The TIM translocase in T. brucei contains Rhomboid-like proteins that are essential for mitochondrial protein import

Harsman, Anke Judith (21 September 2015). The TIM translocase in T. brucei contains Rhomboid-like proteins that are essential for mitochondrial protein import (Unpublished). In: MitoCross Symposium 2015. Strasbourg, France. 21.09.2015-22.09.2015.

The parasitic protozoon Trypanosoma brucei is one of the earliest branching eukaryotes that have mitochondria capable of oxidative phosphorylation. Their protein import systems are of similar complexity yet different composition than those in other eukaryotes. To elucidate the composition of the trypanosomal translocase of the inner mitochondrial membrane (TIM) we performed CoIPs of epitope-tagged TbTim17 and two other candidates in combination with SILAC-based quantitative mass spectrometry. This led to the identification of ten candidates for core TIM subunits. Eight of them were present in the previously determined inner membrane proteome and four show homology to small Tim chaperones. Three candidates, a trypanosomatid-specific 42 kDa protein (Tim42) and two putative orthologues of inactive rhomboid proteases were analyzed further. All three proteins are essential in both life cycle stages and their ablation results in a strong protein import defect in vivo and in vitro. Blue native PAGE revealed their presence in a high molecular weight complex. Unlike anticipated, trypanosomes have a highly complex TIM translocase that has extensively been redesigned. None of the three novel TIM subunits has ever been associated with mitochondrial protein import. Two of them belong to the rhomboid protease family, a member of which recently has been implicated in the ERAD translocation system. This suggests an exciting analogy between protein translocases of mitochondria and the ER.

Item Type:

Conference or Workshop Item (Speech)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

Harsman, Anke Judith

Subjects:

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

Language:

English

Submitter:

Christina Schüpbach

Date Deposited:

19 Jan 2016 08:06

Last Modified:

19 Jan 2016 08:10

URI:

https://boris.unibe.ch/id/eprint/74772

Actions (login required)

Edit item Edit item
Provide Feedback