Unique Interactions of the Small Translocases of the Mitochondrial Inner Membrane (Tims) in <i>Trypanosoma brucei</i>

The infectious agent for African trypanosomiasis, <i>Trypanosoma brucei</i>, 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...

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Bibliographic Details
Main Authors: Linda S. Quiñones, Fidel Soto Gonzalez, Chauncey Darden, Muhammad Khan, Anuj Tripathi, Joseph T. Smith, Jamaine Davis, Smita Misra, Minu Chaudhuri
Format: Article
Language:English
Published: MDPI AG 2024-01-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/25/3/1415
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Summary:The infectious agent for African trypanosomiasis, <i>Trypanosoma brucei</i>, 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 <i>T. brucei</i>.
ISSN:1661-6596
1422-0067