特里科莫纳斯基体含有线粒体复合体I的NADH脱酶模块
Ivan Hrdy1, Robert P Hirt, Pavel Dolezal
1Department of Parasitology, Charles University, Vinicna 7, 128 44 Prague 2, Czech Republic.
Nature
|December 4, 2004
概括
无氧真核生物中的有机体,含有来自复杂I的活性NADH脱酶子单元. 这一发现支持了基体和线粒体是源自内共生的同类有机体的假设.
科学领域:
- 细胞生物学 细胞生物学
- 进化生物学 进化生物学
- 生物化学 生物化学
背景情况:
- 基体是无氧真核生物中的双膜有机细胞,负责ATP和的生产.
- 基体的进化起源是有争议的,一些理论认为它们与线粒体相同,或是具有不同的细菌起源.
- 一个关键的问题是,基体如何在酸盐氧化后再生NAD+以实现连续功能.
研究的目的:
- 为了研究Trichomonas vaginalis基体中NADH脱基酶子单元的存在和功能.
- 为了确定体和线粒体复合I组件之间的进化关系.
- 解决基体中NAD+再生的机制及其对内共生理论的影响.
主要方法:
- 生物化学分析检测和描述T. vaginalis基体中的NADH脱酶活性.
- 酶净化和基质特异性的测试,包括乌比金和铁素.
- 对复杂I子单元的遗传学分析,以推断进化关系.
主要成果:
- 在T. vaginalis基体中,NADH脱酶 (复合I) 的51kDa和24kDa子单元是活跃的.
- 净化后的基体酶可减少乌比奎和费雷多克辛,后者对于生产至关重要.
- 遗传学分析表明,51-kDa子单元与其线粒体对应物具有共同的祖先.
结论:
- 基体中活性NADH脱酶的存在解释了酸盐氧化后的NAD+再生.
- 这些发现提供了强有力的证据,表明基体和线粒体是同源的有机体.
- 这支持两个器官的内共生起源,代表有氧 (线粒体) 和无氧 (基体) 形式.
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