动运动抑制剂揭示了FimX在IV型柱体延伸动态中的作用
Nathan Roberge1, Nathan Yuen1, Hanjeong Harvey1
1Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada, L8S4K1.
bioRxiv : the preprint server for biology
|July 17, 2025
概括
通过调节 PilB ATPase 活性,FimX 调节了 Pseudomonas aeruginosa 类型 IV pili (T4P) 的扩展. 抑制器突变增强PilB活性恢复T4P组装和FimX突变中的动性.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 细菌的运动性 细菌的运动性
背景情况:
- 第四类 pili (T4P) 对于*Pseudomonas aeruginosa*表面粘附,感应和动性至关重要,对于急性感染至关重要.
- 柱状延伸由PilB ATPase提供动力,具有像FimX协调组件这样的调节效应,尽管FimX的确切作用尚不清楚.
研究的目的:
- 阐明FimX在调节类型IV pili (T4P) 组合和功能中的作用.
- 确定在没有FimX.的情况下恢复动性的基因抑制剂.
主要方法:
- 基因查以识别 *fimX* 删除突变体中的抑制器突变,该突变体表现出抽运动缺陷.
- 在体外生化试验测量PilB ATPase活性.
- 光显微镜可可视化和量化T4P延伸动态在活体细菌.
主要成果:
- 在循环-AMP恒温机制和PilB ATPase中发现了抑制器突变.
- 特定的PilB突变在体外增强了ATP水解活性,该活性由FimX调节.
- 显微镜检测显示,fimX*突变产生的短,缓慢延伸的皮利,一种由突变促进PilB活动或FimX再引入所拯救的表型.
结论:
- FimX作为PilB酶功能调节剂,控制IV型 pili (T4P) 延伸动态.
- 这一规则允许*Pseudomonas aeruginosa*在响应环境信号时微调柱的组装,从而影响细菌病原性.
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