title: Common features and differences in the expression of the three genes forming the UGA regulon in Saccharomyces cerevisiae.
abstract: The three genes that form the UGA regulon in Saccharomyces cerevisiae are responsible for the transport and degradation of γ-aminobutyric acid (GABA) in this organism. Despite the differences in the sequence of their promoters, these genes similarly respond to GABA stimuli. The expression of UGA1, UGA2 and UGA4 depends on GABA induction and nitrogen catabolite repression (NCR). The induction of these genes requires the action of at least two positive proteins, the specific Uga3 and the pleiotropic Uga35/Dal81 transcription factors. Here we show that all the members of the UGA regulon, as was already demonstrated for UGA4, are negatively regulated by extracellular amino acids through the SPS amino acid sensor. We also show that this negative effect is caused by a low availability of Uga35/Dal81 transcription factor and that Leu3 transcription factor negatively regulates UGA4 and UGA1 expression but it does not affect UGA2 expression.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.
authors.forename: Sabrina B
authors.initials: SB
authors.lastname: Cardillo
authors.forename: Susana
authors.initials: S
authors.lastname: Correa García
authors.forename: Mariana
authors.initials: M
authors.lastname: Bermúdez Moretti
mesh_terms: D000612:4-Aminobutyrate Transaminase / Q000235:genetics*; D015536:Down-Regulation; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D007930:Leucine / Q000378:metabolism*; D018085:Regulon; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D050604:Succinate-Semialdehyde Dehydrogenase (NADP+) / Q000235:genetics*; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C067023:DAL81 protein, S cerevisiae; D050485:GABA Plasma Membrane Transport Proteins; C063667:LEU3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C513599:UGA4 protein, S cerevisiae; D050604:Succinate-Semialdehyde Dehydrogenase (NADP+); C493646:UGA2 protein, S cerevisiae; D000612:4-Aminobutyrate Transaminase; C558424:UGA1 protein, S cerevisiae; D007930:Leucine