1
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Eghbalsaied S, Lawler C, Petersen B, Hajiyev RA, Bischoff SR, Frankenberg S. CRISPR/Cas9-mediated base editors and their prospects for mitochondrial genome engineering. Gene Ther 2024; 31:209-223. [PMID: 38177342 DOI: 10.1038/s41434-023-00434-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
Base editors are a type of double-stranded break (DSB)-free gene editing technology that has opened up new possibilities for precise manipulation of mitochondrial DNA (mtDNA). This includes cytosine and adenosine base editors and more recently guanosine base editors. Because of having low off-target and indel rates, there is a growing interest in developing and evolving this research field. Here, we provide a detailed update on DNA base editors. While base editing has widely been used for nuclear genome engineering, the growing interest in applying this technology to mitochondrial DNA has been faced with several challenges. While Cas9 protein has been shown to enter mitochondria, use of smaller Cas proteins, such as Cas12a, has higher import efficiency. However, sgRNA transfer into mitochondria is the most challenging step. sgRNA structure and ratio of Cas protein to sgRNA are both important factors for efficient sgRNA entry into mitochondria. In conclusion, while there are still several challenges to be addressed, ongoing research in this field holds the potential for new treatments and therapies for mitochondrial disorders.
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Affiliation(s)
- Shahin Eghbalsaied
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.
- Department of Animal Science, Isfahan Branch, Islamic Azad University (IAU), Isfahan, Iran.
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany.
| | - Clancy Lawler
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Björn Petersen
- Department of Biotechnology, Institute of Farm Animal Genetics, Friedrich-Loeffler-Institute (FLI), Mariensee, Germany
- eGenesis, 2706 HWY E, 53572, Mount Horeb, WI, USA
| | - Raul A Hajiyev
- Department of Genome Engineering, NovoHelix, Miami, FL, USA
- Department of Computer Science, Kent State University, Kent, OH, USA
| | - Steve R Bischoff
- Department of Genome Engineering, NovoHelix, Miami, FL, USA
- Foundry for Genome Engineering & Reproductive Medicine (FGERM), Miami, FL, USA
| | - Stephen Frankenberg
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.
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2
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Głodowicz P, Kuczyński K, Val R, Dietrich A, Rolle K. Mitochondrial transport of catalytic RNAs and targeting of the organellar transcriptome in human cells. J Mol Cell Biol 2024; 15:mjad051. [PMID: 37591617 PMCID: PMC11148835 DOI: 10.1093/jmcb/mjad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
Mutations in the small genome present in mitochondria often result in severe pathologies. Different genetic strategies have been explored, aiming to rescue such mutations. A number of these strategies were based on the capacity of human mitochondria to import RNAs from the cytosol and designed to repress the replication of the mutated genomes or to provide the organelles with wild-type versions of mutant transcripts. However, the mutant RNAs present in mitochondria turned out to be an obstacle to therapy and little attention has been devoted so far to their elimination. Here, we present the development of a strategy to knockdown mitochondrial RNAs in human cells using the transfer RNA-like structure of Brome mosaic virus or Tobacco mosaic virus as a shuttle to drive trans-cleaving ribozymes into the organelles in human cell lines. We obtained a specific knockdown of the targeted mitochondrial ATP6 mRNA, followed by a deep drop in ATP6 protein and a functional impairment of the oxidative phosphorylation chain. Our strategy provides a powerful approach to eliminate mutant organellar transcripts and to analyse the control and communication of the human organellar genetic system.
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Affiliation(s)
- Paweł Głodowicz
- Department of Molecular Neurooncology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Konrad Kuczyński
- Department of Molecular Neurooncology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Romain Val
- Institute of Plant Molecular Biology, French National Center for Scientific Research (CNRS) and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - André Dietrich
- Institute of Plant Molecular Biology, French National Center for Scientific Research (CNRS) and University of Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Katarzyna Rolle
- Department of Molecular Neurooncology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Z. Noskowskiego 12/14, 61-704 Poznan, Poland
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3
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Aydemir HB, Korkmaz EM. microRNAs in Syrista parreyssi (Hymenoptera) and Lepisma saccharina (Zygentoma) possibly involved in the mitochondrial function. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 115:e22062. [PMID: 37905458 DOI: 10.1002/arch.22062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/06/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023]
Abstract
Mitochondria are essential organelles for maintaining vital cellular functions, and microRNAs (miRNAs) regulate gene expression posttranscriptionally. miRNAs exhibit tissue and time-specific patterns in mitochondria and specifically mitochondrial miRNAs (mitomiRs) can regulate the mRNA expression both originating from mitochondrial and nuclear transcription which affect mitochondrial metabolic activity and cell homeostasis. In this study, miRNAs of two insect species, Syrista parreyssi (Hymenoptera) and Lepisma saccharina (Zygentoma), were investigated for the first time. The known and possible novel miRNAs were predicted and characterized and their potential effects on mitochondrial transcription were investigated in these insect species using deep sequencing. The previously reported mitomiRs were also investigated and housekeeping miRNAs were characterized. miRNAs that are involved in mitochondrial processes such as apoptosis and signaling and that affect genes encoding the subunits of OXPHOS complexes have been identified in each species. Here, 81 and 161 novel mature miRNA candidates were bioinformatically predicted and 9 and 24 of those were aligned with reference mitogenomes of S. parreyssi and L. saccharina, respectively. As a result of RNAHybrid analysis, 51 and 69 potential targets of miRNAs were found in the mitogenome of S. parreyssi and L. saccharina, respectively. cox1 gene was the most targeted gene and cytB, rrnS, and rrnL genes were highly targeted in both of the species by novel miRNAs, hypothetically. We speculate that these novel miRNAs, originating from or targeting mitochondria, influence on rRNA genes or positively selected mitochondrial protein-coding genes. These findings may provide a new perspective in evaluating miRNAs for maintaining mitochondrial function and transcription.
