Bassler B L, Wright M, Silverman M R
Agouron Institute, La Jolla, California 92037.
Mol Microbiol. 1994 Jul;13(2):273-86. doi: 10.1111/j.1365-2958.1994.tb00422.x.
Density-dependent expression of luminescence in Vibrio harveyi is regulated by the concentration of extracellular signal molecules (autoinducers) in the culture medium. One signal-response system is encoded by the luxL,M,N locus. The luxL and luxM genes are required for the production of an autoinducer (probably beta-hydroxybutyl homoserine lactone), and the luxN gene is required for the response to that autoinducer. Analysis of the phenotypes of LuxL,M and N mutants indicated that an additional signal-response system also controls density sensing. We report here the identification, cloning and analysis of luxP and luxQ, which encode functions required for a second density-sensing system. Mutants with defects in luxP and luxQ are defective in response to a second autoinducer substance. LuxQ, like LuxN, is similar to members of the family of two-component, signal transduction proteins and contains both a histidine protein kinase and a response regulator domain. Analysis of signalling mutant phenotypes indicates that there are at least two separate signal-response pathways which converge to regulate expression of luminescence in V. harveyi.
哈维氏弧菌中发光的密度依赖性表达受培养基中细胞外信号分子（自诱导物）浓度的调节。一个信号响应系统由luxL、M、N基因座编码。luxL和luxM基因是产生一种自诱导物（可能是β-羟基丁基高丝氨酸内酯）所必需的，而luxN基因是对该自诱导物作出响应所必需的。对LuxL、M和N突变体表型的分析表明，另一个信号响应系统也控制密度感应。我们在此报告luxP和luxQ的鉴定、克隆及分析，它们编码第二个密度感应系统所需的功能。luxP和luxQ有缺陷的突变体对第二种自诱导物物质的响应存在缺陷。与LuxN一样，LuxQ类似于双组分信号转导蛋白家族的成员，同时包含一个组氨酸蛋白激酶和一个响应调节结构域。对信号突变体表型的分析表明，至少有两条独立的信号响应途径汇聚在一起，共同调节哈维氏弧菌中发光的表达。
