定数感应采用双重调节机制来抑制T3SS基因表达
bioRxiv : the preprint server for biology
|August 30, 2024
概括
病原体Vibrio campbellii使用定数感应来控制其III型分泌系统 (T3SS). 卢克斯R抑制T3SS基因表达在转录和后翻译水平,关闭高细胞密度的毒性.
科学领域:
- 微生物学 微生物学
- 细菌病原体的产生
- 分子生物学分子生物学
背景情况:
- 第三类分泌系统 (T3SS) 是许多细菌病原体的关键毒性因素,包括*Vibrio campbellii*,使毒素能够直接注入宿主细胞.
- T3SS基因表达受到环境线索的严格调节,包括细胞密度 (定数感应),温度和宿主细胞接触.
研究的目的:
- 阐明由何数感应控制Vibrio campbellii*中T3SS基因表达的调节机制.
- 调查主定决数感应调节器LuxR在调节T3SS活动中的作用.
主要方法:
- 基因表达的分析使用促进者-报告者测试.
- 电泳运动转移试验 (EMSAs) 用于确定DNA-蛋白相互作用.
- 突变性研究,以评估调节蛋白的功能.
主要成果:
- LuxR直接抑制了T3SS结构基因的主调节者*exsA*的转录.
- 此外,LuxR还通过抑制*exsC*的转录来间接抑制ExsA的活性,LuxR是一种ExsA的抗抗激活剂.
- 这种由LuxR进行的双重抑制导致T3SS表达在高细胞密度下显著停止.
结论:
- *Vibrio campbellii*采用双重调控策略,包括转录和后翻译控制,以降低对T3SS活动的调控,以应对高细胞密度.
- 这种机制确保当细菌种群达到高密度时,有效关闭毒性因素,可能节约资源并避免宿主免疫检测.
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