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The transcription factors Pap1 and Prr1 collaborate to activate antioxidant, but not drug tolerance, genes in response to H2O2.

Calvo IA, García P, Ayté J, Hidalgo E - Nucleic Acids Res. (2012)

Bottom Line: Oxidation and nuclear accumulation of Pap1 can also be accomplished by genetic inhibition of thioredoxin reductase.Furthermore, genetic alteration of the nuclear export pathway, or mutations in Pap1 nuclear export signal trigger nuclear accumulation of reduced Pap1.We show here that a subset of Pap1-dependent genes, such as those coding for the efflux pump Caf5, the ubiquitin-like protein Obr1 or the dehydrogenase SPCC663.08c, only require nuclear Pap1 for activation, whereas another subset of genes, those coding for the antioxidants catalase, sulfiredoxin or thioredoxin reductase, do need oxidized Pap1 to form a heterodimer with the constitutively nuclear transcription factor Prr1.

View Article: PubMed Central - PubMed

Affiliation: Oxidative Stress and Cell Cycle Group, Department de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 88, E-08003 Barcelona, Spain.

ABSTRACT
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 accomplished by genetic inhibition of thioredoxin reductase. Furthermore, genetic alteration of the nuclear export pathway, or mutations in Pap1 nuclear export signal trigger nuclear accumulation of reduced Pap1. We show here that a subset of Pap1-dependent genes, such as those coding for the efflux pump Caf5, the ubiquitin-like protein Obr1 or the dehydrogenase SPCC663.08c, only require nuclear Pap1 for activation, whereas another subset of genes, those coding for the antioxidants catalase, sulfiredoxin or thioredoxin reductase, do need oxidized Pap1 to form a heterodimer with the constitutively nuclear transcription factor Prr1. The ability of Pap1 to bind and activate drug tolerance promoters is independent on Prr1, whereas its affinity for the antioxidant promoters is significantly enhanced upon association with Prr1. This finding suggests that the activation of both antioxidant and drug resistance genes in response to oxidative stress share a common inducer, H(2)O(2), but alternative effectors.

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Prr1 is recruited to all Pap1-dependent promoters in an oxidized Pap1-dependent manner. (A) Strains MC40 (prr1-HA) and IC64 (Δpap1 prr1-HA) were treated or not with 0.2 mM H2O2 for 5 min. ChIP of Prr1 using anti-HA antibody was performed as described in Figure 2B. (B) Same as in Figure 4A, with strains MC40 (prr1-HA), PG7 (Δtrr1 prr1-HA) and PG3 (pap1.C523D prr1-HA).
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gks141-F4: Prr1 is recruited to all Pap1-dependent promoters in an oxidized Pap1-dependent manner. (A) Strains MC40 (prr1-HA) and IC64 (Δpap1 prr1-HA) were treated or not with 0.2 mM H2O2 for 5 min. ChIP of Prr1 using anti-HA antibody was performed as described in Figure 2B. (B) Same as in Figure 4A, with strains MC40 (prr1-HA), PG7 (Δtrr1 prr1-HA) and PG3 (pap1.C523D prr1-HA).

Mentions: We then analysed the capacity of Prr1 to bind to both sets of promoters by ChIP. As observed in Figure 4A, Prr1 is recruited to all six promoters after mild oxidative stress in a Pap1-dependent manner. Importantly enough, Pap1 is only able to drag Prr1 to DNA in its oxidized form: cells lacking Trr1 constitutively display Prr1 bound to all promoters, whereas in cells expressing Pap1.C523D, which is nuclear and cannot become oxidized, Prr1 is not detected at DNA either before or after stress imposition (Figure 4B).Figure 4.


The transcription factors Pap1 and Prr1 collaborate to activate antioxidant, but not drug tolerance, genes in response to H2O2.

Calvo IA, García P, Ayté J, Hidalgo E - Nucleic Acids Res. (2012)

Prr1 is recruited to all Pap1-dependent promoters in an oxidized Pap1-dependent manner. (A) Strains MC40 (prr1-HA) and IC64 (Δpap1 prr1-HA) were treated or not with 0.2 mM H2O2 for 5 min. ChIP of Prr1 using anti-HA antibody was performed as described in Figure 2B. (B) Same as in Figure 4A, with strains MC40 (prr1-HA), PG7 (Δtrr1 prr1-HA) and PG3 (pap1.C523D prr1-HA).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3367182&req=5

gks141-F4: Prr1 is recruited to all Pap1-dependent promoters in an oxidized Pap1-dependent manner. (A) Strains MC40 (prr1-HA) and IC64 (Δpap1 prr1-HA) were treated or not with 0.2 mM H2O2 for 5 min. ChIP of Prr1 using anti-HA antibody was performed as described in Figure 2B. (B) Same as in Figure 4A, with strains MC40 (prr1-HA), PG7 (Δtrr1 prr1-HA) and PG3 (pap1.C523D prr1-HA).
Mentions: We then analysed the capacity of Prr1 to bind to both sets of promoters by ChIP. As observed in Figure 4A, Prr1 is recruited to all six promoters after mild oxidative stress in a Pap1-dependent manner. Importantly enough, Pap1 is only able to drag Prr1 to DNA in its oxidized form: cells lacking Trr1 constitutively display Prr1 bound to all promoters, whereas in cells expressing Pap1.C523D, which is nuclear and cannot become oxidized, Prr1 is not detected at DNA either before or after stress imposition (Figure 4B).Figure 4.

Bottom Line: Oxidation and nuclear accumulation of Pap1 can also be accomplished by genetic inhibition of thioredoxin reductase.Furthermore, genetic alteration of the nuclear export pathway, or mutations in Pap1 nuclear export signal trigger nuclear accumulation of reduced Pap1.We show here that a subset of Pap1-dependent genes, such as those coding for the efflux pump Caf5, the ubiquitin-like protein Obr1 or the dehydrogenase SPCC663.08c, only require nuclear Pap1 for activation, whereas another subset of genes, those coding for the antioxidants catalase, sulfiredoxin or thioredoxin reductase, do need oxidized Pap1 to form a heterodimer with the constitutively nuclear transcription factor Prr1.

View Article: PubMed Central - PubMed

Affiliation: Oxidative Stress and Cell Cycle Group, Department de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 88, E-08003 Barcelona, Spain.

ABSTRACT
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 accomplished by genetic inhibition of thioredoxin reductase. Furthermore, genetic alteration of the nuclear export pathway, or mutations in Pap1 nuclear export signal trigger nuclear accumulation of reduced Pap1. We show here that a subset of Pap1-dependent genes, such as those coding for the efflux pump Caf5, the ubiquitin-like protein Obr1 or the dehydrogenase SPCC663.08c, only require nuclear Pap1 for activation, whereas another subset of genes, those coding for the antioxidants catalase, sulfiredoxin or thioredoxin reductase, do need oxidized Pap1 to form a heterodimer with the constitutively nuclear transcription factor Prr1. The ability of Pap1 to bind and activate drug tolerance promoters is independent on Prr1, whereas its affinity for the antioxidant promoters is significantly enhanced upon association with Prr1. This finding suggests that the activation of both antioxidant and drug resistance genes in response to oxidative stress share a common inducer, H(2)O(2), but alternative effectors.

Show MeSH
Related in: MedlinePlus