Pulse Generation in the Quorum Machinery of Pseudomonas aeruginosa.
Pulse Generation in the Quorum Machinery of Pseudomonas aeruginosa.
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DOI：
10.1007/s11538-017-0288-z
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发表时间：
2017-06
影响因子：
3.5
通讯作者：
Wood AJ
中科院分区：
文献类型：
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作者：
Alfiniyah C;Bees MA;Wood AJ
铜绿假单胞菌是一种革兰氏阴性细菌，可引起人类多种感染。菌落利用群体感应（QS）来协调基因表达，包括毒力因子、群体运动和复杂的社会特征。已知铜绿假单胞菌的 QS 信号系统涉及多个控制组件，特别是 las、rhl 和 pqs 系统。在本文中，我们研究了 las 系统，特别是 rsaL（一种嵌入式小调节蛋白）的抑制相互作用，利用最新的生化信息来帮助模型构建。使用分析方法，我们展示了这一特征如何在该子系统中产生可兴奋脉冲，并对鼠李糖脂生产产生重要的下游影响。我们采用对称竞争性抑制来捕获 lasI-rsaL 基因间区域的结合，并表明我们的结果不依赖于该功能形式的确切选择。此外，我们还研究了 lasR 与 rhl 系统的耦合、脉冲生成预测能力的影响以及这种行为的生物物理后果。我们假设 las 和 rhl 系统之间的相互作用可能提供群体记忆，使细胞只有在处于已建立聚集的边缘时才能触发鼠李糖脂的产生。
Pseudomonas aeruginosa is a Gram-negative bacterium that is responsible for a wide range of infections in humans. Colonies employ quorum sensing (QS) to coordinate gene expression, including for virulence factors, swarming motility and complex social traits. The QS signalling system of P. aeruginosa is known to involve multiple control components, notably the las, rhl and pqs systems. In this paper, we examine the las system and, in particular, the repressive interaction of rsaL, an embedded small regulative protein, employing recent biochemical information to aid model construction. Using analytic methods, we show how this feature can give rise to excitable pulse generation in this subsystem with important downstream consequences for rhamnolipid production. We adopt a symmetric competitive inhibition to capture the binding in the lasI–rsaL intergenic region and show our results are not dependent on the exact choice of this functional form. Furthermore, we examine the coupling of lasR to the rhl system, the impact of the predicted capacity for pulse generation and the biophysical consequences of this behaviour. We hypothesize that the interaction between the las and rhl systems may provide a quorum memory to enable cells to trigger rhamnolipid production only when they are at the edge of an established aggregation.