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Affiliation(s)
- Habeş Bilal Aydemir
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Tokat Gaziosmanpaşa University, Tokat, Turkey
| | - Ertan Mahir Korkmaz
- Department of Molecular Biology and Genetics, Faculty of Science, Sivas Cumhuriyet University, Sivas, Turkey
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4
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Key J, Gispert S, Koepf G, Steinhoff-Wagner J, Reichlmeir M, Auburger G. Translation Fidelity and Respiration Deficits in CLPP-Deficient Tissues: Mechanistic Insights from Mitochondrial Complexome Profiling. Int J Mol Sci 2023; 24:17503. [PMID: 38139332 PMCID: PMC10743472 DOI: 10.3390/ijms242417503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The mitochondrial matrix peptidase CLPP is crucial during cell stress. Its loss causes Perrault syndrome type 3 (PRLTS3) with infertility, neurodegeneration, and a growth deficit. Its target proteins are disaggregated by CLPX, which also regulates heme biosynthesis via unfolding ALAS enzymes, providing access for pyridoxal-5'-phosphate (PLP). Despite efforts in diverse organisms with multiple techniques, CLPXP substrates remain controversial. Here, avoiding recombinant overexpression, we employed complexomics in mitochondria from three mouse tissues to identify endogenous targets. A CLPP absence caused the accumulation and dispersion of CLPX-VWA8 as AAA+ unfoldases, and of PLPBP. Similar changes and CLPX-VWA8 co-migration were evident for mitoribosomal central protuberance clusters, translation factors like GFM1-HARS2, the RNA granule components LRPPRC-SLIRP, and enzymes OAT-ALDH18A1. Mitochondrially translated proteins in testes showed reductions to <30% for MTCO1-3, the mis-assembly of the complex IV supercomplex, and accumulated metal-binding assembly factors COX15-SFXN4. Indeed, heavy metal levels were increased for iron, molybdenum, cobalt, and manganese. RT-qPCR showed compensatory downregulation only for Clpx mRNA; most accumulated proteins appeared transcriptionally upregulated. Immunoblots validated VWA8, MRPL38, MRPL18, GFM1, and OAT accumulation. Co-immunoprecipitation confirmed CLPX binding to MRPL38, GFM1, and OAT, so excess CLPX and PLP may affect their activity. Our data mechanistically elucidate the mitochondrial translation fidelity deficits which underlie progressive hearing impairment in PRLTS3.
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Affiliation(s)
- Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Suzana Gispert
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Gabriele Koepf
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Julia Steinhoff-Wagner
- TUM School of Life Sciences, Animal Nutrition and Metabolism, Technical University of Munich, Liesel-Beckmann-Str. 2, 85354 Freising-Weihenstephan, Germany;
| | - Marina Reichlmeir
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
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5
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Jeandard D, Smirnova A, Fasemore AM, Coudray L, Entelis N, Förstner K, Tarassov I, Smirnov A. CoLoC-seq probes the global topology of organelle transcriptomes. Nucleic Acids Res 2022; 51:e16. [PMID: 36537202 PMCID: PMC9943681 DOI: 10.1093/nar/gkac1183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Proper RNA localisation is essential for physiological gene expression. Various kinds of genome-wide approaches permit to comprehensively profile subcellular transcriptomes. Among them, cell fractionation methods, that couple RNase treatment of isolated organelles to the sequencing of protected transcripts, remain most widely used, mainly because they do not require genetic modification of the studied system and can be easily implemented in any cells or tissues, including in non-model species. However, they suffer from numerous false-positives since incompletely digested contaminant RNAs can still be captured and erroneously identified as resident transcripts. Here we introduce Controlled Level of Contamination coupled to deep sequencing (CoLoC-seq) as a new subcellular transcriptomics approach that efficiently bypasses this caveat. CoLoC-seq leverages classical enzymatic kinetics and tracks the depletion dynamics of transcripts in a gradient of an exogenously added RNase, with or without organellar membranes. By means of straightforward mathematical modelling, CoLoC-seq infers the localisation topology of RNAs and robustly distinguishes between genuinely resident, luminal transcripts and merely abundant surface-attached contaminants. Our generic approach performed well on human mitochondria and is in principle applicable to other membrane-bounded organelles, including plastids, compartments of the vacuolar system, extracellular vesicles, and viral particles.
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Affiliation(s)
| | | | | | - Léna Coudray
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
| | - Nina Entelis
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
| | - Konrad U Förstner
- ZB MED – Information Centre for Life Sciences, Cologne, D-50931, Germany,TH Köln – University of Applied Sciences, Faculty of Information Science and Communication Studies, Institute of Information Science, Cologne, D-50678, Germany
| | - Ivan Tarassov
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
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6
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Erturk E, Enes Onur O, Akgun O, Tuna G, Yildiz Y, Ari F. Mitochondrial miRNAs (MitomiRs): Their potential roles in breast and other cancers. Mitochondrion 2022; 66:74-81. [PMID: 35963496 DOI: 10.1016/j.mito.2022.08.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/19/2022] [Accepted: 08/02/2022] [Indexed: 11/15/2022]
Abstract
Breast cancer is the most common cancer in women worldwide. MicroRNAs (miRNAs) are non-coding RNAs that are involved in the post-transcriptional regulation of gene expression. Although miRNAs mainly act in the cytoplasm, they can be found in the mitochondrial compartment of the cell. These miRNAs called "MitomiR", they can change mitochondrial functions by regulating proteins at the mitochondrial level and cause cancer. In this review, we have aimed to explain miRNA biogenesis, transport pathways to mitochondria, and summarize mitomiRs that have been shown to play an important role in mitochondrial function, especially in the initiation and progression of breast cancer.
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Affiliation(s)
- Elif Erturk
- Bursa Uludag University, Vocational School of Health Services, 16059, Bursa, Turkey
| | - Omer Enes Onur
- Bursa Uludag University, Department of Biology, Science and Art Faculty, 16059, Bursa, Turkey
| | - Oguzhan Akgun
- Bursa Uludag University, Department of Biology, Science and Art Faculty, 16059, Bursa, Turkey
| | - Gonca Tuna
- Bursa Uludag University, Department of Biology, Science and Art Faculty, 16059, Bursa, Turkey
| | - Yaren Yildiz
- Bursa Uludag University, Department of Biology, Science and Art Faculty, 16059, Bursa, Turkey
| | - Ferda Ari
- Bursa Uludag University, Department of Biology, Science and Art Faculty, 16059, Bursa, Turkey.
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7
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Berná L, Rego N, Francia ME. The Elusive Mitochondrial Genomes of Apicomplexa: Where Are We Now? Front Microbiol 2021; 12:751775. [PMID: 34721355 PMCID: PMC8554336 DOI: 10.3389/fmicb.2021.751775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/16/2021] [Indexed: 11/16/2022] Open
Abstract
Mitochondria are vital organelles of eukaryotic cells, participating in key metabolic pathways such as cellular respiration, thermogenesis, maintenance of cellular redox potential, calcium homeostasis, cell signaling, and cell death. The phylum Apicomplexa is entirely composed of obligate intracellular parasites, causing a plethora of severe diseases in humans, wild and domestic animals. These pathogens include the causative agents of malaria, cryptosporidiosis, neosporosis, East Coast fever and toxoplasmosis, among others. The mitochondria in Apicomplexa has been put forward as a promising source of undiscovered drug targets, and it has been validated as the target of atovaquone, a drug currently used in the clinic to counter malaria. Apicomplexans present a single tubular mitochondria that varies widely both in structure and in genomic content across the phylum. The organelle is characterized by massive gene migrations to the nucleus, sequence rearrangements and drastic functional reductions in some species. Recent third generation sequencing studies have reignited an interest for elucidating the extensive diversity displayed by the mitochondrial genomes of apicomplexans and their intriguing genomic features. The underlying mechanisms of gene transcription and translation are also ill-understood. In this review, we present the state of the art on mitochondrial genome structure, composition and organization in the apicomplexan phylum revisiting topological and biochemical information gathered through classical techniques. We contextualize this in light of the genomic insight gained by second and, more recently, third generation sequencing technologies. We discuss the mitochondrial genomic and mechanistic features found in evolutionarily related alveolates, and discuss the common and distinct origins of the apicomplexan mitochondria peculiarities.
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Affiliation(s)
- Luisa Berná
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Molecular Biology Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Bioinformatics Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Sección Biomatemática-Laboratorio de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Natalia Rego
- Bioinformatics Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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8
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Liu X, Shan G. Mitochondria Encoded Non-coding RNAs in Cell Physiology. Front Cell Dev Biol 2021; 9:713729. [PMID: 34395442 PMCID: PMC8362354 DOI: 10.3389/fcell.2021.713729] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/12/2021] [Indexed: 01/05/2023] Open
Abstract
Mitochondria are the powerhouses of mammalian cells, which participate in series of metabolic processes and cellular events. Mitochondria have their own genomes, and it is generally acknowledged that human mitochondrial genome encodes 13 proteins, 2 rRNAs and 22 tRNAs. However, the complexity of mitochondria derived transcripts is just starting to be envisaged. Currently, there are at least 8 lncRNAs, some dsRNAs, various small RNAs, and hundreds of circRNAs known to be generated from mitochondrial genome. These non-coding RNAs either translocate into cytosol/nucleus or reside in mitochondria to play various biological functions. Here we present an overview of regulatory non-coding RNAs encoded by the mammalian mitochondria genome. For overall understandings of non-coding RNAs in mitochondrial function, a brief summarization of nuclear-encoded non-coding RNAs in mitochondria is also included. We discuss about roles of these non-coding RNAs in cellular physiology and the communication between mitochondria and the nucleus.
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Affiliation(s)
- Xu Liu
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Science and Medicine, Department of Clinical Laboratory, The First Affiliated Hospital of USTC, School of Basic Medical Sciences, University of Science and Technology of China, Hefei, China
| | - Ge Shan
- Hefei National Laboratory for Physical Sciences at Microscale, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Science and Medicine, Department of Clinical Laboratory, The First Affiliated Hospital of USTC, School of Basic Medical Sciences, University of Science and Technology of China, Hefei, China
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9
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Jang YH, Ahn SR, Shim JY, Lim KI. Engineering Genetic Systems for Treating Mitochondrial Diseases. Pharmaceutics 2021; 13:810. [PMID: 34071708 PMCID: PMC8227772 DOI: 10.3390/pharmaceutics13060810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are intracellular energy generators involved in various cellular processes. Therefore, mitochondrial dysfunction often leads to multiple serious diseases, including neurodegenerative and cardiovascular diseases. A better understanding of the underlying mitochondrial dysfunctions of the molecular mechanism will provide important hints on how to mitigate the symptoms of mitochondrial diseases and eventually cure them. In this review, we first summarize the key parts of the genetic processes that control the physiology and functions of mitochondria and discuss how alterations of the processes cause mitochondrial diseases. We then list up the relevant core genetic components involved in these processes and explore the mutations of the components that link to the diseases. Lastly, we discuss recent attempts to apply multiple genetic methods to alleviate and further reverse the adverse effects of the core component mutations on the physiology and functions of mitochondria.
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Affiliation(s)
- Yoon-ha Jang
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Sae Ryun Ahn
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
| | - Ji-yeon Shim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Kwang-il Lim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
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10
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Zakirova EG, Muzyka VV, Mazunin IO, Orishchenko KE. Natural and Artificial Mechanisms of Mitochondrial Genome Elimination. Life (Basel) 2021; 11:life11020076. [PMID: 33498399 PMCID: PMC7909434 DOI: 10.3390/life11020076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 01/11/2023] Open
Abstract
The generally accepted theory of the genetic drift of mitochondrial alleles during mammalian ontogenesis is based on the presence of a selective bottleneck in the female germline. However, there is a variety of different theories on the pathways of genetic regulation of mitochondrial DNA (mtDNA) dynamics in oogenesis and adult somatic cells. The current review summarizes present knowledge on the natural mechanisms of mitochondrial genome elimination during mammalian development. We also discuss the variety of existing and developing methodologies for artificial manipulation of the mtDNA heteroplasmy level. Understanding of the basics of mtDNA dynamics will shed the light on the pathogenesis and potential therapies of human diseases associated with mitochondrial dysfunction.
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Affiliation(s)
- Elvira G. Zakirova
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
| | - Vladimir V. Muzyka
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
- Department of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Ilya O. Mazunin
- Skolkovo Institute of Science and Technology, 143026 Skolkovo, Russia;
| | - Konstantin E. Orishchenko
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
- Department of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
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11
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Gusic M, Prokisch H. ncRNAs: New Players in Mitochondrial Health and Disease? Front Genet 2020; 11:95. [PMID: 32180794 PMCID: PMC7059738 DOI: 10.3389/fgene.2020.00095] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/28/2020] [Indexed: 12/19/2022] Open
Abstract
The regulation of mitochondrial proteome is unique in that its components have origins in both mitochondria and nucleus. With the development of OMICS technologies, emerging evidence indicates an interaction between mitochondria and nucleus based not only on the proteins but also on the non-coding RNAs (ncRNAs). It is now accepted that large parts of the non‐coding genome are transcribed into various ncRNA species. Although their characterization has been a hot topic in recent years, the function of the majority remains unknown. Recently, ncRNA species microRNA (miRNA) and long-non coding RNAs (lncRNA) have been gaining attention as direct or indirect modulators of the mitochondrial proteome homeostasis. These ncRNA can impact mitochondria indirectly by affecting transcripts encoding for mitochondrial proteins in the cytoplasm. Furthermore, reports of mitochondria-localized miRNAs, termed mitomiRs, and lncRNAs directly regulating mitochondrial gene expression suggest the import of RNA to mitochondria, but also transcription from the mitochondrial genome. Interestingly, ncRNAs have been also shown to hide small open reading frames (sORFs) encoding for small functional peptides termed micropeptides, with several examples reported with a role in mitochondria. In this review, we provide a literature overview on ncRNAs and micropeptides found to be associated with mitochondrial biology in the context of both health and disease. Although reported, small study overlap and rare replications by other groups make the presence, transport, and role of ncRNA in mitochondria an attractive, but still challenging subject. Finally, we touch the topic of their potential as prognosis markers and therapeutic targets.
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Affiliation(s)
- Mirjana Gusic
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany
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12
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Kamenski PA, Krasheninnikov IA, Tarassov I. 40 Years of Studying RNA Import into Mitochondria: From Basic Mechanisms to Gene Therapy Strategies. Mol Biol 2019. [DOI: 10.1134/s0026893319060074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Al Khatib I, Shutt TE. Advances Towards Therapeutic Approaches for mtDNA Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:217-246. [PMID: 31452143 DOI: 10.1007/978-981-13-8367-0_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondria maintain and express their own genome, referred to as mtDNA, which is required for proper mitochondrial function. While mutations in mtDNA can cause a heterogeneous array of disease phenotypes, there is currently no cure for this collection of diseases. Here, we will cover characteristics of the mitochondrial genome important for understanding the pathology associated with mtDNA mutations, and review recent approaches that are being developed to treat and prevent mtDNA disease. First, we will discuss mitochondrial replacement therapy (MRT), where mitochondria from a healthy donor replace maternal mitochondria harbouring mutant mtDNA. In addition to ethical concerns surrounding this procedure, MRT is only applicable in cases where the mother is known or suspected to carry mtDNA mutations. Thus, there remains a need for other strategies to treat patients with mtDNA disease. To this end, we will also discuss several alternative means to reduce the amount of mutant mtDNA present in cells. Such methods, referred to as heteroplasmy shifting, have proven successful in animal models. In particular, we will focus on the approach of targeting engineered endonucleases to specifically cleave mutant mtDNA. Together, these approaches offer hope to prevent the transmission of mtDNA disease and potentially reduce the impact of mtDNA mutations.
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Affiliation(s)
- Iman Al Khatib
- Deparments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Timothy E Shutt
- Deparments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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14
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Import of Non-Coding RNAs into Human Mitochondria: A Critical Review and Emerging Approaches. Cells 2019; 8:cells8030286. [PMID: 30917553 PMCID: PMC6468882 DOI: 10.3390/cells8030286] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/19/2019] [Accepted: 03/23/2019] [Indexed: 01/26/2023] Open
Abstract
Mitochondria harbor their own genetic system, yet critically depend on the import of a number of nuclear-encoded macromolecules to ensure their expression. In all eukaryotes, selected non-coding RNAs produced from the nuclear genome are partially redirected into the mitochondria, where they participate in gene expression. Therefore, the mitochondrial RNome represents an intricate mixture of the intrinsic transcriptome and the extrinsic RNA importome. In this review, we summarize and critically analyze data on the nuclear-encoded transcripts detected in human mitochondria and outline the proposed molecular mechanisms of their mitochondrial import. Special attention is given to the various experimental approaches used to study the mitochondrial RNome, including some recently developed genome-wide and in situ techniques.
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15
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Loutre R, Heckel AM, Jeandard D, Tarassov I, Entelis N. Anti-replicative recombinant 5S rRNA molecules can modulate the mtDNA heteroplasmy in a glucose-dependent manner. PLoS One 2018; 13:e0199258. [PMID: 29912984 PMCID: PMC6005506 DOI: 10.1371/journal.pone.0199258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/04/2018] [Indexed: 12/19/2022] Open
Abstract
Mutations in mitochondrial DNA are an important source of severe and incurable human diseases. The vast majority of these mutations are heteroplasmic, meaning that mutant and wild-type genomes are present simultaneously in the same cell. Only a very high proportion of mutant mitochondrial DNA (heteroplasmy level) leads to pathological consequences. We previously demonstrated that mitochondrial targeting of small RNAs designed to anneal with mutant mtDNA can decrease the heteroplasmy level by specific inhibition of mutant mtDNA replication, thus representing a potential therapy. We have also shown that 5S ribosomal RNA, partially imported into human mitochondria, can be used as a vector to deliver anti-replicative oligoribonucleotides into human mitochondria. So far, the efficiency of cellular expression of recombinant 5S rRNA molecules bearing therapeutic insertions remained very low. In the present study, we designed new versions of anti-replicative recombinant 5S rRNA targeting a large deletion in mitochondrial DNA which causes the KSS syndrome, analyzed their specific annealing to KSS mitochondrial DNA and demonstrated their import into mitochondria of cultured human cells. To obtain an increased level of the recombinant 5S rRNA stable expression, we created transmitochondrial cybrid cell line bearing a site for Flp-recombinase and used this system for the recombinase-mediated integration of genes coding for the anti-replicative recombinant 5S rRNAs into nuclear genome. We demonstrated that stable expression of anti-replicative 5S rRNA versions in human transmitochondrial cybrid cells can induce a shift in heteroplasmy level of KSS mutation in mtDNA. This shift was directly dependent on the level of the recombinant 5S rRNA expression and the sequence of the anti-replicative insertion. Quantification of mtDNA copy number in transfected cells revealed the absence of a non-specific effect on wild type mtDNA replication, indicating that the decreased proportion between mutant and wild type mtDNA molecules is not a consequence of a random repopulation of depleted pool of mtDNA genomes. The heteroplasmy change could be also modulated by cell growth conditions, namely increased by cells culturing in a carbohydrate-free medium, thus forcing them to use oxidative phosphorylation and providing a selective advantage for cells with improved respiration capacities. We discuss the advantages and limitations of this approach and propose further development of the anti-replicative strategy based on the RNA import into human mitochondria.
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Affiliation(s)
- Romuald Loutre
- UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), Strasbourg University-CNRS, Strasbourg, France
| | - Anne-Marie Heckel
- UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), Strasbourg University-CNRS, Strasbourg, France
| | - Damien Jeandard
- UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), Strasbourg University-CNRS, Strasbourg, France
| | - Ivan Tarassov
- UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), Strasbourg University-CNRS, Strasbourg, France
| | - Nina Entelis
- UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), Strasbourg University-CNRS, Strasbourg, France
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16
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Markantone DM, Towheed A, Crain AT, Collins JM, Celotto AM, Palladino MJ. Protein coding mitochondrial-targeted RNAs rescue mitochondrial disease in vivo. Neurobiol Dis 2018; 117:203-210. [PMID: 29908326 DOI: 10.1016/j.nbd.2018.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 11/28/2022] Open
Abstract
Mitochondrial encephalomyopathies (MEs) result from mutations in mitochondrial genes critical to oxidative phosphorylation. Severe and untreatable ME results from mutations affecting each endogenous mitochondrial encoded gene, including all 13 established protein coding genes. Effective techniques to manipulate mitochondrial genome are limited and targeted mitochondrial protein expression is currently unavailable. Here we report the development of a mitochondrial-targeted RNA expression (mtTRES) vector capable of protein expression within mitochondria (mtTRESPro). We demonstrate that mtTRESPro expressed RNAs are targeted to mitochondria and are capable of being translated using EGFP encoded constructs in vivo. We additionally test mtTRESPro constructs encoding wild type ATP6 for their ability to rescue an established ATP61Drosophila model of ME. Genetic rescue is examined including tests with co-expression of mitochondrial targeted translational inhibitors TLI-NCL::ATP6 RNAs that function to reduce expression of the endogenous mutant protein. The data demonstrate allotopic RNA expression of mitochondrial targeted wild type ATP6 coding RNAs are sufficient to partially rescue a severe and established animal model of ME but only when combined with a method to inhibit mutant protein expression, which likely competes for incorporation into complex V.
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Affiliation(s)
- Desiree M Markantone
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Atif Towheed
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Aaron T Crain
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Jessica M Collins
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alicia M Celotto
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Michael J Palladino
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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17
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Verechshagina NA, Konstantinov YM, Kamenski PA, Mazunin IO. Import of Proteins and Nucleic Acids into Mitochondria. BIOCHEMISTRY (MOSCOW) 2018; 83:643-661. [DOI: 10.1134/s0006297918060032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Gammage PA, Moraes CT, Minczuk M. Mitochondrial Genome Engineering: The Revolution May Not Be CRISPR-Ized. Trends Genet 2018; 34:101-110. [PMID: 29179920 PMCID: PMC5783712 DOI: 10.1016/j.tig.2017.11.001] [Citation(s) in RCA: 210] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/28/2017] [Accepted: 11/02/2017] [Indexed: 12/17/2022]
Abstract
In recent years mitochondrial DNA (mtDNA) has transitioned to greater prominence across diverse areas of biology and medicine. The recognition of mitochondria as a major biochemical hub, contributions of mitochondrial dysfunction to various diseases, and several high-profile attempts to prevent hereditary mtDNA disease through mitochondrial replacement therapy have roused interest in the organellar genome. Subsequently, attempts to manipulate mtDNA have been galvanized, although with few robust advances and much controversy. Re-engineered protein-only nucleases such as mtZFN and mitoTALEN function effectively in mammalian mitochondria, although efficient delivery of nucleic acids into the organelle remains elusive. Such an achievement, in concert with a mitochondria-adapted CRISPR/Cas9 platform, could prompt a revolution in mitochondrial genome engineering and biological understanding. However, the existence of an endogenous mechanism for nucleic acid import into mammalian mitochondria, a prerequisite for mitochondrial CRISPR/Cas9 gene editing, remains controversial.
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Affiliation(s)
- Payam A Gammage
- Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
| | - Carlos T Moraes
- Miller School of Medicine, University of Miami, Miami, FL, USA.
| | - Michal Minczuk
- Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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19
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Abstract
Mitochondria are cytosolic organelles essential for generating energy and maintaining cell homeostasis. Despite their critical function, the handful of proteins expressed by the mitochondrial genome is insufficient to maintain mitochondrial structure or activity. Accordingly, mitochondrial metabolism is fully dependent on factors encoded by the nuclear DNA, including many proteins synthesized in the cytosol and imported into mitochondria via established mechanisms. However, there is growing evidence that mammalian mitochondria can also import cytosolic noncoding RNA via poorly understood processes. Here, we summarize our knowledge of mitochondrial RNA, discuss recent progress in understanding the molecular mechanisms and functional impact of RNA import into mitochondria, and identify rising challenges and opportunities in this rapidly evolving field.
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Affiliation(s)
- Kyoung Mi Kim
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Ji Heon Noh
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Kotb Abdelmohsen
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA
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20
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Baleva MV, Meyer M, Entelis N, Tarassov I, Kamenski P, Masquida B. Factors beyond Enolase 2 and Mitochondrial Lysyl-tRNA Synthetase Precursor Are Required for tRNA Import into Yeast Mitochondria. BIOCHEMISTRY (MOSCOW) 2017; 82:1324-1335. [PMID: 29223159 DOI: 10.1134/s0006297917110104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In yeast, the import of tRNALys with CUU anticodon (tRK1) relies on a complex mechanism where interaction with enolase 2 (Eno2p) dictates a deep conformational change of the tRNA. This event is believed to mask the tRNA from the cytosolic translational machinery to re-direct it towards the mitochondria. Once near the mitochondrial outer membrane, the precursor of the mitochondrial lysyl-tRNA synthetase (preMsk1p) takes over enolase to carry the tRNA within the mitochondrial matrix, where it is supposed to participate in translation following correct refolding. Biochemical data presented in this report focus on the role of enolase. They show that despite the inability of Eno2p alone to form a complex with tRK1, mitochondrial import can be recapitulated in vitro using fractions of yeast extracts sharing either recombinant or endogenous yeast Eno2p as one of the main components. Taken together, our data suggest the existence of a protein complex containing Eno2p that is involved in RNA mitochondrial import.
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Affiliation(s)
- M V Baleva
- GMGM, CNRS - University of Strasbourg, UMR 7156, Strasbourg, 67081, France.
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21
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Shepherd DL, Hathaway QA, Pinti MV, Nichols CE, Durr AJ, Sreekumar S, Hughes KM, Stine SM, Martinez I, Hollander JM. Exploring the mitochondrial microRNA import pathway through Polynucleotide Phosphorylase (PNPase). J Mol Cell Cardiol 2017; 110:15-25. [PMID: 28709769 PMCID: PMC5854179 DOI: 10.1016/j.yjmcc.2017.06.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/20/2017] [Accepted: 06/27/2017] [Indexed: 01/01/2023]
Abstract
Cardiovascular disease is the primary cause of mortality for individuals with type 2 diabetes mellitus. During the diabetic condition, cardiovascular dysfunction can be partially attributed to molecular changes in the tissue, including alterations in microRNA (miRNA) interactions. MiRNAs have been reported in the mitochondrion and their presence may influence cellular bioenergetics, creating decrements in functional capacity. In this study, we examined the roles of Argonaute 2 (Ago2), a protein associated with cytosolic and mitochondrial miRNAs, and Polynucleotide Phosphorylase (PNPase), a protein found in the inner membrane space of the mitochondrion, to determine their role in mitochondrial miRNA import. In cardiac tissue from human and mouse models of type 2 diabetes mellitus, Ago2 protein levels were unchanged while PNPase protein expression levels were increased; also, there was an increase in the association between both proteins in the diabetic state. MiRNA-378 was found to be significantly increased in db/db mice, leading to decrements in ATP6 levels and ATP synthase activity, which was also exhibited when overexpressing PNPase in HL-1 cardiomyocytes and in HL-1 cells with stable miRNA-378 overexpression (HL-1-378). To assess potential therapeutic interventions, flow cytometry evaluated the capacity for targeting miRNA-378 species in mitochondria through antimiR treatment, revealing miRNA-378 level-dependent inhibition. Our study establishes PNPase as a contributor to mitochondrial miRNA import through the transport of miRNA-378, which may regulate bioenergetics during type 2 diabetes mellitus. Further, our data provide evidence that manipulation of PNPase levels may enhance the delivery of antimiR therapeutics to mitochondria in physiological and pathological conditions.
