Bacteria have evolved a variety of signal transduction mechanisms that generate different outputs in response to external stimuli. Chemosensory pathways are widespread in bacteria and are among the most complex signaling mechanisms, requiring the participation of at least six proteins. These pathways mediate flagellar chemotaxis, in addition to controlling alternative functions such as second messenger levels or twitching motility. The human pathogen Pseudomonas aeruginosa has four different chemosensory pathways that carry out different functions and are stimulated by signal binding to 26 chemoreceptors. Recent research employing a diverse range of experimental approaches has advanced enormously our knowledge on these four pathways, establishing P. aeruginosa as a primary model organism in this field. In the first part of this article, we review data on the function and physiological relevance of chemosensory pathways as well as their involvement in virulence, whereas the different transcriptional and posttranscriptional regulatory mechanisms that govern pathway function are summarized in the second part. The information presented will be of help to advance the understanding of pathway function in other organisms.

中文翻译：

---

铜绿假单胞菌作为研究化学感觉通路信号的模型

细菌已经进化出多种信号转导机制，这些机制产生不同的输出以响应外部刺激。化学感觉通路广泛存在于细菌中，是最复杂的信号传导机制之一，需要至少六种蛋白质的参与。除了控制第二信使水平或抽搐运动等替代功能外，这些途径还介导鞭毛趋化性。人类病原体铜绿假单胞菌具有四种不同的化学感应途径，它们执行不同的功能并受到与 26 种化学感受器的信号结合的刺激。最近采用多种实验方法的研究极大地提高了我们对这四种途径的认识，建立了铜绿假单胞菌作为该领域的主要模式生物。在本文的第一部分，我们回顾了有关化学感应通路的功能和生理相关性以及它们参与毒力的数据，而在第二部分中总结了控制通路功能的不同转录和转录后调控机制。所提供的信息将有助于促进对其他生物中通路功能的理解。