Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany.
Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany; Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany.
Cell Metab. 2015 May 5;21(5):747-55. doi: 10.1016/j.cmet.2015.04.007.
The mitochondrial contact site and cristae organizing system (MICOS) is a conserved multi-subunit complex crucial for maintaining the characteristic architecture of mitochondria. Studies with deletion mutants identified Mic10 and Mic60 as core subunits of MICOS. Mic60 has been studied in detail; however, topogenesis and function of Mic10 are unknown. We report that targeting of Mic10 to the mitochondrial inner membrane requires a positively charged internal loop, but no cleavable presequence. Both transmembrane segments of Mic10 carry a characteristic four-glycine motif, which has been found in the ring-forming rotor subunit of F1Fo-ATP synthases. Overexpression of Mic10 profoundly alters the architecture of the inner membrane independently of other MICOS components. The four-glycine motifs are dispensable for interaction of Mic10 with other MICOS subunits but are crucial for the formation of large Mic10 oligomers. Our studies identify a unique role of Mic10 oligomers in promoting the formation of inner membrane crista junctions.
线粒体接触和嵴组织系统（MICOS）是一个保守的多亚基复合物，对于维持线粒体的特征结构至关重要。通过缺失突变体的研究，确定了 Mic10 和 Mic60 是 MICOS 的核心亚基。Mic60 已经被详细研究过；然而，Mic10 的拓扑发生和功能尚不清楚。我们报告说，Mic10 靶向线粒体内膜需要一个带正电荷的内部环，但不需要可切割的前导序列。Mic10 的两个跨膜段都带有特征的四甘氨酸基序，该基序存在于 F1Fo-ATP 合酶的环形转子亚基中。Mic10 的过表达会独立于其他 MICOS 成分深刻地改变内膜的结构。四甘氨酸基序对于 Mic10 与其他 MICOS 亚基的相互作用不是必需的，但对于形成大的 Mic10 寡聚物是至关重要的。我们的研究确定了 Mic10 寡聚物在促进内膜嵴连接形成中的独特作用。
