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Khawaja A, Cipullo M, Krüger A, Rorbach J. Insights into mitoribosomal biogenesis from recent structural studies. Trends Biochem Sci 2023; 48:629-641. [PMID: 37169615 DOI: 10.1016/j.tibs.2023.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/13/2023]
Abstract
The mitochondrial ribosome (mitoribosome) is a multicomponent machine that has unique structural features. Biogenesis of the human mitoribosome includes correct maturation and folding of the mitochondria-encoded RNA components (12S and 16S mt-rRNAs, and mt-tRNAVal) and their assembly together with 82 nucleus-encoded mitoribosomal proteins. This complex process requires the coordinated action of multiple assembly factors. Recent advances in single-particle cryo-electron microscopy (cryo-EM) have provided detailed insights into the specific functions of several mitoribosome assembly factors and have defined their timing. In this review we summarize mitoribosomal small (mtSSU) and large subunit (mtLSU) biogenesis based on structural findings, and we discuss potential crosstalk between mtSSU and mtLSU assembly pathways as well as coordination between mitoribosome biogenesis and other processes involved in mitochondrial gene expression.
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Affiliation(s)
- Anas Khawaja
- 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
| | - Miriam Cipullo
- 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
| | - 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
| | - 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.
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2
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Chrzanowska-Lightowlers ZM, Lightowlers RN. Translation in Mitochondrial Ribosomes. Methods Mol Biol 2023; 2661:53-72. [PMID: 37166631 DOI: 10.1007/978-1-0716-3171-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mitochondrial protein synthesis is essential for the life of aerobic eukaryotes. Without it, oxidative phosphorylation cannot be coupled. Evolution has shaped a battery of factors and machinery that are key to production of just a handful of critical proteins. In this general concept chapter, we attempt to briefly summarize our current knowledge of the overall process in mitochondria from a variety of species, breaking this down to the four parts of translation: initiation, elongation, termination, and recycling. Where appropriate, we highlight differences between species and emphasize gaps in our understanding. Excitingly, with the current revolution in cryoelectron microscopy and mitochondrial genome editing, it is highly likely that many of these gaps will be resolved in the near future. However, the absence of a faithful in vitro reconstituted system to study mitochondrial translation is still problematic.
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Affiliation(s)
- Zofia M Chrzanowska-Lightowlers
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK.
| | - Robert N Lightowlers
- Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
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3
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Mitochondrial Spermidine Synthase is Essential for Blood-stage growth of the Malaria Parasite. Microbiol Res 2022; 265:127181. [PMID: 36162149 DOI: 10.1016/j.micres.2022.127181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/14/2022] [Accepted: 08/28/2022] [Indexed: 11/21/2022]
Abstract
Positively-charged polyamines are essential molecules for the replication of eukaryotic cells and are particularly important for the rapid proliferation of parasitic protozoa and cancer cells. Unlike in Trypanosoma brucei, the inhibition of the synthesis of intermediate polyamine Putrescine caused only partial defect in malaria parasite blood-stage growth. In contrast, reducing the intracellular concentrations of Spermidine and Spermine by polyamine analogs caused significant defects in blood-stage growth in Plasmodium yoelii and P. falciparum. However, little is known about the synthesizing enzyme of Spermidine and Spermine in the malaria parasite. Herein, malaria parasite conserved Spermidine Synthase (SpdS) gene was targeted for deletion/complementation analyses by knockout/knock-in constructs in P. yoelii. SpdS was found to be essential for blood-stage growth. Live fluorescence imaging in blood-stages and sporozoites confirmed a specific mitochondrial localization, which is not known for any polyamine-synthesizing enzyme so far. This study identifies SpdS as an excellent drug targeting candidate against the malaria parasite, which is localized to the parasite mitochondrion.
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4
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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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5
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mtIF3 is locally translated in axons and regulates mitochondrial translation for axonal growth. BMC Biol 2022; 20:12. [PMID: 34996455 PMCID: PMC8742369 DOI: 10.1186/s12915-021-01215-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Background The establishment and maintenance of functional neural connections relies on appropriate distribution and localization of mitochondria in neurites, as these organelles provide essential energy and metabolites. In particular, mitochondria are transported to axons and support local energy production to maintain energy-demanding neuronal processes including axon branching, growth, and regeneration. Additionally, local protein synthesis is required for structural and functional changes in axons, with nuclear-encoded mitochondrial mRNAs having been found localized in axons. However, it remains unclear whether these mRNAs are locally translated and whether the potential translated mitochondrial proteins are involved in the regulation of mitochondrial functions in axons. Here, we aim to further understand the purpose of such compartmentalization by focusing on the role of mitochondrial initiation factor 3 (mtIF3), whose nuclear-encoded transcripts have been shown to be present in axonal growth cones. Results We demonstrate that brain-derived neurotrophic factor (BDNF) induces local translation of mtIF3 mRNA in axonal growth cones. Subsequently, mtIF3 protein is translocated into axonal mitochondria and promotes mitochondrial translation as assessed by our newly developed bimolecular fluorescence complementation sensor for the assembly of mitochondrial ribosomes. We further show that BDNF-induced axonal growth requires mtIF3-dependent mitochondrial translation in distal axons. Conclusion We describe a previously unknown function of mitochondrial initiation factor 3 (mtIF3) in axonal protein synthesis and development. These findings provide insight into the way neurons adaptively control mitochondrial physiology and axonal development via local mtIF3 translation. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01215-w.
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6
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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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7
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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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8
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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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9
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Gonçalves AM, Pereira-Santos AR, Esteves AR, Cardoso SM, Empadinhas N. The Mitochondrial Ribosome: A World of Opportunities for Mitochondrial Dysfunction Toward Parkinson's Disease. Antioxid Redox Signal 2021; 34:694-711. [PMID: 32098485 DOI: 10.1089/ars.2019.7997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance: Mitochondrial ribosomes (mitoribosomes) are organelles that translate mitochondrial messenger RNA in the matrix and, in mammals, have evolved to translate 13 polypeptides of the pathway that performs oxidative phosphorylation (OXPHOS). Although a number of devastating diseases result from defects in this mitochondrial translation apparatus, most are associated with genetic mutations and little is known about allelopathic defects caused by antibiotics, toxins, or nonproteinogenic amino acids. Recent Advances: The levels of mitochondrial ribosomal subunits 12S and 16S ribosomal RNA (rRNA) in cells/tissues from patients carrying mutations in these genes have been associated with alterations in mitochondrial translation efficiency and with impaired OXPHOS activities, as well as with the severity of clinical phenotypes. In recent decades, important studies revealed a prominent role of mitochondrial dysfunction in Parkinson's disease (PD); however, the involvement of mitoribosomes remains largely unknown. Critical Issues: Considering that mitoribosomal structure and function can determine the efficiency of OXPHOS and that an impaired mitochondrial respiratory chain is a common finding in PD, we argue that the mitoribosome may be key to disease onset and progression. With this review, we comprehensively integrate the available knowledge on the composition, assembly, and role of the mitoribosome in mitochondrial efficiency, reflecting on its possible involvement in the etiopathogenesis of this epidemic disease as an appealing research avenue. Future Directions: If a direct correlation between mitoribosome failure and PD pathology is demonstrated, these mitochondrial organelles will provide valuable early clinical markers and potentially attractive targets for the development of innovative PD-directed therapeutic agents.
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Affiliation(s)
- Ana Mafalda Gonçalves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Ana Raquel Pereira-Santos
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Ana Raquel Esteves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Sandra M Cardoso
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Nuno Empadinhas
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,IIIUC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
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10
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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: 154] [Impact Index Per Article: 51.3] [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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11
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Levitskii SA, Baleva MV, Chicherin IV, Krasheninnikov IA, Kamenski PA. Protein Biosynthesis in Mitochondria: Past Simple, Present Perfect, Future Indefinite. BIOCHEMISTRY (MOSCOW) 2021; 85:257-263. [PMID: 32564730 DOI: 10.1134/s0006297920030013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondria are obligate organelles of most eukaryotic cells that perform many different functions important for cellular homeostasis. The main role of mitochondria is supplying cells with energy in a form of ATP, which is synthesized in a chain of oxidative phosphorylation reactions on the organelle inner membrane. It is commonly believed now that mitochondria have the endosymbiotic origin. In the course of evolution, they have lost most of their genetic material as a result of genome reduction and gene transfer to the nucleus. The majority of mitochondrial proteins are synthesized in the cytosol and then imported to the mitochondria. However, almost all known mitochondria still contain genomes that are maintained and expressed. The processes of protein biosynthesis in the mitochondria - mitochondrial translation - substantially differs from the analogous processes in bacteria and the cytosol of eukaryotic cells. Mitochondrial translation is characterized by a high degree of specialization and specific regulatory mechanisms. In this review, we analyze available information on the common principles of mitochondrial translation with emphasis on the molecular mechanisms of translation initiation in the mitochondria of yeast and mammalian cells.
