title: Expression of a Yersinia pseudotuberculosis Type VI Secretion System Is Responsive to Envelope Stresses through the OmpR Transcriptional Activator.
abstract: The Type VI secretion system (T6SS) is a macromolecular complex widespread in Gram-negative bacteria. Although several T6SS are required for virulence towards host models, most are necessary to eliminate competitor bacteria. Other functions, such as resistance to amoeba predation, biofilm formation or adaptation to environmental conditions have also been reported. This multitude of functions is reflected by the large repertoire of regulatory mechanisms shown to control T6SS expression, production or activation. Here, we demonstrate that one T6SS gene cluster encoded within the Yersinia pseudotuberculosis genome, T6SS-4, is regulated by OmpR, the response regulator of the two-component system EnvZ-OmpR. We first identified OmpR in a transposon mutagenesis screen. OmpR does not control the expression of the four other Y. pseudotuberculosis T6SS gene clusters and of an isolated vgrG gene, and responds to osmotic stresses to bind to and activate the T6SS-4 promoter. Finally, we show that T6SS-4 promotes Y. pseudotuberculosis survival in high osmolarity conditions and resistance to deoxycholate.
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université, Marseille, France.
authors.forename: Erwan
authors.initials: E
authors.lastname: Gueguen
authors.forename: Eric
authors.initials: E
authors.lastname: Durand
authors.forename: Xiang Y
authors.initials: XY
authors.lastname: Zhang
authors.forename: Quentin
authors.initials: Q
authors.lastname: d'Amalric
authors.forename: Laure
authors.initials: L
authors.lastname: Journet
authors.forename: Eric
authors.initials: E
authors.lastname: Cascales
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004251:DNA Transposable Elements; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000378:metabolism*; D000069376:Type VI Secretion Systems / Q000378:metabolism*; D015011:Yersinia pseudotuberculosis / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D015534:Trans-Activators; D000069376:Type VI Secretion Systems