细菌的陪伴者CsgC通过促进内在无序的核前状态来抑制功能性粉样CsgA的形成
bioRxiv : the preprint server for biology
|April 1, 2025
概括
在大肠杆菌中,Curli粉样蛋白的形成被CsgC抑制,CsgC是一种伴侣蛋白. 这项研究表明,CsgC干扰了早期核形成和后来的纤维延长,在卷曲组装的多个阶段起作用.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 大肠杆菌 (大肠杆菌) 使用纹纤维形成生物膜,这些纤维是功能性粉样蛋白.
- 曲线纤维是CsgA蛋白的聚合物,在纤维化过程中采用了富含β片的结构.
- CsgC是一种伴侣类蛋白质,抑制了CsgA粉样蛋白的形成.
研究的目的:
- 研究CsgC抑制CsgA粉样蛋白形成的机制.
- 为了确定CsgC是否抑制粉样蛋白形成的初始核化或晚期延长阶段.
- 描述来自其他细菌物种的CsgC同类的抑制活性.
主要方法:
- 来自C.youngae,C.davisae和H.alvei的CsgC同类的净化和表征.
- 在CsgC的存在下监测CsgA粉样蛋白形成动力学.
- 使用离子流动性质谱法来检测CsgC-CsgA相互作用.
- 评估CsgC对活性聚合CsgA和预制CsgA种子的影响.
主要成果:
- CsgC同类物延长了大肠杆菌CsgA粉样蛋白形成的滞后阶段,类似于大肠杆菌CsgC.
- 大肠杆菌CsgC与单体,前核CsgA暂时相互作用,延迟了粉样蛋白的形成.
- 观察到一种短暂的CsgC-CsgA异构体.
- 除了积极聚合的CsgC外,CsgA废除了指数增长,预制的CsgA种子没有挽救增长.
- CsgC与CsgA纤维强烈相互作用,抑制了新的纤维生长.
结论:
- CsgC表现出对CsgA粉样蛋白形成的多阶段抑制活性.
- CsgC充当一个能量独立的伴侣,与前纤维素CsgA和粉样蛋白纤维相互作用.
- 这种双重的抑制作用表明,CsgC在子生物发生过程中起着复杂的调节作用.
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