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Affiliation(s)
- S A Levitskii
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - M V Baleva
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - I V Chicherin
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - I A Krasheninnikov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - P A Kamenski
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia.
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12
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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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13
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Latorraca LB, Feitosa WB, Mariano C, Moura MT, Fontes PK, Nogueira MFG, Paula-Lopes FF. Autophagy is a pro-survival adaptive response to heat shock in bovine cumulus-oocyte complexes. Sci Rep 2020; 10:13711. [PMID: 32792582 PMCID: PMC7426922 DOI: 10.1038/s41598-020-69939-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/04/2020] [Indexed: 12/11/2022] Open
Abstract
Autophagy is a physiological mechanism that can be activated under stress conditions. However, the role of autophagy during oocyte maturation has been poorly investigated. Therefore, this study characterized the role of autophagy on developmental competence and gene expression of bovine oocytes exposed to heat shock (HS). Cumulus-oocyte-complexes (COCs) were matured at Control (38.5 °C) and HS (41 °C) temperatures in the presence of 0 and 10 mM 3-methyladenine (3MA; autophagy inhibitor). Western blotting analysis revealed that HS increased autophagy marker LC3-II/LC3-I ratio in oocytes. However, there was no effect of temperature for oocytes matured with 3MA. On cumulus cells, 3MA reduced LC3-II/LC3-I ratio regardless of temperature. Inhibition of autophagy during IVM of heat-shocked oocytes (3MA-41 °C) reduced cleavage and blastocyst rates compared to standard in vitro matured heat-shocked oocytes (IVM-41 °C). Therefore, the magnitude of HS detrimental effects was greater in the presence of autophagy inhibitor. Oocyte maturation under 3MA-41 °C reduced mRNA abundance for genes related to energy metabolism (MTIF3), heat shock response (HSF1), and oocyte maturation (HAS2 and GREM1). In conclusion, autophagy is a stress response induced on heat shocked oocytes. Inhibition of autophagy modulated key functional processes rendering the oocyte more susceptible to the deleterious effects of heat shock.
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Affiliation(s)
- Lais B Latorraca
- Department of Pharmacology, Institute of Bioscience, São Paulo State University (UNESP), District of Rubião Junior S/N, Botucatu, São Paulo, 18618970, Brazil
| | - Weber B Feitosa
- Department of Biological Sciences, Federal University of São Paulo, Diadema, São Paulo, 09972270, Brazil
| | - Camila Mariano
- Department of Biological Sciences, Federal University of São Paulo, Diadema, São Paulo, 09972270, Brazil
| | - Marcelo T Moura
- Department of Biological Sciences, Federal University of São Paulo, Diadema, São Paulo, 09972270, Brazil
| | - Patrícia K Fontes
- Department of Pharmacology, Institute of Bioscience, São Paulo State University (UNESP), District of Rubião Junior S/N, Botucatu, São Paulo, 18618970, Brazil
| | - Marcelo F G Nogueira
- Department of Pharmacology, Institute of Bioscience, São Paulo State University (UNESP), District of Rubião Junior S/N, Botucatu, São Paulo, 18618970, Brazil
- Department of Biological Sciences, School of Sciences and Languages, UNESP, Assis, São Paulo, Brazil
| | - Fabíola F Paula-Lopes
- Department of Pharmacology, Institute of Bioscience, São Paulo State University (UNESP), District of Rubião Junior S/N, Botucatu, São Paulo, 18618970, Brazil.
- Department of Biological Sciences, Federal University of São Paulo, Diadema, São Paulo, 09972270, Brazil.
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14
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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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15
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Initiation Factor 3 is Dispensable For Mitochondrial Translation in Cultured Human Cells. Sci Rep 2020; 10:7110. [PMID: 32346061 PMCID: PMC7188818 DOI: 10.1038/s41598-020-64139-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 04/13/2020] [Indexed: 11/08/2022] Open
Abstract
The initiation of protein synthesis in bacteria is ruled by three canonical factors: IF1, IF2, and IF3. This system persists in human mitochondria; however, it functions in a rather different way due to specialization and adaptation to the organellar micro-environment. We focused on human mitochondrial IF3, which was earlier studied in vitro, but no knock-out cellular models have been published up to date. In this work, we generated human HeLa cell lines deficient in the MTIF3 gene and analyzed their mitochondrial function. Despite the lack of IF3mt in these cells, they preserved functional mitochondria capable of oxygen consumption and protein synthesis; however, the translation of ATP6 mRNA was selectively decreased which compromised the assembly of ATP synthase. Together with the analogous results obtained earlier for baker's yeast mitochondrial IF3, our findings point to a functional divergence of mitochondrial initiation factors from their bacterial ancestors.
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Abstract
The mitochondrial genome encodes 13 proteins that are components of the oxidative phosphorylation system (OXPHOS), suggesting that precise regulation of these genes is crucial for maintaining OXPHOS functions, including ATP production, calcium buffering, cell signaling, ROS production, and apoptosis. Furthermore, heteroplasmy or mis-regulation of gene expression in mitochondria frequently is associated with human mitochondrial diseases. Thus, various approaches have been developed to investigate the roles of genes encoded by the mitochondrial genome. In this review, we will discuss a wide range of techniques available for investigating the mitochondrial genome, mitochondrial transcription, and mitochondrial translation, which provide a useful guide to understanding mitochondrial gene expression.
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Affiliation(s)
- Dongkeun Park
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Soyeon Lee
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Kyung-Tai Min
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
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17
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Rudler DL, Hughes LA, Perks KL, Richman TR, Kuznetsova I, Ermer JA, Abudulai LN, Shearwood AMJ, Viola HM, Hool LC, Siira SJ, Rackham O, Filipovska A. Fidelity of translation initiation is required for coordinated respiratory complex assembly. SCIENCE ADVANCES 2019; 5:eaay2118. [PMID: 31903419 PMCID: PMC6924987 DOI: 10.1126/sciadv.aay2118] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/30/2019] [Indexed: 05/22/2023]
Abstract
Mammalian mitochondrial ribosomes are unique molecular machines that translate 11 leaderless mRNAs; however, it is not clear how mitoribosomes initiate translation, since mitochondrial mRNAs lack untranslated regions. Mitochondrial translation initiation shares similarities with prokaryotes, such as the formation of a ternary complex of fMet-tRNAMet, mRNA and the 28S subunit, but differs in the requirements for initiation factors. Mitochondria have two initiation factors: MTIF2, which closes the decoding center and stabilizes the binding of the fMet-tRNAMet to the leaderless mRNAs, and MTIF3, whose role is not clear. We show that MTIF3 is essential for survival and that heart- and skeletal muscle-specific loss of MTIF3 causes cardiomyopathy. We identify increased but uncoordinated mitochondrial protein synthesis in mice lacking MTIF3, resulting in loss of specific respiratory complexes. Ribosome profiling shows that MTIF3 is required for recognition and regulation of translation initiation of mitochondrial mRNAs and for coordinated assembly of OXPHOS complexes in vivo.
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Affiliation(s)
- Danielle L. Rudler
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Laetitia A. Hughes
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Kara L. Perks
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Tara R. Richman
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Irina Kuznetsova
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Judith A. Ermer
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Laila N. Abudulai
- Centre for Microscopy, Characterisation and Analysis and School of Biomedical Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Anne-Marie J. Shearwood
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Helena M. Viola
- School of Human Sciences (Physiology), The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Livia C. Hool
- School of Human Sciences (Physiology), The University of Western Australia, Crawley, Western Australia 6009, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia
| | - Stefan J. Siira
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Western Australia 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia 6102, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Corresponding author.
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18
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Chicherin IV, Baleva MV, Levitskii SA, Dashinimaev EB, Krasheninnikov IA. Mitochondrial Translation Initiation Factor 3: Structure, Functions, Interactions, and Implication in Human Health and Disease. BIOCHEMISTRY (MOSCOW) 2019; 84:1143-1150. [PMID: 31694510 DOI: 10.1134/s0006297919100031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondria are essential organelles of eukaryotic cell that provide its respiratory function by means of the electron transfer chain. Expression of mitochondrial genes is organized in a bacterial-like manner; however multiple evolutionary differences are observed between the two systems, including translation initiation machinery. This review is dedicated to the mitochondrial translation initiation factor 3 (IF3mt), which plays a key role in the protein synthesis in mitochondria. Involvement of IF3mt in human health and disease is discussed.
