在Escherichia coli中,负反循环对于在压力后恢复RpoS至关重要
Sophie Bouillet1, Issam Hamdallah1, Nadim Majdalani1
1Laboratory of Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, Maryland.
bioRxiv : the preprint server for biology
|December 11, 2023
概括
应激反应调节器RpoS (RNA聚合酶sigma-70子单元S) 在大肠杆菌的应激恢复后迅速降解. 这个过程涉及抗适应器IraP和依赖Crl的反循环,恢复正常的细菌功能.
科学领域:
- 微生物学 微生物学
- 细菌应激反应的细菌应激反应
- 基因调节 基因调节
背景情况:
- RpoS (RNA聚合酶sigma-70子单元S) 是泛型蛋白质细菌一般应激反应的关键调节剂,对细菌生存至关重要.
- RpoS水平受到严格控制;在非压力条件下,适应蛋白RssB针对RpoS通过ClpXP蛋白酶降解.
- 压力会诱导抗适配器将RssB隔离起来,防止RpoS降解并稳定其水平.
研究的目的:
- 研究RpoS稳定在细胞应激恢复期间逆转的机制.
- 了解特定因素,如IraP和Crl在压力后RpoS下调中的作用.
主要方法:
- 从各种压力条件 (酸盐饥饿,碳饥饿,静态到指数相位过渡) 恢复后的RpoS降解动态的分析.
- 调查反适配器IraP和适配器RssB在RpoS不稳定中的参与.
- 检查 * rssB * 基因的 RpoS 中介转录和 RpoS 激活器 Crl 在恢复过程中的作用.
主要成果:
- 在从酸盐饥饿,碳饥饿中恢复后以及过渡到指数增长期间,RpoS降解迅速恢复.
- 反适应器IraP有助于恢复RpoS降解,部分是通过与RssB.相互作用.
- 一个反循环涉及RpoS依赖的*rssB*和RpoS激活器Crl的转录,对于高效的RpoS水平恢复至关重要.
结论:
- 细菌细胞在压力停止时有效地逆转RpoS稳定,确保适当的调节.
- RpoS,RssB,IraP和Crl之间的相互作用对压力反应的动态控制至关重要.
- 涉及RpoS和*rssB*转录的反机制确保及时恢复RpoS平衡.
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