title: Saccharomyces cerevisiae adaptation to weak acids involves the transcription factor Haa1p and Haa1p-regulated genes.
abstract: The understanding of the molecular mechanisms that may contribute to counteract the deleterious effects of organic acids as fungistatic agents is essential to guide suitable preservation strategies. In this work, we show that the recently identified transcription factor Haa1p is required for a more rapid adaptation of a yeast cell population to several weak acid food preservatives. Maximal protection is exerted against the short-chain length acetic or propionic acids. The transcription of nine Haa1p-target genes, many of which are predicted to encode membrane proteins of unknown or poorly characterized function, is activated under weak acid stress. The Haa1-regulated genes required for a more rapid yeast adaptation to weak acids include TPO2 and TPO3, encoding two predicted plasma membrane multidrug transporters of the major facilitator superfamily, and YGP1, encoding a poorly characterized cell wall glycoprotein. The acetic acid-induced prolongation of the lag phase of unadapted cell populations lacking HAA1 or TPO3, compared with wild-type population, was correlated with the level of the acid accumulated into the stressed cells.
authors.affiliation: Biological Sciences Research Group, Centro de Engenharia Biológica e Química, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
authors.forename: A R
authors.initials: AR
authors.lastname: Fernandes
authors.forename: N P
authors.initials: NP
authors.lastname: Mira
authors.forename: R C
authors.initials: RC
authors.lastname: Vargas
authors.forename: I
authors.initials: I
authors.lastname: Canelhas
authors.forename: I
authors.initials: I
authors.lastname: Sá-Correia
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000222:Adaptation, Physiological; D000935:Antifungal Agents / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000494:pharmacology; D005520:Food Preservatives / Q000494:pharmacology*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D026901:Membrane Transport Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors; D015533:Transcriptional Activation
chemical_list: D000935:Antifungal Agents; D002264:Carboxylic Acids; D005520:Food Preservatives; C439059:Haa1 protein, S cerevisiae; D026901:Membrane Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; C505246:TPO3 protein, S cerevisiae; D015534:Trans-Activators; D014157:Transcription Factors; D019342:Acetic Acid