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Affiliation(s)
- I V Chicherin
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia. .,Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - M V Baleva
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - S A Levitskii
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - E B Dashinimaev
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia. .,Pirogov Russian National Research Medical University, Moscow, 117977, Russia
| | - I A Krasheninnikov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
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Ayyub SA, Varshney U. Translation initiation in mammalian mitochondria- a prokaryotic perspective. RNA Biol 2019; 17:165-175. [PMID: 31696767 DOI: 10.1080/15476286.2019.1690099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
ATP is generated in mitochondria of eukaryotic cells by oxidative phosphorylation (OXPHOS). The OXPHOS complex, which is crucial for cellular metabolism, comprises of both nuclear and mitochondrially encoded subunits. Also, the occurrence of several pathologies because of mutations in the mitochondrial translation apparatus indicates the importance of mitochondrial translation and its regulation. The mitochondrial translation apparatus is similar to its prokaryotic counterpart due to a common origin of evolution. However, mitochondrial translation has diverged from prokaryotic translation in many ways by reductive evolution. In this review, we focus on mammalian mitochondrial translation initiation, a highly regulated step of translation, and present a comparison with prokaryotic translation.
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Affiliation(s)
- Shreya Ahana Ayyub
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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20
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Luo Y, Su R, Wang Y, Xie W, Liu Z, Huang Y. Schizosaccharomyces pombe Mti2 and Mti3 act in conjunction during mitochondrial translation initiation. FEBS J 2019; 286:4542-4553. [PMID: 31350787 DOI: 10.1111/febs.15021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/23/2019] [Accepted: 07/24/2019] [Indexed: 01/15/2023]
Abstract
Mitochondrial DNA encodes key subunits of the oxidative phosphorylation complexes essential for ATP production. Translation initiation in mitochondria requires two general factors, mtIF2 and mtIF3, whose counterparts in bacteria are essential for protein synthesis. In this study, we report the characterization of the fission yeast Schizosaccharomyces pombe mtIF2 (Mti2) and mtIF3 (Mti3). Deletion of mti2 impairs cell growth on the respiratory medium. The growth defect of the mti2 deletion mutant can be suppressed by expressing IFM1, the Saccharomyces cerevisiae homolog of Mti2, demonstrating functional conservation between the two proteins. Deletion of mti2 also impairs mitochondrial protein synthesis. Unlike mti2, deletion of mti3 does not affect cell growth on respiratory media and mitochondrial translation. However, deletion of mti3 exacerbates the growth defect of the Δmti2 mutant, suggesting that the two proteins have distinct, but partially overlapping functions during the process of mitochondrial translation initiation in S. pombe. Both Mti2 and Mti3 are associated with the small subunit of the mitochondrial ribosome (mitoribosome). Disruption of mti2, but not mti3, causes dissociation of the mitoribosome and also abolishes Mti3 binding to the small subunit of the mitoribosome. Our results suggest that Mti2 and Mti3 bind in a sequential manner to the small subunit of the mitoribosome and that Mti3 facilitates the function of Mti2 in mitochondrial translation initiation. Our findings also support the view that the importance of the mitochondrial translation initiation factors varies among the organisms.
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Affiliation(s)
- Ying Luo
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
| | - Ruyue Su
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
| | - Yirong Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
| | - Wanqiu Xie
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
| | - Zecheng Liu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
| | - Ying Huang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life Sciences, Nanjing Normal University, China
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21
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Koripella RK, Sharma MR, Haque ME, Risteff P, Spremulli LL, Agrawal RK. Structure of Human Mitochondrial Translation Initiation Factor 3 Bound to the Small Ribosomal Subunit. iScience 2019; 12:76-86. [PMID: 30677741 PMCID: PMC6352543 DOI: 10.1016/j.isci.2018.12.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/11/2018] [Accepted: 12/27/2018] [Indexed: 11/20/2022] Open
Abstract
The human mitochondrial translational initiation factor 3 (IF3mt) carries mitochondrial-specific amino acid extensions at both its N and C termini (N- and C-terminal extensions [NTE and CTE, respectively]), when compared with its eubacterial counterpart. Here we present 3.3- to 3.5-Å-resolution cryoelectron microscopic structures of the mammalian 28S mitoribosomal subunit in complex with human IF3mt. Unique contacts observed between the 28S subunit and N-terminal domain of IF3mt explain its unusually high affinity for the 28S subunit, whereas the position of the mito-specific NTE suggests NTE's role in binding of initiator tRNA to the 28S subunit. The location of the C-terminal domain (CTD) clarifies its anti-association activity, whereas the orientation of the mito-specific CTE provides a mechanistic explanation for its role in destabilizing initiator tRNA in the absence of mRNA. Furthermore, our structure hints at a possible role of the CTD in recruiting leaderless mRNAs for translation initiation. Our findings highlight unique features of IF3mt in mitochondrial translation initiation. High-resolution cryo-EM study of the mammalian 28S mitoribosome-IF3mt complex Interaction between the 28S and IF3mt's NTD explains NTD's unusual high affinity Provides insights into role of IF3mt's N-terminal extension in initiator tRNA binding Provides insights into roles of IF3mt's CTD and C-terminal extension in mRNA sensing
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Affiliation(s)
- Ravi K Koripella
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA
| | - Manjuli R Sharma
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA
| | - Md Emdadul Haque
- Department of Chemistry, Campus Box 3290, University of North Carolina, Chapel Hill, NC, USA
| | - Paul Risteff
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA
| | - Linda L Spremulli
- Department of Chemistry, Campus Box 3290, University of North Carolina, Chapel Hill, NC, USA
| | - Rajendra K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA; Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, Albany, NY, USA.
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22
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Derbikova K, Kuzmenko A, Levitskii S, Klimontova M, Chicherin I, Baleva MV, Krasheninnikov IA, Kamenski P. Biological and Evolutionary Significance of Terminal Extensions of Mitochondrial Translation Initiation Factor 3. Int J Mol Sci 2018; 19:ijms19123861. [PMID: 30518034 PMCID: PMC6321546 DOI: 10.3390/ijms19123861] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/27/2018] [Accepted: 11/30/2018] [Indexed: 01/14/2023] Open
Abstract
Protein biosynthesis in mitochondria is organized in a bacterial manner. However, during evolution, mitochondrial translation mechanisms underwent many organelle-specific changes. In particular, almost all mitochondrial translation factors, being orthologous to bacterial proteins, are characterized by some unique elements of primary or secondary structure. In the case of the organellar initiation factor 3 (IF3), these elements are several dozen amino acids long N- and C-terminal extensions. This study focused on the terminal extensions of baker's yeast mitochondrial IF3, Aim23p. By in vivo deletion and complementation analysis, we show that at least one extension is necessary for Aim23p function. At the same time, human mitochondrial IF3 is fully functional in yeast mitochondria even without both terminal extensions. While Escherichia coli IF3 itself is poorly active in yeast mitochondria, adding Aim23p terminal extensions makes the resulting chimeric protein as functional as the cognate factor. Our results show that the terminal extensions of IF3 have evolved as the "adaptors" that accommodate the translation factor of bacterial origin to the evolutionary changed protein biosynthesis system in mitochondria.
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Affiliation(s)
- Ksenia Derbikova
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
| | - Anton Kuzmenko
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
- Institute of Molecular Genetics, Russian Academy of Science, 119991 Moskva, Russia.
| | - Sergey Levitskii
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
| | - Maria Klimontova
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
- Faculty of Biosciences, Heidelberg University, 69117 Heidelberg, Germany.
| | - Ivan Chicherin
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
| | - Maria V Baleva
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
| | | | - Piotr Kamenski
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moskva, Russia.
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23
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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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Callegari S, Dennerlein S. Sensing the Stress: A Role for the UPR mt and UPR am in the Quality Control of Mitochondria. Front Cell Dev Biol 2018; 6:31. [PMID: 29644217 PMCID: PMC5882792 DOI: 10.3389/fcell.2018.00031] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/12/2018] [Indexed: 01/01/2023] Open
Abstract
Mitochondria exist as compartmentalized units, surrounded by a selectively permeable double membrane. Within is contained the mitochondrial genome and protein synthesis machinery, required for the synthesis of OXPHOS components and ultimately, ATP production. Despite their physical barrier, mitochondria are tightly integrated into the cellular environment. A constant flow of information must be maintained to and from the mitochondria and the nucleus, to ensure mitochondria are amenable to cell metabolic requirements and also to feedback on their functional state. This review highlights the pathways by which mitochondrial stress is signaled to the nucleus, with a particular focus on the mitochondrial unfolded protein response (UPRmt) and the unfolded protein response activated by the mistargeting of proteins (UPRam). Although these pathways were originally discovered to alleviate proteotoxic stress from the accumulation of mitochondrial-targeted proteins that are misfolded or unimported, we review recent findings indicating that the UPRmt can also sense defects in mitochondrial translation. We further discuss the regulation of OXPHOS assembly and speculate on a possible role for mitochondrial stress pathways in sensing OXPHOS biogenesis.
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Affiliation(s)
- Sylvie Callegari
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
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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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26
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Creatine maintains intestinal homeostasis and protects against colitis. Proc Natl Acad Sci U S A 2017; 114:E1273-E1281. [PMID: 28137860 DOI: 10.1073/pnas.1621400114] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Creatine, a nitrogenous organic acid, replenishes cytoplasmic ATP at the expense of mitochondrial ATP via the phosphocreatine shuttle. Creatine levels are maintained by diet and endogenous synthesis from arginine and glycine. Glycine amidinotransferase (GATM) catalyzes the rate-limiting step of creatine biosynthesis: the transfer of an amidino group from arginine to glycine to form ornithine and guanidinoacetate. We screened 36,530 third-generation germline mutant mice derived from N-ethyl-N-nitrosourea-mutagenized grandsires for intestinal homeostasis abnormalities after oral administration of dextran sodium sulfate (DSS). Among 27 colitis susceptibility phenotypes identified and mapped, one was strongly correlated with a missense mutation in Gatm in a recessive model of inheritance, and causation was confirmed by CRISPR/Cas9 gene targeting. Supplementation of homozygous Gatm mutants with exogenous creatine ameliorated the colitis phenotype. CRISPR/Cas9-targeted (Gatmc/c ) mice displayed a normal peripheral immune response and immune cell homeostasis. However, the intestinal epithelium of the Gatmc/c mice displayed increased cell death and decreased proliferation during DSS treatment. In addition, Gatmc/c colonocytes showed increased metabolic stress in response to DSS with higher levels of phospho-AMPK and lower levels of phosphorylation of mammalian target of rapamycin (phospho-mTOR). These findings establish an in vivo requirement for rapid replenishment of cytoplasmic ATP within colonic epithelial cells in the maintenance of the mucosal barrier after injury.
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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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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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29
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Potluri P, Procaccio V, Scheffler IE, Wallace DC. High throughput gene complementation screening permits identification of a mammalian mitochondrial protein synthesis (ρ(-)) mutant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1336-1343. [PMID: 26946086 DOI: 10.1016/j.bbabio.2016.02.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 12/26/2022]
Abstract
To identify nuclear DNA (nDNA) oxidative phosphorylation (OXPHOS) gene mutations using cultured cells, we have developed a complementation system based on retroviral transduction with a full length cDNA expression library and selection for OXHOS function by growth in galactose. We have used this system to transduce the Chinese hamster V79-G7 OXPHOS mutant cell line with a defect in mitochondrial protein synthesis. The complemented cells were found to have acquired the cDNA for the bS6m polypeptide of the small subunit of the mitochondrial ribosome. bS6m is a 14 kDa polypeptide located on the outside of the mitochondrial 28S ribosomal subunit and interacts with the rRNA. The V79-G7 mutant protein was found to harbor a methionine to threonine missense mutation at codon 13. The hamster bS6m null mutant could also be complemented by its orthologs from either mouse or human. bS6m protein tagged at its C-terminus by HA, His or GFP localized to the mitochondrion and was fully functional. Through site-directed mutagenesis we identified the probable RNA interacting residues of the bS6m peptide and tested the functional significance of mammalian specific C-terminal region. The N-terminus of the bS6m polypeptide functionally corresponds to that of the prokaryotic small ribosomal subunit, but deletion of C-terminal residues along with the zinc ion coordinating cysteine had no functional effect. Since mitochondrial diseases can result from hundreds to thousands of different nDNA gene mutations, this one step viral complementation cloning may facilitate the molecular diagnosis of a range of nDNA mitochondrial disease mutations. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Prasanth Potluri
- Center for Mitochondrial and Epigenomic Medicine, The Children's Hospital of Philadelphia, Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Vincent Procaccio
- Dépt. de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Immo E Scheffler
- Division of Biological Sciences, University of California - San Diego, La Jolla, CA, United States
| | - Douglas C Wallace
- Center for Mitochondrial and Epigenomic Medicine, The Children's Hospital of Philadelphia, Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
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30
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Papandonatos GD, Pan Q, Pajewski NM, Delahanty LM, Peter I, Erar B, Ahmad S, Harden M, Chen L, Fontanillas P, Wagenknecht LE, Kahn SE, Wing RR, Jablonski KA, Huggins GS, Knowler WC, Florez JC, McCaffery JM, Franks PW. Genetic Predisposition to Weight Loss and Regain With Lifestyle Intervention: Analyses From the Diabetes Prevention Program and the Look AHEAD Randomized Controlled Trials. Diabetes 2015; 64:4312-21. [PMID: 26253612 PMCID: PMC4657576 DOI: 10.2337/db15-0441] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/04/2015] [Indexed: 12/22/2022]
Abstract
Clinically relevant weight loss is achievable through lifestyle modification, but unintentional weight regain is common. We investigated whether recently discovered genetic variants affect weight loss and/or weight regain during behavioral intervention. Participants at high-risk of type 2 diabetes (Diabetes Prevention Program [DPP]; N = 917/907 intervention/comparison) or with type 2 diabetes (Look AHEAD [Action for Health in Diabetes]; N = 2,014/1,892 intervention/comparison) were from two parallel arm (lifestyle vs. comparison) randomized controlled trials. The associations of 91 established obesity-predisposing loci with weight loss across 4 years and with weight regain across years 2-4 after a minimum of 3% weight loss were tested. Each copy of the minor G allele of MTIF3 rs1885988 was consistently associated with greater weight loss following lifestyle intervention over 4 years across the DPP and Look AHEAD. No such effect was observed across comparison arms, leading to a nominally significant single nucleotide polymorphism×treatment interaction (P = 4.3 × 10(-3)). However, this effect was not significant at a study-wise significance level (Bonferroni threshold P < 5.8 × 10(-4)). Most obesity-predisposing gene variants were not associated with weight loss or regain within the DPP and Look AHEAD trials, directly or via interactions with lifestyle.
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Affiliation(s)
| | - Qing Pan
- The Biostatistics Center, George Washington University, Rockville, MD
| | - Nicholas M Pajewski
- Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC
| | - Linda M Delahanty
- Diabetes Research Center (Diabetes Unit), Massachusetts General Hospital, Boston, MA Department of Medicine, Harvard Medical School, Boston, MA
| | - Inga Peter
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Bahar Erar
- Center for Statistical Sciences, Brown University, Providence, RI
| | - Shafqat Ahmad
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Lund University, Skåne University Hospital Malmö, Malmö, Sweden
| | | | - Ling Chen
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA Program in Medical and Population Genetics, Broad Institute, Cambridge, MA
| | - Pierre Fontanillas
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA Program in Medical and Population Genetics, Broad Institute, Cambridge, MA
| | | | - Lynne E Wagenknecht
- Look AHEAD Coordinating Center, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC
| | - Steven E Kahn
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, VA Puget Sound Health Care System and University of Washington, Seattle, WA
| | - Rena R Wing
- Weight Control and Diabetes Research Center, The Miriam Hospital and The Warren Alpert Medical School of Brown University, Providence, RI
| | | | - Gordon S Huggins
- Center for Translational Genomics, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA
| | - William C Knowler
- National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, AZ
| | - Jose C Florez
- Diabetes Research Center (Diabetes Unit), Massachusetts General Hospital, Boston, MA Department of Medicine, Harvard Medical School, Boston, MA Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA Program in Medical and Population Genetics, Broad Institute, Cambridge, MA
| | - Jeanne M McCaffery
- Weight Control and Diabetes Research Center, The Miriam Hospital and The Warren Alpert Medical School of Brown University, Providence, RI
| | - Paul W Franks
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Lund University, Skåne University Hospital Malmö, Malmö, Sweden Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA
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31
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Nettleton JA, Follis JL, Ngwa JS, Smith CE, Ahmad S, Tanaka T, Wojczynski MK, Voortman T, Lemaitre RN, Kristiansson K, Nuotio ML, Houston DK, Perälä MM, Qi Q, Sonestedt E, Manichaikul A, Kanoni S, Ganna A, Mikkilä V, North KE, Siscovick DS, Harald K, Mckeown NM, Johansson I, Rissanen H, Liu Y, Lahti J, Hu FB, Bandinelli S, Rukh G, Rich S, Booij L, Dmitriou M, Ax E, Raitakari O, Mukamal K, Männistö S, Hallmans G, Jula A, Ericson U, Jacobs DR, Van Rooij FJA, Deloukas P, Sjögren P, Kähönen M, Djousse L, Perola M, Barroso I, Hofman A, Stirrups K, Viikari J, Uitterlinden AG, Kalafati IP, Franco OH, Mozaffarian D, Salomaa V, Borecki IB, Knekt P, Kritchevsky SB, Eriksson JG, Dedoussis GV, Qi L, Ferrucci L, Orho-Melander M, Zillikens MC, Ingelsson E, Lehtimäki T, Renström F, Cupples LA, Loos RJF, Franks PW. Gene × dietary pattern interactions in obesity: analysis of up to 68 317 adults of European ancestry. Hum Mol Genet 2015; 24:4728-38. [PMID: 25994509 PMCID: PMC4512626 DOI: 10.1093/hmg/ddv186] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/17/2015] [Indexed: 11/14/2022] Open
Abstract
Obesity is highly heritable. Genetic variants showing robust associations with obesity traits have been identified through genome-wide association studies. We investigated whether a composite score representing healthy diet modifies associations of these variants with obesity traits. Totally, 32 body mass index (BMI)- and 14 waist-hip ratio (WHR)-associated single nucleotide polymorphisms were genotyped, and genetic risk scores (GRS) were calculated in 18 cohorts of European ancestry (n = 68 317). Diet score was calculated based on self-reported intakes of whole grains, fish, fruits, vegetables, nuts/seeds (favorable) and red/processed meats, sweets, sugar-sweetened beverages and fried potatoes (unfavorable). Multivariable adjusted, linear regression within each cohort followed by inverse variance-weighted, fixed-effects meta-analysis was used to characterize: (a) associations of each GRS with BMI and BMI-adjusted WHR and (b) diet score modification of genetic associations with BMI and BMI-adjusted WHR. Nominally significant interactions (P = 0.006-0.04) were observed between the diet score and WHR-GRS (but not BMI-GRS), two WHR loci (GRB14 rs10195252; LYPLAL1 rs4846567) and two BMI loci (LRRN6C rs10968576; MTIF3 rs4771122), for the respective BMI-adjusted WHR or BMI outcomes. Although the magnitudes of these select interactions were small, our data indicated that associations between genetic predisposition and obesity traits were stronger with a healthier diet. Our findings generate interesting hypotheses; however, experimental and functional studies are needed to determine their clinical relevance.
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Affiliation(s)
- Jennifer A Nettleton
- Division of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, University of Texas, Health Science Center, Houston, TX, USA
| | - Jack L Follis
- Department of Mathematics, University of St. Thomas, Houston, TX, USA
| | - Julius S Ngwa
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Caren E Smith
- Jean Mayer USDA Human Nutrition Research Center on Aging, Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Shafqat Ahmad
- Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit
| | - Toshiko Tanaka
- Clinical Research Branch, National Institute on Aging, Baltimore, MD, USA
| | - Mary K Wojczynski
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Trudy Voortman
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands, Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | | | | | - Marja-Liisa Nuotio
- Unit of Public Health Genomics, Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Tukholmankatu 8, Helsinki 00290, Finland
| | | | - Mia-Maria Perälä
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Haartmaninkatu 8, Helsinki 00290, Finland
| | - Qibin Qi
- Department of Nutrition, Harvard Chan School of Public Health, Boston, MA, USA, Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Emily Sonestedt
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | - Ani Manichaikul
- Center for Public Health Genomics, Department of Public Health Sciences, Division of Biostatistics and Epidemiology, University of Virginia, Charlottesville, VA, USA
| | - Stavroula Kanoni
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrea Ganna
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Vera Mikkilä
- Department of Food and Environmental Sciences, Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
| | - Kari E North
- Department of Epidemiology and Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | | | - Kennet Harald
- THL-National Institute for Health and Welfare, Mannerheimintie 166, Helsinki 00300, Finland
| | - Nicola M Mckeown
- Jean Mayer USDA Human Nutrition Research Center on Aging, Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | | | - Harri Rissanen
- THL-National Institute for Health and Welfare, Mannerheimintie 166, Helsinki 00300, Finland
| | - Yongmei Liu
- Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Jari Lahti
- Institute of Behavioral Sciences, Folkhälsan Research Centre, Helsinki, Finland
| | - Frank B Hu
- Department of Nutrition, Harvard Chan School of Public Health, Boston, MA, USA
| | | | - Gull Rukh
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | | | - Lisanne Booij
- Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Maria Dmitriou
- Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Erika Ax
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism
| | - Olli Raitakari
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland, Department of Clinical Physiology and Nuclear Medicine
| | - Kenneth Mukamal
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Satu Männistö
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Haartmaninkatu 8, Helsinki 00290, Finland
| | - Göran Hallmans
- Department of Public Health and Clinical Medicine, Nutritional Research
| | - Antti Jula
- THL-National Institute for Health and Welfare, Mannerheimintie 166, Helsinki 00300, Finland
| | - Ulrika Ericson
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | - David R Jacobs
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Frank J A Van Rooij
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands, Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - Panos Deloukas
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Per Sjögren
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism
| | - Mika Kähönen
- Department of Clinical Physiology, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Luc Djousse
- Division of Aging, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA, Harvard Medical School and Boston VA Healthcare System, Boston, MA, USA
| | - Markus Perola
- Unit of Public Health Genomics, Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Tukholmankatu 8, Helsinki 00290, Finland, University of Tartu, Estonian Genome Center, Ülikooli 18, Tartu 50090, Estonia
| | - Inês Barroso
- Metabolic Disease Group, Wellcome Trust Sanger Institute, Hinxton, UK, University of Cambridge Metabolic Research Labs, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
| | - Albert Hofman
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands, Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - Kathleen Stirrups
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Jorma Viikari
- Department of Medicine, University of Turku and Division of Medicine, Turku University Hospital, Turku, Finland
| | - André G Uitterlinden
- Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ioanna P Kalafati
- Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Oscar H Franco
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands, Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands
| | - Dariush Mozaffarian
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Veikko Salomaa
- THL-National Institute for Health and Welfare, Mannerheimintie 166, Helsinki 00300, Finland
| | - Ingrid B Borecki
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Paul Knekt
- THL-National Institute for Health and Welfare, Mannerheimintie 166, Helsinki 00300, Finland
| | | | - Johan G Eriksson
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Haartmaninkatu 8, Helsinki 00290, Finland, Folkhälsan Research Centre, Helsinki, Finland, Department of General Practice and Primary Health Care, Institute of Clinical Medicine, University of Helsinki, Helsinki, Finland, Unit of General Practice, Helsinki University Central Hospital, Helsinki, Finland
| | - George V Dedoussis
- Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Lu Qi
- Department of Nutrition, Harvard Chan School of Public Health, Boston, MA, USA
| | - Luigi Ferrucci
- Clinical Research Branch, National Institute on Aging, Baltimore, MD, USA
| | | | - M Carola Zillikens
- Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Leiden, The Netherlands, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Erik Ingelsson
- Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories and School of Medicine, University of Tampere, Tampere, Finland
| | - Frida Renström
- Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Department of Biobank Research
| | - L Adrienne Cupples
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Ruth J F Loos
- The Genetics of Obesity and Related Metabolic Traits Program, The Charles Bronfman Institute for Personalized Medicine and The Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Paul W Franks
- Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Department of Nutrition, Harvard Chan School of Public Health, Boston, MA, USA, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden,
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32
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Haider A, Allen SM, Jackson KE, Ralph SA, Habib S. Targeting and function of proteins mediating translation initiation in organelles of Plasmodium falciparum. Mol Microbiol 2015; 96:796-814. [PMID: 25689481 DOI: 10.1111/mmi.12972] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2015] [Indexed: 01/13/2023]
Abstract
The malaria parasite Plasmodium falciparum has two translationally active organelles - the apicoplast and mitochondrion, which import nuclear-encoded translation factors to mediate protein synthesis. Initiation of translation is a complex step wherein initiation factors (IFs) act in a regulated manner to form an initiation complex. We identified putative organellar IFs and investigated the targeting, structure and function of IF1, IF2 and IF3 homologues encoded by the parasite nuclear genome. A single PfIF1 is targeted to the apicoplast. Apart from its critical ribosomal interactions, PfIF1 also exhibited nucleic-acid binding and melting activities and mediated transcription anti-termination. This suggests a prominent ancillary function for PfIF1 in destabilisation of DNA and RNA hairpin loops encountered during transcription and translation of the A+T rich apicoplast genome. Of the three putative IF2 homologues, only one (PfIF2a) was an organellar protein with mitochondrial localisation. We additionally identified an IF3 (PfIF3a) that localised exclusively to the mitochondrion and another protein, PfIF3b, that was apicoplast targeted. PfIF3a exhibited ribosome anti-association activity, and monosome splitting by PfIF3a was enhanced by ribosome recycling factor (PfRRF2) and PfEF-G(Mit). These results fill a gap in our understanding of organellar translation in Plasmodium, which is the site of action of several anti-malarial compounds.
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Affiliation(s)
- Afreen Haider
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Stacey M Allen
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Vic., 3010, Australia
| | - Katherine E Jackson
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Vic., 3010, Australia
| | - Stuart A Ralph
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Vic., 3010, Australia
| | - Saman Habib
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
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Tu YT, Barrientos A. The Human Mitochondrial DEAD-Box Protein DDX28 Resides in RNA Granules and Functions in Mitoribosome Assembly. Cell Rep 2015; 10:854-864. [PMID: 25683708 DOI: 10.1016/j.celrep.2015.01.033] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 12/10/2014] [Accepted: 01/13/2015] [Indexed: 10/24/2022] Open
Abstract
Human mitochondrial ribosomes are specialized in the synthesis of 13 proteins, which are fundamental components of the oxidative phosphorylation system. The pathway of mitoribosome biogenesis, the compartmentalization of the process, and factors involved remain largely unknown. Here, we have identified the DEAD-box protein DDX28 as an RNA granule component essential for the biogenesis of the mitoribosome large subunit (mt-LSU). DDX28 interacts with the 16S rRNA and the mt-LSU. RNAi-mediated DDX28 silencing in HEK293T cells does not affect mitochondrial mRNA stability or 16S rRNA processing or modification. However, it leads to reduced levels of 16S rRNA and mt-LSU proteins, impaired mt-LSU assembly, deeply attenuated mitochondrial protein synthesis, and consequent failure to assemble oxidative phosphorylation complexes. Our findings identify DDX28 as essential during the early stages of mitoribosome mt-LSU biogenesis, a process that takes place mainly near the mitochondrial nucleoids, in the compartment defined by the RNA granules.
