在Bacillus anthracis中产生毒素的环境调节
Ankur Bothra1, Andrei Pomerantsev1, Benjamin Schwarz2
1Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
PLoS pathogens
|December 1, 2025
概括
甲状腺杆菌毒性因子的产生受转录因子AtxA的调节,该转录因子通过葡萄糖光转移酶系统 (PTS) 集成葡萄糖和CO2信号. 这种涉及PtsG和histidine phosphorelay的相互作用对于毒素基因表达和细菌致病性至关重要.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 病变的发生和发病.
背景情况:
- 病原性 Bacillus anthracis 使用质粒 pX01 和 pX02 进行毒性,分别编码外毒素和囊.
- 多域转录因子AtxA调节这些毒性基因,拥有螺旋转 (HTH) 和转移酶系统调节域 (PRD1,PRD2).
- 像葡萄糖和CO2这样的环境因素通过PRD1和PRD2的histidine酸化影响AtxA活性和毒性基因表达.
研究的目的:
- 阐明Bacillus anthracis中AtxA依赖的毒性基因表达的调节机制.
- 研究葡萄糖转移酶系统 (PTS) 和其组件在AtxA调节中的作用.
- 了解葡萄糖和二氧化碳对毒素产生和细菌致病性的协同作用.
主要方法:
- 病毒性因子的转录分析和PA分泌量测试.
- 光记者菌株分析和删除突变结构 (ΔatxA, ΔptsG, Δpyc).
- 对AtxA的EIIB域的突变分析,用于蛋白质相互作用研究的FLIM,以及使用相仿/代突变物.
主要成果:
- 葡萄糖和CO2协同增强AtxA-依赖的毒素的产生.
- 删除AtxA减少了细菌的葡萄糖吸收,这意味着AtxA在葡萄糖-PTS中.
- 删除PtsG在小鼠模型中显著降低了毒素表达和细菌毒性.
- PtsG与AtxA的EIIB领域之间的物理相互作用对于AtxA活动至关重要.
- 通过Pyc删除证实了PEP在通过葡萄糖-PTS基中继体增强AtxA活性方面的作用.
结论:
- AtxA作为葡萄糖-PTS的组成部分,将环境信号与毒性基因表达联系起来.
- 烯酸 (PEP) 中的一种histidine phosphorelay通过与PtsG的物理相互作用来调节AtxA的活性.
- 通过葡萄糖-PTS通过葡萄糖和CO2的协同调节对于Bacillus anthracis的致病性至关重要.
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