一种细菌III型效应体家族的松氨酸溶解酶活性
1National Institute of Biological Sciences, Beijing, 102206, China.
概括
石格拉细菌使用III型分泌系统注射OspF,这种蛋白质通过去除酸盐组来使基因激活蛋白激酶 (MAPKs) 失活. 这种索氨酸溶解活性会破坏宿主细胞的信号传递.
科学领域:
- 微生物学 微生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 病原性细菌使用III型分泌系统 (T3SS) 将效应蛋白注入宿主细胞.
- 这些效应器操纵宿主细胞信号通路,以促进感染.
- 中原激活蛋白激酶 (MAPKs) 是重要的信号分子,通常是细菌病原体的目标.
研究的目的:
- 调查Shigella III型效应物 OspF 通过何种机制使基因激活蛋白激酶 (MAPKs) 不活化.
- 描述负责OspF介导的MAPK失活的酶活性.
主要方法:
- 在体外测试以评估OspF在MAPK上的酶活性.
- 质谱测量用于分析OspF治疗后MAPKs的修改.
- 将OspF活性与其他相关的效应蛋白进行比较.
主要成果:
- 石格拉 OspF 无可逆转地使MAPK 失活,包括细胞外信号调节激酶 1 和 2 (Erk1/2),c-Jun N-终端激酶和p38.
- 在MAPK激活循环中,OspF专门从phosphothreonine残留物中去除酸盐组.
- 质谱测量证实了p-Erk2的98达尔顿质量损失,这表明三烯分裂.
- 这种新型的酶活性被称为三氨酸酶,并且在OspF家族成员中被发现是保存的.
结论:
- OspF作为索氨酸溶解酶起作用,向MAPK进行非激活.
- 这种酶活性代表了细菌操纵宿主信号通路的新机制.
- 对于MAPK的特异性表明Shigella有一个有针对性的策略来破坏宿主防御.
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