title: A sulphite-inducible form of the sulphite efflux gene SSU1 in a Saccharomyces cerevisiae wine yeast.
abstract: Sulphite is widely used as a preservative in foods and beverages for its antimicrobial and antioxidant activities, particularly in winemaking where SO(2) is frequently added. Thus, sulphite resistance mechanisms have been extensively studied in the fermenting yeast Saccharomyces cerevisiae. Sulphite detoxification, involving a plasma membrane protein encoded by the SSU1 gene, is the most efficient resistance mechanism in S. cerevisiae. In this study, we characterized the unusual expression pattern of SSU1 in the wine strain 71B. We provide, for the first time, evidence of SSU1 induction by sulphite. The study of SSU1 expression during fermentation and in different growth conditions showed that sulphite is the main regulator of SSU1 expression, explaining its specific pattern. Combining analyses of gene expression and growth behaviour in response to sulphite, we found that 71B displayed unique behavioural patterns in response to sulphite pre-adaptation that may be explained by changes in SSU1 expression. Examination of the genomic organization of the SSU1 locus and sequencing of the region revealed three different alleles in 71B, two of which corresponded to translocated VIII-XVI forms. The lack of differences between promoter regions suggests that this inducible SSU1 expression pattern is due to modification of regulatory/signalling pathways.
authors.affiliation: Dipartimento Biotecnologie Agrarie, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Nardi
authors.affiliation: Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia, Università degli Studi di Padova, Viale XXVIII Aprile 14, I-31015 Conegliano, Italy.|Dipartimento Biotecnologie Agrarie, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Corich
authors.affiliation: Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia, Università degli Studi di Padova, Viale XXVIII Aprile 14, I-31015 Conegliano, Italy.|Dipartimento Biotecnologie Agrarie, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Giacomini
authors.affiliation: INRA, Montpellier SupAgro, UMR 1083 Sciences pour l'Oenologie, 2 Place Viala, F-34060 Montpellier, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Blondin
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics*; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013447:Sulfites / Q000378:metabolism*; D014920:Wine / Q000382:microbiology
chemical_list: D027321:Anion Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; C108311:Ssu1 protein, S cerevisiae; D013447:Sulfites