H2O2 activates the nuclear localization of Msn2 and Maf1 through thioredoxins in Saccharomyces cerevisiae.
The cellular response to hydrogen peroxide (H(2)O(2)) is characterized by a repression of growth-related processes and an enhanced expression of genes important for cell defense. In budding yeast, this response requires the activation of a set of transcriptional effectors. Some of them, such as the transcriptional activator Yap1, are specific to oxidative stress, and others, such as the transcriptional activators Msn2/4 and the negative regulator Maf1, are activated by a wide spectrum of stress conditions. How these general effectors are activated in response to oxidative stress remains an open question. In this study, we demonstrate that the two cytoplasmic thioredoxins, Trx1 and Trx2, are essential to trigger the nuclear accumulation of Msn2/4 and Maf1, specifically under H(2)O(2) treatment. Contrary to the case with many stress conditions previously described for yeast, the H(2)O(2)-induced nuclear accumulation of Msn2 and Maf1 does not correlate with the downregulation of PKA kinase activity. Nevertheless, we show that PP2A phosphatase activity is essential for driving Maf1 dephosphorylation and its subsequent nuclear accumulation in response to H(2)O(2) treatment. Interestingly, under this condition, the lack of PP2A activity has no impact on the subcellular localization of Msn2, demonstrating that the H(2)O(2) signaling pathways share a common route through the thioredoxin system and then diverge to activate Msn2 and Maf1, the final integrators of these pathways.
Boisnard
Stéphanie
S
CEA, IBITECS, SBIGEM, LBI, Gif-sur-Yvette Cedex, France.
Lagniel
Gilles
G
Garmendia-Torres
Cecilia
C
Molin
Mikael
M
Boy-Marcotte
Emmanuelle
E
Jacquet
Michel
M
Toledano
Michel B
MB
Labarre
Jean
J
Chédin
Stéphane
S
D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; C104954:MAF1 protein, S cerevisiae; C081935:MSN2 protein, S cerevisiae; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; C103243:TRX1 protein, S cerevisiae; C516110:TRX2 protein, S cerevisiae; D014157:Transcription Factors; D013879:Thioredoxins; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins