聚A结合蛋白通过增强酸化eIFiso4F和eIFiso4F∙eIF4B的结合促进了病毒的VPg依赖转化
Mateen A Khan1, Sumeyra Yumak2, Hiroshi Miyoshi3
1Department of Life Sciences, College of Science and General Studies, Alfaisal University Riyadh, Riyadh, Saudi Arabia.
PloS one
|May 2, 2024
概括
植物转化因子,如真核细胞启动因子iso4F (eIFiso4F) 被酸化,影响蛋白质合成. 这项研究表明,素酶2酸化物小麦eIFiso4E,通过促进VPg结合来增强病毒mRNA翻译.
科学领域:
- 分子生物学分子生物学
- 植物科学 植物科学
- 病毒学 病毒学
背景情况:
- 欧核细胞转化启动因子的酸化调节了蛋白质合成.
- 植物启动因子在应对环境压力和病毒感染时经历酸化/脱酸化.
研究的目的:
- 调查素激酶2在酸化小麦真核生物启动因子中的作用.
- 阐明化eIFiso4F增强病毒mRNA翻译的机制,特别是未封闭的mRNA.
主要方法:
- 在实验室中使用素激酶2进行重组小麦eIFiso4E和eIFiso4G的酸化.
- 对小麦eIFiso4E.E.上的酸化部位的分析.
- 使用枯竭的小麦芽提取物 (WGE) 进行翻译试验,其中使用了VPg,化eIFiso4F (eIFiso4Fp),PABP和eIF4B的不同组合.
- 使用表面等离子体共振或类似技术,确定VPg和eIFiso4Fp之间的结合亲缘关系 (Kd).
- 对VPg-eIFiso4Fp相互作用的热力学分析.
主要成果:
- 凯激酶2酸化小麦eIFiso4E在Ser-207和eIFiso4G在体外.
- 化eIFiso4F增强了WGE中封闭和未封闭的病毒mRNA的翻译.
- 化eIFiso4F促进VPg结合,同时可能阻碍盖结合,有利于未盖的mRNA转化.
- PABP和eIF4B显著增加了VPg与eIFiso4Fp的结合亲和力 (Kd = 24 ± 1.7 nM与41.0 ± 3.1 nM对比).
- VPg-eIFiso4Fp相互作用是以力驱动的,这表明它对键有作用.
结论:
- 小麦eIFiso4E是由素激酶2酸化,影响VPg结合.
- TEV病毒可能利用一种涉及化eIFiso4Fp和PABP的机制进行VPg依赖的翻译.
- PABP与eIFiso4Fp·4B的结合诱导了形状变化,稳定了VPg-eIFiso4Fp复合体并增强了病毒翻译.
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