Tags

Type your tag names separated by a space and hit enter

Yeast oxidative stress response. Influences of cytosolic thioredoxin peroxidase I and of the mitochondrial functional state.
FEBS J. 2006 Feb; 273(4):805-16.FJ

Abstract

We investigated the changes in the oxidative stress response of yeast cells suffering mitochondrial dysfunction that could impair their viability. First, we demonstrated that cells with this dysfunction rely exclusively on cytosolic thioredoxin peroxidase I (cTPxI) and its reductant sulfiredoxin, among other antioxidant enzymes tested, to protect them against H2O2-induced death. This cTPxI-dependent protection could be related to its dual functions, as peroxidase and as molecular chaperone, suggested by mixtures of low and high molecular weight oligomeric structures of cTPxI observed in cells challenged with H2O2. We found that cTPxI deficiency leads to increased basal sulfhydryl levels and transcriptional activation of most of the H2O2-responsive genes, interpreted as an attempt by the cells to improve their antioxidant defense. On the other hand, mitochondrial dysfunction, specifically the electron transport blockage, provoked a huge depletion of sulfhydryl groups after H2O2 treatment and reduced the H2O2-mediated activation of some genes otherwise observed, impairing cell defense and viability. The transcription factors Yap1 and Skn7 are crucial for the antioxidant response of cells under inhibited electron flow condition and probably act in the same pathway of cTPxI to protect cells affected by this disorder. Yap1 cellular distribution was not affected by cTpxI deficiency and by mitochondrial dysfunction, in spite of the observed expression alterations of several Yap1-target genes, indicating alternative mechanisms of Yap1 activation/deactivation. Therefore, we propose that cTPxI is specifically important in the protection of yeast with mitochondrial dysfunction due to its functional versatility as an antioxidant, chaperone and modulator of gene expression.

Authors+Show Affiliations

Demasi AP
Departamento de Genética e Evolução - IB - UNICAMP, Campinas, Brazil.
Pereira GA
No affiliation info available
Netto LE
No affiliation info available

MeSH

CytoplasmGene DeletionGene Expression Regulation, FungalMitochondriaOxidantsOxidation-ReductionOxidative StressPeroxidasesPeroxiredoxinsReactive Oxygen SpeciesRecombinant Fusion ProteinsSaccharomyces cerevisiaeSaccharomyces cerevisiae ProteinsTranscription Factors

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16441666

Citation

Demasi, Ana P D., et al. "Yeast Oxidative Stress Response. Influences of Cytosolic Thioredoxin Peroxidase I and of the Mitochondrial Functional State." The FEBS Journal, vol. 273, no. 4, 2006, pp. 805-16.
Demasi AP, Pereira GA, Netto LE. Yeast oxidative stress response. Influences of cytosolic thioredoxin peroxidase I and of the mitochondrial functional state. FEBS J. 2006;273(4):805-16.
Demasi, A. P., Pereira, G. A., & Netto, L. E. (2006). Yeast oxidative stress response. Influences of cytosolic thioredoxin peroxidase I and of the mitochondrial functional state. The FEBS Journal, 273(4), 805-16.
Demasi AP, Pereira GA, Netto LE. Yeast Oxidative Stress Response. Influences of Cytosolic Thioredoxin Peroxidase I and of the Mitochondrial Functional State. FEBS J. 2006;273(4):805-16. PubMed PMID: 16441666.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Yeast oxidative stress response. Influences of cytosolic thioredoxin peroxidase I and of the mitochondrial functional state. AU - Demasi,Ana P D, AU - Pereira,Gonçalo A G, AU - Netto,Luis E S, PY - 2006/1/31/pubmed PY - 2006/4/11/medline PY - 2006/1/31/entrez SP - 805 EP - 16 JF - The FEBS journal JO - FEBS J VL - 273 IS - 4 N2 - We investigated the changes in the oxidative stress response of yeast cells suffering mitochondrial dysfunction that could impair their viability. First, we demonstrated that cells with this dysfunction rely exclusively on cytosolic thioredoxin peroxidase I (cTPxI) and its reductant sulfiredoxin, among other antioxidant enzymes tested, to protect them against H2O2-induced death. This cTPxI-dependent protection could be related to its dual functions, as peroxidase and as molecular chaperone, suggested by mixtures of low and high molecular weight oligomeric structures of cTPxI observed in cells challenged with H2O2. We found that cTPxI deficiency leads to increased basal sulfhydryl levels and transcriptional activation of most of the H2O2-responsive genes, interpreted as an attempt by the cells to improve their antioxidant defense. On the other hand, mitochondrial dysfunction, specifically the electron transport blockage, provoked a huge depletion of sulfhydryl groups after H2O2 treatment and reduced the H2O2-mediated activation of some genes otherwise observed, impairing cell defense and viability. The transcription factors Yap1 and Skn7 are crucial for the antioxidant response of cells under inhibited electron flow condition and probably act in the same pathway of cTPxI to protect cells affected by this disorder. Yap1 cellular distribution was not affected by cTpxI deficiency and by mitochondrial dysfunction, in spite of the observed expression alterations of several Yap1-target genes, indicating alternative mechanisms of Yap1 activation/deactivation. Therefore, we propose that cTPxI is specifically important in the protection of yeast with mitochondrial dysfunction due to its functional versatility as an antioxidant, chaperone and modulator of gene expression. SN - 1742-464X UR - https://www.unboundmedicine.com/medline/citation/16441666/Yeast_oxidative_stress_response__Influences_of_cytosolic_thioredoxin_peroxidase_I_and_of_the_mitochondrial_functional_state_ DB - PRIME DP - Unbound Medicine ER -