病毒抑制TIR gcADPR信号以克服细菌防御
Azita Leavitt1, Erez Yirmiya1, Gil Amitai1
1Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
Nature
|September 29, 2022
概括
被称为Tad1的菌体蛋白作为海绵,隔离由Toll/interleukin-1受体 (TIR) 域产生的免疫信号分子. 这种机制抑制了细菌和植物的免疫力,
科学领域:
- 分子生物学
- 免疫学
- 生物化学
背景情况:
- 托尔/互白素-1受体 (TIR) 域对于细菌,植物和动物的免疫反应至关重要.
- 在感染时,TIR域产生信号分子,激活免疫效应器,但它们的结构是未知的.
- 像Thoeris这样的细菌抗菌系统利用TIR域进行防御.
研究的目的:
- 确定TIR域产生的免疫信号分子的分子结构.
- 阐明由菌体编码的蛋白质抑制Thoeris免疫系统的机制.
- 研究菌体蛋白与植物TIR领域衍生分子之间的相互作用.
主要方法:
- 用菌体编码的Thoeris抗防御1 (Tad1) 蛋白的鉴定和特征.
- 生物化学测试以评估Tad1对信号分子的结合和封存.
- 对Tad1与植物分子结合的高分辨率晶体结构的确定.
主要成果:
- Tad1蛋白质的功能如海绵,将TIR域产生的信号分子隔离起来.
- Tad1有效地将来自植物TIR域蛋白质的分子隔离起来.
- 晶体结构显示出一种独特的1' - 2' 糖循环ADPR (gcADPR) 分子.
- TIR蛋白可能会产生1'-3'gcADPR,它比1'-2'gcADPR更有效地激活ThsA.
结论:
- 一个关键的免疫信号分子 (gcADPR) 的化学结构已被定义.
- 菌体编码的Tad1蛋白通过隔离信号分子来抑制宿主免疫的新机制.
- 这一发现揭示了病原体在各种生物体中逃避免疫反应的策略.
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