SuhB Regulates the Motile-Sessile Switch in Pseudomonas aeruginosa through the Gac/Rsm Pathway and c-di-GMP Signaling.
SuhB Regulates the Motile-Sessile Switch in Pseudomonas aeruginosa through the Gac/Rsm Pathway and c-di-GMP Signaling.
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SuhB 通过 Gac/Rsm 途径和 c-di-GMP 信号调节铜绿假单胞菌中的运动-固着开关
DOI：
10.3389/fmicb.2017.01045
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发表时间：
2017
影响因子：
5.2
通讯作者：
Bao Q
中科院分区：
文献类型：
--
作者：
Li K;Yang G;Debru AB;Li P;Zong L;Li P;Xu T;Wu W;Jin S;Bao Q
许多铜绿假单胞菌的毒力特性，有助于人类感染被认为是与其环境的生活方式。因此，确定控制生活方式选择的分子机制具有重要意义。我们以前报道，suhB的突变导致游泳运动减少和增加的生物膜形成相比，野生型菌株。然而，很少有人知道这是如何发生的。在这项研究中，我们证明了SuhB通过GacA-RsmY/Z-RsmA级联反应反向调节运动性和生物膜形成。gacA或两个小RNA rsmY/rsmZ的突变，或RsmA蛋白的过度产生基本上挽救了suhB突变体的运动缺陷。此外，我们确定了一个c-di-GMP介导的机制SuhB调节运动和生物膜形成。我们发现ΔsuhB突变体显示c-di-GMP水平升高，并且ΔsuhB运动性和生物膜表型可以通过人为降低c-di-GMP水平来切换。进一步的实验导致鉴定出负责调节ΔsuhB中c-di-GMP浓度的二鸟苷酸环化酶GcbA，从而在促生长和表面相关生长之间切换。总之，我们的研究结果表明，在铜绿假单胞菌中，SuhB通过Gac/Rsm和c-di-GMP信号网络调节生活方式转变的新机制。
Many Pseudomonas aeruginosa virulence traits that contribute to human infections are accepted as being associated with its environmental lifestyle. Therefore, identifying the molecular mechanisms that govern the lifestyle choice is of high significance. We previously reported that a mutation in suhB results in a decrease in swimming motility and increased biofilm formation compared to the wild-type strain. Yet, little is known about how this occurs. In this study, we demonstrated that SuhB inversely regulates motility and biofilm formation through the GacA-RsmY/Z-RsmA cascade. Mutations in gacA or the two small RNAs rsmY/rsmZ, or overproduction of the RsmA protein essentially rescued the motility defect of the suhB mutant. Additionally, we identified a c-di-GMP mediated mechanism for SuhB regulation of motility and biofilm formation. We showed that the ΔsuhB mutant displayed elevated levels of c-di-GMP, and the ΔsuhB motility and biofilm phenotypes could be switched by artificially decreasing c-di-GMP levels. Further experiments led to the identification of the diguanylate cyclase GcbA responsible for regulating the c-di-GMP concentration in ΔsuhB and hence the switch between planktonic and surface-associated growth. Together, our results demonstrate a novel mechanism for SuhB regulation of the lifestyle transition via the Gac/Rsm and c-di-GMP signaling networks in P. aeruginosa.