1
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Dinh N, Bonnefoy N. Schizosaccharomyces pombe as a fundamental model for research on mitochondrial gene expression: Progress, achievements and outlooks. IUBMB Life 2024; 76:397-419. [PMID: 38117001 DOI: 10.1002/iub.2801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023]
Abstract
Schizosaccharomyces pombe (fission yeast) is an attractive model for mitochondrial research. The organism resembles human cells in terms of mitochondrial inheritance, mitochondrial transport, sugar metabolism, mitogenome structure and dependence of viability on the mitogenome (the petite-negative phenotype). Transcriptions of these genomes produce only a few polycistronic transcripts, which then undergo processing as per the tRNA punctuation model. In general, the machinery for mitochondrial gene expression is structurally and functionally conserved between fission yeast and humans. Furthermore, molecular research on S. pombe is supported by a considerable number of experimental techniques and database resources. Owing to these advantages, fission yeast has significantly contributed to biomedical and fundamental research. Here, we review the current state of knowledge regarding S. pombe mitochondrial gene expression, and emphasise the pertinence of fission yeast as both a model and tool, especially for studies on mitochondrial translation.
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Affiliation(s)
- Nhu Dinh
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
| | - Nathalie Bonnefoy
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
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2
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Antolínez-Fernández Á, Esteban-Ramos P, Fernández-Moreno MÁ, Clemente P. Molecular pathways in mitochondrial disorders due to a defective mitochondrial protein synthesis. Front Cell Dev Biol 2024; 12:1410245. [PMID: 38855161 PMCID: PMC11157125 DOI: 10.3389/fcell.2024.1410245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/09/2024] [Indexed: 06/11/2024] Open
Abstract
Mitochondria play a central role in cellular metabolism producing the necessary ATP through oxidative phosphorylation. As a remnant of their prokaryotic past, mitochondria contain their own genome, which encodes 13 subunits of the oxidative phosphorylation system, as well as the tRNAs and rRNAs necessary for their translation in the organelle. Mitochondrial protein synthesis depends on the import of a vast array of nuclear-encoded proteins including the mitochondrial ribosome protein components, translation factors, aminoacyl-tRNA synthetases or assembly factors among others. Cryo-EM studies have improved our understanding of the composition of the mitochondrial ribosome and the factors required for mitochondrial protein synthesis and the advances in next-generation sequencing techniques have allowed for the identification of a growing number of genes involved in mitochondrial pathologies with a defective translation. These disorders are often multisystemic, affecting those tissues with a higher energy demand, and often present with neurodegenerative phenotypes. In this article, we review the known proteins required for mitochondrial translation, the disorders that derive from a defective mitochondrial protein synthesis and the animal models that have been established for their study.
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Affiliation(s)
- Álvaro Antolínez-Fernández
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Esteban-Ramos
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Ángel Fernández-Moreno
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Clemente
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
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3
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Hughes LA, Rackham O, Filipovska A. Illuminating mitochondrial translation through mouse models. Hum Mol Genet 2024; 33:R61-R79. [PMID: 38779771 PMCID: PMC11112386 DOI: 10.1093/hmg/ddae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/22/2024] [Accepted: 01/31/2024] [Indexed: 05/25/2024] Open
Abstract
Mitochondria are hubs of metabolic activity with a major role in ATP conversion by oxidative phosphorylation (OXPHOS). The mammalian mitochondrial genome encodes 11 mRNAs encoding 13 OXPHOS proteins along with 2 rRNAs and 22 tRNAs, that facilitate their translation on mitoribosomes. Maintaining the internal production of core OXPHOS subunits requires modulation of the mitochondrial capacity to match the cellular requirements and correct insertion of particularly hydrophobic proteins into the inner mitochondrial membrane. The mitochondrial translation system is essential for energy production and defects result in severe, phenotypically diverse diseases, including mitochondrial diseases that typically affect postmitotic tissues with high metabolic demands. Understanding the complex mechanisms that underlie the pathologies of diseases involving impaired mitochondrial translation is key to tailoring specific treatments and effectively targeting the affected organs. Disease mutations have provided a fundamental, yet limited, understanding of mitochondrial protein synthesis, since effective modification of the mitochondrial genome has proven challenging. However, advances in next generation sequencing, cryoelectron microscopy, and multi-omic technologies have revealed unexpected and unusual features of the mitochondrial protein synthesis machinery in the last decade. Genome editing tools have generated unique models that have accelerated our mechanistic understanding of mitochondrial translation and its physiological importance. Here we review the most recent mouse models of disease pathogenesis caused by defects in mitochondrial protein synthesis and discuss their value for preclinical research and therapeutic development.
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Affiliation(s)
- Laetitia A Hughes
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
| | - Oliver Rackham
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
- Curtin Medical School, Curtin University, Kent Street, Bentley, WA 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Aleksandra Filipovska
- Telethon Kids Institute, Northern Entrance, Perth Children’s Hospital, 15 Hospital Avenue, Nedlands, WA 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, 35 Stirling Highway, Crawley, WA 6009, The University of Western Australia, Crawley, WA 6009, Australia
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, 19 Innovation Walk, Clayton, Clayton, VIC 3168, Australia
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4
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Krüger A, Kovalchuk D, Shiriaev D, Rorbach J. Decoding the Enigma: Translation Termination in Human Mitochondria. Hum Mol Genet 2024; 33:R42-R46. [PMID: 38779770 PMCID: PMC11112381 DOI: 10.1093/hmg/ddae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 05/25/2024] Open
Abstract
Mitochondrial translation is a complex process responsible for the synthesis of essential proteins involved in oxidative phosphorylation, a fundamental pathway for cellular energy production. Central to this process is the termination phase, where dedicated factors play a pivotal role in ensuring accurate and timely protein production. This review provides a comprehensive overview of the current understanding of translation termination in human mitochondria, emphasizing structural features and molecular functions of two mitochondrial termination factors mtRF1 and mtRF1a.
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Affiliation(s)
- Annika Krüger
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, Solna 171 65, Sweden
| | - Daria Kovalchuk
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, Solna 171 65, Sweden
| | - Dmitrii Shiriaev
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, Solna 171 65, Sweden
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, Solna 171 65, Sweden
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5
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Dohnálek V, Doležal P. Installation of LYRM proteins in early eukaryotes to regulate the metabolic capacity of the emerging mitochondrion. Open Biol 2024; 14:240021. [PMID: 38772414 DOI: 10.1098/rsob.240021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 03/13/2024] [Indexed: 05/23/2024] Open
Abstract
Core mitochondrial processes such as the electron transport chain, protein translation and the formation of Fe-S clusters (ISC) are of prokaryotic origin and were present in the bacterial ancestor of mitochondria. In animal and fungal models, a family of small Leu-Tyr-Arg motif-containing proteins (LYRMs) uniformly regulates the function of mitochondrial complexes involved in these processes. The action of LYRMs is contingent upon their binding to the acylated form of acyl carrier protein (ACP). This study demonstrates that LYRMs are structurally and evolutionarily related proteins characterized by a core triplet of α-helices. Their widespread distribution across eukaryotes suggests that 12 specialized LYRMs were likely present in the last eukaryotic common ancestor to regulate the assembly and folding of the subunits that are conserved in bacteria but that lack LYRM homologues. The secondary reduction of mitochondria to anoxic environments has rendered the function of LYRMs and their interaction with acylated ACP dispensable. Consequently, these findings strongly suggest that early eukaryotes installed LYRMs in aerobic mitochondria as orchestrated switches, essential for regulating core metabolism and ATP production.
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Affiliation(s)
- Vít Dohnálek
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV , Vestec 252 50, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV , Vestec 252 50, Czech Republic
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6
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Jung SJ, Sridhara S, Ott M. Early steps in the biogenesis of mitochondrially encoded oxidative phosphorylation subunits. IUBMB Life 2024; 76:125-139. [PMID: 37712772 DOI: 10.1002/iub.2784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/10/2023] [Indexed: 09/16/2023]
Abstract
The complexes mediating oxidative phosphorylation (OXPHOS) in the inner mitochondrial membrane consist of proteins encoded in the nuclear or the mitochondrial DNA. The mitochondrially encoded membrane proteins (mito-MPs) represent the catalytic core of these complexes and follow complicated pathways for biogenesis. Owing to their overall hydrophobicity, mito-MPs are co-translationally inserted into the inner membrane by the Oxa1 insertase. After insertion, OXPHOS biogenesis factors mediate the assembly of mito-MPs into complexes and participate in the regulation of mitochondrial translation, while protein quality control factors recognize and degrade faulty or excess proteins. This review summarizes the current understanding of these early steps occurring during the assembly of mito-MPs by concentrating on results obtained in the model organism baker's yeast.
