Thioredoxins (Trxs) are small ubiquitous oxidoreductase proteins with two redox-active Cys residues in a conserved active site (WCG/PPC) that regulate numerous target proteins via thiol/disulfide exchanges in the cells of prokaryotes and eukaryotes. The isoforms OsTrx23 with a typical active site (WCGPC) and OsTrx20 with an atypical active site (WCTPC) are two Trx h- type isoforms in rice that w...

S-Nitrosylation is a reversible post-translational modification on cysteinyl thiols that can modulate the function of redox-sensitive proteins. The S-nitrosylation of mitochondrial proteins has been shown to regulate various mitochondrial activities involved in energy-transducing systems and mitochondrion-driven apoptosis. In isolated rat brain mitochondria, we demonstrate that mitochondrial pr...

Reactive oxygen species serve as second messengers for signal transduction; however, molecular targets of oxidant signaling have not been defined. Here, we show that ligand-receptor-mediated signaling promotes reactive oxygen species-dependent protein carbonylation. Treatment of pulmonary artery smooth muscle cells with endothelin-1 increased protein carbonyls. Carbonylation of the majority of ...

The chloroplast-localized NADPH-dependent thioredoxin reductase (NTRC) has been found to be able to reduce hydrogen peroxide scavenging 2-Cys peroxiredoxins. We show that the Arabidopsis ntrc mutant is perturbed in chlorophyll biosynthesis and accumulate intermediates preceding protochlorophyllide formation. A specific involvement of NTRC during biosynthesis of protochlorophyllide is indicated ...

In response to hydrogen peroxide (H(2)O(2)), the transcription factor Pap1 from Schizosaccharomyces pombe regulates transcription of genes required for adaptation to oxidative stress and for tolerance to toxic drugs. H(2)O(2) induces oxidation of Pap1, its nuclear accumulation and expression of more than fifty Pap1-dependent genes. Oxidation and nuclear accumulation of Pap1 can also be accompli...

A search of the disulfide reductase activities expressed in the adult stage of the free-living platyhelminth Dugesia dorotocephala was carried out. Using GSSG or DTNB as substrates, it was possible to obtain a purified fraction containing both GSSG and DTNB reductase activities. Through the purification procedure, both disulfide reductase activities were obtained in the same chromatographic pea...

Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that dismutates potentially toxic superoxide radical into hydrogen peroxide and dioxygen. This enzyme is critical for protection against cellular injury due to elevated partial pressures of oxygen. Thioredoxin (TRX) is a potent protein disulfide reductase found in most organisms that participates in many thiol-dependent cellular r...