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Affiliation(s)
- Danielle L Shepherd
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Quincy A Hathaway
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Mark V Pinti
- Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Cody E Nichols
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Andrya J Durr
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Shruthi Sreekumar
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Kristen M Hughes
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Seth M Stine
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - Ivan Martinez
- Cancer Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, United States
| | - John M Hollander
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV 26506, United States.
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22
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tRNAs and proteins use the same import channel for translocation across the mitochondrial outer membrane of trypanosomes. Proc Natl Acad Sci U S A 2017; 114:E7679-E7687. [PMID: 28847952 DOI: 10.1073/pnas.1711430114] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial tRNA import is widespread, but the mechanism by which tRNAs are imported remains largely unknown. The mitochondrion of the parasitic protozoan Trypanosoma brucei lacks tRNA genes, and thus imports all tRNAs from the cytosol. Here we show that in T. brucei in vivo import of tRNAs requires four subunits of the mitochondrial outer membrane protein translocase but not the two receptor subunits, one of which is essential for protein import. The latter shows that it is possible to uncouple mitochondrial tRNA import from protein import. Ablation of the intermembrane space domain of the translocase subunit, archaic translocase of the outer membrane (ATOM)14, on the other hand, while not affecting the architecture of the translocase, impedes both protein and tRNA import. A protein import intermediate arrested in the translocation channel prevents both protein and tRNA import. In the presence of tRNA, blocking events of single-channel currents through the pore formed by recombinant ATOM40 were detected in electrophysiological recordings. These results indicate that both types of macromolecules use the same import channel across the outer membrane. However, while tRNA import depends on the core subunits of the protein import translocase, it does not require the protein import receptors, indicating that the two processes are not mechanistically linked.
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23
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Dong Y, Yoshitomi T, Hu JF, Cui J. Long noncoding RNAs coordinate functions between mitochondria and the nucleus. Epigenetics Chromatin 2017; 10:41. [PMID: 28835257 PMCID: PMC5569521 DOI: 10.1186/s13072-017-0149-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 08/17/2017] [Indexed: 11/23/2022] Open
Abstract
In animal cells, mitochondria are the primary powerhouses and metabolic factories. They also contain genomes and can produce mitochondrial-specific nucleic acids and proteins. To maintain homeostasis of the entire cell, an intense cross-talk between mitochondria and the nucleus, mediated by encoded noncoding RNAs (ncRNAs), as well as proteins, is required. Long ncRNAs (lncRNAs) contain characteristic structures, and they are involved in the regulation of almost every stage of gene expression, as well as being implicated in a variety of disease states, such as cancer. In the coordinated signaling system, several lncRNAs, transcribed in the nucleus but residing in mitochondria, play a key role in regulating mitochondrial functions or dynamics. For example, RMRP, a component of the mitochondrial RNase MRP, is important for mitochondrial DNA replication and RNA processing, and the steroid receptor RNA activator, SRA, is a key modulator of hormone signaling and is present in both the nucleus and mitochondria. Some RNA-binding proteins maybe play a role in the lncRNAs transport system, such as HuR, GRSF1, SHARP, SLIRP, PPR, and PNPASE. Furthermore, a series of nuclear DNA-encoded lncRNAs were implicated in mitochondria-mediated apoptosis, mitochondrial bioenergetics and biosynthesis, and glutamine metabolism. The mitochondrial genome can also encode a set of lncRNAs, and they are divided into three categories: (1) lncND5, lncND6, and lncCyt b RNA; (2) chimeric mitochondrial DNA-encoded lncRNAs; and (3) putative mitochondrial DNA-encoded lncRNAs. It has been reported that the mitochondrial DNA-encoded lncRNAs appear to operate in the nucleus. The molecular mechanisms underlying trafficking of the mitochondrial DNA-encoded lncRNAs to the nucleus in mammals are only now beginning to emerge. In conclusion, both nuclear- and mitochondrial DNA-encoded lncRNAs mediate an intense intercompartmental cross-talk, which opens a rich field for investigation of the mechanism underlying the intercompartmental coordination and the maintenance of whole cell homeostasis.
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Affiliation(s)
- Yaru Dong
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun, 130041, Jilin, China.,Stanford University Medical School, VA Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA, 94304, USA
| | - Takeshi Yoshitomi
- Department of Ophthalmology, Akita University School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan
| | - Ji-Fan Hu
- Stanford University Medical School, VA Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA, 94304, USA. .,Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, 130061, Jilin, China.
| | - Jizhe Cui
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Changchun, 130041, Jilin, China.
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24
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Konstantinov YM, Dietrich A, Weber-Lotfi F, Ibrahim N, Klimenko ES, Tarasenko VI, Bolotova TA, Koulintchenko MV. DNA import into mitochondria. BIOCHEMISTRY (MOSCOW) 2016; 81:1044-1056. [DOI: 10.1134/s0006297916100035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Darbandi S, Darbandi M, Khorshid HRK, Sadeghi MR, Al-Hasani S, Agarwal A, Shirazi A, Heidari M, Akhondi MM. Experimental strategies towards increasing intracellular mitochondrial activity in oocytes: A systematic review. Mitochondrion 2016; 30:8-17. [PMID: 27234976 DOI: 10.1016/j.mito.2016.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/04/2016] [Accepted: 05/20/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE The mitochondrial complement is critical in sustaining the earliest stages of life. To improve the Assisted Reproductive Technology (ART), current methods of interest were evaluated for increasing the activity and copy number of mitochondria in the oocyte cell. METHODS This covered the researches from 1966 to September 2015. RESULTS The results provided ten methods that can be studied individually or simultaneously. CONCLUSION Though the use of these techniques generated great concern about heteroplasmy observation in humans, it seems that with study on these suggested methods there is real hope for effective treatments of old oocyte or oocytes containing mitochondrial problems in the near future.
