在Mycobacterium tuberculosis中对一种必不可少的酶进行脱皮调节者的鉴定
Shoshanna C Kahne1, Jin Hee Yoo1, James Chen2
1Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016.
概括
协酶A生物合成蛋白CoaX调节了Mycobacterium结核病中必需的营养素托酸的丰富性. CoaX控制着泛酸合成酶的作用.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 分子生物学分子生物学
背景情况:
- 结核菌菌 (Mtb) 通过细菌蛋白质体利用一种 prokaryotic ubiquitin-like protein (Pup) 系统来降解蛋白质.
- 由单个Pup-ligase和depopylase调节的瞳孔细胞对Mtb生存至关重要,但基质特异性机制尚不清楚.
研究的目的:
- 确定脱皮的调节剂,并了解它们在Mtb Pup-proteasome系统 (PPS) 中对基质特异性的作用.
- 阐明Coenzyme A生物合成蛋白CoaX在调节泛氨酸代谢和蛋白质降解中的功能.
主要方法:
- 与脱皮酶Dop共同净化CoaX以确定脱皮调节剂.
- 酶性测试以评估CoaX与潘托酸的相互作用及其对Pup~PanB脱皮化的影响.
- 对∆coaX突变菌株的分析,以确定对泛多酸合成酶和PanB水平的影响.
主要成果:
- CoaX被确定为一种脱皮调节剂,它结合泛酸盐,但不酸化它.
- 在∆coaX突变体中,包括PanB在内的托酸合成酶被上调.
- 在试验室中,CoaX加速了Pup~PanB脱皮化,这种效果被泛氨酸抑制;泛氨酸补充剂以依赖于CoaX的方式降低了PanB水平.
结论:
- CoaX 作为泛酸盐水平的传感器,调节了 PanB.的稳定性.
- CoaX通过影响其易受Mtb蛋白质酶蛋白解的敏感性来调节PanB的丰富性,将营养素的可用性与蛋白质周转率联系起来.
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