Translation initiation of leaderless and polycistronic transcripts in mammalian mitochondria
| العنوان: | Translation initiation of leaderless and polycistronic transcripts in mammalian mitochondria |
|---|---|
| المؤلفون: | Cristina Remes, Anas Khawaja, Sarah F Pearce, Adam M Dinan, Shreekara Gopalakrishna, Miriam Cipullo, Vasileios Kyriakidis, Jingdian Zhang, Xaquin Castro Dopico, Olessya Yukhnovets, Ilian Atanassov, Andrew E Firth, Barry Cooperman, Joanna Rorbach |
| المساهمون: | Gopalakrishna, Shreekara [0000-0002-8555-0292], Atanassov, Ilian [0000-0001-8259-2545], Rorbach, Joanna [0000-0002-2891-2840], Apollo - University of Cambridge Repository |
| المصدر: | Nucleic acids research 51(2), 891-907 (2023). doi:10.1093/nar/gkac1233 |
| بيانات النشر: | Oxford Univ. Press, 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Mammals, Mitochondrial Proteins, Bacteria, Peptide Initiation Factors, ddc:570, Genetics, Animals, Humans, RNA, Messenger, Peptide Chain Initiation, Translational, Mitochondria |
| الوصف: | Funder: International Helmholtz Research School of Biophysics and Soft Matter Funder: Karolinska Institutet The synthesis of mitochondrial OXPHOS complexes is central to cellular metabolism, yet many molecular details of mitochondrial translation remain elusive. It has been commonly held view that translation initiation in human mitochondria proceeded in a manner similar to bacterial systems, with the mitoribosomal small subunit bound to the initiation factors, mtIF2 and mtIF3, along with initiator tRNA and an mRNA. However, unlike in bacteria, most human mitochondrial mRNAs lack 5' leader sequences that can mediate small subunit binding, raising the question of how leaderless mRNAs are recognized by mitoribosomes. By using novel in vitro mitochondrial translation initiation assays, alongside biochemical and genetic characterization of cellular knockouts of mitochondrial translation factors, we describe unique features of translation initiation in human mitochondria. We show that in vitro, leaderless mRNA transcripts can be loaded directly onto assembled 55S mitoribosomes, but not onto the mitoribosomal small subunit (28S), in a manner that requires initiator fMet-tRNAMet binding. In addition, we demonstrate that in human cells and in vitro, mtIF3 activity is not required for translation of leaderless mitochondrial transcripts but is essential for translation of ATP6 in the case of the bicistronic ATP8/ATP6 transcript. Furthermore, we show that mtIF2 is indispensable for mitochondrial protein synthesis. Our results demonstrate an important evolutionary divergence of the mitochondrial translation system and further our fundamental understanding of a process central to eukaryotic metabolism. |
| وصف الملف: | application/pdf |
| اللغة: | English |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6a43cefb429b702d650f138bf4a239fa https://hdl.handle.net/2128/34449 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....6a43cefb429b702d650f138bf4a239fa |
| قاعدة البيانات: | OpenAIRE |
| الوصف غير متاح. |