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Affiliation(s)
- Sara Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahsa Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | | | - Mohammad Reza Sadeghi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Safaa Al-Hasani
- Reproductive Medicine Unit, University of Schleswig-Holstein, Luebeck, Germany.
| | - Ashok Agarwal
- Center for Reproductive Medicine, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.
| | - Abolfazl Shirazi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahnaz Heidari
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. M.@avicenna.ar.ir
| | - Mohammad Mehdi Akhondi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
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Revisiting trends on mitochondrial mega-channels for the import of proteins and nucleic acids. J Bioenerg Biomembr 2016; 49:75-99. [DOI: 10.1007/s10863-016-9662-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/25/2016] [Indexed: 12/14/2022]
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27
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Nucleic acid import into mitochondria: New insights into the translocation pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3165-81. [DOI: 10.1016/j.bbamcr.2015.09.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/16/2015] [Accepted: 09/10/2015] [Indexed: 11/18/2022]
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28
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Dietrich A, Wallet C, Iqbal RK, Gualberto JM, Lotfi F. Organellar non-coding RNAs: Emerging regulation mechanisms. Biochimie 2015; 117:48-62. [DOI: 10.1016/j.biochi.2015.06.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/29/2015] [Indexed: 02/06/2023]
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29
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Furukawa R, Yamada Y, Kawamura E, Harashima H. Mitochondrial delivery of antisense RNA by MITO-Porter results in mitochondrial RNA knockdown, and has a functional impact on mitochondria. Biomaterials 2015; 57:107-15. [PMID: 25913255 DOI: 10.1016/j.biomaterials.2015.04.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 04/07/2015] [Accepted: 04/08/2015] [Indexed: 10/23/2022]
Abstract
Mitochondrial genome-targeting nucleic acids are promising therapeutic candidates for treating mitochondrial diseases. To date, a number of systems for delivering genetic information to the cytosol and the nucleus have been reported, and several successful gene therapies involving gene delivery targeted to the cytosol and the nucleus have been reported. However, much less progress has been made concerning mitochondrial gene delivery systems, and mitochondrial gene therapy has never been achieved. Here, we report on the mitochondrial delivery of an antisense RNA oligonucleotide (ASO) to perform mitochondrial RNA knockdown to regulate mitochondrial function. Mitochondrial delivery of the ASO was achieved using a combination of a MITO-Porter system, which contains mitochondrial fusogenic lipid envelopes for mitochondrial delivery via membrane fusion and D-arm, a mitochondrial import signal of tRNA to the matrix. Mitochondrial delivery of the ASO induces the knockdown of the targeted mitochondria-encoded mRNA and protein, namely cytochrome c oxidase subunit II, a component of the mitochondrial respiratory chain. Furthermore, the mitochondrial membrane potential was depolarized by the down regulation of the respiratory chain as the result of the mitochondrial delivery of ASO. This finding constitutes the first report to demonstrate that the nanocarrier-mediated mitochondrial genome targeting of antisense RNA effects mitochondrial function.
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Affiliation(s)
- Ryo Furukawa
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Yuma Yamada
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Eriko Kawamura
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Hideyoshi Harashima
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan.
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30
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Baleva M, Gowher A, Kamenski P, Tarassov I, Entelis N, Masquida B. A Moonlighting Human Protein Is Involved in Mitochondrial Import of tRNA. Int J Mol Sci 2015; 16:9354-67. [PMID: 25918939 PMCID: PMC4463592 DOI: 10.3390/ijms16059354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 04/02/2015] [Accepted: 04/15/2015] [Indexed: 12/29/2022] Open
Abstract
In yeast Saccharomyces cerevisiae, ~3% of the lysine transfer RNA acceptor 1 (tRK1) pool is imported into mitochondria while the second isoacceptor, tRK2, fully remains in the cytosol. The mitochondrial function of tRK1 is suggested to boost mitochondrial translation under stress conditions. Strikingly, yeast tRK1 can also be imported into human mitochondria in vivo, and can thus be potentially used as a vector to address RNAs with therapeutic anti-replicative capacity into mitochondria of sick cells. Better understanding of the targeting mechanism in yeast and human is thus critical. Mitochondrial import of tRK1 in yeast proceeds first through a drastic conformational rearrangement of tRK1 induced by enolase 2, which carries this freight to the mitochondrial pre-lysyl-tRNA synthetase (preMSK). The latter may cross the mitochondrial membranes to reach the matrix where imported tRK1 could be used by the mitochondrial translation apparatus. This work focuses on the characterization of the complex that tRK1 forms with human enolases and their role on the interaction between tRK1 and human pre-lysyl-tRNA synthetase (preKARS2).
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Affiliation(s)
- Maria Baleva
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS-Université de Strasbourg, 67084 Strasbourg, France.
- Department of Molecular Biology, Biology Faculty of Moscow State University, 119992 Moscow, Russia.
| | - Ali Gowher
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS-Université de Strasbourg, 67084 Strasbourg, France.
| | - Piotr Kamenski
- Department of Molecular Biology, Biology Faculty of Moscow State University, 119992 Moscow, Russia.
| | - Ivan Tarassov
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS-Université de Strasbourg, 67084 Strasbourg, France.
| | - Nina Entelis
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS-Université de Strasbourg, 67084 Strasbourg, France.
| | - Benoît Masquida
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS-Université de Strasbourg, 67084 Strasbourg, France.
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31
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Cannon MV, Irwin MH, Pinkert CA. Mitochondrially-Imported RNA in Drug Discovery. Drug Dev Res 2015; 76:61-71. [DOI: 10.1002/ddr.21241] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 12/14/2014] [Indexed: 12/15/2022]
Affiliation(s)
| | | | - Carl A. Pinkert
- Department of Pathobiology; Auburn University; Auburn AL USA
- Department of Biology; The University of Alabama; Tuscaloosa AL USA
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Salinas-Giegé T, Giegé R, Giegé P. tRNA biology in mitochondria. Int J Mol Sci 2015; 16:4518-59. [PMID: 25734984 PMCID: PMC4394434 DOI: 10.3390/ijms16034518] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/23/2015] [Accepted: 01/29/2015] [Indexed: 01/23/2023] Open
Abstract
Mitochondria are the powerhouses of eukaryotic cells. They are considered as semi-autonomous because they have retained genomes inherited from their prokaryotic ancestor and host fully functional gene expression machineries. These organelles have attracted considerable attention because they combine bacterial-like traits with novel features that evolved in the host cell. Among them, mitochondria use many specific pathways to obtain complete and functional sets of tRNAs as required for translation. In some instances, tRNA genes have been partially or entirely transferred to the nucleus and mitochondria require precise import systems to attain their pool of tRNAs. Still, tRNA genes have also often been maintained in mitochondria. Their genetic arrangement is more diverse than previously envisaged. The expression and maturation of mitochondrial tRNAs often use specific enzymes that evolved during eukaryote history. For instance many mitochondria use a eukaryote-specific RNase P enzyme devoid of RNA. The structure itself of mitochondrial encoded tRNAs is also very diverse, as e.g., in Metazoan, where tRNAs often show non canonical or truncated structures. As a result, the translational machinery in mitochondria evolved adapted strategies to accommodate the peculiarities of these tRNAs, in particular simplified identity rules for their aminoacylation. Here, we review the specific features of tRNA biology in mitochondria from model species representing the major eukaryotic groups, with an emphasis on recent research on tRNA import, maturation and aminoacylation.
