the destruction of peroxides. In doing so, a reactive cysteine in the peroxiredoxin active site is weakly oxidized (disulfide or sulfenic acid) by the destroyed peroxides. Cellular thiols (e.g. thioredoxin) are used to regenerate the peroxiredoxins to their active state. Tandem mass spectrometry was carried out to characterize the modified form of the protein produced in vivo by oxidative stress. The cysteine present in the active site was shown to be oxidized into cysteic acid, leading to an inactivated form of peroxiredoxin. This strongly suggested that peroxiredoxins behave as a dam upon oxidative stress, being both important peroxidedestroying enzymes and peroxide targets. Results obtained in a primary culture of Leydig cells challenged with tumor necrosis factor ␣ suggested that this oxidized/native balance of peroxiredoxin 2 may play an active role in resistance or susceptibility to tumor necrosis factor ␣-induced apoptosis.

Analysis of the Cytosolic Proteome in a Cell Culture Model of Familial Amyotrophic Lateral Sclerosis Reveals Alterations to the Proteasome, Antioxidant Defenses, and Nitric Oxide Synthetic Pathways

“…Prx I, II, and III (62,63) have all been shown to undergo acidic shifts when cultured cells are subjected to hydroperoxide-mediated oxidative stress. A recent study (64) has demonstrated that the acidic shift of Prx II produced under conditions of oxidative stress was due to conversion of an essential active site cysteine to cysteic acid. The possibility that Prx I undergoes over-oxidation of its cysteine residues due to mutant SOD1 expression FIG.…”

Reaction Mechanism of Plant 2-Cys Peroxiredoxin

“…Only the reduced form is prone to overoxidation, whereas the oxidized form is stable. As a consequence, the sulfinic acid form accumulates as a function of turnover number in in vitro assays as well as in cell cultures that could be detected for nonplant 2-Cys Prx by matrix-assisted laser desorption-ionization measurements (40,47). Accumulation during stress treatments (Fig.…”

A cysteine-sulfinic acid in peroxiredoxin regulates H 2 O 2 -sensing by the antioxidant Pap1 pathway

“…In eukaryotes, 2-Cys Prxs can be temporarily inactivated during catalysis by further reaction of the Cys-SOH with hydroperoxide and formation of a cysteine-sulfinic acid (Cys-SO 2 H) (26,27), and the extent of this inactivation is in proportion with the amount of H 2 O 2 present (28, 29). Cys-SO 2 H in Prx is eventually reduced by the sulfiredoxin Srx1 in S. cerevisiae (22) and mammals (30) and also by mammalian sestrin Hi-95 (31).…”