title: Quorum sensing regulates the osmotic stress response in Vibrio harveyi.
abstract: Bacteria use a chemical communication process called quorum sensing to monitor cell density and to alter behavior in response to fluctuations in population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates and represses >600 genes. These include six genes that encode homologs of the Escherichia coli Bet and ProU systems for synthesis and transport, respectively, of glycine betaine, an osmoprotectant used during osmotic stress. Here we show that LuxR activates expression of the glycine betaine operon betIBA-proXWV, which enhances growth recovery under osmotic stress conditions. BetI, an autorepressor of the V. harveyi betIBA-proXWV operon, activates the expression of genes encoding regulatory small RNAs that control quorum-sensing transitions. Connecting quorum-sensing and glycine betaine pathways presumably enables V. harveyi to tune its execution of collective behaviors to its tolerance to stress.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA jcvk@indiana.edu bbassler@princeton.edu.
authors.forename: Julia C
authors.initials: JC
authors.lastname: van Kessel
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Rutherford
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Cong
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Sofia
authors.initials: S
authors.lastname: Quinodoz
authors.affiliation: Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA.
authors.forename: James
authors.initials: J
authors.lastname: Healy
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey, USA jcvk@indiana.edu bbassler@princeton.edu.
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Bassler
mesh_terms: D001622:Betaine / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D009997:Osmotic Pressure / Q000502:physiology*; D053038:Quorum Sensing / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014733:Vibrio / Q000235:genetics / Q000502:physiology*
chemical_list: D012097:Repressor Proteins; D015534:Trans-Activators; C064778:LuxR autoinducer binding proteins; D001622:Betaine