Homologue replacement in the import motor of the mitochondrial inner membrane of trypanosomes
Abstract
Many mitochondrial proteins contain N-terminal presequences that direct them to the organelle. The main driving force for their translocation across the inner membrane is provided by the presequence translocase-associated motor (PAM) which contains the J-protein Pam18. Here, we show that in the PAM of Trypanosoma brucei the function of Pam18 has been replaced by the non-orthologous euglenozoan-specific J-protein TbPam27. TbPam27 is specifically required for the import of mitochondrial presequence-containing but not for carrier proteins. Similar to yeast Pam18, TbPam27 requires an intact J-domain to function. Surprisingly, T. brucei still contains a bona fide Pam18 orthologue that, while essential for normal growth, is not involved in protein import. Thus, during evolution of kinetoplastids, Pam18 has been replaced by TbPam27. We propose that this replacement is linked to the transition from two ancestral and functionally distinct TIM complexes, found in most eukaryotes, to the single bifunctional TIM complex present in trypanosomes.
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All produced data are contained within the manuscript (e.g. Data Source files)
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Author details
Funding
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (175563)
- Andre Schneider
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (NCCR RNA and Disease)
- Andre Schneider
ERC Consolidator grant (648235)
- Bettina Warscheid
Deutsche Forschungsgemeinschaft (403222702/SFB 1381)
- Bettina Warscheid
Germany's Excellence Strategy (CIBSS - EXC-2189 - Project ID 390939984)
- Bettina Warscheid
Excellence Initiative of the German Federal and State Governments (EXC 294 BIOSS)
- Bettina Warscheid
Peter und Traudl Engelhorn foundation
- Anke Harsman
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Agnieszka Chacinska, University of Warsaw, Poland
Publication history
- Received: October 8, 2019
- Accepted: February 26, 2020
- Accepted Manuscript published: February 27, 2020 (version 1)
- Version of Record published: March 10, 2020 (version 2)
Copyright
© 2020, von Känel et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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