TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes

PLoS Pathogens

Martin Jakob¹  Nicholas Doiron¹  Achim Schnaufer²  Anneliese Hoffmann³  Bernd Schimanski³  Roman Trikin³  Beat Haenni³  Torsten Ochsenreiter³  Benoît Zuber⁴ 

[1] Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland;Institute of Anatomy, University of Bern, Bern, Switzerland;Institute of Cell Biology, University of Bern, Bern, Switzerland;Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, Scotland, United Kingdom

关键词: Kinetoplasts;    Trypanosoma;    Mitochondria;    RNA interference;    DAPI staining;    Flagella;    Fractionation;    Mitochondrial membrane;   

DOI  :  10.1371/journal.ppat.1005586

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

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.

【 授权许可】

CC BY