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Affiliation(s)
- Sung-Jun Jung
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Sagar Sridhara
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Martin Ott
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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7
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Nadler F, Richter-Dennerlein R. Translation termination in human mitochondria - substrate specificity of mitochondrial release factors. Biol Chem 2023; 404:769-779. [PMID: 37377370 DOI: 10.1515/hsz-2023-0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
Mitochondria are the essential players in eukaryotic ATP production by oxidative phosphorylation, which relies on the maintenance and accurate expression of the mitochondrial genome. Even though the basic principles of translation are conserved due to the descendance from a bacterial ancestor, some deviations regarding translation factors as well as mRNA characteristics and the applied genetic code are present in human mitochondria. Together, these features are certain challenges during translation the mitochondrion has to handle. Here, we discuss the current knowledge regarding mitochondrial translation focusing on the termination process and the associated quality control mechanisms. We describe how mtRF1a resembles bacterial RF1 mechanistically and summarize in vitro and recent in vivo data leading to the conclusion of mtRF1a being the major mitochondrial release factor. On the other hand, we discuss the ongoing debate about the function of the second codon-dependent mitochondrial release factor mtRF1 regarding its role as a specialized termination factor. Finally, we link defects in mitochondrial translation termination to the activation of mitochondrial rescue mechanisms highlighting the importance of ribosome-associated quality control for sufficient respiratory function and therefore for human health.
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Affiliation(s)
- Franziska Nadler
- Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Ricarda Richter-Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, D-37075 Göttingen, Germany
- Goettingen Center for Molecular Biosciences, University of Göttingen, D-37077 Göttingen, Germany
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8
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Saurer M, Leibundgut M, Nadimpalli HP, Scaiola A, Schönhut T, Lee RG, Siira SJ, Rackham O, Dreos R, Lenarčič T, Kummer E, Gatfield D, Filipovska A, Ban N. Molecular basis of translation termination at noncanonical stop codons in human mitochondria. Science 2023; 380:531-536. [PMID: 37141370 DOI: 10.1126/science.adf9890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The genetic code that specifies the identity of amino acids incorporated into proteins during protein synthesis is almost universally conserved. Mitochondrial genomes feature deviations from the standard genetic code, including the reassignment of two arginine codons to stop codons. The protein required for translation termination at these noncanonical stop codons to release the newly synthesized polypeptides is not currently known. In this study, we used gene editing and ribosomal profiling in combination with cryo-electron microscopy to establish that mitochondrial release factor 1 (mtRF1) detects noncanonical stop codons in human mitochondria by a previously unknown mechanism of codon recognition. We discovered that binding of mtRF1 to the decoding center of the ribosome stabilizes a highly unusual conformation in the messenger RNA in which the ribosomal RNA participates in specific recognition of the noncanonical stop codons.
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Affiliation(s)
- Martin Saurer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Marc Leibundgut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Alain Scaiola
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Tanja Schönhut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Richard G Lee
- Harry Perkins Institute of Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, Western Australia, Australia
| | - Stefan J Siira
- Harry Perkins Institute of Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, The University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, Western Australia, Australia
- Curtin Medical School and Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia 6102, Australia
| | - René Dreos
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Tea Lenarčič
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Eva Kummer
- Novo Nordisk Foundation Center for Protein Research, Protein Structure and Function Program, Blegdamsvej 3B, 2200 København N, Denmark
| | - David Gatfield
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, Western Australia, Australia
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
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9
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Imami K, Selbach M, Ishihama Y. Monitoring mitochondrial translation by pulse SILAC. J Biol Chem 2023; 299:102865. [PMID: 36603763 PMCID: PMC9922817 DOI: 10.1016/j.jbc.2022.102865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 12/27/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Mitochondrial ribosomes are specialized to translate the 13 membrane proteins encoded in the mitochondrial genome, which shapes the oxidative phosphorylation complexes essential for cellular energy metabolism. Despite the importance of mitochondrial translation (MT) control, it is challenging to identify and quantify the mitochondrial-encoded proteins because of their hydrophobic nature and low abundance. Here, we introduce a mass spectrometry-based proteomic method that combines biochemical isolation of mitochondria with pulse stable isotope labeling by amino acids in cell culture. Our method provides the highest protein identification rate with the shortest measurement time among currently available methods, enabling us to quantify 12 of the 13 mitochondrial-encoded proteins. We applied this method to uncover the global picture of (post-)translational regulation of both mitochondrial- and nuclear-encoded subunits of oxidative phosphorylation complexes. We found that inhibition of MT led to degradation of orphan nuclear-encoded subunits that are considered to form subcomplexes with the mitochondrial-encoded subunits. This method should be readily applicable to study MT programs in many contexts, including oxidative stress and mitochondrial disease.
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Affiliation(s)
- Koshi Imami
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; RIKEN Center for Integrative Medical Sciences, Yokohama, Japan.
| | - Matthias Selbach
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany; Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Yasushi Ishihama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; Laboratory of Clinical and Analytical Chemistry, National Institute of Biomedical Innovation, Health and Nutrition, Osaka, Japan.
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10
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Krüger A, Remes C, Shiriaev DI, Liu Y, Spåhr H, Wibom R, Atanassov I, Nguyen MD, Cooperman BS, Rorbach J. Human mitochondria require mtRF1 for translation termination at non-canonical stop codons. Nat Commun 2023; 14:30. [PMID: 36596788 PMCID: PMC9810596 DOI: 10.1038/s41467-022-35684-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 12/19/2022] [Indexed: 01/04/2023] Open
Abstract
The mitochondrial translation machinery highly diverged from its bacterial counterpart. This includes deviation from the universal genetic code, with AGA and AGG codons lacking cognate tRNAs in human mitochondria. The locations of these codons at the end of COX1 and ND6 open reading frames, respectively, suggest they might function as stop codons. However, while the canonical stop codons UAA and UAG are known to be recognized by mtRF1a, the release mechanism at AGA and AGG codons remains a debated issue. Here, we show that upon the loss of another member of the mitochondrial release factor family, mtRF1, mitoribosomes accumulate specifically at AGA and AGG codons. Stalling of mitoribosomes alters COX1 transcript and protein levels, but not ND6 synthesis. In addition, using an in vitro reconstituted mitochondrial translation system, we demonstrate the specific peptide release activity of mtRF1 at the AGA and AGG codons. Together, our results reveal the role of mtRF1 in translation termination at non-canonical stop codons in mitochondria.
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Affiliation(s)
- Annika Krüger
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Cristina Remes
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Dmitrii Igorevich Shiriaev
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Yong Liu
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Henrik Spåhr
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Rolf Wibom
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ilian Atanassov
- Proteomics Core Facility, Max-Planck-Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, 50931, Cologne, Germany
| | - Minh Duc Nguyen
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Barry S Cooperman
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65, Solna, Sweden. .,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden. .,S.T.I.A.S: Stellenbosch Institute for Advanced Study, Marais Rd, Mostertsdrift, Stellenbosch, 7600, South Africa.
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11
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Nadler F, Lavdovskaia E, Krempler A, Cruz-Zaragoza LD, Dennerlein S, Richter-Dennerlein R. Human mtRF1 terminates COX1 translation and its ablation induces mitochondrial ribosome-associated quality control. Nat Commun 2022; 13:6406. [PMID: 36302763 PMCID: PMC9613700 DOI: 10.1038/s41467-022-34088-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/11/2022] [Indexed: 12/25/2022] Open
Abstract
Translation termination requires release factors that read a STOP codon in the decoding center and subsequently facilitate the hydrolysis of the nascent peptide chain from the peptidyl tRNA within the ribosome. In human mitochondria eleven open reading frames terminate in the standard UAA or UAG STOP codon, which can be recognized by mtRF1a, the proposed major mitochondrial release factor. However, two transcripts encoding for COX1 and ND6 terminate in the non-conventional AGA or AGG codon, respectively. How translation termination is achieved in these two cases is not known. We address this long-standing open question by showing that the non-canonical release factor mtRF1 is a specialized release factor that triggers COX1 translation termination, while mtRF1a terminates the majority of other mitochondrial translation events including the non-canonical ND6. Loss of mtRF1 leads to isolated COX deficiency and activates the mitochondrial ribosome-associated quality control accompanied by the degradation of COX1 mRNA to prevent an overload of the ribosome rescue system. Taken together, these results establish the role of mtRF1 in mitochondrial translation, which had been a mystery for decades, and lead to a comprehensive picture of translation termination in human mitochondria.
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Affiliation(s)
- Franziska Nadler
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Elena Lavdovskaia
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany ,grid.7450.60000 0001 2364 4210Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Goettingen, D-37075 Goettingen, Germany
| | - Angelique Krempler
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Luis Daniel Cruz-Zaragoza
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Sven Dennerlein
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Ricarda Richter-Dennerlein
- grid.411984.10000 0001 0482 5331Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany ,grid.7450.60000 0001 2364 4210Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Goettingen, D-37075 Goettingen, Germany ,grid.7450.60000 0001 2364 4210Goettingen Center for Molecular Biosciences, University of Goettingen, D-37077 Goettingen, Germany
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12
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Mitochondria homeostasis: Biology and involvement in hepatic steatosis to NASH. Acta Pharmacol Sin 2022; 43:1141-1155. [PMID: 35105958 PMCID: PMC9061859 DOI: 10.1038/s41401-022-00864-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/09/2022] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial biology and behavior are central to the physiology of liver. Multiple mitochondrial quality control mechanisms remodel mitochondrial homeostasis under physiological and pathological conditions. Mitochondrial dysfunction and damage induced by overnutrition lead to oxidative stress, inflammation, liver cell death, and collagen production, which advance hepatic steatosis to nonalcoholic steatohepatitis (NASH). Accumulating evidence suggests that specific interventions that target mitochondrial homeostasis, including energy metabolism, antioxidant effects, and mitochondrial quality control, have emerged as promising strategies for NASH treatment. However, clinical translation of these findings is challenging due to the complex and unclear mechanisms of mitochondrial homeostasis in the pathophysiology of NASH.
