title: Positive control of a regulon for defenses against oxidative stress and some heat-shock proteins in Salmonella typhimurium.
abstract: S. typhimurium become resistant to killing by hydrogen peroxide and other oxidants when pretreated with nonlethal levels of hydrogen peroxide. During adaptation to hydrogen peroxide, 30 proteins are induced. Nine are constitutively overexpressed in dominant hydrogen peroxide-resistant oxyR mutants. Mutant oxyR1 is resistant to a variety of oxidizing agents and overexpresses at least five enzyme activities involved in defenses against oxidative damage. Deletions of oxyR are recessive and uninducible by hydrogen peroxide for the nine proteins overexpressed in oxyR1, demonstrating that oxyR is a positive regulatory element. The oxyR1 mutant is also more resistant than the wild-type parent to killing by heat, and it constitutively overexpresses three heat-shock proteins. The oxyR regulatory network is a previously uncharacterized global regulatory system in enteric bacteria.
authors.forename: M F
authors.initials: MF
authors.lastname: Christman
authors.forename: R W
authors.initials: RW
authors.lastname: Morgan
authors.forename: F S
authors.initials: FS
authors.lastname: Jacobson
authors.forename: B N
authors.initials: BN
authors.lastname: Ames
mesh_terms: D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000096:biosynthesis; D002374:Catalase / Q000096:biosynthesis; D004352:Drug Resistance, Microbial; D004790:Enzyme Induction; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005980:Glutathione Reductase / Q000096:biosynthesis; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007527:Isoenzymes / Q000096:biosynthesis; D008345:Manganese / Q000494:pharmacology; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000096:biosynthesis*; D009195:Peroxidase; D010544:Peroxidases / Q000096:biosynthesis; D012486:Salmonella typhimurium / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D007527:Isoenzymes; D008345:Manganese; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D010544:Peroxidases; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase