Williams P, Bainton N J, Swift S, Chhabra S R, Winson M K, Stewart G S, Salmond G P, Bycroft B W
Department of Pharmaceutical Sciences, University of Nottingham, University Park, UK.
FEMS Microbiol Lett. 1992 Dec 15;100(1-3):161-7. doi: 10.1111/j.1574-6968.1992.tb14035.x.
Sophisticated signal transduction systems enable prokaryotes to sense their growth environment and mount an appropriate adaptive response. Signal transduction and gene regulation through the phosphorylation of two regulatory components is now recognised as one of the major global regulatory networks in bacteria. However, not all types of sensor-regulator circuits relay information via phosphoryl transfer. The Vibrio fischeri LuxR protein which has previously been characterised as a member of the response-regulator superfamily responds to a small diffusible signal molecule N-(3-oxohexanoyl)homoserine lactone (HSL). Biosynthesis of HSL in V. fischeri is dependent on the expression of the luxI gene. Until recently, the role of HSL as an 'autoinducer' was thought to be restricted to V. fischeri and a few related marine bacteria in which it controls the onset of bioluminescence. However, we have discovered that a diverse group of terrestrial bacteria: (1) produce HSL; (2) possess genes analogous to luxI; and (3) exhibit cell density-dependent induction of bioluminesence when transformed with a recombinant plasmid carrying V. fischeri lux genes but lacking luxI. In one of these, Erwinia carotovora, HSL is shown to mediate the cell density-dependent biosynthesis of a carbapenem antibiotic.
复杂的信号转导系统使原核生物能够感知其生长环境并做出适当的适应性反应。通过两个调节成分的磷酸化进行信号转导和基因调控，现在被认为是细菌中主要的全局调控网络之一。然而，并非所有类型的传感器-调节器电路都通过磷酰基转移来传递信息。费氏弧菌的LuxR蛋白先前被鉴定为响应调节超家族的成员，它对一种小的可扩散信号分子N-(3-氧代己酰基)高丝氨酸内酯(HSL)作出反应。费氏弧菌中HSL的生物合成依赖于luxI基因的表达。直到最近，HSL作为“自诱导物”的作用还被认为仅限于费氏弧菌和一些相关的海洋细菌，在这些细菌中它控制生物发光的开始。然而，我们发现了一组不同的陆生细菌：(1)产生HSL；(2)拥有与luxI类似的基因；(3)当用携带费氏弧菌lux基因但缺乏luxI的重组质粒转化时，表现出细胞密度依赖性的生物发光诱导。在其中一种细菌，胡萝卜软腐欧文氏菌中，HSL被证明介导了碳青霉烯抗生素的细胞密度依赖性生物合成。
