Oxidation of a eukaryotic 2-Cys peroxiredoxin is a molecular switch controlling the transcriptional response to increasing levels of hydrogen peroxide.
Although activation of the AP-1-like transcription factor Pap1 in Schizosaccharomyces pombe is important for oxidative stress-induced gene expression, this activation is delayed at higher concentrations of peroxide. Here, we reveal that the 2-Cys peroxiredoxin (2-Cys Prx) Tpx1 is required for the peroxide-induced activation of Pap1. Tpx1, like other eukaryotic 2-Cys Prxs, is highly sensitive to oxidation, which inactivates its thioredoxin peroxidase activity. Our data suggest that the reduced thioredoxin peroxidase-active form of Tpx1 is required for the peroxide-induced oxidation and nuclear accumulation of Pap1. Indeed, in contrast to the previously described role for Tpx1 in the activation of the Sty1 stress-activated protein kinase by peroxide, we find that both catalytic cysteines of Tpx1 are required for Pap1 activation. Moreover, overexpression of the conserved sulfiredoxin Srx1, which interacts with and reduces Tpx1, allows rapid activation of Pap1 at higher concentrations of H(2)O(2). Conversely, loss of Srx1 prevents the reduction of oxidized Tpx1 and prolongs the inhibition of Pap1 activation. Collectively, these data suggest that redox regulation of the thioredoxin peroxidase activity of Tpx1 acts as a molecular switch controlling the transcriptional response to H(2)O(2). Furthermore, they reveal that a single eukaryotic 2-Cys Prx regulates peroxide signaling by multiple independent mechanisms.
Bozonet
Stephanie M
SM
Institute of Cell and Molecular Biosciences, Faculty of Medical Sciences, University of Newcastle upon Tyne, UK.
Findlay
Victoria J
VJ
Day
Alison M
AM
Cameron
Jannine
J
Veal
Elizabeth A
EA
Morgan
Brian A
BA
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D015153:Blotting, Western; D002384:Catalysis; D002467:Cell Nucleus / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D019084:Fluorescent Antibody Technique, Indirect; D005656:Fungal Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047468:Immunoprecipitation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D050862:Oxidoreductases Acting on Sulfur Group Donors; D010100:Oxygen / Q000378:metabolism*; D000073718:Pancreatitis-Associated Proteins; D010544:Peroxidases / Q000737:chemistry / Q000502:physiology*; D010545:Peroxides / Q000378:metabolism*; D054464:Peroxiredoxins; D012367:RNA, Viral / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D000073718:Pancreatitis-Associated Proteins; C105096:Pap1 protein, S pombe; D010545:Peroxides; C000612141:REG3A protein, human; D012367:RNA, Viral; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C515985:Tpx1 protein, S pombe; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D010544:Peroxidases; D054464:Peroxiredoxins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C479426:SRX1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; C095409:sty1 protein, S pombe; D003545:Cysteine; D010100:Oxygen