title: Characterization of two signal transduction systems involved in intracellular macrophage survival and environmental stress response in Enterococcus faecalis.
abstract: The intracellular survival in mouse peritoneal macrophages of 8 Enterococcus faecalis response regulator mutants was tested to assess if the corresponding 2-component signal transduction systems (TCS) are involved in the ability of E. faecalis to survive in macrophages. Three mutants (err04, err05 and err06) are more susceptible than the wild-type JH2-2 strain and 1 is more resistant (err10). Then, characterization of the TCS Err04-Ehk04 and Err06-Ehk06 reveals that the first (homolog of PhoP-PhoR of Bacillus subtilis) is induced in phosphate deprivation conditions, regulates its own expression and plays a role in the expression of pstF encoding a phosphate-binding protein. The Err06-Ehk06 is involved in oxidative stress response. A mutation in the err06 gene increases sensitivity of the bacterium to H(2)O(2). The err06-ehk06 operon is induced by H(2)O(2) stress and controlled by 2 transcriptional start sites, of which 1 is specifically active in oxidative stress conditions. We also demonstrated that the expression of the catalase gene (kat) is partly dependant of the Err06-Ehk06 TCS.
authors.affiliation: USC INRA 2017, Microbiologie de l'Environnement, EA 956, IRBA, Université de Caen, Caen, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Muller
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.forename: Eliette
authors.initials: E
authors.lastname: Riboulet
authors.forename: Laurent
authors.initials: L
authors.lastname: Hébert
authors.forename: Brunella
authors.initials: B
authors.lastname: Posteraro
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fadda
authors.forename: Yanick
authors.initials: Y
authors.lastname: Auffray
authors.forename: Alain
authors.initials: A
authors.lastname: Rincé
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D017737:Macrophages, Peritoneal / Q000382:microbiology*; D051379:Mice; D009154:Mutation; D018384:Oxidative Stress; D028044:Phosphate-Binding Proteins / Q000235:genetics / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D028044:Phosphate-Binding Proteins; D010710:Phosphates; D002374:Catalase