title: TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes.
abstract: Trypanosomes show an intriguing organization of their mitochondrial DNA into a catenated network, the kinetoplast DNA (kDNA). While more than 30 proteins involved in kDNA replication have been described, only few components of kDNA segregation machinery are currently known. Electron microscopy studies identified a high-order structure, the tripartite attachment complex (TAC), linking the basal body of the flagellum via the mitochondrial membranes to the kDNA. Here we describe TAC102, a novel core component of the TAC, which is essential for proper kDNA segregation during cell division. Loss of TAC102 leads to mitochondrial genome missegregation but has no impact on proper organelle biogenesis and segregation. The protein is present throughout the cell cycle and is assembled into the newly developing TAC only after the pro-basal body has matured indicating a hierarchy in the assembly process. Furthermore, we provide evidence that the TAC is replicated de novo rather than using a semi-conservative mechanism. Lastly, we demonstrate that TAC102 lacks an N-terminal mitochondrial targeting sequence and requires sequences in the C-terminal part of the protein for its proper localization.
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.|Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
authors.forename: Roman
authors.initials: R
authors.lastname: Trikin
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Doiron
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.|Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
authors.forename: Anneliese
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Institute of Anatomy, University of Bern, Bern, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Haenni
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Jakob
authors.affiliation: Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, Scotland, United Kingdom.
authors.forename: Achim
authors.initials: A
authors.lastname: Schnaufer
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Schimanski
authors.affiliation: Institute of Anatomy, University of Bern, Bern, Switzerland.
authors.forename: Benoît
authors.initials: B
authors.lastname: Zuber
authors.affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.
authors.forename: Torsten
authors.initials: T
authors.lastname: Ochsenreiter
mesh_terms: D020090:Chromosome Segregation / Q000502:physiology*; D018105:DNA, Kinetoplast / Q000378:metabolism; D005407:Flagella; D005455:Fluorescent Antibody Technique; D054629:Genome, Mitochondrial; D015151:Immunoblotting; D046529:Microscopy, Electron, Transmission; D015800:Protozoan Proteins / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D018105:DNA, Kinetoplast; D015800:Protozoan Proteins