ATP 合酶单点突变可补偿锥虫中线粒体基因组缺失。
Single point mutations in ATP synthase compensate for mitochondrial genome loss in trypanosomes.
机构信息
Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom.
出版信息
Proc Natl Acad Sci U S A. 2013 Sep 3;110(36):14741-6. doi: 10.1073/pnas.1305404110. Epub 2013 Aug 19.
Viability of the tsetse fly-transmitted African trypanosome Trypanosoma brucei depends on maintenance and expression of its kinetoplast (kDNA), the mitochondrial genome of this parasite and a putative target for veterinary and human antitrypanosomatid drugs. However, the closely related animal pathogens T. evansi and T. equiperdum are transmitted independently of tsetse flies and survive without a functional kinetoplast for reasons that have remained unclear. Here, we provide definitive evidence that single amino acid changes in the nuclearly encoded F1FO-ATPase subunit γ can compensate for complete physical loss of kDNA in these parasites. Our results provide insight into the molecular mechanism of compensation for kDNA loss by showing FO-independent generation of the mitochondrial membrane potential with increased dependence on the ADP/ATP carrier. Our findings also suggest that, in the pathogenic bloodstream stage of T. brucei, the huge and energetically demanding apparatus required for kDNA maintenance and expression serves the production of a single F1FO-ATPase subunit. These results have important implications for drug discovery and our understanding of the evolution of these parasites.
采采蝇传播的非洲锥虫(Trypanosoma brucei)的生存能力取决于其动基体(kDNA)的维持和表达,kDNA 是该寄生虫的线粒体基因组,也是兽医和抗锥虫药物的潜在靶点。然而,密切相关的动物病原体 T. evansi 和 T. equiperdum 无需采采蝇即可独立传播,并且在没有功能动基体的情况下存活,其原因仍不清楚。在这里,我们提供了确凿的证据表明,核编码 F1FO-ATP 酶亚基 γ中的单个氨基酸变化可以补偿这些寄生虫中 kDNA 的完全物理缺失。我们的研究结果为 kDNA 缺失的分子机制提供了新的见解,表明 FO 独立的线粒体膜电位产生增加了对 ADP/ATP 载体的依赖性。我们的发现还表明,在 T. brucei 的致病性血液阶段,需要大量能量的庞大的 kDNA 维持和表达装置用于生产单个 F1FO-ATP 酶亚基。这些结果对药物发现和我们对这些寄生虫进化的理解具有重要意义。