title: The two-component system PrlS/PrlR of Brucella melitensis is required for persistence in mice and appears to respond to ionic strength.
abstract: Bacterial adaptation to environmental conditions is essential to ensure maximal fitness in the face of several stresses. In this context, two-component systems (TCSs) represent a predominant signal transduction mechanism, allowing an appropriate response to be mounted when a stimulus is sensed. As facultative intracellular pathogens, Brucella spp. face various environmental conditions, and an adequate response is required for a successful infection process. Recently, bioinformatic analysis of Brucella genomes predicted a set of 15 bona fide TCS pairs, among which some have been previously investigated. In this report, we characterized a new TCS locus called prlS/R, for probable proline sensor-regulator. It encodes a hybrid histidine kinase (PrlS) with an unusual Na(+)/solute symporter N-terminal domain and a transcriptional regulator (belonging to the LuxR family) (PrlR). In vitro, Brucella spp. with a functional PrlR/S system form bacterial aggregates, which seems to be an adaptive response to a hypersaline environment, while a prlS/R mutant does not. We identified ionic strength as a possible signal sensed by this TCS. Finally, this work correlates the absence of a functional PrlR/S system with the lack of hypersaline-induced aggregation in particular marine Brucella spp.
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Mirabella
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Rosse-Mary
authors.initials: RM
authors.lastname: Yañez Villanueva
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Rose-May
authors.initials: RM
authors.lastname: Delrue
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Uzureau
authors.affiliation: Université François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France.|INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
authors.forename: Michel S
authors.initials: MS
authors.lastname: Zygmunt
authors.affiliation: Université François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France.|INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: De Bolle
authors.affiliation: Unité de Recherche en Biologie des Microorganismes (URBM), NARILIS, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Letesson
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017347:Brucella melitensis / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity* / Q000502:physiology*; D002006:Brucellosis / Q000382:microbiology; D002478:Cells, Cultured; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009994:Osmolar Concentration; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction; D014327:Trophoblasts / Q000382:microbiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase