The archaic protein translocase of the outer mitochondrial membrane drives organellar tRNA import in Trypanosoma brucei

Huot, Jonathan (20 January 2016). The archaic protein translocase of the outer mitochondrial membrane drives organellar tRNA import in Trypanosoma brucei (Unpublished). In: 1st NCCR RNA and Disease Retreat. Kandersteg, Switzerland. 20.01.2016.

Trypanosoma brucei is a eukaryotic, unicellular pathogen with health and economy related consequences as the causative agent of African trypanosomiasis (Sleeping Sickness) in humans, and nagana in cattle. This organism is a member of the early-branching Excavata phylum and therefore its study also provides a useful outside point of comparison with the abundantly studied Ophistokonta phylum, particularly for ancient, conserved mechanisms. T. brucei is unusual in having lost all of its mitochondrially-encoded tRNA genes. Mitochondrial translation depends on the import of a fraction of the active cytosolic tRNA pool. In yeast, a tRNA is imported bound by a specific protein partner, which raises questions as to how this is organized in T. brucei where more than 30 tRNAs are imported. We have investigated the role of the pore-forming protein of archaic translocase of the outer membrane (ATOM40) of T. brucei in mitochondrial tRNA import and have found that silencing it reduces tRNA levels in the organelle. Silencing of the ATOM46 and ATOM69 receptors, deleterious to protein import, did not reduce mitochondrial tRNA levels significantly. This suggests that tRNA translocation through the outer membrane may by a subfunction of the ATOM complex, relying on ATOM40 and possibly on as-of-yet unidentified protein partners. We are now testing candidates designated because of their role in protein import for their role in tRNA import, and attempting to identify new tRNA import factors through cross-linking and co-immunoprecipitation. This approach is being used concomitantly to identify the proteins responsible for translocation through the inner membrane, in addition to the previously identified TbTim17.

Item Type:

Conference or Workshop Item (Speech)


08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

Huot, Jonathan


500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry




Christina Schüpbach

Date Deposited:

26 Jan 2017 11:34

Last Modified:

26 Jan 2017 11:34


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