Quorum sensing regulates the osmotic stress response in Vibrio harveyi. Author Julia van Kessel, Steven Rutherford, Jian-Ping Cong, Sofia Quinodoz, James Healy, Bonnie Bassler Publication Year 2015 Type Journal Article 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. Keywords Betaine, Gene Expression Regulation, Bacterial, Osmotic Pressure, Quorum Sensing, Repressor Proteins, Stress, Physiological, Trans-Activators, Vibrio Journal J Bacteriol Volume 197 Issue 1 Pages 73-80 Date Published 2015 Jan 01 ISSN Number 1098-5530 DOI 10.1128/JB.02246-14 Alternate Journal J Bacteriol PMCID PMC4288691 PMID 25313392 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML