Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA.
Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA.
Int J Mol Sci. 2024 Jan 24;25(3):1415. doi: 10.3390/ijms25031415.
The infectious agent for African trypanosomiasis, , possesses a unique and essential translocase of the mitochondrial inner membrane, known as the TbTIM17 complex. TbTim17 associates with six small TbTims (TbTim9, TbTim10, TbTim11, TbTim12, TbTim13, and TbTim8/13). However, the interaction patterns of these smaller TbTims with each other and TbTim17 are not clear. Through yeast two-hybrid (Y2H) and co-immunoprecipitation analyses, we demonstrate that all six small TbTims interact with each other. Stronger interactions were found among TbTim8/13, TbTim9, and TbTim10. However, TbTim10 shows weaker associations with TbTim13, which has a stronger connection with TbTim17. Each of the small TbTims also interacts strongly with the C-terminal region of TbTim17. RNAi studies indicated that among all small TbTims, TbTim13 is most crucial for maintaining the steady-state levels of the TbTIM17 complex. Further analysis of the small TbTim complexes by size exclusion chromatography revealed that each small TbTim, except for TbTim13, is present in ~70 kDa complexes, possibly existing in heterohexameric forms. In contrast, TbTim13 is primarily present in the larger complex (>800 kDa) and co-fractionates with TbTim17. Altogether, our results demonstrate that, relative to other eukaryotes, the architecture and function of the small TbTim complexes are specific to .
引起非洲锥虫病的病原体 拥有一种独特而必需的线粒体内膜易位酶，称为 TbTIM17 复合物。TbTim17 与六个小的 TbTims（TbTim9、TbTim10、TbTim11、TbTim12、TbTim13 和 TbTim8/13）相关联。然而，这些较小的 TbTims 彼此以及与 TbTim17 的相互作用模式尚不清楚。通过酵母双杂交（Y2H）和共免疫沉淀分析，我们证明了这六个小的 TbTims 彼此之间相互作用。在 TbTim8/13、TbTim9 和 TbTim10 之间发现了更强的相互作用。然而，TbTim10 与 TbTim13 的关联较弱，而 TbTim13 与 TbTim17 的关联较强。每个小的 TbTim 也与 TbTim17 的 C 端区域强烈相互作用。RNAi 研究表明，在所有小的 TbTims 中，TbTim13 对于维持 TbTIM17 复合物的稳态水平最为关键。通过大小排阻层析对小 TbTim 复合物进一步分析表明，除了 TbTim13 之外，每个小的 TbTim 都存在于~70 kDa 的复合物中，可能以异六聚体形式存在。相比之下，TbTim13 主要存在于较大的复合物（>800 kDa）中，并与 TbTim17 共分馏。总的来说，我们的结果表明，与其他真核生物相比，小 TbTim 复合物的结构和功能是 特有的。
