Specific activation of the Bacillus quorum-sensing systems by isoprenylated pheromone variants
Specific activation of the Bacillus quorum-sensing systems by isoprenylated pheromone variants
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DOI：
10.1046/j.1365-2958.2002.02977.x
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发表时间：
2002-06-01
影响因子：
3.6
通讯作者：
Dubnau, D
中科院分区：
文献类型：
--
作者：
Ansaldi, M;Marolt, D;Dubnau, D
枯草芽孢杆菌的天然遗传感受态是由群体感应（quorum-sensing，QS）控制的。ComP-ComA双组分系统检测信号分子ComX，并且该信号通过保守的磷酸转移机制转导。ComX作为无活性前体合成，然后在输出到细胞外环境之前被ComQ切割和修饰。一组天然芽孢杆菌属分离物的comQXP '基因座已被测序，并显示具有显著的多态性，其决定群体感应反应的激活和抑制的特定模式。我们已经开发了一种简单的纯化方法，允许表征四个不同的ComX分子代表不同的pherotypes的修饰肽信号信息素。遗传和生物化学证据表明，所有的ComX变体是异戊二烯化的保守的色氨酸残基的翻译后修饰和ComX肽骨架上的修饰不同的质量之间的各种表型。这些结果为革兰氏阳性菌中肽介导的群体感应信号提供了新的见解，并强调了异戊二烯化在细菌信号转导中的作用。
Natural genetic competence in Bacillus subtilis is controlled by quorum-sensing (QS). The ComP- ComA two-component system detects the signalling molecule ComX, and this signal is transduced by a conserved phosphotransfer mechanism. ComX is synthesized as an inactive precursor and is then cleaved and modified by ComQ before export to the extracellular environment. The comQXP ' loci of a set of natural Bacillus isolates have been sequenced and shown to possess a striking polymorphism that determines specific patterns of both activation and inhibition of the quorum-sensing response. We have developed a simple purification method for the modified peptide signalling pheromones allowing the characterization of four distinct ComX molecules representing different pherotypes. Genetic and biochemical evidence demonstrate that all the ComX variants are isoprenylated by the post-translational modification of a conserved tryptophan residue and that the modifications on the ComX peptide backbones vary in mass among the various pherotypes. These results give new insights into peptidemediated quorum-sensing signalling in Gram-positive bacteria and emphasize the role of isoprenylation in bacterial signal transduction.