title: Saccharomyces cerevisiae resistance to chlorinated phenoxyacetic acid herbicides involves Pdr1p-mediated transcriptional activation of TPO1 and PDR5 genes.
abstract: The transcription regulator Pdr1p is a determinant of Saccharomyces cerevisiae resistance to 2-methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetic acid (2,4-D). The Pdr1p-regulated genes, TPO1 and PDR5, encoding putative multidrug transporters belonging to the major facilitator superfamily (MFS) and to the ATP-binding cassette (ABC) superfamily, respectively, are required for yeast resistance to sudden exposure to these herbicides. A rapid and transient activation of TPO1 (sixfold) and PDR5 (twofold) transcription takes place during the adaptation period preceding cell division under MCPA or 2,4-D moderate stress. These activations are mediated by both Pdr1p and Pdr3p and, as soon as adapted cells start duplication under herbicide stress, mRNA levels are drastically reduced to basal values. The longer duration of the adaptation period, observed for the Delta(pdr1) population, may involve the abolishment of the Pdr1p-mediated transcriptional activation of TPO1 and PDR5 genes, whose expression is critical to surpass the viability loss during the initial period of adaptation to the herbicides.
authors.affiliation: Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Avenida Rovisco Pais, Lisbon, Portugal.
authors.forename: Miguel Cacho
authors.initials: MC
authors.lastname: Teixeira
authors.forename: Isabel
authors.initials: I
authors.lastname: Sá-Correia
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology*; D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000494:pharmacology*; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000235:genetics; D000222:Adaptation, Physiological; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D025141:Drug Resistance, Fungal; D015966:Gene Expression Regulation, Fungal; D006540:Herbicides / Q000494:pharmacology*; D007700:Kinetics; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D008826:Microbial Sensitivity Tests; D009154:Mutation; D012331:RNA, Fungal / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D018528:ATP-Binding Cassette Transporters; D004268:DNA-Binding Proteins; D006540:Herbicides; D008565:Membrane Proteins; C085480:PDR1 protein, S cerevisiae; C089261:PDR3 protein, S cerevisiae; C092438:PDR5 protein, S cerevisiae; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D015084:2,4-Dichlorophenoxyacetic Acid; D008456:2-Methyl-4-chlorophenoxyacetic Acid