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13
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Organization and expression of the mammalian mitochondrial genome. Nat Rev Genet 2022; 23:606-623. [PMID: 35459860 DOI: 10.1038/s41576-022-00480-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
The mitochondrial genome encodes core subunits of the respiratory chain that drives oxidative phosphorylation and is, therefore, essential for energy conversion. Advances in high-throughput sequencing technologies and cryoelectron microscopy have shed light on the structure and organization of the mitochondrial genome and revealed unique mechanisms of mitochondrial gene regulation. New animal models of impaired mitochondrial protein synthesis have shown how the coordinated regulation of the cytoplasmic and mitochondrial translation machineries ensures the correct assembly of the respiratory chain complexes. These new technologies and disease models are providing a deeper understanding of mitochondrial genome organization and expression and of the diseases caused by impaired energy conversion, including mitochondrial, neurodegenerative, cardiovascular and metabolic diseases. They also provide avenues for the development of treatments for these conditions.
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14
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Kumar R, Harilal S, Thomas Parambi DG, Kanthlal S, Rahman MA, Alexiou A, Batiha GES, Mathew B. The Role of Mitochondrial Genes in Neurodegenerative Disorders. Curr Neuropharmacol 2022; 20:824-835. [PMID: 34503413 PMCID: PMC9881096 DOI: 10.2174/1570159x19666210908163839] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 07/09/2021] [Accepted: 09/07/2021] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial disorders are clinically heterogeneous, resulting from nuclear gene and mitochondrial mutations that disturb the mitochondrial functions and dynamics. There is a lack of evidence linking mtDNA mutations to neurodegenerative disorders, mainly due to the absence of noticeable neuropathological lesions in postmortem samples. This review describes various gene mutations in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and stroke. These abnormalities, including PINK1, Parkin, and SOD1 mutations, seem to reveal mitochondrial dysfunctions due to either mtDNA mutation or deletion, the mechanism of which remains unclear in depth.
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Affiliation(s)
- Rajesh Kumar
- Department of Pharmacy, Kerala University of Health Sciences, Thrissur, Kerala, India
| | - Seetha Harilal
- Department of Pharmacy, Kerala University of Health Sciences, Thrissur, Kerala, India
| | - Della Grace Thomas Parambi
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka, Al Jouf-2014, Saudi Arabia
| | - S.K. Kanthlal
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi-682 041, India
| | - Md Atiar Rahman
- Department of Biochemistry and Molecular Biology, University of Chittagong, Chittagong, Bangladesh
| | - Athanasios Alexiou
- Novel Global Community Educational Foundation, Hebersham, Australia;,AFNP Med Austria, Wien, Austria
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, AlBeheira, Egypt
| | - Bijo Mathew
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi-682 041, India,Address correspondence to this author at the Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi-682 041, India; E-mails: ;
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15
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Mammalian HEMK1 methylates glutamine residue of the GGQ motif of mitochondrial release factors. Sci Rep 2022; 12:4104. [PMID: 35260756 PMCID: PMC8904536 DOI: 10.1038/s41598-022-08061-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 03/01/2022] [Indexed: 02/04/2023] Open
Abstract
Despite limited reports on glutamine methylation, methylated glutamine is found to be highly conserved in a "GGQ" motif in both prokaryotes and eukaryotes. In bacteria, glutamine methylation of peptide chain release factors 1/2 (RF1/2) by the enzyme PrmC is essential for translational termination and transcript recycling. Two PrmC homologs, HEMK1 and HEMK2, are found in mammals. In contrast to those of HEMK2, the biochemical properties and biological significance of HEMK1 remain largely unknown. In this study, we demonstrated that HEMK1 is an active methyltransferase for the glutamine residue of the GGQ motif of all four putative mitochondrial release factors (mtRFs)-MTRF1, MTRF1L, MRPL58, and MTRFR. In HEMK1-deficient HeLa cells, GGQ motif glutamine methylation was absent in all the mtRFs. We examined cell growth and mitochondrial properties, but disruption of the HEMK1 gene had no considerable impact on the overall cell growth, mtDNA copy number, mitochondrial membrane potential, and mitochondrial protein synthesis under regular culture condition with glucose as a carbon source. Furthermore, cell growth potential of HEMK1 KO cells was still maintained in the respiratory condition with galactose medium. Our results suggest that HEMK1 mediates the GGQ methylation of all four mtRFs in human cells; however, this specific modification seems mostly dispensable in cell growth and mitochondrial protein homeostasis at least for HeLa cells under fermentative culture condition.
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16
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Małecki JM, Davydova E, Falnes PØ. Protein methylation in mitochondria. J Biol Chem 2022; 298:101791. [PMID: 35247388 PMCID: PMC9006661 DOI: 10.1016/j.jbc.2022.101791] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Many proteins are modified by posttranslational methylation, introduced by a number of methyltransferases (MTases). Protein methylation plays important roles in modulating protein function and thus in optimizing and regulating cellular and physiological processes. Research has mainly focused on nuclear and cytosolic protein methylation, but it has been known for many years that also mitochondrial proteins are methylated. During the last decade, significant progress has been made on identifying the MTases responsible for mitochondrial protein methylation and addressing its functional significance. In particular, several novel human MTases have been uncovered that methylate lysine, arginine, histidine, and glutamine residues in various mitochondrial substrates. Several of these substrates are key components of the bioenergetics machinery, e.g., respiratory Complex I, citrate synthase, and the ATP synthase. In the present review, we report the status of the field of mitochondrial protein methylation, with a particular emphasis on recently discovered human MTases. We also discuss evolutionary aspects and functional significance of mitochondrial protein methylation and present an outlook for this emergent research field.
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Affiliation(s)
- Jędrzej M Małecki
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway.
| | - Erna Davydova
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Pål Ø Falnes
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway.
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17
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Nadler F, Lavdovskaia E, Richter-Dennerlein R. Maintaining mitochondrial ribosome function: The role of ribosome rescue and recycling factors. RNA Biol 2021; 19:117-131. [PMID: 34923906 PMCID: PMC8786322 DOI: 10.1080/15476286.2021.2015561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The universally conserved process of protein biosynthesis is crucial for maintaining cellular homoeostasis and in eukaryotes, mitochondrial translation is essential for aerobic energy production. Mitochondrial ribosomes (mitoribosomes) are highly specialized to synthesize 13 core subunits of the oxidative phosphorylation (OXPHOS) complexes. Although the mitochondrial translation machinery traces its origin from a bacterial ancestor, it has acquired substantial differences within this endosymbiotic environment. The cycle of mitoribosome function proceeds through the conserved canonical steps of initiation, elongation, termination and mitoribosome recycling. However, when mitoribosomes operate in the context of limited translation factors or on aberrant mRNAs, they can become stalled and activation of rescue mechanisms is required. This review summarizes recent advances in the understanding of protein biosynthesis in mitochondria, focusing especially on the mechanistic and physiological details of translation termination, and mitoribosome recycling and rescue.
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Affiliation(s)
- Franziska Nadler
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany
| | - Elena Lavdovskaia
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
| | - Ricarda Richter-Dennerlein
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
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18
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Criscuolo D, Avolio R, Matassa DS, Esposito F. Targeting Mitochondrial Protein Expression as a Future Approach for Cancer Therapy. Front Oncol 2021; 11:797265. [PMID: 34888254 PMCID: PMC8650000 DOI: 10.3389/fonc.2021.797265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/03/2021] [Indexed: 12/20/2022] Open
Abstract
Extensive metabolic remodeling is a fundamental feature of cancer cells. Although early reports attributed such remodeling to a loss of mitochondrial functions, it is now clear that mitochondria play central roles in cancer development and progression, from energy production to synthesis of macromolecules, from redox modulation to regulation of cell death. Biosynthetic pathways are also heavily affected by the metabolic rewiring, with protein synthesis dysregulation at the hearth of cellular transformation. Accumulating evidence in multiple organisms shows that the metabolic functions of mitochondria are tightly connected to protein synthesis, being assembly and activity of respiratory complexes highly dependent on de novo synthesis of their components. In turn, protein synthesis within the organelle is tightly connected with the cytosolic process. This implies an entire network of interactions and fine-tuned regulations that build up a completely under-estimated level of complexity. We are now only preliminarily beginning to reconstitute such regulatory level in human cells, and to perceive its role in diseases. Indeed, disruption or alterations of these connections trigger conditions of proteotoxic and energetic stress that could be potentially exploited for therapeutic purposes. In this review, we summarize the available literature on the coordinated regulation of mitochondrial and cytosolic mRNA translation, and their effects on the integrity of the mitochondrial proteome and functions. Finally, we highlight the potential held by this topic for future research directions and for the development of innovative therapeutic approaches.