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Affiliation(s)
- Ya-Ting Tu
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Antoni Barrientos
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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Lightowlers RN, Rozanska A, Chrzanowska-Lightowlers ZM. Mitochondrial protein synthesis: figuring the fundamentals, complexities and complications, of mammalian mitochondrial translation. FEBS Lett 2014; 588:2496-503. [PMID: 24911204 PMCID: PMC4099522 DOI: 10.1016/j.febslet.2014.05.054] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 12/28/2022]
Abstract
Mitochondrial protein synthesis is essential for all mammals, being responsible for providing key components of the oxidative phosphorylation complexes. Although only thirteen different polypeptides are made, the molecular details of this deceptively simple process remain incomplete. Central to this process is a non-canonical ribosome, the mitoribosome, which has evolved to address its unique mandate. In this review, we integrate the current understanding of the molecular aspects of mitochondrial translation with recent advances in structural biology. We identify numerous key questions that we will need to answer if we are to increase our knowledge of the molecular mechanisms underlying mitochondrial protein synthesis.
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Affiliation(s)
- Robert N Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Agata Rozanska
- The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Zofia M Chrzanowska-Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Kuzmenko AV, Levitskii SA, Vinogradova EN, Atkinson GC, Hauryliuk V, Zenkin N, Kamenski PA. Protein biosynthesis in mitochondria. BIOCHEMISTRY (MOSCOW) 2014; 78:855-66. [PMID: 24228873 DOI: 10.1134/s0006297913080014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Translation, that is biosynthesis of polypeptides in accordance with information encoded in the genome, is one of the most important processes in the living cell, and it has been in the spotlight of international research for many years. The mechanisms of protein biosynthesis in bacteria and in the eukaryotic cytoplasm are now understood in great detail. However, significantly less is known about translation in eukaryotic mitochondria, which is characterized by a number of unusual features. In this review, we summarize current knowledge about mitochondrial translation in different organisms while paying special attention to the aspects of this process that differ from cytoplasmic protein biosynthesis.
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Affiliation(s)
- A V Kuzmenko
- Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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36
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Boczonadi V, Horvath R. Mitochondria: impaired mitochondrial translation in human disease. Int J Biochem Cell Biol 2014; 48:77-84. [PMID: 24412566 PMCID: PMC3988845 DOI: 10.1016/j.biocel.2013.12.011] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/13/2013] [Accepted: 12/26/2013] [Indexed: 10/28/2022]
Abstract
Defects of the mitochondrial protein synthesis cause a subgroup of mitochondrial diseases, which are usually associated with decreased activities of multiple respiratory chain (RC) enzymes. The clinical presentations of these disorders are often disabling, progressive or fatal, affecting the brain, liver, skeletal muscle, heart and other organs. Currently there are no effective cures for these disorders and treatment is at best symptomatic. The diagnosis in patients with multiple respiratory chain complex defects is particularly difficult because of the massive number of nuclear genes potentially involved in intra-mitochondrial protein synthesis. Many of these genes are not yet linked to human disease. Whole exome sequencing rapidly changed the diagnosis of these patients by identifying the primary defect in DNA, and preventing the need for invasive and complex biochemical testing. Better understanding of the mitochondrial protein synthesis apparatus will help us to explore disease mechanisms and will provide clues for developing novel therapies.
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Affiliation(s)
- Veronika Boczonadi
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK.
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37
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Kuzmenko A, Atkinson GC, Levitskii S, Zenkin N, Tenson T, Hauryliuk V, Kamenski P. Mitochondrial translation initiation machinery: conservation and diversification. Biochimie 2013; 100:132-40. [PMID: 23954798 PMCID: PMC3978653 DOI: 10.1016/j.biochi.2013.07.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 07/29/2013] [Indexed: 11/29/2022]
Abstract
The highly streamlined mitochondrial genome encodes almost exclusively a handful of transmembrane components of the respiratory chain complex. In order to ensure the correct assembly of the respiratory chain, the products of these genes must be produced in the correct stoichiometry and inserted into the membrane, posing a unique challenge to the mitochondrial translational system. In this review we describe the proteins orchestrating mitochondrial translation initiation: bacterial-like general initiation factors mIF2 and mIF3, as well as mitochondria-specific components – mRNA-specific translational activators and mRNA-nonspecific accessory initiation factors. We consider how the fast rate of evolution in these organelles has not only created a system that is divergent from that of its bacterial ancestors, but has led to a huge diversity in lineage specific mechanistic features of mitochondrial translation initiation among eukaryotes. Mitochondrially-encoded proteins are mostly respiratory chain components. The mitochondrial translation system is thus organized in a very specific way. Initiation involves mRNA-specific activators and bacteria-like initiation factors. We show that Saccharomyces cerevisiae Aim23p is a functional ortholog of bacterial IF3. We review the lineage specific features of mitochondrial translation initiation.
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Affiliation(s)
- Anton Kuzmenko
- University of Tartu, Institute of Technology, Nooruse 1, Tartu, Estonia; Molecular Biology Department, Faculty of Biology, M.V. Lomonosov Moscow State University, 1/12 Leninskie Gory, 119991 Moscow, Russia
| | - Gemma C Atkinson
- University of Tartu, Institute of Technology, Nooruse 1, Tartu, Estonia
| | - Sergey Levitskii
- Molecular Biology Department, Faculty of Biology, M.V. Lomonosov Moscow State University, 1/12 Leninskie Gory, 119991 Moscow, Russia
| | - Nikolay Zenkin
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, United Kingdom
| | - Tanel Tenson
- University of Tartu, Institute of Technology, Nooruse 1, Tartu, Estonia
| | - Vasili Hauryliuk
- University of Tartu, Institute of Technology, Nooruse 1, Tartu, Estonia; Department of Molecular Biology, Umeå University, Umeå, Sweden; Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden.
| | - Piotr Kamenski
- Molecular Biology Department, Faculty of Biology, M.V. Lomonosov Moscow State University, 1/12 Leninskie Gory, 119991 Moscow, Russia.
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38
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Shen Y, Li C, McCarty DR, Meeley R, Tan BC. Embryo defective12 encodes the plastid initiation factor 3 and is essential for embryogenesis in maize. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 74:792-804. [PMID: 23451851 DOI: 10.1111/tpj.12161] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 05/09/2023]
Abstract
Embryo-specific mutants in maize define a unique class of genetic loci that affect embryogenesis without a significant deleterious impact on endosperm development. Here we report the characterization of an embryo specific12 (emb12) mutant in maize. Embryogenesis in the emb12 mutants is arrested at or before transition stage. The mutant embryo at an early stage exhibits abnormal cell structure with increased vacuoles and dramatically reduced internal membrane organelles. In contrast, the mutant endosperm appears normal in morphology, cell structure, starch, lipid and protein accumulation. The Emb12 locus was cloned by transposon tagging and predicts a protein with a high similarity to prokaryotic translation initiation factor 3 (IF3). EMB12-GFP fusion analysis indicates that EMB12 is localized in plastids. The RNA in situ hybridization and protein immunohistochemical analyses indicate that a high level of Emb12 expression localizes in the embryo proper at early developmental stages and in the embryo axis at later stages. Western analysis indicates that plastid protein synthesis is impaired. These results indicate that Emb12 encodes the plastid IF3 which is essential for embryogenesis but not for endosperm development in maize.
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Affiliation(s)
- Yun Shen
- State Key Lab of Agrobiotechnology, Institute of Plant Molecular Biology and Agrobiotechnology, School of Life Science, The Chinese University of Hong Kong, N.T. Hong Kong, China
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Rackham O, Mercer TR, Filipovska A. The human mitochondrial transcriptome and the RNA-binding proteins that regulate its expression. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 3:675-95. [DOI: 10.1002/wrna.1128] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Anvret A, Ran C, Westerlund M, Sydow O, Willows T, Olson L, Galter D, Belin AC. Genetic Screening of the Mitochondrial Rho GTPases MIRO1 and MIRO2 in Parkinson's Disease. Open Neurol J 2012; 6:1-5. [PMID: 22496713 PMCID: PMC3322431 DOI: 10.2174/1874205x01206010001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/20/2012] [Accepted: 02/20/2012] [Indexed: 12/18/2022] Open
Abstract
MIRO1 and MIRO2 (mitochondrial Ras homolog gene family, member T1 and T2) also referred to as RHOT1 and RHOT2, belong to the mitochondrial Rho GTPase family and are involved in axonal transport of mitochondria in neurons. Because mitochondrial dysfunction is strongly implicated in Parkinson’s disease (PD), MIRO1 and MIRO2 can be considered as new candidate genes for PD. We analyzed two non-synonymous polymorphisms and one synonymous polymorphism in MIRO1 and two non-synonymous polymorphisms in MIRO2, in a Swedish Parkinson case-control material consisting of 241 patients and 307 neurologically healthy controls. None of the analyzed polymorphisms in MIRO1 and MIRO2 were significantly associated with PD. Although we did not find a significant association with PD in our Swedish case-control material, we cannot exclude these Rho GTPases as candidate genes for PD or other neurodegenerative disorders.
