Octanoyl-homoserine lactone is the cognate signal for Burkholderia mallei BmaR1-BmaI1 quorum sensing
Octanoyl-homoserine lactone is the cognate signal for Burkholderia mallei BmaR1-BmaI1 quorum sensing
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DOI：
10.1128/jb.00317-07
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发表时间：
2007-07-01
影响因子：
3.2
通讯作者：
Greenberg, E. Peter
中科院分区：
文献类型：
--
作者：
Duerkop, Breck A.;Ulrich, Ricky L.;Greenberg, E. Peter
酰基高丝氨酸内酯（HSL）作为许多变形菌的群体感应信号。信号发生器的LuxI家族的成员催化酰基-HSL的产生，所述酰基-HSL结合至转录因子的LuxR家族中的同源受体。专性动物病原体鼻疽伯克霍尔德菌产生几种酰基-HSL，而B。鼻疽基因组有4个lurR和2个luxI同源物，每个都已被确定为毒力因子。开始描绘B的相关酰基-HSL信号。通过对鼻疽LuxR同源物的分析，我们分析了BmaR 1-BmaI 1系统。来自B的酰基-HSL图谱的比较。mallei ATCC 23344和B. mallei bmaI 1突变体表明辛酰-HSL合成是BmaI 1依赖性的。此外，辛酰基-HSL是BmaI 1在重组大肠杆菌中产生的主要酰基-HSL。在重组E.大肠杆菌需要辛酰基-HSL或癸酰基-HSL。在存在其他酰基-HSL和不存在酰基-HSL的情况下产生BmaR 1的不溶性聚集体。bmaI 1启动子被BmaR 1和辛酰基-HSL激活，并且bmaI 1启动子中的20 bp反向重复序列是bmaI 1激活所必需的。纯化的BmaR 1与该启动子区结合。这些发现暗示辛酰基-HSL作为Bmalk 1-BmaI 1群体感应的信号，并显示辛酰基-HSL和BmaR 1激活bmaT 1转录。
Acyl-homoserine lactones (HSLs) serve as quorum-sensing signals for many Proteobacteria. Members of the LuxI family of signal generators catalyze the production of acyl-HSLs, which bind to a cognate receptor in the LuxR family of transcription factors. The obligate animal pathogen Burkholderia mallei produces several acyl-HSLs, and the B. mallei genome has four lurR and two luxI homologs, each of which has been established as a virulence factor. To begin to delineate the relevant acyl-HSL signals for B. mallei LuxR homologs, we analyzed the BmaR1-BmaI1 system. A comparison of acyl-HSL profiles from B. mallei ATCC 23344 and a B. mallei bmaI1 mutant indicates that octanoyl-HSL synthesis is BmaI1 dependent. Furthermore, octanoyl-HSL is the predominant acyl-HSL produced by BmaI1 in recombinant Escherichia coli. The synthesis of soluble BmaR1 in recombinant E. coli requires octanoyl-HSL or decanoyl-HSL. Insoluble aggregates of BmaR1 are produced in the presence of other acyl-HSLs and in the absence of acyl-HSLs. The bmaI1 promoter is activated by BmaR1 and octanoyl-HSL, and a 20-bp inverted repeat in the bmaI1 promoter is required for bmaI1 activation. Purified BmaR1 binds to this promoter region. These findings implicate octanoyl-HSL as the signal for Bmalk1-BmaI1 quorum sensing and show that octanoyl-HSL and BmaR1 activate bmaT1 transcription.