Zou Mei, Wang Kaiying, Zhao Jiajun, Lu Huifang, Yang Hui, Huang Meirong, Wang Lu, Wang Guangli, Huang Jian, Min Xun
Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.
School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China.
Front Microbiol. 2023 Apr 5;14:1159986. doi: 10.3389/fmicb.2023.1159986. eCollection 2023.
In bacteria, DegS protease functions as an activating factor of the σ envelope stress response system, which ultimately activates the transcription of stress response genes in the cytoplasm. On the basis of high-throughput RNA sequencing, we have previously found that knockout inhibits the expression of flagellum synthesis- and chemotaxis-related genes, thereby indicating that DegS may be involved in the regulation of motility. In this study, we examined the relationships between DegS and motility in . Swimming motility and chemotaxis assays revealed that or deletion promotes a substantial reduction in the motility and chemotaxis of , whereas these activities were restored in and strains, indicating that DegS is partially dependent on σ to positively regulate activity. Gene-act network analysis revealed that the cAMP-CRP-RpoS signaling pathway, which plays an important role in flagellar synthesis, is significantly inhibited in mutants, whereas in response to the overexpression of and in the strain, the motility and chemotaxis of the + / and + strains were partially restored compared with the strain. We further demonstrated that transcription levels of the flagellar regulatory gene are regulated by DegS the cAMP-CRP-RpoS signaling pathway. Overexpression of the gene in the strain partially restored motility and chemotaxis. In addition, suckling mouse intestinal colonization experiments indicated that the and strains were characterized by the poor colonization of mouse intestines, whereas colonization efficacy was restored in the , , , and strains. Collectively, our findings indicate that DegS regulates the motility and chemotaxis of the cAMP-CRP-RpoS-FlhF pathway, thereby influencing the colonization of suckling mouse intestines.
在细菌中，DegS蛋白酶作为σ包膜应激反应系统的激活因子，最终激活细胞质中应激反应基因的转录。基于高通量RNA测序，我们之前发现敲除会抑制鞭毛合成和趋化相关基因的表达，从而表明DegS可能参与运动性的调控。在本研究中，我们检测了DegS与[细菌名称未给出]运动性之间的关系。游泳运动性和趋化分析表明，[细菌名称未给出]或[基因名称未给出]缺失会导致[细菌名称未给出]的运动性和趋化性大幅降低，而在[菌株名称未给出]和[菌株名称未给出]菌株中这些活性得以恢复，表明DegS部分依赖于σ来正向调节[细菌名称未给出]的活性。基因作用网络分析显示，在鞭毛合成中起重要作用的cAMP - CRP - RpoS信号通路在[细菌名称未给出]突变体中受到显著抑制，而在[细菌名称未给出]菌株中过表达[基因名称未给出]和[基因名称未给出]时，与[细菌名称未给出]菌株相比，[细菌名称未给出]+/[菌株名称未给出]和[细菌名称未给出]+/[菌株名称未给出]菌株的运动性和趋化性部分恢复。我们进一步证明，鞭毛调节基因[基因名称未给出]的转录水平受DegS通过cAMP - CRP - RpoS信号通路调控。在[细菌名称未给出]菌株中过表达[基因名称未给出]基因可部分恢复运动性和趋化性。此外，乳鼠肠道定植实验表明，[细菌名称未给出]和[细菌名称未给出]菌株的特点是在小鼠肠道中的定植能力较差，而在[细菌名称未给出]、[细菌名称未给出]、[细菌名称未给出]和[细菌名称未给出]菌株中定植效果得以恢复。总的来说，我们的研究结果表明，DegS通过cAMP - CRP - RpoS - FlhF途径调节[细菌名称未给出]的运动性和趋化性，从而影响乳鼠肠道的定植。