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Affiliation(s)
- Anna Anvret
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Atkinson GC, Kuzmenko A, Kamenski P, Vysokikh MY, Lakunina V, Tankov S, Smirnova E, Soosaar A, Tenson T, Hauryliuk V. Evolutionary and genetic analyses of mitochondrial translation initiation factors identify the missing mitochondrial IF3 in S. cerevisiae. Nucleic Acids Res 2012; 40:6122-34. [PMID: 22457064 PMCID: PMC3401457 DOI: 10.1093/nar/gks272] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Mitochondrial translation is essentially bacteria-like, reflecting the bacterial endosymbiotic ancestry of the eukaryotic organelle. However, unlike the translation system of its bacterial ancestors, mitochondrial translation is limited to just a few mRNAs, mainly coding for components of the respiratory complex. The classical bacterial initiation factors (IFs) IF1, IF2 and IF3 are universal in bacteria, but only IF2 is universal in mitochondria (mIF2). We analyse the distribution of mitochondrial translation initiation factors and their sequence features, given two well-propagated claims: first, a sequence insertion in mitochondrial IF2 (mIF2) compensates for the universal lack of IF1 in mitochondria, and secondly, no homologue of mitochondrial IF3 (mIF3) is identifiable in Saccharomyces cerevisiae. Our comparative sequence analysis shows that, in fact, the mIF2 insertion is highly variable and restricted in length and primary sequence conservation to vertebrates, while phylogenetic and in vivo complementation analyses reveal that an uncharacterized S. cerevisiae mitochondrial protein currently named Aim23p is a bona fide evolutionary and functional orthologue of mIF3. Our results highlight the lineage-specific nature of mitochondrial translation and emphasise that comparative analyses among diverse taxa are essential for understanding whether generalizations from model organisms can be made across eukaryotes.
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Christian BE, Spremulli LL. Mechanism of protein biosynthesis in mammalian mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:1035-54. [PMID: 22172991 DOI: 10.1016/j.bbagrm.2011.11.009] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/03/2011] [Accepted: 11/08/2011] [Indexed: 01/25/2023]
Abstract
Protein synthesis in mammalian mitochondria produces 13 proteins that are essential subunits of the oxidative phosphorylation complexes. This review provides a detailed outline of each phase of mitochondrial translation including initiation, elongation, termination, and ribosome recycling. The roles of essential proteins involved in each phase are described. All of the products of mitochondrial protein synthesis in mammals are inserted into the inner membrane. Several proteins that may help bind ribosomes to the membrane during translation are described, although much remains to be learned about this process. Mutations in mitochondrial or nuclear genes encoding components of the translation system often lead to severe deficiencies in oxidative phosphorylation, and a summary of these mutations is provided. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Brooke E Christian
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Škrtić M, Sriskanthadevan S, Jhas B, Gebbia M, Wang X, Wang Z, Hurren R, Jitkova Y, Gronda M, Maclean N, Lai CK, Eberhard Y, Bartoszko J, Spagnuolo P, Rutledge AC, Datti A, Ketela T, Moffat J, Robinson BH, Cameron JH, Wrana J, Eaves CJ, Minden MD, Wang JC, Dick JE, Humphries K, Nislow C, Giaever G, Schimmer AD. Inhibition of mitochondrial translation as a therapeutic strategy for human acute myeloid leukemia. Cancer Cell 2011; 20:674-88. [PMID: 22094260 PMCID: PMC3221282 DOI: 10.1016/j.ccr.2011.10.015] [Citation(s) in RCA: 483] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/05/2011] [Accepted: 10/14/2011] [Indexed: 12/17/2022]
Abstract
To identify FDA-approved agents targeting leukemic cells, we performed a chemical screen on two human leukemic cell lines and identified the antimicrobial tigecycline. A genome-wide screen in yeast identified mitochondrial translation inhibition as the mechanism of tigecycline-mediated lethality. Tigecycline selectively killed leukemia stem and progenitor cells compared to their normal counterparts and also showed antileukemic activity in mouse models of human leukemia. ShRNA-mediated knockdown of EF-Tu mitochondrial translation factor in leukemic cells reproduced the antileukemia activity of tigecycline. These effects were derivative of mitochondrial biogenesis that, together with an increased basal oxygen consumption, proved to be enhanced in AML versus normal hematopoietic cells and were also important for their difference in tigecycline sensitivity.
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Affiliation(s)
- Marko Škrtić
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Shrivani Sriskanthadevan
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Bozhena Jhas
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Marinella Gebbia
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Xiaoming Wang
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Zezhou Wang
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Rose Hurren
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Yulia Jitkova
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Marcela Gronda
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Neil Maclean
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Courteney K. Lai
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3 Canada
| | - Yanina Eberhard
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Justyna Bartoszko
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Paul Spagnuolo
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Angela C. Rutledge
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Alessandro Datti
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5 Canada
| | - Troy Ketela
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Jason Moffat
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Brian H. Robinson
- Genetics and Genome Biology, The Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 1X8 Canada
| | - Jessie H. Cameron
- Genetics and Genome Biology, The Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 1X8 Canada
| | - Jeffery Wrana
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5 Canada
| | - Connie J. Eaves
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3 Canada
| | - Mark D. Minden
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
| | - Jean C.Y. Wang
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
- Division of Stem Cell and Developmental Biology, Campbell Family Institute for Cancer Research/Ontario Cancer Institute, Toronto, Ontario M5G 1L7, Canada
| | - John E. Dick
- Division of Stem Cell and Developmental Biology, Campbell Family Institute for Cancer Research/Ontario Cancer Institute, Toronto, Ontario M5G 1L7, Canada
| | - Keith Humphries
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3 Canada
| | - Corey Nislow
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Guri Giaever
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Aaron D. Schimmer
- The Campbell Family Cancer Research Institute, The Princess Margaret Hospital, The Ontario Cancer Institute, Toronto, ON, M5G 2M9 Canada
- To whom correspondence should be addressed: Aaron D. Schimmer, Princess Margaret Hospital, Rm 9-516, 610 University Ave, Toronto, ON, Canada M5G 2M9, Tel: 416-946-2838, Fax: 416-946-6546,
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Haque ME, Koc H, Cimen H, Koc EC, Spremulli LL. Contacts between mammalian mitochondrial translational initiation factor 3 and ribosomal proteins in the small subunit. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1779-84. [PMID: 22015679 DOI: 10.1016/j.bbapap.2011.09.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 09/26/2011] [Accepted: 09/28/2011] [Indexed: 11/18/2022]
Abstract
Mammalian mitochondrial translational initiation factor 3 (IF3(mt)) binds to the small subunit of the ribosome displacing the large subunit during the initiation of protein biosynthesis. About half of the proteins in mitochondrial ribosomes have homologs in bacteria while the remainder are unique to the mitochondrion. To obtain information on the ribosomal proteins located near the IF3(mt) binding site, cross-linking studies were carried out followed by identification of the cross-linked proteins by mass spectrometry. IF3(mt) cross-links to mammalian mitochondrial homologs of the bacterial ribosomal proteins S5, S9, S10, and S18-2 and to unique mitochondrial ribosomal proteins MRPS29, MRPS32, MRPS36 and PTCD3 (Pet309) which has now been identified as a small subunit ribosomal protein. IF3(mt) has extensions on both the N- and C-termini compared to the bacterial factors. Cross-linking of a truncated derivative lacking these extensions gives the same hits as the full length IF3(mt) except that no cross-links were observed to MRPS36. IF3 consists of two domains separated by a flexible linker. Cross-linking of the isolated N- and C-domains was observed to a range of ribosomal proteins particularly with the C-domain carrying the linker which showed significant cross-linking to several ribosomal proteins not found in prokaryotes.