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Affiliation(s)
- Daniela Criscuolo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Rosario Avolio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Danilo Swann Matassa
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Franca Esposito
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
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19
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Korostelev AA. Diversity and Similarity of Termination and Ribosome Rescue in Bacterial, Mitochondrial, and Cytoplasmic Translation. BIOCHEMISTRY (MOSCOW) 2021; 86:1107-1121. [PMID: 34565314 DOI: 10.1134/s0006297921090066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
When a ribosome encounters the stop codon of an mRNA, it terminates translation, releases the newly made protein, and is recycled to initiate translation on a new mRNA. Termination is a highly dynamic process in which release factors (RF1 and RF2 in bacteria; eRF1•eRF3•GTP in eukaryotes) coordinate peptide release with large-scale molecular rearrangements of the ribosome. Ribosomes stalled on aberrant mRNAs are rescued and recycled by diverse bacterial, mitochondrial, or cytoplasmic quality control mechanisms. These are catalyzed by rescue factors with peptidyl-tRNA hydrolase activity (bacterial ArfA•RF2 and ArfB, mitochondrial ICT1 and mtRF-R, and cytoplasmic Vms1), that are distinct from each other and from release factors. Nevertheless, recent structural studies demonstrate a remarkable similarity between translation termination and ribosome rescue mechanisms. This review describes how these pathways rely on inherent ribosome dynamics, emphasizing the active role of the ribosome in all translation steps.
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Affiliation(s)
- Andrei A Korostelev
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA.
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20
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Zheng X, Zhong W, O'Connell CM, Liu Y, Haggerty CL, Geisler WM, Anyalechi GE, Kirkcaldy RD, Wiesenfeld HC, Hillier SL, Steinkampf MP, Hammond KR, Fine J, Li Y, Darville T. Host Genetic Risk Factors for Chlamydia trachomatis-Related Infertility in Women. J Infect Dis 2021; 224:S64-S71. [PMID: 34396400 DOI: 10.1093/infdis/jiab149] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Chlamydia trachomatis (Ct) infection ascending to the upper genital tract can cause infertility. Direct association of genetic variants as contributors is challenging because infertility may not be diagnosed until years after infection. Investigating the intermediate trait of ascension bridges this gap. METHODS We identified infertility genome-wide association study (GWAS) loci using deoxyribonucleic acid from Ct-seropositive cisgender women in a tubal factor infertility study and Ct-infected cisgender women from a longitudinal pelvic inflammatory disease cohort with known fertility status. Deoxyribonucleic acid and blood messenger ribonucleic acid from 2 additional female cohorts with active Ct infection and known endometrial infection status were used to investigate the impact of infertility single-nucleotide polymorphisms (SNPs) on Ct ascension. A statistical mediation test examined whether multiple infertility SNPs jointly influenced ascension risk by modulating expression of mediator genes. RESULTS We identified 112 candidate infertility GWAS loci, and 31 associated with Ct ascension. The SNPs altered chlamydial ascension by modulating expression of 40 mediator genes. Mediator genes identified are involved in innate immune responses including type I interferon production, T-cell function, fibrosis, female reproductive tract health, and protein synthesis and degradation. CONCLUSIONS We identified Ct-related infertility loci and their potential functional effects on Ct ascension.
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Affiliation(s)
- Xiaojing Zheng
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Wujuan Zhong
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Catherine M O'Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yutong Liu
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Catherine L Haggerty
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - William M Geisler
- Departments of Medicine and Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Gloria E Anyalechi
- Centers for Disease Control and Prevention, Division of STD Prevention, Atlanta, Georgia, USA
| | - Robert D Kirkcaldy
- Centers for Disease Control and Prevention, Division of STD Prevention, Atlanta, Georgia, USA
| | - Harold C Wiesenfeld
- Department of Obstetrics, Gynecology and Reproductive Sciences, the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sharon L Hillier
- Department of Obstetrics, Gynecology and Reproductive Sciences, the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | | | - Jason Fine
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yun Li
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Toni Darville
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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21
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Chicherin IV, Dukhalin SV, Khannanov RA, Baleva MV, Levitskii SA, Patrushev MV, Sergiev PV, Kamenski P. Functional Diversity of Mitochondrial Peptidyl-tRNA Hydrolase ICT1 in Human Cells. Front Mol Biosci 2021; 8:716885. [PMID: 34336930 PMCID: PMC8322449 DOI: 10.3389/fmolb.2021.716885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/30/2021] [Indexed: 11/13/2022] Open
Abstract
Mitochondria are energy producing organelles of the eukaryotic cell, involved in the synthesis of key metabolites, calcium homeostasis and apoptosis. Protein biosynthesis in these organelles is a relic of its endosymbiotic origin. While mitochondrial translational factors have homologues among prokaryotes, they possess a number of unique traits. Remarkably as many as four mammalian mitochondrial proteins possess a clear similarity with translation termination factors. The review focuses on the ICT1, which combines several functions. It is a non-canonical termination factor for protein biosynthesis, a rescue factor for stalled mitochondrial ribosomes, a structural protein and a regulator of proliferation, cell cycle, and apoptosis. Such a diversity of roles demonstrates the high functionality of mitochondrial translation associated proteins and their relationship with numerous processes occurring in a living cell.
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Affiliation(s)
- I V Chicherin
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia.,National Research Center "Kurchatov Institute", NBICS Center, Moscow, Russia
| | - S V Dukhalin
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia
| | - R A Khannanov
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia
| | - M V Baleva
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia
| | - S A Levitskii
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia
| | - M V Patrushev
- National Research Center "Kurchatov Institute", NBICS Center, Moscow, Russia
| | - P V Sergiev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Center of Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia.,Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, Russia
| | - P Kamenski
- Department of Molecular Biology, M.V.Lomonosov Moscow State University, Moscow, Russia
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22
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Wang F, Zhang D, Zhang D, Li P, Gao Y. Mitochondrial Protein Translation: Emerging Roles and Clinical Significance in Disease. Front Cell Dev Biol 2021; 9:675465. [PMID: 34277617 PMCID: PMC8280776 DOI: 10.3389/fcell.2021.675465] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/09/2021] [Indexed: 12/28/2022] Open
Abstract
Mitochondria are one of the most important organelles in cells. Mitochondria are semi-autonomous organelles with their own genetic system, and can independently replicate, transcribe, and translate mitochondrial DNA. Translation initiation, elongation, termination, and recycling of the ribosome are four stages in the process of mitochondrial protein translation. In this process, mitochondrial protein translation factors and translation activators, mitochondrial RNA, and other regulatory factors regulate mitochondrial protein translation. Mitochondrial protein translation abnormalities are associated with a variety of diseases, including cancer, cardiovascular diseases, and nervous system diseases. Mutation or deletion of various mitochondrial protein translation factors and translation activators leads to abnormal mitochondrial protein translation. Mitochondrial tRNAs and mitochondrial ribosomal proteins are essential players during translation and mutations in genes encoding them represent a large fraction of mitochondrial diseases. Moreover, there is crosstalk between mitochondrial protein translation and cytoplasmic translation, and the imbalance between mitochondrial protein translation and cytoplasmic translation can affect some physiological and pathological processes. This review summarizes the regulation of mitochondrial protein translation factors, mitochondrial ribosomal proteins, mitochondrial tRNAs, and mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) in the mitochondrial protein translation process and its relationship with diseases. The regulation of mitochondrial protein translation and cytoplasmic translation in multiple diseases is also summarized.
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Affiliation(s)
- Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Deyu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.,Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
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23
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Liang H, Liu J, Su S, Zhao Q. Mitochondrial noncoding RNAs: new wine in an old bottle. RNA Biol 2021; 18:2168-2182. [PMID: 34110970 DOI: 10.1080/15476286.2021.1935572] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial noncoding RNAs (mt-ncRNAs) include noncoding RNAs inside the mitochondria that are transcribed from the mitochondrial genome or nuclear genome, and noncoding RNAs transcribed from the mitochondrial genome that are transported to the cytosol or nucleus. Recent findings have revealed that mt-ncRNAs play important roles in not only mitochondrial functions, but also other cellular activities. This review proposes a classification of mt-ncRNAs and outlines the emerging understanding of mitochondrial circular RNAs (mt-circRNAs), mitochondrial microRNAs (mitomiRs), and mitochondrial long noncoding RNAs (mt-lncRNAs), with an emphasis on their identification and functions.
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Affiliation(s)
- Huixin Liang
- Department of Infectious Diseases, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.,Guangdong Provincial Key Laboratory of Liver Disease Research, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Jiayu Liu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Shicheng Su
- Department of Infectious Diseases, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.,Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.,Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.,Department of Immunology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Qiyi Zhao
- Department of Infectious Diseases, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.,Guangdong Provincial Key Laboratory of Liver Disease Research, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China.,Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
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24
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Kummer E, Schubert KN, Schoenhut T, Scaiola A, Ban N. Structural basis of translation termination, rescue, and recycling in mammalian mitochondria. Mol Cell 2021; 81:2566-2582.e6. [PMID: 33878294 DOI: 10.1016/j.molcel.2021.03.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/12/2021] [Accepted: 03/24/2021] [Indexed: 12/26/2022]
Abstract
The mitochondrial translation system originates from a bacterial ancestor but has substantially diverged in the course of evolution. Here, we use single-particle cryo-electron microscopy (cryo-EM) as a screening tool to identify mitochondrial translation termination mechanisms and to describe them in molecular detail. We show how mitochondrial release factor 1a releases the nascent chain from the ribosome when it encounters the canonical stop codons UAA and UAG. Furthermore, we define how the peptidyl-tRNA hydrolase ICT1 acts as a rescue factor on mitoribosomes that have stalled on truncated messages to recover them for protein synthesis. Finally, we present structural models detailing the process of mitochondrial ribosome recycling to explain how a dedicated elongation factor, mitochondrial EFG2 (mtEFG2), has specialized for cooperation with the mitochondrial ribosome recycling factor to dissociate the mitoribosomal subunits at the end of the translation process.
