title: Activator and repressor functions of the Mot3 transcription factor in the osmostress response of Saccharomyces cerevisiae.
abstract: Mot3 and Rox1 are transcriptional repressors of hypoxic genes. Both factors recently have been found to be involved in the adaptive response to hyperosmotic stress, with an important function in the adjustment of ergosterol biosynthesis. Here, we determine the gene expression profile of a mot3 rox1 double mutant under acute osmostress at the genomic scale in order to identify the target genes affected by both transcription factors upon stress. Unexpectedly, we find a specific subgroup of osmostress-inducible genes to be under positive control of Mot3. These Mot3-activated stress genes also depend on the general stress activators Msn2 and Msn4. We confirm that both Mot3 and Msn4 bind directly to some promoter regions of this gene group. Furthermore, osmostress-induced binding of the Msn2 and Msn4 factors to these target promoters is severely affected by the loss of Mot3 function. The genes repressed by Mot3 and Rox1 preferentially encode proteins of the cell wall and plasma membrane. Cell conjugation was the most significantly enriched biological process which was negatively regulated by both factors and by osmotic stress. The mating response was repressed by salt stress dependent on Mot3 and Rox1 function. Taking our findings together, the Mot3 transcriptional regulator has unanticipated diverse functions in the cellular adjustment to osmotic stress, including transcriptional activation and modulation of mating efficiency.
authors: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia, CSIC, Valencia, Spain.
authors: Fernando
authors: F
authors: Martínez-Montañés
authors: Alessandro
authors: A
authors: Rienzo
authors: Daniel
authors: D
authors: Poveda-Huertes
authors: Amparo
authors: A
authors: Pascual-Ahuir
authors: Markus
authors: M
authors: Proft
mesh_terms: D004268:DNA-Binding Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D009997:Osmotic Pressure; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*; D055049:Salt Tolerance; D013312:Stress, Physiological; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D015533:Transcriptional Activation; D059467:Transcriptome
chemical_list: D004268:DNA-Binding Proteins; C112006:MOT3 protein, S cerevisiae; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; C083348:ROX1 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors