Department of Chemistry and Biochemistry, University of Bern, Freiestr. 3, CH-3012 Bern, Switzerland
Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Bern CH-3012, Switzerland
J Cell Sci. 2018 Sep 17;131(18):jcs221820. doi: 10.1242/jcs.221820.
Unlike most other model eukaryotes, and its relatives have a single mitochondrion with a single-unit mitochondrial genome that is termed kinetoplast DNA (kDNA). Replication of the kDNA is coordinated with the cell cycle. During binary mitochondrial fission and prior to cytokinesis, the replicated kDNA has to be faithfully segregated to the daughter organelles. This process depends on the tripartite attachment complex (TAC) that physically links the kDNA across the two mitochondrial membranes with the basal body of the flagellum. Thus, the TAC couples segregation of the replicated kDNA with segregation of the basal bodies of the old and the new flagellum. In this Review, we provide an overview of the role of the TAC in kDNA inheritance in We focus on recent advances regarding the molecular composition of the TAC, and discuss how the TAC is assembled and how its subunits are targeted to their respective TAC subdomains. Finally, we will contrast the segregation of the single-unit kDNA in trypanosomes to mitochondrial genome inheritance in yeast and mammals, both of which have numerous mitochondria that each contain multiple genomes.
与大多数其他模式真核生物不同， 和它的亲缘关系只有一个线粒体，带有一个被称为动基体 DNA（kDNA）的单一线粒体基因组。kDNA 的复制与细胞周期相协调。在二分裂线粒体裂变和胞质分裂之前，复制的 kDNA 必须准确地分配到子细胞器。这个过程依赖于三部分附着复合物（TAC），它将 kDNA 穿过两个线粒体膜与鞭毛的基体物理连接起来。因此，TAC 将复制的 kDNA 的分离与旧和新鞭毛基体的分离联系起来。在这篇综述中，我们概述了 TAC 在 kDNA 遗传中的作用。我们专注于 TAC 分子组成的最新进展，并讨论了 TAC 是如何组装的，以及它的亚基如何靶向它们各自的 TAC 亚结构域。最后，我们将对比锥虫中单单位 kDNA 的分离与酵母和哺乳动物中多个线粒体的线粒体基因组遗传，酵母和哺乳动物中的每个线粒体都包含多个基因组。