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MESH Headings
- Animals
- Cattle
- Eukaryotic Initiation Factor-3/chemistry
- Eukaryotic Initiation Factor-3/genetics
- Eukaryotic Initiation Factor-3/metabolism
- Humans
- Mammals/genetics
- Mammals/metabolism
- Mitochondrial Proteins/chemistry
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Models, Biological
- Models, Molecular
- Peptide Chain Initiation, Translational/genetics
- Protein Binding
- Protein Interaction Mapping
- Protein Structure, Secondary
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Small, Eukaryotic/chemistry
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
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Affiliation(s)
- Md Emdadul Haque
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
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Abstract
Mitochondria are ubiquitous and essential organelles for all nucleated cells of higher eukaryotes. They contain their own genome [mtDNA (mitochondrial DNA)], and this autosomally replicating extranuclear DNA encodes a complement of genes whose products are required to couple oxidative phosphorylation. Sequencing of this human mtDNA more than 20 years ago revealed unusual features that included a modified codon usage. Specific deviations from the standard genetic code include recoding of the conventional UGA stop to tryptophan, and, strikingly, the apparent recoding of two arginine triplets (AGA and AGG) to termination signals. This latter reassignment was made because of the absence of cognate mtDNA-encoded tRNAs, and a lack of tRNAs imported from the cytosol. Each of these codons only occurs once and, in both cases, at the very end of an open reading frame. The presence of both AGA and AGG is rarely found in other mammals, and the molecular mechanism that has driven the change from encoding arginine to dictating a translational stop has posed a challenging conundrum. Mitochondria from the majority of other organisms studied use only UAA and UAG, leaving the intriguing question of why human organelles appear to have added the complication of a further two stop codons, AGA and AGG, or have they? In the present review, we report recent data to show that mammalian mitochondria can utilize a -1 frameshift such that only the standard UAA and UAG stop codons are required to terminate the synthesis of all 13 polypeptides.
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Behrouz B, Vilariño-Güell C, Heckman MG, Soto-Ortolaza AI, Aasly JO, Sando S, Lynch T, Craig D, Uitti RJ, Wszolek ZK, Ross OA, Farrer MJ. Mitochondrial translation initiation factor 3 polymorphism and Parkinson's disease. Neurosci Lett 2010; 486:228-30. [PMID: 20887776 DOI: 10.1016/j.neulet.2010.09.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 09/14/2010] [Accepted: 09/22/2010] [Indexed: 10/19/2022]
Abstract
Mitochondrial dysfunction has been proposed to play a role in the pathogenesis of Parkinson's disease (PD). Supportive of this hypothesis, several genetic variants that regulate mitochondrial function and homeostasis have been described to alter PD susceptibility. A recent report demonstrated association of a single nucleotide polymorphism in the mitochondrial translation initiation factor 3 (MTIF3) gene with PD risk. The protein encoded by this nuclear gene is essential for initiation complex formation on the mitochondrial 55S ribosome and regulates translation of proteins within the mitochondria. Changes in the function or expression of the MTIF3 protein may result in altered mitochondrial function, ATP production or formation of reactive oxygen species thereby affecting susceptibility to PD. We examined the association of rs7669 with sporadic PD in three Caucasian case control series (n=2434). A significant association was observed in the largest series (Norwegian; n=1650) when comparing CC vs. CT/TT genotypes, with the Irish and US series having a similar but non-significant trend. The combined series also revealed an association with risk of PD (P=0.01), supporting the possible involvement of this gene in PD etiology.
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Affiliation(s)
- Bahareh Behrouz
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
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Christian BE, Spremulli LL. Preferential selection of the 5'-terminal start codon on leaderless mRNAs by mammalian mitochondrial ribosomes. J Biol Chem 2010; 285:28379-86. [PMID: 20610392 DOI: 10.1074/jbc.m110.149054] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian mitochondrial mRNAs are basically leaderless, having few or no untranslated nucleotides prior to the 5'-start codon. We demonstrate here that mammalian mitochondrial 55 S ribosomes preferentially form initiation complexes at a 5'-terminal AUG codon over an internal AUG. The preferential use of the 5'-start codon is also seen on mitochondrial 28 S small subunits, which suggests that mitochondrial translation initiation on leaderless mRNAs does not require the large ribosomal subunit. The selection of the 5'-AUG is dependent on the presence of fMet-tRNA and is enhanced by the presence of the mitochondrial initiation factor IF2(mt). In prokaryotes, IF3 is believed to antagonize initiation on leaderless mRNAs. However, IF3(mt) stimulates initiation complex formation on leaderless mRNAs when tested with 55 S ribosomes. The addition of even a few nucleotides 5' to the AUG codon significantly reduces the efficiency of initiation, highlighting the importance of the leaderless or nearly leaderless nature of mitochondrial mRNAs. In addition, very few initiation complexes could form on a hybrid mRNA construct consisting of tRNA(Met) attached at the 5'-end of a mitochondrial protein-coding sequence. This observation demonstrates that post-transcriptional processing must occur prior to translation in mammalian mitochondria.
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Affiliation(s)
- Brooke E Christian
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
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Shutt TE, Shadel GS. A compendium of human mitochondrial gene expression machinery with links to disease. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2010; 51:360-79. [PMID: 20544879 PMCID: PMC2886302 DOI: 10.1002/em.20571] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Mammalian mitochondrial DNA encodes 37 essential genes required for ATP production via oxidative phosphorylation, instability or misregulation of which is associated with human diseases and aging. Other than the mtDNA-encoded RNA species (13 mRNAs, 12S and 16S rRNAs, and 22 tRNAs), the remaining factors needed for mitochondrial gene expression (i.e., transcription, RNA processing/modification, and translation), including a dedicated set of mitochondrial ribosomal proteins, are products of nuclear genes that are imported into the mitochondrial matrix. Herein, we inventory the human mitochondrial gene expression machinery, and, while doing so, we highlight specific associations of these regulatory factors with human disease. Major new breakthroughs have been made recently in this burgeoning area that set the stage for exciting future studies on the key outstanding issue of how mitochondrial gene expression is regulated differentially in vivo. This should promote a greater understanding of why mtDNA mutations and dysfunction cause the complex and tissue-specific pathology characteristic of mitochondrial disease states and how mitochondrial dysfunction contributes to more common human pathology and aging.
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Affiliation(s)
- Timothy E. Shutt
- Department of Pathology, Yale University School of Medicine, 310 Cedar Street, P.O. Box 208023, New haven, CT 06520-8023
| | - Gerald S. Shadel
- Department of Pathology, Yale University School of Medicine, 310 Cedar Street, P.O. Box 208023, New haven, CT 06520-8023
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, P.O. Box 208005, New haven, CT 06520-8005
- corresponding author: Department of Pathology, Yale University School of Medicine, P.O. Box 208023, New Haven, CT 06520-8023 phone: (203) 785-2475 FAX: (203) 785-2628
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Mitochondrial translation and beyond: processes implicated in combined oxidative phosphorylation deficiencies. J Biomed Biotechnol 2010; 2010:737385. [PMID: 20396601 PMCID: PMC2854570 DOI: 10.1155/2010/737385] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Accepted: 01/29/2010] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial disorders are a heterogeneous group of often multisystemic and early fatal diseases, which are amongst the most common inherited human diseases. These disorders are caused by defects in the oxidative phosphorylation (OXPHOS) system, which comprises five multisubunit enzyme complexes encoded by both the nuclear and the mitochondrial genomes. Due to the multitude of proteins and intricacy of the processes required for a properly functioning OXPHOS system, identifying the genetic defect that underlies an OXPHOS deficiency is not an easy task, especially in the case of combined OXPHOS defects. In the present communication we give an extensive overview of the proteins and processes (in)directly involved in mitochondrial translation and the biogenesis of the OXPHOS system and their roles in combined OXPHOS deficiencies. This knowledge is important for further research into the genetic causes, with the ultimate goal to effectively prevent and cure these complex and often devastating disorders.
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50
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The effect of spermine on the initiation of mitochondrial protein synthesis. Biochem Biophys Res Commun 2009; 391:942-6. [PMID: 19962967 DOI: 10.1016/j.bbrc.2009.11.169] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 11/27/2009] [Indexed: 11/23/2022]
Abstract
Polyamines are important in both prokaryotic and eukaryotic translational systems. Spermine is a quaternary aliphatic amine that is cationic under physiological conditions. In this paper, we demonstrate that spermine stimulates fMet-tRNA binding to mammalian mitochondrial 55S ribosomes. The stimulatory effect of spermine is independent of the identity of the mRNA. The degree of stimulation of spermine is the same at all concentrations of mitochondrial initiation factor 2 (IF2(mt)) and mitochondrial initiation factor 3 (IF3(mt)). This observation indicates that IF2(mt) and IF3(mt), while essential for initiation, are not the primary components of the translation initiation system affected by spermine. IF3(mt) dissociates 55S ribosomes detectably in the absence of spermine, but this effect is strongly inhibited in the presence of spermine. This observation indicates that the positive effect of spermine on initiation is not due to an increase in the availability of the small subunits for initiation. Spermine also promotes fMet-tRNA binding to small subunits of the mitochondrial ribosome in the presence of IF2(mt). The major effect of spermine in promoting initiation complex formation thus appears to be on the interaction of fMet-tRNA with the ribosome.
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