title: SoxS regulates the expression of the Salmonella enterica serovar Typhimurium ompW gene.
abstract: OmpW of Salmonella enterica serovar Typhimurium has been described as a minor porin involved in osmoregulation, and is also affected by environmental conditions. Biochemical and genetic evidence from our laboratory indicates that OmpW is involved in efflux of and resistance towards paraquat (PQ), and its expression has been shown to be activated in response to oxidative stress. In this study we have explored ompW expression in response to PQ. Primer extension and transcriptional fusions showed that its expression was induced in the presence of PQ. In silico analyses suggested a putative binding site for the SoxS transcriptional factor at the ompW regulatory region. Electrophoretic mobility shift assays (EMSAs) and footprinting experiments showed that SoxS binds at a region that starts close to -54 and ends at about -197 upstream of the transcription start site. Transcriptional fusions support the relevance of this region in ompW activation. The SoxS site is in the forward orientation and its location suggests that the ompW gene has a class I SoxS-dependent promoter.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: F
authors.initials: F
authors.lastname: Gil
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: I
authors.initials: I
authors.lastname: Hernández-Lucas
authors.affiliation: Laboratorio de Bioquímica, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: R
authors.initials: R
authors.lastname: Polanco
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: N
authors.initials: N
authors.lastname: Pacheco
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: B
authors.initials: B
authors.lastname: Collao
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: J M
authors.initials: JM
authors.lastname: Villarreal
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: G
authors.initials: G
authors.lastname: Nardocci
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Calva
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: C P
authors.initials: CP
authors.lastname: Saavedra
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000378:metabolism*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006540:Herbicides / Q000494:pharmacology; D010269:Paraquat / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006540:Herbicides; C485381:SoxS protein, Salmonella enterica; D015534:Trans-Activators; D010269:Paraquat