title: Small outer-membrane lipoprotein, SmpA, is regulated by sigmaE and has a role in cell envelope integrity and virulence of Salmonella enterica serovar Typhimurium.
abstract: SmpA is a small outer-membrane lipoprotein that is a component of the essential YaeT outer-membrane protein assembly complex. In Salmonella enterica serovar Typhimurium (S. Typhimurium), expression of the smpA gene was shown to be directed by two promoters, smpAp1 and smpAp2. The more distal promoter, smpAp1, is dependent upon the extracytoplasmic stress response sigma factor sigma(E). An smpA null mutant was constructed in S. Typhimurium SL1344 and was shown to be more sensitive than its wild-type parent to growth at high temperature and in the presence of sodium cholate, SDS plus EDTA, and the hydrophobic antibiotic rifampicin. The lack of SmpA in S. Typhimurium elicits a sigma(E)-dependent stress response. These findings are indicative of altered outer-membrane integrity in the smpA mutant, probably due to a defect in outer-membrane protein biogenesis. SmpA was not important for entry or survival within murine macrophages; however, the S. Typhimurium smpA mutant was attenuated in mice by both the oral and parenteral routes of infection, and SmpA appeared to be most important for the growth of S. Typhimurium at systemic sites.
authors.affiliation: Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Lewis
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Science, Dubravska cesta 21, 845 51 Bratislava, Slovak Republik.
authors.forename: Henrieta
authors.initials: H
authors.lastname: Skovierova
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Gary
authors.initials: G
authors.lastname: Rowley
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Science, Dubravska cesta 21, 845 51 Bratislava, Slovak Republik.
authors.forename: Bronislava
authors.initials: B
authors.lastname: Rezuchova
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Science, Dubravska cesta 21, 845 51 Bratislava, Slovak Republik.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Homerova
authors.affiliation: Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Stevenson
authors.affiliation: Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: Aileen
authors.initials: A
authors.lastname: Sherry
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Science, Dubravska cesta 21, 845 51 Bratislava, Slovak Republik.
authors.forename: Jan
authors.initials: J
authors.lastname: Kormanec
authors.affiliation: Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Roberts
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D004492:Edetic Acid / Q000494:pharmacology; D017353:Gene Deletion; D023061:Gene Order; D006358:Hot Temperature; D007928:Lethal Dose 50; D008099:Liver / Q000382:microbiology; D008198:Lymph Nodes / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D050296:Microbial Viability; D008969:Molecular Sequence Data; D010581:Peyer's Patches / Q000382:microbiology; D011401:Promoter Regions, Genetic; D012293:Rifampin / Q000494:pharmacology; D012481:Salmonella Infections, Animal; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D012808:Sigma Factor / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013154:Spleen / Q000382:microbiology; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D012808:Sigma Factor; D014157:Transcription Factors; D037521:Virulence Factors; C063202:sporulation-specific sigma factors; D012967:Sodium Dodecyl Sulfate; D004492:Edetic Acid; D012293:Rifampin