SARS-CoV-2 核体蛋白通过 RNA 结合域 N2b 抑制 PKR 介导的综合应激反应
Chiara Aloise1, Jelle G Schipper1, Arno van Vliet1
1Virology Section, Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
PLoS pathogens
|August 22, 2023
概括
SARS-CoV-2 核体蛋白 N 通过与 dsRNA 结合来抑制先天免疫,防止 PKR 激活和干扰素反应. 这种由N2b域介导的机制对于病毒复制至关重要,并且在其他冠状病毒中得到保护.
科学领域:
- 病毒学 病毒学
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
背景情况:
- 严重急性呼吸道综合征冠状病毒2 (SARS-CoV-2) 核体 (N) 蛋白包装病毒基因组并对抗天生的抗病毒防御.
- 该N蛋白抑制了综合应激反应 (ISR),并抑制了I型干扰素的产生,可能是通过与G3BP1/2相互作用并阻止应激颗粒的形成.
研究的目的:
- 阐明SARS-CoV-2 N蛋白质抑制先天性抗病毒反应的机制.
- 确定负责抑制ISR和干扰素生产的N蛋白的特定域和功能.
主要方法:
- 系统地删除和过度表达SARS-CoV-2 N蛋白的不同区域和域.
- 评估N蛋白突变对PKR介导的ISR激活,转化停止和压力颗粒形成的影响.
- 评估N蛋白域在脑肌心炎病毒感染模型中的作用,测量PKR激活,干扰素表达和病毒复制.
主要成果:
- N蛋白的N2b域被确定为阻断PKR介导的ISR激活和压力颗粒形成的关键区域.
- 防止双链RNA (dsRNA) 结合的N2b中的突变取消了这些抑制活动,即使在完整的N蛋白中也是如此.
- 通过隔离dRNA,N蛋白抑制先天免疫,防止PKR和RIG-I类受体的激活.
- 对于人类冠状病毒229E的N蛋白也观察到类似的抑制功能,这表明一种保存机制.
结论:
- SARS-CoV-2 N 蛋白质,特别是其 N2b 域,通过隔离 dsRNA 抑制先天免疫力,从而防止 PKR 和 RIG-I 类受体的激活.
- 这种dsRNA封存机制对于抑制抗病毒反应,促进病毒复制至关重要,并且似乎是正确冠状病毒中保存的特征.
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