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Affiliation(s)
- Eva Kummer
- Swiss Federal Institute of Technology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zurich, Switzerland.
| | - Katharina Noel Schubert
- Swiss Federal Institute of Technology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zurich, Switzerland
| | - Tanja Schoenhut
- Swiss Federal Institute of Technology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zurich, Switzerland
| | - Alain Scaiola
- Swiss Federal Institute of Technology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zurich, Switzerland
| | - Nenad Ban
- Swiss Federal Institute of Technology, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zurich, Switzerland.
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25
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Mechanisms and regulation of protein synthesis in mitochondria. Nat Rev Mol Cell Biol 2021; 22:307-325. [PMID: 33594280 DOI: 10.1038/s41580-021-00332-2] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 02/06/2023]
Abstract
Mitochondria are cellular organelles responsible for generation of chemical energy in the process called oxidative phosphorylation. They originate from a bacterial ancestor and maintain their own genome, which is expressed by designated, mitochondrial transcription and translation machineries that differ from those operating for nuclear gene expression. In particular, the mitochondrial protein synthesis machinery is structurally and functionally very different from that governing eukaryotic, cytosolic translation. Despite harbouring their own genetic information, mitochondria are far from being independent of the rest of the cell and, conversely, cellular fitness is closely linked to mitochondrial function. Mitochondria depend heavily on the import of nuclear-encoded proteins for gene expression and function, and hence engage in extensive inter-compartmental crosstalk to regulate their proteome. This connectivity allows mitochondria to adapt to changes in cellular conditions and also mediates responses to stress and mitochondrial dysfunction. With a focus on mammals and yeast, we review fundamental insights that have been made into the biogenesis, architecture and mechanisms of the mitochondrial translation apparatus in the past years owing to the emergence of numerous near-atomic structures and a considerable amount of biochemical work. Moreover, we discuss how cellular mitochondrial protein expression is regulated, including aspects of mRNA and tRNA maturation and stability, roles of auxiliary factors, such as translation regulators, that adapt mitochondrial translation rates, and the importance of inter-compartmental crosstalk with nuclear gene expression and cytosolic translation and how it enables integration of mitochondrial translation into the cellular context.
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26
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Lee M, Matsunaga N, Akabane S, Yasuda I, Ueda T, Takeuchi-Tomita N. Reconstitution of mammalian mitochondrial translation system capable of correct initiation and long polypeptide synthesis from leaderless mRNA. Nucleic Acids Res 2021; 49:371-382. [PMID: 33300043 PMCID: PMC7797035 DOI: 10.1093/nar/gkaa1165] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/31/2022] Open
Abstract
Mammalian mitochondria have their own dedicated protein synthesis system, which produces 13 essential subunits of the oxidative phosphorylation complexes. We have reconstituted an in vitro translation system from mammalian mitochondria, utilizing purified recombinant mitochondrial translation factors, 55S ribosomes from pig liver mitochondria, and a tRNA mixture from either Escherichia coli or yeast. The system is capable of translating leaderless mRNAs encoding model proteins (DHFR and nanoLuciferase) or some mtDNA-encoded proteins. We show that a leaderless mRNA, encoding nanoLuciferase, is faithfully initiated without the need for any auxiliary factors other than IF-2mt and IF-3mt. We found that the ribosome-dependent GTPase activities of both the translocase EF-G1mt and the recycling factor EF-G2mt are insensitive to fusidic acid (FA), the translation inhibitor that targets bacterial EF-G homologs, and consequently the system is resistant to FA. Moreover, we demonstrate that a polyproline sequence in the protein causes 55S mitochondrial ribosome stalling, yielding ribosome nascent chain complexes. Analyses of the effects of the Mg concentration on the polyproline-mediated ribosome stalling suggested the unique regulation of peptide elongation by the mitoribosome. This system will be useful for analyzing the mechanism of translation initiation, and the interactions between the nascent peptide chain and the mitochondrial ribosome.
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Affiliation(s)
- Muhoon Lee
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Noriko Matsunaga
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Shiori Akabane
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan.,Department of Life Science, Rikkyo University, Tokyo, 171-8501, Japan
| | - Ippei Yasuda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan.,Department of Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Tokyo, Shinjuku 162-8480, Japan
| | - Nono Takeuchi-Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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27
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Lavdovskaia E, Denks K, Nadler F, Steube E, Linden A, Urlaub H, Rodnina MV, Richter-Dennerlein R. Dual function of GTPBP6 in biogenesis and recycling of human mitochondrial ribosomes. Nucleic Acids Res 2021; 48:12929-12942. [PMID: 33264405 PMCID: PMC7736812 DOI: 10.1093/nar/gkaa1132] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/19/2020] [Accepted: 11/09/2020] [Indexed: 01/01/2023] Open
Abstract
Translation and ribosome biogenesis in mitochondria require auxiliary factors that ensure rapid and accurate synthesis of mitochondrial proteins. Defects in translation are associated with oxidative phosphorylation deficiency and cause severe human diseases, but the exact roles of mitochondrial translation-associated factors are not known. Here we identify the functions of GTPBP6, a homolog of the bacterial ribosome-recycling factor HflX, in human mitochondria. Similarly to HflX, GTPBP6 facilitates the dissociation of ribosomes in vitro and in vivo. In contrast to HflX, GTPBP6 is also required for the assembly of mitochondrial ribosomes. GTPBP6 ablation leads to accumulation of late assembly intermediate(s) of the large ribosomal subunit containing ribosome biogenesis factors MTERF4, NSUN4, MALSU1 and the GTPases GTPBP5, GTPBP7 and GTPBP10. Our data show that GTPBP6 has a dual function acting in ribosome recycling and biogenesis. These findings contribute to our understanding of large ribosomal subunit assembly as well as ribosome recycling pathway in mitochondria.
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Affiliation(s)
- Elena Lavdovskaia
- Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany.,Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Goettingen, Goettingen, Germany
| | - Kärt Denks
- Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Goettingen, Goettingen, Germany.,Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Goettingen, Germany
| | - Franziska Nadler
- Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Emely Steube
- Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Andreas Linden
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, D-37077 Goettingen, Germany.,Bioanalytics, Institute for Clinical Chemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, D-37077 Goettingen, Germany.,Bioanalytics, Institute for Clinical Chemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany
| | - Marina V Rodnina
- Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Goettingen, Goettingen, Germany.,Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Goettingen, Germany
| | - Ricarda Richter-Dennerlein
- Department of Cellular Biochemistry, University Medical Center Goettingen, D-37073 Goettingen, Germany.,Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Goettingen, Goettingen, Germany
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28
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Ferrari A, Del'Olio S, Barrientos A. The Diseased Mitoribosome. FEBS Lett 2020; 595:1025-1061. [PMID: 33314036 DOI: 10.1002/1873-3468.14024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022]
Abstract
Mitochondria control life and death in eukaryotic cells. Harboring a unique circular genome, a by-product of an ancient endosymbiotic event, mitochondria maintains a specialized and evolutionary divergent protein synthesis machinery, the mitoribosome. Mitoribosome biogenesis depends on elements encoded in both the mitochondrial genome (the RNA components) and the nuclear genome (all ribosomal proteins and assembly factors). Recent cryo-EM structures of mammalian mitoribosomes have illuminated their composition and provided hints regarding their assembly and elusive mitochondrial translation mechanisms. A growing body of literature involves the mitoribosome in inherited primary mitochondrial disorders. Mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors impede mitoribosome biogenesis, causing protein synthesis defects that lead to respiratory chain failure and mitochondrial disorders such as encephalo- and cardiomyopathy, deafness, neuropathy, and developmental delays. In this article, we review the current fundamental understanding of mitoribosome assembly and function, and the clinical landscape of mitochondrial disorders driven by mutations in mitoribosome components and assembly factors, to portray how basic and clinical studies combined help us better understand both mitochondrial biology and medicine.
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Affiliation(s)
- Alberto Ferrari
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Samuel Del'Olio
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
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29
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Desai N, Yang H, Chandrasekaran V, Kazi R, Minczuk M, Ramakrishnan V. Elongational stalling activates mitoribosome-associated quality control. Science 2020; 370:1105-1110. [PMID: 33243891 PMCID: PMC7116630 DOI: 10.1126/science.abc7782] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 09/24/2020] [Indexed: 02/02/2023]
Abstract
The human mitochondrial ribosome (mitoribosome) and associated proteins regulate the synthesis of 13 essential subunits of the oxidative phosphorylation complexes. We report the discovery of a mitoribosome-associated quality control pathway that responds to interruptions during elongation, and we present structures at 3.1- to 3.3-angstrom resolution of mitoribosomal large subunits trapped during ribosome rescue. Release factor homolog C12orf65 (mtRF-R) and RNA binding protein C6orf203 (MTRES1) eject the nascent chain and peptidyl transfer RNA (tRNA), respectively, from stalled ribosomes. Recruitment of mitoribosome biogenesis factors to these quality control intermediates suggests additional roles for these factors during mitoribosome rescue. We also report related cryo-electron microscopy structures (3.7 to 4.4 angstrom resolution) of elongating mitoribosomes bound to tRNAs, nascent polypeptides, the guanosine triphosphatase elongation factors mtEF-Tu and mtEF-G1, and the Oxa1L translocase.
