title: The osmotic regulator OmpR is involved in the response of Yersinia enterocolitica O:9 to environmental stresses and survival within macrophages.
abstract: Various environmental signals control the expression of the virulence factors in pathogenic Yersinia enterocolitica strains. The role of the osmotic regulator OmpR protein in controlling the production of Yop proteins, virulence determinants in Y. enterocolitica O:9 (European type) has been studied. An ompR deletion mutant was constructed via allelic exchange with an ompR gene of Y. enterocolitica mutagenized in vitro by a reverse genetic polymerase chain reaction (PCR)-based strategy. The ompR mutant showed a reduced ability to survive under conditions of various environmental stresses in vitro. In particular, low pH stress resulted in increased cell mortality levels. Under conditions of high osmolarity, the wild strain's Yop protein production was reduced, whereas protein levels from the mutant strain remained constant regardless of osmolarity variance. In J774A.1 macrophage cell culture survival of the ompR mutant was decidedly lower than that of the wild-type strain, suggesting that the OmpR protein may play a significant role in protecting cells against intracellular conditions associated with macrophage phagocytosis.
authors.affiliation: Institute of Microbiology, Warsaw University, 02-096 Warsaw Miecznikowa 1, Poland. kbrzostek@biol.uw.edu.pl
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Brzostek
authors.forename: Adrianna
authors.initials: A
authors.lastname: Raczkowska
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Zasada
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D006863:Hydrogen-Ion Concentration; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D016296:Mutagenesis; D009154:Mutation; D009994:Osmolar Concentration; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis; D015534:Trans-Activators / Q000235:genetics* / Q000502:physiology*; D015008:Yersinia enterocolitica / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D015534:Trans-Activators; C112177:osmolarity response regulator proteins; D017027:Protein Tyrosine Phosphatases; C067571:yopH protein, Yersinia