van Kessel Julia C, Rutherford Steven T, Cong Jian-Ping, Quinodoz Sofia, Healy James, Bassler Bonnie L
Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
J Bacteriol. 2015 Jan 1;197(1):73-80. doi: 10.1128/JB.02246-14. Epub 2014 Oct 13.
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.
细菌利用一种称为群体感应的化学通讯过程来监测细胞密度，并根据种群数量的波动改变行为。先前对哈维氏弧菌的研究表明，群体感应的主要调节因子LuxR可激活和抑制600多个基因。其中包括六个基因，分别编码大肠杆菌Bet和ProU系统的同源物，用于合成和运输甘氨酸甜菜碱，这是一种在渗透胁迫期间使用的渗透保护剂。在这里，我们表明LuxR激活了甘氨酸甜菜碱操纵子betIBA-proXWV的表达，这增强了在渗透胁迫条件下的生长恢复。BetI是哈维氏弧菌betIBA-proXWV操纵子的自抑制因子，它激活编码控制群体感应转变的调节性小RNA的基因的表达。将群体感应和甘氨酸甜菜碱途径联系起来可能使哈维氏弧菌能够根据其对压力的耐受性来调整其集体行为的执行。