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Affiliation(s)
- Nirupa Desai
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Hanting Yang
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - Razina Kazi
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - V. Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK,Corresponding author.
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30
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Yokokawa T, Mori R, Suga T, Isaka T, Hayashi T, Fujita S. Muscle denervation reduces mitochondrial biogenesis and mitochondrial translation factor expression in mice. Biochem Biophys Res Commun 2020; 527:146-152. [DOI: 10.1016/j.bbrc.2020.04.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/13/2020] [Indexed: 11/30/2022]
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31
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Mitochondrial OXPHOS Biogenesis: Co-Regulation of Protein Synthesis, Import, and Assembly Pathways. Int J Mol Sci 2020; 21:ijms21113820. [PMID: 32481479 PMCID: PMC7312649 DOI: 10.3390/ijms21113820] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 02/07/2023] Open
Abstract
The assembly of mitochondrial oxidative phosphorylation (OXPHOS) complexes is an intricate process, which—given their dual-genetic control—requires tight co-regulation of two evolutionarily distinct gene expression machineries. Moreover, fine-tuning protein synthesis to the nascent assembly of OXPHOS complexes requires regulatory mechanisms such as translational plasticity and translational activators that can coordinate mitochondrial translation with the import of nuclear-encoded mitochondrial proteins. The intricacy of OXPHOS complex biogenesis is further evidenced by the requirement of many tightly orchestrated steps and ancillary factors. Early-stage ancillary chaperones have essential roles in coordinating OXPHOS assembly, whilst late-stage assembly factors—also known as the LYRM (leucine–tyrosine–arginine motif) proteins—together with the mitochondrial acyl carrier protein (ACP)—regulate the incorporation and activation of late-incorporating OXPHOS subunits and/or co-factors. In this review, we describe recent discoveries providing insights into the mechanisms required for optimal OXPHOS biogenesis, including the coordination of mitochondrial gene expression with the availability of nuclear-encoded factors entering via mitochondrial protein import systems.
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32
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Bruni F, Proctor-Kent Y, Lightowlers RN, Chrzanowska-Lightowlers ZM. Messenger RNA delivery to mitoribosomes - hints from a bacterial toxin. FEBS J 2020; 288:437-451. [PMID: 32329962 PMCID: PMC7891357 DOI: 10.1111/febs.15342] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 04/06/2020] [Accepted: 04/21/2020] [Indexed: 11/28/2022]
Abstract
In mammalian mitochondria, messenger RNA is processed and matured from large primary transcripts in structures known as RNA granules. The identity of the factors and process transferring the matured mRNA to the mitoribosome for translation is unclear. Nascent mature transcripts are believed to associate initially with the small mitoribosomal subunit prior to recruitment of the large subunit to form the translationally active monosome. When the small subunit fails to assemble, however, the stability of mt‐mRNA is only marginally affected, and under these conditions, the LRPPRC/SLIRP RNA‐binding complex has been implicated in maintaining mt‐mRNA stability. Here, we exploit the activity of a bacterial ribotoxin, VapC20, to show that in the absence of the large mitoribosomal subunit, mt‐mRNA species are selectively lost. Further, if the small subunit is also depleted, the mt‐mRNA levels are recovered. As a consequence of these data, we suggest a natural pathway for loading processed mt‐mRNA onto the mitoribosome.
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Affiliation(s)
- Francesco Bruni
- The Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, UK.,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Italy
| | - Yasmin Proctor-Kent
- The Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, UK
| | - Robert N Lightowlers
- The Wellcome Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, UK
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33
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Ayyub SA, Gao F, Lightowlers RN, Chrzanowska-Lightowlers ZM. Rescuing stalled mammalian mitoribosomes - what can we learn from bacteria? J Cell Sci 2020; 133:133/1/jcs231811. [PMID: 31896602 DOI: 10.1242/jcs.231811] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In the canonical process of translation, newly completed proteins escape from the ribosome following cleavage of the ester bond that anchors the polypeptide to the P-site tRNA, after which the ribosome can be recycled to initiate a new round of translation. Not all protein synthesis runs to completion as various factors can impede the progression of ribosomes. Rescuing of stalled ribosomes in mammalian mitochondria, however, does not share the same mechanisms that many bacteria use. The classic method for rescuing bacterial ribosomes is trans-translation. The key components of this system are absent from mammalian mitochondria; however, four members of a translation termination factor family are present, with some evidence of homology to members of a bacterial back-up rescue system. To date, there is no definitive demonstration of any other member of this family functioning in mitoribosome rescue. Here, we provide an overview of the processes and key players of canonical translation termination in both bacteria and mammalian mitochondria, followed by a perspective of the bacterial systems used to rescue stalled ribosomes. We highlight any similarities or differences with the mitochondrial translation release factors, and suggest potential roles for these proteins in ribosome rescue in mammalian mitochondria.
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Affiliation(s)
- Shreya Ahana Ayyub
- The Wellcome Centre for Mitochondrial Research, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Fei Gao
- The Wellcome Centre for Mitochondrial Research, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert N Lightowlers
- The Wellcome Centre for Mitochondrial Research, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Zofia M Chrzanowska-Lightowlers
- The Wellcome Centre for Mitochondrial Research, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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34
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Gopalakrishna S, Pearce SF, Dinan AM, Schober FA, Cipullo M, Spåhr H, Khawaja A, Maffezzini C, Freyer C, Wredenberg A, Atanassov I, Firth AE, Rorbach J. C6orf203 is an RNA-binding protein involved in mitochondrial protein synthesis. Nucleic Acids Res 2019; 47:9386-9399. [PMID: 31396629 PMCID: PMC6755124 DOI: 10.1093/nar/gkz684] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/22/2019] [Accepted: 07/26/2019] [Indexed: 01/17/2023] Open
Abstract
In all biological systems, RNAs are associated with RNA-binding proteins (RBPs), forming complexes that control gene regulatory mechanisms, from RNA synthesis to decay. In mammalian mitochondria, post-transcriptional regulation of gene expression is conducted by mitochondrial RBPs (mt-RBPs) at various stages of mt-RNA metabolism, including polycistronic transcript production, its processing into individual transcripts, mt-RNA modifications, stability, translation and degradation. To date, only a handful of mt-RBPs have been characterized. Here, we describe a putative human mitochondrial protein, C6orf203, that contains an S4-like domain-an evolutionarily conserved RNA-binding domain previously identified in proteins involved in translation. Our data show C6orf203 to bind highly structured RNA in vitro and associate with the mitoribosomal large subunit in HEK293T cells. Knockout of C6orf203 leads to a decrease in mitochondrial translation and consequent OXPHOS deficiency, without affecting mitochondrial RNA levels. Although mitoribosome stability is not affected in C6orf203-depleted cells, mitoribosome profiling analysis revealed a global disruption of the association of mt-mRNAs with the mitoribosome, suggesting that C6orf203 may be required for the proper maturation and functioning of the mitoribosome. We therefore propose C6orf203 to be a novel RNA-binding protein involved in mitochondrial translation, expanding the repertoire of factors engaged in this process.
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Affiliation(s)
- Shreekara Gopalakrishna
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Sarah F Pearce
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Adam M Dinan
- Department of Pathology, University of Cambridge, CB2 0QQ Cambridge, UK
| | - Florian A Schober
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Miriam Cipullo
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Henrik Spåhr
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Anas Khawaja
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Camilla Maffezzini
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Christoph Freyer
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Anna Wredenberg
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Ilian Atanassov
- Proteomics Core Facility, Max-Planck-Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, 50931 Cologne, Germany
| | - Andrew E Firth
- Department of Pathology, University of Cambridge, CB2 0QQ Cambridge, UK
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solnavägen 9, 171 77 Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, 171 77 Stockholm, Sweden
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35
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Yokokawa T, Kido K, Suga T, Isaka T, Hayashi T, Fujita S. Exercise-induced mitochondrial biogenesis coincides with the expression of mitochondrial translation factors in murine skeletal muscle. Physiol Rep 2018; 6:e13893. [PMID: 30369085 PMCID: PMC6204255 DOI: 10.14814/phy2.13893] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 09/24/2018] [Indexed: 01/01/2023] Open
Abstract
The process of mitochondrial translation, in which mitochondrial (mt)DNA-encoded genes are translated into proteins, is crucial for mitochondrial function and biogenesis. In each phase, a series of mitochondrial translation factors is required for the synthesis of mtDNA-encoded mitochondrial proteins. Two mitochondrial initiation factors (mtIF2 and mtIF3), three mitochondrial elongation factors (mtEFTu, mtEFTs, and mtEFG1), one mitochondrial release factor (mtRF1L), and two mitochondrial recycling factors (mtRRF1 and mtRRF2) are mitochondrial translation factors that coordinate each translational phase. Exercise increases both nuclear DNA- and mtDNA-encoded mitochondrial proteins, resulting in mitochondrial biogenesis in skeletal muscles. Therefore, mitochondrial translation factors are likely regulated by exercise; however, it is unclear whether exercise affects mitochondrial translation factors in the skeletal muscles. We investigated whether exercise training comprehensively increases this series of mitochondrial translation factors, as well as mtDNA-encoded proteins, in the skeletal muscle. Mice were randomly assigned to either the sedentary or exercise group and housed in standard cages with or without a running wheel for 1 and 8 weeks. The expression levels of mitochondrial translation factors in the plantaris and soleus muscles were then measured. Exercise training concomitantly upregulated mitochondrial translation factors and mitochondrial proteins in the plantaris muscle. However, in the soleus muscle, these comprehensive upregulations were not detected. These results indicate that exercise-induced mitochondrial biogenesis coincides with the upregulation of mitochondrial translation factors.
