Kinetoplastid-specific pATOM36 mediates membrane insertion of a subset of mitochondrial outer membrane proteins

Käser, Sandro (27 April 2015). Kinetoplastid-specific pATOM36 mediates membrane insertion of a subset of mitochondrial outer membrane proteins (Unpublished). In: Kinetoplastid Molecular Cell Biology Meeting. Woods Hole, MA, USA. 25.-29.04.2015.

In trypanosomes, as in other eukaryotes, more than 95% of all mitochondrial proteins are imported into the mitochondrion. The recently characterized multisubunit ATOM complex mediates import of essentially all proteins across the outer mitochondrial membrane in T. brucei. Moreover, an additional protein termed pATOM36, which is loosely associated with the ATOM complex, has been implicated in the import of only a subset of mitochondrial matrix proteins. Here we have investigated more precisely which role pATOM36 plays in mitochondrial protein import. RNAi mediated ablation of pATOM36 specifically depletes a subset of ATOM complex subunits and as a consequence results in the collapse of the ATOM complex as shown by Blue native PAGE. In addition, a SILAC-based global proteomic analysis of uninduced and induced pATOM36 RNAi cells together with in vitro import experiments suggest that pATOM36 might be a novel protein insertase acting on a subset of alpha-helically anchored mitochondrial outer membrane proteins.
Identification of pATOM36 interaction partners by co-immunoprecipitation together with immunofluorescence analysis furthermore shows that unexpectedly a fraction of the protein is associated with the tripartite attachment complex (TAC). This complex is essential for proper inheritance of the kDNA as it forms a physical connection between the kDNA and the basal body of the flagellum throughout the cell cycle. Thus, the presence of pATOM36 in the TAC provides an exciting link between mitochondrial protein import and kDNA inheritance.

Item Type:

Conference or Workshop Item (Speech)

Division/Institute:

08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP)

Graduate School:

Graduate School for Cellular and Biomedical Sciences (GCB)

UniBE Contributor:

Käser, Sandro

Subjects:

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

Language:

English

Submitter:

Christina Schüpbach

Date Deposited:

02 Feb 2016 14:44

Last Modified:

05 Dec 2022 14:51

URI:

https://boris.unibe.ch/id/eprint/75828

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