Liang Haihua, Li Lingling, Kong Weina, Shen Lixin, Duan Kangmin
Molecular Microbiology Laboratory, Faculty of Life Sciences, Northwest University, Shaanxi, China.
FEMS Microbiol Lett. 2009 Apr;293(2):196-204. doi: 10.1111/j.1574-6968.2009.01544.x. Epub 2009 Mar 2.
Quorum sensing is a global gene-regulatory mechanism in bacteria that enables individual bacterial cells to communicate and coordinate their population behaviors. Quorum sensing is central to the pathogenesis of many bacterial pathogens including Pseudomonas aeruginosa and therefore has been exploited as a target for developing novel antipathogenic drugs. In P. aeruginosa, three intertwined quorum-sensing systems, las, rhl, and the 2-alkyl-4(1H)-quinolone system, which includes the Pseudomonas quinolone signal (PQS), control virulence factor production, and pathogenesis processes. Previously, we obtained a mutant with diminished expression of the phzA1B1C1D1E1F1G1 operon that is involved in the production of virulence factor phenazine compounds. In this study, the mutant was further characterized, and evidence indicating that the disrupted gene PA1196 in the mutant is a potential regulator of the rhl and PQS systems is presented. PA1196 positively controls the expression of the rhl and PQS systems and affects bacterial motility and multiple virulence factor expression via the quorum-sensing systems. This adds an important new player in the complex quorum-sensing network in P. aeruginosa.
群体感应是细菌中的一种全局基因调控机制，它使单个细菌细胞能够进行通讯并协调其群体行为。群体感应是包括铜绿假单胞菌在内的许多细菌病原体发病机制的核心，因此已被用作开发新型抗病原体药物的靶点。在铜绿假单胞菌中，三个相互交织的群体感应系统，即las、rhl和2-烷基-4(1H)-喹诺酮系统（其中包括铜绿假单胞菌喹诺酮信号（PQS）），控制毒力因子的产生和发病过程。此前，我们获得了一个phzA1B1C1D1E1F1G1操纵子表达降低的突变体，该操纵子参与毒力因子吩嗪化合物的产生。在本研究中，对该突变体进行了进一步表征，并提供了证据表明该突变体中被破坏的基因PA1196是rhl和PQS系统的潜在调节因子。PA1196正向控制rhl和PQS系统的表达，并通过群体感应系统影响细菌的运动性和多种毒力因子的表达。这为铜绿假单胞菌复杂的群体感应网络增添了一个重要的新成员。
