Zhou Tian, Huang Jiahui, Liu Zhiqing, Xu Zeling, Zhang Lian-Hui
Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China.
Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China.
Front Microbiol. 2021 Jul 21;12:707711. doi: 10.3389/fmicb.2021.707711. eCollection 2021.
, a major cause of nosocomial infection, can survive under diverse environmental conditions. Its great adaptive ability is dependent on its multiple signaling systems such as the two-component system (TCS). A TCS FleS/FleR has been previously identified to positively regulate a variety of virulence-related traits in PAO1 including motility and biofilm formation which are involved in the acute and chronic infections, respectively. However, the molecular mechanisms underlying these regulations are still unclear. In this study, we first analyzed the regulatory roles of each domains in FleS/FleR and characterized key residues in the FleS-HisKA, FleR-REC and FleR-AAA domains that are essential for the signaling. Next, we revealed that FleS/FleR regulates biofilm formation in a c-di-GMP and FleQ dependent manner. Lastly, we demonstrated that FleR can regulate flagellum biosynthesis independently without FleS, which explains the discrepant regulation of swimming motility by FleS and FleR.
作为医院感染的主要原因之一，可在多种环境条件下存活。其强大的适应能力依赖于其多种信号系统，如双组分系统（TCS）。先前已鉴定出一种TCS FleS/FleR可正向调节PAO1中多种与毒力相关的特性，包括分别参与急性和慢性感染的运动性和生物膜形成。然而，这些调节的分子机制仍不清楚。在本研究中，我们首先分析了FleS/FleR中每个结构域的调节作用，并鉴定了FleS-HisKA、FleR-REC和FleR-AAA结构域中对信号传导至关重要的关键残基。接下来，我们揭示了FleS/FleR以c-di-GMP和FleQ依赖的方式调节生物膜形成。最后，我们证明FleR可以独立于FleS调节鞭毛生物合成，这解释了FleS和FleR对游泳运动性的不同调节。
