病毒PKR抑制剂E3宿主范围功能的分子基础
bioRxiv : the preprint server for biology
|May 27, 2024
概括
疫苗病毒 (VACV) E3和K3蛋白质是抑制抗病毒蛋白激酶R (PKR) 的宿主范围因子. VACV E3/K3和PKR之间的特定物种相互作用挑战了E3仅通过隔离双链RNA来抑制PKR的模型.
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:
- 抗病毒蛋白激酶R (PKR) 对于先天免疫至关重要,由病毒双链RNA (dsRNA) 激活,以抑制蛋白质合成.
- 像疫苗病毒 (VACV) 一样,Poxvirus编码了E3和K3等抑制剂,以逃避PKR介导的抗病毒反应,从而影响病毒宿主范围.
- 主流模型认为,E3通过隔离dsRNA来抑制PKR,防止PKR激活.
研究的目的:
- 研究VACV E3和K3抑制剂与PKR.之间的物种特异相互作用.
- 阐明基于子PKR变体对E3和K3的敏感差异的分子机制.
- 挑战和完善PKR抑制中E3功能的现有模型.
主要方法:
- 叙利亚和亚美尼亚仓鼠对E3和K3的PKR敏感性的比较分析.
- 仓鼠PKR的局部定向突变发生,以确定参与抑制剂相互作用的关键残留物.
- 在先天细胞中表达工程子PKR变异,以评估VACV感染表型.
主要成果:
- 叙利亚仓鼠PKR对E3有抗性,但对K3有敏感性,而亚美尼亚仓鼠PKR则表现出相反的敏感性.
- 连接PKR的dsRNA结合和激酶域的区域对E3敏感性至关重要,而激酶域 (螺旋αG) 的两个残留物决定了K3敏感性.
- 工程叙利亚仓鼠PKR与亚美尼亚仓鼠PKR残留在螺旋体αG中对VACV感染产生了耐药性,证实了这些相互作用在宿主范围中的作用.
结论:
- PKR和VACV E3/K3蛋白之间的物种特异性相互作用是病毒宿主范围的关键决定因素.
- 叙利亚仓鼠PKR对E3的耐药性挑战了E3主要通过非特异的dsRNA封存来发挥作用的模型.
- 这些发现突显了病毒逃避机制的复杂性,并建议dRNA结合PKR抑制剂的替代作用模式.
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