LuxR- and acyl-homoserine-lactone-controlled non-lux genes define a quorum-sensing regulon in Vibrio fischeri
LuxR- and acyl-homoserine-lactone-controlled non-lux genes define a quorum-sensing regulon in Vibrio fischeri
复制标题
DOI：
10.1128/jb.182.10.2811-2822.2000
复制
发表时间：
2000-05-01
影响因子：
3.2
通讯作者：
Dunlap, PV
中科院分区：
文献类型：
--
作者：
Callahan, SM;Dunlap, PV
共生细菌费氏弧菌的发光（lux）操纵子（luxICDABEG）由转录激活因子LuxR和两种酰基高丝氨酸内酯（酰基-HSL）自诱导物（luxI依赖性3-氧代-己酰基-HSL [3-oxo-C6-HSL]和ainS依赖性辛酰基-HSL [C8-HSL]）以称为群体感应的群体密度响应方式调节。为了鉴定与lux基因编码的QSR蛋白不同的QSR蛋白，我们采用双向聚丙烯酰胺凝胶电泳技术对luxI、ainS和luxR缺失的费氏弧菌群体感应突变体进行了蛋白质图谱分析。它们的产生优先发生在高种群密度下，需要LuxR和3-氧代-C6-HSL，并且在低种群密度下被C8-HSL抑制。编码两种QSR蛋白的基因的特征在于：qsrP指导细胞合成一种明显新颖的周质蛋白，ribB是大肠杆菌3，4-二羟基-2-丁酮4-磷酸合酶基因的同源物，这是核黄素合成的关键酶。qsrP和ribB启动子区各自含有类似于lux操纵子lux盒的序列，lux操纵子转录的LuxR/3-oxo-C6-HSL依赖性激活所必需的二分体对称性的20 bp区域。费氏弧菌qsrP和ribB突变体在培养中没有表现出明显的表型。然而，一个qsrP突变体，在竞争中与其亲本菌株，是不太成功的定殖Euprymna callopes，共生宿主的V. fischeri。新鉴定的QSR基因与毛皮操纵子一起定义了费氏弧菌中的LuxR/酰基-HSL应答性群体感应调节子。
The luminescence (lux) operon (luxICDABEG) of the symbiotic bacterium Vibrio fischeri is regulated by the transcriptional activator LuxR and two acyl-homoserine lactone (acyl-HSL) autoinducers (the luxI-dependent 3-oxo-hexanoyl-HSL [3-oxo-C6-HSL] and the ainS-dependent octanoyl-HSL [C8-HSL]) in a population density-responsive manner called quorum sensing. To identify quorum-sensing-regulated (QSR) proteins different from those encoded by lux genes, we examined the protein patterns of V. fischeri quorum-sensing mutants defective in luxI, ainS, and luxR by two-dimensional polyacrylamide gel electrophoresis, Five non-lux QSR proteins, QsrP, RibB, AcfA, QsrV, and QSR 7, were identified; their production occurred preferentially at high population density, required both LuxR and 3-oxo-C6-HSL, and was inhibited by C8-HSL at low population density. The genes encoding two of the QSR proteins were characterized: qsrP directs cells to synthesize an apparently novel periplasmic protein, and ribB is a homolog of the Escherichia coli gene for 3,4-dihydroxy-2-butanone 4-phosphate synthase, a key enzyme for riboflavin synthesis. The qsrP and ribB promoter regions each contained a sequence similar to the lux operon lux box, a 20-bp region of dyad symmetry necessary for LuxR/3-oxo-C6-HSL-dependent activation of lux: operon transcription. V. fischeri qsrP and ribB mutants exhibited no distinct phenotype in culture. However, a qsrP mutant, in competition with its parent strain, was less successful in colonizing Euprymna scolopes, the symbiotic host of V. fischeri. The newly identified QSR genes, together with the fur operon, define a LuxR/acyl-HSL-responsive quorum-sensing regulon in V. fischeri.