title: Diethylmaleate activates the transcription factor Pap1 by covalent modification of critical cysteine residues.
abstract: During the last decade, much has been learnt about the mechanisms by which oxidative stress is perceived by aerobic organisms. The Schizosaccharomyces pombe Pap1 protein is a transcription factor localized at the cytoplasm, which accumulates in the nucleus in response to different inducers, such as the pro-oxidant hydrogen peroxide (H2O2) or the glutathione-depleting agent diethylmaleate (DEM). As described for other H2O2 sensors, our genetic data indicates that H2O2 reversibly oxidizes two cysteine residues in Pap1 (Cys278 and Cys501). Surprisingly, our studies demonstrate that DEM generates a non-reversible modification of at least two cysteine residues located in or close to the nuclear export signal of Pap1 (Cys523 and Cys532). This modification impedes the interaction of the nuclear exporter Crm1 with the nuclear export signal located at the carboxy-terminal domain of Pap1. Mass spectrometry data suggest that DEM binds to the thiol groups of the target cysteine residues through the formation of a thioether. Here we show that DEM triggers Pap1 nuclear accumulation by a novel molecular mechanism.
authors.affiliation: Cell Signalling Unit, Department de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Esther A
authors.initials: EA
authors.lastname: Castillo
authors.forename: José
authors.initials: J
authors.lastname: Ayté
authors.forename: Cristina
authors.initials: C
authors.lastname: Chiva
authors.forename: Alberto
authors.initials: A
authors.lastname: Moldón
authors.forename: Montse
authors.initials: M
authors.lastname: Carrascal
authors.forename: Joaquín
authors.initials: J
authors.lastname: Abián
authors.forename: Nic
authors.initials: N
authors.lastname: Jones
authors.forename: Elena
authors.initials: E
authors.lastname: Hidalgo
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors; D002467:Cell Nucleus / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D008298:Maleates / Q000378:metabolism / Q000494:pharmacology*; D018384:Oxidative Stress; D000073718:Pancreatitis-Associated Proteins; D012568:Schizosaccharomyces / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008298:Maleates; D000073718:Pancreatitis-Associated Proteins; C105096:Pap1 protein, S pombe; C000612141:REG3A protein, human; D029702:Schizosaccharomyces pombe Proteins; D006861:Hydrogen Peroxide; C014476:diethyl maleate; D003545:Cysteine