@article{mbs:/content/journal/micro/10.1099/mic.0.060863-0, author = "Mirabella, Aurélie and Yañez Villanueva, Rosse-Mary and Delrue, Rose-May and Uzureau, Sophie and Zygmunt, Michel S. and Cloeckaert, Axel and De Bolle, Xavier and Letesson, Jean-Jacques", title = "The two-component system PrlS/PrlR of Brucella melitensis is required for persistence in mice and appears to respond to ionic strength", journal= "Microbiology", year = "2012", volume = "158", number = "10", pages = "2642-2651", doi = "https://doi.org/10.1099/mic.0.060863-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.060863-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", 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.", }