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Affiliation(s)
- Takumi Yokokawa
- Laboratory of Sports and Exercise MedicineGraduate School of Human and Environmental StudiesKyoto UniversityKyotoJapan
| | - Kohei Kido
- Faculty of Sport and Health ScienceRitsumeikan UniversityKusatsuShigaJapan
| | - Tadashi Suga
- Faculty of Sport and Health ScienceRitsumeikan UniversityKusatsuShigaJapan
| | - Tadao Isaka
- Faculty of Sport and Health ScienceRitsumeikan UniversityKusatsuShigaJapan
| | - Tatsuya Hayashi
- Laboratory of Sports and Exercise MedicineGraduate School of Human and Environmental StudiesKyoto UniversityKyotoJapan
| | - Satoshi Fujita
- Faculty of Sport and Health ScienceRitsumeikan UniversityKusatsuShigaJapan
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36
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Mitochondrial transcription and translation: overview. Essays Biochem 2018; 62:309-320. [PMID: 30030363 PMCID: PMC6056719 DOI: 10.1042/ebc20170102] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
Mitochondria are the major source of ATP in the cell. Five multi-subunit complexes in the inner membrane of the organelle are involved in the oxidative phosphorylation required for ATP production. Thirteen subunits of these complexes are encoded by the mitochondrial genome often referred to as mtDNA. For this reason, the expression of mtDNA is vital for the assembly and functioning of the oxidative phosphorylation complexes. Defects of the mechanisms regulating mtDNA gene expression have been associated with deficiencies in assembly of these complexes, resulting in mitochondrial diseases. Recently, numerous factors involved in these processes have been identified and characterized leading to a deeper understanding of the mechanisms that underlie mitochondrial diseases.
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37
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Cultured bloodstream Trypanosoma brucei adapt to life without mitochondrial translation release factor 1. Sci Rep 2018; 8:5135. [PMID: 29572512 PMCID: PMC5865105 DOI: 10.1038/s41598-018-23472-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/13/2018] [Indexed: 01/07/2023] Open
Abstract
Trypanosoma brucei is an extracellular parasite that alternates between an insect vector (procyclic form) and the bloodstream of a mammalian host (bloodstream form). While it was previously reported that mitochondrial release factor 1 (TbMrf1) is essential in cultured procyclic form cells, we demonstrate here that in vitro bloodstream form cells can tolerate the elimination of TbMrf1. Therefore, we explored if this discrepancy is due to the unique bioenergetics of the parasite since procyclic form cells rely on oxidative phosphorylation; whereas bloodstream form cells utilize glycolysis for ATP production and FoF1-ATPase to maintain the essential mitochondrial membrane potential. The observed disruption of intact bloodstream form FoF1-ATPases serves as a proxy to indicate that the translation of its mitochondrially encoded subunit A6 is impaired without TbMrf1. While these null mutants have a decreased mitochondrial membrane potential, they have adapted by increasing their dependence on the electrogenic contributions of the ADP/ATP carrier to maintain the mitochondrial membrane potential above the minimum threshold required for T. brucei viability in vitro. However, this inefficient compensatory mechanism results in avirulent mutants in mice. Finally, the depletion of the codon-independent release factor TbPth4 in the TbMrf1 knockouts further exacerbates the characterized mitchondrial phenotypes.
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38
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Abstract
Mitochondria are intracellular organelles responsible for adenosine triphosphate production. The strict control of intracellular energy needs require proper mitochondrial functioning. The mitochondria are under dual controls of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). Mitochondrial dysfunction can arise from changes in either mtDNA or nDNA genes regulating function. There are an estimated ∼1500 proteins in the mitoproteome, whereas the mtDNA genome has 37 proteins. There are, to date, ∼275 genes shown to give rise to disease. The unique physiology of mitochondrial functioning contributes to diverse gene expression. The onset and range of phenotypic expression of disease is diverse, with onset from neonatal to seventh decade of life. The range of dysfunction is heterogeneous, ranging from single organ to multisystem involvement. The complexity of disease expression has severely limited gene discovery. Combining phenotypes with improvements in gene sequencing strategies are improving the diagnosis process. This chapter focuses on the interplay of the unique physiology and gene discovery in the current knowledge of genetically derived mitochondrial disease.
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Affiliation(s)
- Russell P Saneto
- Seattle Children's Hospital/University of Washington, Seattle, WA, United States.
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39
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Mitochondrial diseases: the contribution of organelle stress responses to pathology. Nat Rev Mol Cell Biol 2017; 19:77-92. [DOI: 10.1038/nrm.2017.66] [Citation(s) in RCA: 264] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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40
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The human RNA-binding protein RBFA promotes the maturation of the mitochondrial ribosome. Biochem J 2017; 474:2145-2158. [PMID: 28512204 PMCID: PMC5468982 DOI: 10.1042/bcj20170256] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 05/09/2017] [Accepted: 05/15/2017] [Indexed: 11/17/2022]
Abstract
Accurate assembly and maturation of human mitochondrial ribosomes is essential for synthesis of the 13 polypeptides encoded by the mitochondrial genome. This process requires the correct integration of 80 proteins, 1 mt (mitochondrial)-tRNA and 2 mt-rRNA species, the latter being post-transcriptionally modified at many sites. Here, we report that human ribosome-binding factor A (RBFA) is a mitochondrial RNA-binding protein that exerts crucial roles in mitoribosome biogenesis. Unlike its bacterial orthologue, RBFA associates mainly with helices 44 and 45 of the 12S rRNA in the mitoribosomal small subunit to promote dimethylation of two highly conserved consecutive adenines. Characterization of RBFA-depleted cells indicates that this dimethylation is not a prerequisite for assembly of the small ribosomal subunit. However, the RBFA-facilitated modification is necessary for completing mt-rRNA maturation and regulating association of the small and large subunits to form a functional monosome implicating RBFA in the quality control of mitoribosome formation.
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Abstract
Mitochondria play fundamental roles in the regulation of life and death of eukaryotic cells. They mediate aerobic energy conversion through the oxidative phosphorylation (OXPHOS) system, and harbor and control the intrinsic pathway of apoptosis. As a descendant of a bacterial endosymbiont, mitochondria retain a vestige of their original genome (mtDNA), and its corresponding full gene expression machinery. Proteins encoded in the mtDNA, all components of the multimeric OXPHOS enzymes, are synthesized in specialized mitochondrial ribosomes (mitoribosomes). Mitoribosomes are therefore essential in the regulation of cellular respiration. Additionally, an increasing body of literature has been reporting an alternative role for several mitochondrial ribosomal proteins as apoptosis-inducing factors. No surprisingly, the expression of genes encoding for mitoribosomal proteins, mitoribosome assembly factors and mitochondrial translation factors is modified in numerous cancers, a trait that has been linked to tumorigenesis and metastasis. In this article, we will review the current knowledge regarding the dual function of mitoribosome components in protein synthesis and apoptosis and their association with cancer susceptibility and development. We will also highlight recent developments in targeting mitochondrial ribosomes for the treatment of cancer.
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Habib S, Vaishya S, Gupta K. Translation in Organelles of Apicomplexan Parasites. Trends Parasitol 2016; 32:939-952. [DOI: 10.1016/j.pt.2016.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/19/2016] [Accepted: 07/25/2016] [Indexed: 01/27/2023]
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Abstract
Oxidative phosphorylation (OXPHOS) is the mechanism whereby ATP, the major energy source for the cell, is produced by harnessing cellular respiration in the mitochondrion. This is facilitated by five multi-subunit complexes housed within the inner mitochondrial membrane. These complexes, with the exception of complex II, are of a dual genetic origin, requiring expression from nuclear and mitochondrial genes. Mitochondrially encoded mRNA is translated on the mitochondrial ribosome (mitoribosome) and the recent release of the near atomic resolution structure of the mammalian mitoribosome has highlighted its peculiar features. However, whereas some aspects of mitochondrial translation are understood, much is to be learnt about the presentation of mitochondrial mRNA to the mitoribosome, the biogenesis of the machinery, the exact role of the membrane, the constitution of the translocon/insertion machinery and the regulation of translation in the mitochondrion. This review addresses our current knowledge of mammalian mitochondrial gene expression, highlights key questions and indicates how defects in this process can result in profound mitochondrial disease.
