title: War1p, a novel transcription factor controlling weak acid stress response in yeast.
abstract: The Saccharomyces cerevisiae ATP-binding cassette (ABC) transporter Pdr12p effluxes weak acids such as sorbate and benzoate, thus mediating stress adaptation. In this study, we identify a novel transcription factor, War1p, as the regulator of this stress adaptation through transcriptional induction of PDR12. Cells lacking War1p are weak acid hypersensitive, since they fail to induce Pdr12p. The nuclear Zn2Cys6 transcriptional regulator War1p forms homodimers and is rapidly phosphorylated upon sorbate stress. The appearance of phosphorylated War1p isoforms coincides with transcriptional activation of PDR12. Promoter deletion analysis identified a novel cis-acting weak acid response element (WARE) in the PDR12 promoter required for PDR12 induction. War1p recognizes and decorates the WARE both in vitro and in vivo, as demonstrated by band shift assays and in vivo footprinting. Importantly, War1p occupies the WARE in the presence and absence of stress, demonstrating constitutive DNA binding in vivo. Our results suggest that weak acid stress triggers phosphorylation and perhaps activation of War1p. In turn, War1p activation is necessary for the induction of PDR12 through a novel signal transduction event that elicits weak organic acid stress adaptation.
authors.affiliation: Department of Molecular Genetics, Institute of Medical Biochemistry, University and BioCenter of Vienna, A-1030 Vienna, Austria.
authors.forename: Angelika
authors.initials: A
authors.lastname: Kren
authors.forename: Yasmine M
authors.initials: YM
authors.lastname: Mamnun
authors.forename: Bettina E
authors.initials: BE
authors.lastname: Bauer
authors.forename: Christoph
authors.initials: C
authors.lastname: Schüller
authors.forename: Hubert
authors.initials: H
authors.lastname: Wolfger
authors.forename: Kostas
authors.initials: K
authors.lastname: Hatzixanthis
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mollapour
authors.forename: Christa
authors.initials: C
authors.lastname: Gregori
authors.forename: Peter
authors.initials: P
authors.lastname: Piper
authors.forename: Karl
authors.initials: K
authors.lastname: Kuchler
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D017353:Gene Deletion; D005982:Glutathione Transferase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020033:Protein Isoforms; D012313:RNA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; C472673:Pdr12 protein, S cerevisiae; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C472674:War1 protein, S cerevisiae; D012313:RNA; D004247:DNA; D005982:Glutathione Transferase; D001616:beta-Galactosidase