Elektro, Technical University of Denmark, DK-2800 Lyngby, Denmark.
J Mol Biol. 2010 Mar 5;396(4):849-57. doi: 10.1016/j.jmb.2010.01.002. Epub 2010 Jan 11.
We present detailed results on the C4-HSL-mediated quorum sensing (QS) regulatory system of the opportunistic Gram-negative bacterium Aeromonas hydrophila. This bacterium contains a particularly simple QS system that allows for a detailed modeling of kinetics. In a model system (i.e., the Escherichia coli monitor strain MH205), the C4-HSL production of A. hydrophila is interrupted by fusion of gfp(ASV). In the present in vitro study, we measure the response of the QS regulatory ahyRI locus in the monitor strain to predetermined concentrations of C4-HSL signal molecules. A minimal kinetic model describes the data well. It can be solved analytically, providing substantial insight into the QS mechanism: at high concentrations of signal molecules, a slow decay of the activated regulator sets the timescale for the QS regulation loop. Slow saturation ensures that, in an A. hydrophila cell, the QS system is activated only by signal molecules produced by other A. hydrophila cells. Separate information on the ahyR and ahyI loci can be extracted, thus allowing the probe to be used in identifying the target when testing QS inhibitors.
我们介绍了关于机会性革兰氏阴性细菌嗜水气单胞菌的 C4-HSL 介导的群体感应 (QS) 调节系统的详细结果。该细菌含有一个特别简单的 QS 系统，允许对动力学进行详细建模。在模型系统（即大肠杆菌监测菌株 MH205）中，通过 gfp(ASV)融合中断了 C4-HSL 的产生。在本体外研究中，我们测量了监测菌株中 QS 调节 ahyrI 基因座对预定浓度 C4-HSL 信号分子的反应。一个最小的动力学模型很好地描述了数据。它可以通过解析求解，为 QS 机制提供了深刻的见解：在高浓度的信号分子下，激活调节剂的缓慢衰减为 QS 调节回路设定了时间尺度。缓慢的饱和确保了在一个嗜水气单胞菌细胞中，QS 系统仅被其他嗜水气单胞菌细胞产生的信号分子激活。可以提取关于 ahyrR 和 ahyrI 基因座的单独信息，从而允许在测试 QS 抑制剂时使用该探针来识别靶标。
