Gray K M, Passador L, Iglewski B H, Greenberg E P
Department of Microbiology, University of Iowa, Iowa City 52242.
J Bacteriol. 1994 May;176(10):3076-80. doi: 10.1128/jb.176.10.3076-3080.1994.
Autoinduction is a conserved mechanism of cell density-dependent gene regulation that occurs in a variety of gram-negative bacteria. Autoinducible luminescence in Vibrio fischeri requires a transcriptional activator, LuxR, while a LuxR homolog, LasR, activates elastase expression in Pseudomonas aeruginosa. Both LuxR and LasR require specific signal molecules, called autoinducers, for activity. We show here the activation in Escherichia coli of the V. fischeri luminescence (lux) operon by LasR and of the P. aeruginosa elastase gene (lasB) by LuxR when each is in the presence of its cognate autoinducer. Neither LuxR nor LasR showed appreciable activity with the heterologous V. fischeri or P. aeruginosa autoinducer. This supports the view that there is a direct interaction of each transcriptional activator with its proper autoinducer and suggests that there are conserved, autoinduction-related elements within the promoter regions of these genes.
自诱导是一种细胞密度依赖性基因调控的保守机制，存在于多种革兰氏阴性细菌中。费氏弧菌中的自诱导发光需要转录激活因子LuxR，而LuxR的同源物LasR则激活铜绿假单胞菌中的弹性蛋白酶表达。LuxR和LasR都需要特定的信号分子（称为自诱导物）来发挥活性。我们在此表明，当LasR存在其同源自诱导物时，它能激活大肠杆菌中的费氏弧菌发光（lux）操纵子；当LuxR存在其同源自诱导物时，它能激活铜绿假单胞菌中的弹性蛋白酶基因（lasB）。LuxR和LasR与异源的费氏弧菌或铜绿假单胞菌自诱导物均未表现出明显活性。这支持了每种转录激活因子与其合适的自诱导物直接相互作用的观点，并表明这些基因的启动子区域内存在保守的、与自诱导相关的元件。
