Department of Mitochondrial Biology, Max-Planck-Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, 50931 Cologne, Germany; Faculty of Mathematics and Natural Sciences, University of Cologne, Albertus-Magnus-Platz, 50923 Cologne, Germany.
Department of Medical Biochemistry and Biophysics, Research Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 65 Solna, Sweden; Max-Planck-Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
Cell Rep. 2019 Nov 5;29(6):1728-1738.e9. doi: 10.1016/j.celrep.2019.09.080.
Mitochondria harbor specialized ribosomes (mitoribosomes) necessary for the synthesis of key membrane proteins of the oxidative phosphorylation (OXPHOS) machinery located in the mitochondrial inner membrane. To date, no animal model exists to study mitoribosome composition and mitochondrial translation coordination in mammals in vivo. Here, we create MitoRibo-Tag mice as a tool enabling affinity purification and proteomics analyses of mitoribosomes and their interactome in different tissues. We also define the composition of an assembly intermediate formed in the absence of MTERF4, necessary for a late step in mitoribosomal biogenesis. We identify the orphan protein PUSL1, which interacts with a large subunit assembly intermediate, and demonstrate that it is an inner-membrane-associated mitochondrial matrix protein required for efficient mitochondrial translation. This work establishes MitoRibo-Tag mice as a powerful tool to study mitoribosomes in vivo, enabling future studies on the mitoribosome interactome under different physiological states, as well as in disease and aging.
线粒体拥有专门的核糖体（线粒体核糖体），对于合成位于线粒体内膜的氧化磷酸化（OXPHOS）机器的关键膜蛋白是必需的。迄今为止，还没有动物模型可以在体内研究哺乳动物的线粒体核糖体组成和线粒体翻译协调。在这里，我们创建了 MitoRibo-Tag 小鼠，作为一种工具，可以用于亲和纯化和不同组织中线粒体核糖体及其相互作用组的蛋白质组学分析。我们还定义了在没有 MTERF4 的情况下形成的组装中间体的组成，这对于线粒体核糖体生物发生的最后一步是必需的。我们鉴定了孤儿蛋白 PUSL1，它与大亚基组装中间体相互作用，并证明它是一种与内膜相关的线粒体基质蛋白，对于有效的线粒体翻译是必需的。这项工作确立了 MitoRibo-Tag 小鼠作为研究体内线粒体核糖体的有力工具，使未来能够在不同生理状态下、在疾病和衰老中研究线粒体核糖体相互作用组。