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Affiliation(s)
- Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden;
| | - Alexey Amunts
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden;
- Science for Life Laboratory, Stockholm University, SE-171 21 Solna, Sweden;
| | - Alan Brown
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, United Kingdom;
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Vaishya S, Kumar V, Gupta A, Siddiqi MI, Habib S. Polypeptide release factors and stop codon recognition in the apicoplast and mitochondrion of Plasmodium falciparum. Mol Microbiol 2016; 100:1080-95. [PMID: 26946524 DOI: 10.1111/mmi.13369] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2016] [Indexed: 11/30/2022]
Abstract
Correct termination of protein synthesis would be a critical step in translation of organellar open reading frames (ORFs) of the apicoplast and mitochondrion of the malaria parasite. We identify release factors (RFs) responsible for recognition of the UAA and UGA stop-codons of apicoplast ORFs and the sole UAA stop-codon that terminates translation from the three mitochondrial ORFs. A single nuclear-encoded canonical RF2, PfRF2Api , localizes to the apicoplast. It has a conserved tripeptide motif (SPF) for stop-codon recognition and is sufficient for peptidyl-tRNA hydrolysis (PTH) from both UAA and UGA. Two RF family proteins are targeted to the parasite mitochondrion; a canonical RF1, PfRF1Mit , with a variant codon-recognition motif (PxN instead of the conserved RF1 PxT) is the major peptidyl-hydrolase with specific recognition of the UAA codon relevant to mitochondrial ORFs. Mutation of the N residue of the PfRF1Mit PxN motif and two other conserved residues of the codon recognition domain lowers PTH activity from pre-termination ribosomes indicating their role in codon-recognition. The second RF imported by the mitochondrion is the non-canonical PfICT1 that functions as a dimer and mediates codon nonspecific peptide release. Our results help delineate a critical step in organellar translation in Plasmodium, which is an important target for anti-malarials.
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Affiliation(s)
- Suniti Vaishya
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Vikash Kumar
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Ankit Gupta
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Mohammad Imran Siddiqi
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Saman Habib
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
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Nemcova L, Jansova D, Vodickova-Kepkova K, Vodicka P, Jeseta M, Machatkova M, Kanka J. Detection of genes associated with developmental competence of bovine oocytes. Anim Reprod Sci 2016; 166:58-71. [PMID: 26811294 DOI: 10.1016/j.anireprosci.2016.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/10/2015] [Accepted: 01/04/2016] [Indexed: 01/22/2023]
Abstract
The developmental competence of oocytes is acquired progressively during folliculogenesis and is linked to follicular size. It has been documented that oocytes originating from larger follicles exhibit a greater ability to develop to the blastocyst stage. The differences in cytoplasmic factors such as mRNA transcripts could explain the differences in oocyte developmental potential. We used bovine oligonucleotide microarrays to characterize differences between the gene expression profiles of germinal vesicle stage (GV) oocytes with greater developmental competence from medium follicles (MF) and those with less developmental competence from small follicles (SF). After normalizing the microarray data, our analysis found differences in the level of 60 transcripts (≥1.4 fold), corresponding to 49 upregulated and 11 downregulated transcripts in MF oocytes compared to SF oocytes. The gene expression data were classified according to gene ontology, the majority of the genes were associated with the regulation of transcription, translation, the cell cycle, and mitochondrial activity. A subset of 16 selected genes was validated for GV oocytes by quantitative real-time RT-PCR; significant differences (P˂0.01) were found in the level of TAF1A, MTRF1L, ATP5C1, UBL5 and MAP3K13 between the MF and SF oocytes. After maturation the transcript level remained stable for ATP5F1, BRD7, and UBL5 in both oocyte categories. The transcript level of another 13 genes substantially dropped in the MF and/or SF oocytes. It can be concluded that the developmental competence of bovine oocytes and embryos may be a quantitative trait dependent on small changes in the transcription profiles of many genes.
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Affiliation(s)
- Lucie Nemcova
- Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic.
| | - Denisa Jansova
- Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic
| | - Katerina Vodickova-Kepkova
- Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic
| | - Petr Vodicka
- Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Michal Jeseta
- Department of Genetics and Reproduction, Veterinary Research Institute, Brno, Czech Republic
| | - Marie Machatkova
- Department of Genetics and Reproduction, Veterinary Research Institute, Brno, Czech Republic
| | - Jiri Kanka
- Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic
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Chrzanowska-Lightowlers ZM, Lightowlers RN. Response to "Ribosome Rescue and Translation Termination at Non-standard Stop Codons by ICT1 in Mammalian Mitochondria". PLoS Genet 2015; 11:e1005227. [PMID: 26087262 PMCID: PMC4472777 DOI: 10.1371/journal.pgen.1005227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 01/15/2015] [Indexed: 11/18/2022] Open
Affiliation(s)
- Zofia Maria Chrzanowska-Lightowlers
- Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Medical School, Newcastle upon Tyne, United Kingdom
- * E-mail: (ZMCL); (RNL)
| | - Robert Neil Lightowlers
- Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Medical School, Newcastle upon Tyne, United Kingdom
- * E-mail: (ZMCL); (RNL)
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Response to the Formal Letter of Z. Chrzanowska-Lightowlers and R. N. Lightowlers Regarding Our Article "Ribosome Rescue and Translation Termination at Non-Standard Stop Codons by ICT1 in Mammalian Mitochondria". PLoS Genet 2015; 11:e1005218. [PMID: 26087150 PMCID: PMC4472662 DOI: 10.1371/journal.pgen.1005218] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/13/2015] [Indexed: 11/18/2022] Open
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Akabane S, Ueda T, Nierhaus KH, Takeuchi N. Ribosome rescue and translation termination at non-standard stop codons by ICT1 in mammalian mitochondria. PLoS Genet 2014; 10:e1004616. [PMID: 25233460 PMCID: PMC4169044 DOI: 10.1371/journal.pgen.1004616] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 07/18/2014] [Indexed: 12/13/2022] Open
Abstract
Release factors (RFs) govern the termination phase of protein synthesis. Human mitochondria harbor four different members of the class 1 RF family: RF1Lmt/mtRF1a, RF1mt, C12orf65 and ICT1. The homolog of the essential ICT1 factor is widely distributed in bacteria and organelles and has the peculiar feature in human mitochondria to be part of the ribosome as a ribosomal protein of the large subunit. The factor has been suggested to rescue stalled ribosomes in a codon-independent manner. The mechanism of action of this factor was obscure and is addressed here. Using a homologous mitochondria system of purified components, we demonstrate that the integrated ICT1 has no rescue activity. Rather, purified ICT1 binds stoichiometrically to mitochondrial ribosomes in addition to the integrated copy and functions as a general rescue factor, i.e. it releases the polypeptide from the peptidyl tRNA from ribosomes stalled at the end or in the middle of an mRNA or even from non-programmed ribosomes. The data suggest that the unusual termination at a sense codon (AGA/G) of the oxidative-phosphorylation enzymes CO1 and ND6 is also performed by ICT1 challenging a previous model, according to which RF1Lmt/mtRF1a is responsible for the translation termination at non-standard stop codons. We also demonstrate by mutational analyses that the unique insertion sequence present in the N-terminal domain of ICT1 is essential for peptide release rather than for ribosome binding. The function of RF1mt, another member of the class1 RFs in mammalian mitochondria, was also examined and is discussed. Mammalian mitochondrial ICT1, a bacterial ArfB homolog, is interestingly an integral component of the mitoribosome (MRPL58). The mechanism of ribosome rescue by this factor was obscure and is addressed here. Utilizing a homologous mitochondria system of purified components we demonstrate that the integrated ICT1 has no rescue activity, as opposed to a previous model. Rather, purified ICT1 added to mitoribosomes has a general rescue activity; it recycles ribosomes stalled at the end or in the middle of mRNAs and can even hydrolyze peptidyl-tRNA bound to non-programmed ribosomes. These results further imply that ICT1 can function in the translation termination at non-standard stop codons AGA/G in mammalian mitochondria. Our data challenge a previous model claiming that RF1Lmt/mtRF1a is responsible for the translation termination at non-standard stop codons. A mutational study indicates that the unique insertion sequence in ICT1 is essential for peptide release. The function of RF1mt, another member of the class1 RFs in mammalian mitochondria, was also examined and is discussed.
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Affiliation(s)
- Shiori Akabane
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa-shi, Chiba, Japan
| | - Takuya Ueda
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa-shi, Chiba, Japan
| | - Knud H. Nierhaus
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nono Takeuchi
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa-shi, Chiba, Japan
- * E-mail:
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Abstract
Understanding regulation of mitochondrial DNA (mtDNA) expression is of considerable interest given that mitochondrial dysfunction is important in human pathology and aging. Similar to the situation in bacteria, there is no compartmentalization between transcription and translation in mitochondria; hence, both processes are likely to have a direct molecular crosstalk. Accumulating evidence suggests that there are important mechanisms for regulation of mammalian mtDNA expression at the posttranscriptional level. Regulation of mRNA maturation, mRNA stability, translational coordination, ribosomal biogenesis, and translation itself all form the basis for controlling oxidative phosphorylation capacity. Consequently, a wide variety of inherited human mitochondrial diseases are caused by mutations of nuclear genes regulating various aspects of mitochondrial translation. Furthermore, mutations of mtDNA, associated with human disease and aging, often affect tRNA genes critical for mitochondrial translation. Recent advances in molecular understanding of mitochondrial translation regulation will most likely provide novel avenues for modulating mitochondrial function for treating human disease.
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Affiliation(s)
- B Martin Hällberg
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology, DESY Campus, 22603 Hamburg, Germany; European Molecular Biology Laboratory, Hamburg Unit, 22603 Hamburg, Germany.
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 509 31 Cologne, Germany; Department of Laboratory Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden.
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