通过I开关I的酸化通过Toxoplasma gondii对Irgb6无活化的结构基础
Hiromichi Okuma1, Yumiko Saijo-Hamano1, Hiroshi Yamada2
1Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Genes to cells : devoted to molecular & cellular mechanisms
|November 20, 2023
概括
在Thr95中对Irgb6的酸化会在Toxoplasma gondii感染期间使这种免疫蛋白失活. 这一发现揭示了一种新的全性机制,控制了细胞对寄生虫的自主免疫力.
科学领域:
- 免疫学 免疫学 免疫学
- 细胞生物学 细胞生物学
- 寄生虫学的寄生虫学
背景情况:
- 与免疫相关的GTPase (IRG) 对细胞内病原体的细胞自主免疫至关重要.
- Irgb6是一种初始化IRG,其向的是Toxoplasma gondii的寄生虫性真空体 (PV).
- 寄生虫感染后IRG无活化的机制在很大程度上是未知的.
研究的目的:
- 为了阐明Toxoplasma gondii感染后Irgb6无活化的分子机制.
- 研究Irgb6酸化在调节其功能和局部化的作用.
主要方法:
- 局部定向的突变发生,以产生相仿的Irgb6变体 (T95D).
- 使用显微镜分析Irgb6局部化到T. gondii PV.
- 在体外GTPase活性测定.
- 结构分析和in silico对接,以评估蛋白质构成和膜结合.
主要成果:
- 在感染低毒性II型T. gondii时,Irgb6的Thr95被酸化.
- 一种相仿T95D突变损害了Irgb6 PV局部化,并降低了GTPase活性.
- 结构分析揭示了Irgb6-T95D的异常构造,影响G域和PV膜结合接口.
- 在合式对接证实了生理膜结合部位的破坏.
结论:
- 在Thr95处,T. gondii感染会诱导Irgb6的酸化,导致其失活.
- 这种酸化事件触发了全形状变化,损害了Irgb6的功能和局部化.
- 这些发现揭示了T. gondii驱动的Irgb6全性失活机制,这对于调节宿主免疫力至关重要.
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