2025-11-13 理化学研究所,東京大学,東北大学,熊本大学,筑波大学
MitoIP-Thor-Ribo-Seq法によるミトコンドリア翻訳のダイナミクスと複雑性の解明
<関連情報>
- https://www.riken.jp/press/2025/20251113_1/index.html
- https://www.sciencedirect.com/science/article/abs/pii/S1097276525008639
ミトコンドリア翻訳の複雑さとダイナミクスのモニタリング Monitoring the complexity and dynamics of mitochondrial translation
Taisei Wakigawa, Mari Mito, Yushin Ando, Haruna Yamashiro, Kotaro Tomuro, Haruna Tani, Kazuhito Tomizawa, Takeshi Chujo, Asuteka Nagao, Takeo Suzuki, Osamu Nureki, Fan-Yan Wei, Yuichi Shichino, Yuzuru Itoh, Tsutomu Suzuki, Shintaro Iwasaki
Molecular Cell Available online: 12 November 2025
DOI:https://doi.org/10.1016/j.molcel.2025.10.022
Highlights
- MitoIP-Thor-Ribo-seq with retapamulin reveals the mitochondrial translation kinetics
- mtIF3 drives internal ORF initiation
- Mitoribosomes pause and form queues when tRNA anticodon stem loops are not modified
- MitoIP-Thor-Disome-seq maps mitoribosome collision sites at codon resolution
Summary
Since mitochondrial translation leads to the synthesis of the essential oxidative phosphorylation (OXPHOS) subunits, exhaustive and quantitative delineation of mitoribosome traversal is needed. Here, we developed a variety of high-resolution mitochondrial ribosome profiling derivatives and revealed the intricate regulation of mammalian mitochondrial translation. Harnessing a translation inhibitor, retapamulin, our approach assessed the stoichiometry and kinetics of mitochondrial translation flux, such as the number of mitoribosomes on a transcript, the elongation rate, and the initiation rate. We also surveyed the impacts of modifications at the anticodon stem loop in mitochondrial tRNAs (mt-tRNAs), including all possible modifications at the 34th position, in cells deleting the corresponding enzymes and derived from patients, as well as in mouse tissues. Moreover, a retapamulin-assisted derivative and mito-disome profiling revealed mitochondrial translation initiation factor (mtIF) 3-mediated translation initiation from internal open reading frames (ORFs) and programmed mitoribosome collision sites across the mitochondrial transcriptome. Our work provides a useful platform for investigating protein synthesis within the energy powerhouse of the cell.