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Affiliation(s)
- Thalia Salinas-Giegé
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, F-67084 Strasbourg Cedex, France.
| | - Richard Giegé
- Institut de Biologie Moléculaire et Cellulaire, CNRS and Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France.
| | - Philippe Giegé
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, F-67084 Strasbourg Cedex, France.
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33
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Borralho PM, Rodrigues CMP, Steer CJ. microRNAs in Mitochondria: An Unexplored Niche. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 887:31-51. [PMID: 26662985 DOI: 10.1007/978-3-319-22380-3_3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondria are pivotal organelles involved in the regulation of a myriad of crucial biological processes, including cell survival and cell death, rendering mitochondrial dysfunction a relevant step in numerous pathophysiological processes. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that add a new layer of complexity to the control of gene expression. miRNAs function as master regulators and fine-tuners of gene expression, primarily via posttranscriptional mechanisms, and are increasingly demonstrated as a paramount class of endogenous molecules with relevant diagnostic, prognostic, and therapeutic applications. miRNAs and other RNA interference have recently been reported to be present in mitochondria from several species, and we are now beginning to unveil mitochondrial miRNA transport mechanisms, biological function and targets to ascertain their role in this unexplored niche. Here, we describe miRNA biogenesis and present key findings regarding miRNA localization to mitochondria, origin, putative biological function, and implications for human disease.
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Affiliation(s)
- Pedro M Borralho
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Cecília M P Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Clifford J Steer
- Departments of Medicine, and Genetics, Cell Biology and Development, University of Minnesota Medical School, VFW Cancer Research Center, 406 Harvard Street S.E., Minneapolis, MN, 55455, USA.
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Mitochondrial MicroRNAs and Their Potential Role in Cell Function. CURRENT PATHOBIOLOGY REPORTS 2014. [DOI: 10.1007/s40139-014-0047-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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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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Towheed A, Markantone DM, Crain AT, Celotto AM, Palladino MJ. Small mitochondrial-targeted RNAs modulate endogenous mitochondrial protein expression in vivo. Neurobiol Dis 2014; 69:15-22. [PMID: 24807207 DOI: 10.1016/j.nbd.2014.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/04/2014] [Accepted: 04/27/2014] [Indexed: 11/26/2022] Open
Abstract
Endogenous mitochondrial genes encode critical oxidative phosphorylation components and their mutation results in a set of disorders known collectively as mitochondrial encephalomyopathies. There is intensive interest in modulating mitochondrial function as organelle dysfunction has been associated with numerous disease states. Proteins encoded by the mitochondrial genome cannot be genetically manipulated by current techniques. Here we report the development of a mitochondrial-targeted RNA expression system (mtTRES) utilizing distinct non-coding leader sequences (NCLs) and enabling in vivo expression of small mitochondrial-targeted RNAs. mtTRES expressing small chimeric antisense RNAs was used as translational inhibitors (TLIs) to target endogenous mitochondrial protein expression in vivo. By utilizing chimeric antisense RNA we successfully modulate expression of two mitochondrially-encoded proteins, ATP6 and COXII, and demonstrate the utility of this system in vivo and in human cells. This technique has important and obvious research and clinical implications.
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Affiliation(s)
- Atif Towheed
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Desiree M Markantone
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Aaron T Crain
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alicia M Celotto
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Michael J Palladino
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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Bandiera S, Matégot R, Girard M, Demongeot J, Henrion-Caude A. MitomiRs delineating the intracellular localization of microRNAs at mitochondria. Free Radic Biol Med 2013; 64:12-9. [PMID: 23792138 DOI: 10.1016/j.freeradbiomed.2013.06.013] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 06/05/2013] [Accepted: 06/06/2013] [Indexed: 12/12/2022]
Abstract
Mitochondria play a crucial role in energetic metabolism, signaling pathways, and overall cell viability. Mitochondrial dysfunctions are known to cause a wide range of human diseases that affect tissues especially those with high energetic requirements, such as skeletal muscle, heart, kidney, and central nervous system, while being involved in cancer, aging, and metabolic processes. At the same time, the microRNA (miRNA) gene family has been demonstrated to be involved in most cellular processes through modulation of proteins critical for cellular homeostasis. Given the broad scope of reactivity profiles and the ability of miRNAs to modify numerous proteomic and genomic processes, new emphasis is being placed on the influence of miRNAs at the mitochondrial level. Recently, the localization of miRNAs in mitochondria was characterized in different species. This raises the idea that those miRNAs, noted "mitomiRs," could act as "vectors" that sense and respond dynamically to the changing microenvironment of mitochondria at the cellular level. Reciprocally, we present the involvement of mitochondria in small RNA biogenesis. With the aim of deciphering the significance of this localization, we discuss the putative mechanism of import of miRNAs at mitochondria, their origin, and their hypothetical roles within the organelle.
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Affiliation(s)
- S Bandiera
- INSERM U781 Hôpital Necker-Enfants Malades, Université Paris Descartes-Sorbonne Cité, Institut Imagine, 75015, Paris, France
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Gowher A, Smirnov A, Tarassov I, Entelis N. Induced tRNA import into human mitochondria: implication of a host aminoacyl-tRNA-synthetase. PLoS One 2013; 8:e66228. [PMID: 23799079 PMCID: PMC3683045 DOI: 10.1371/journal.pone.0066228] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/02/2013] [Indexed: 11/19/2022] Open
Abstract
In human cell, a subset of small non-coding RNAs is imported into mitochondria from the cytosol. Analysis of the tRNA import pathway allowing targeting of the yeast tRNA(Lys)(CUU) into human mitochondria demonstrates a similarity between the RNA import mechanisms in yeast and human cells. We show that the cytosolic precursor of human mitochondrial lysyl-tRNA synthetase (preKARS2) interacts with the yeast tRNA(Lys)(CUU) and small artificial RNAs which contain the structural elements determining the tRNA mitochondrial import, and facilitates their internalization by isolated human mitochondria. The tRNA import efficiency increased upon addition of the glycolytic enzyme enolase, previously found to be an actor of the yeast RNA import machinery. Finally, the role of preKARS2 in the RNA mitochondrial import has been directly demonstrated in vivo, in cultured human cells transfected with the yeast tRNA and artificial importable RNA molecules, in combination with preKARS2 overexpression or downregulation by RNA interference. These findings suggest that the requirement of protein factors for the RNA mitochondrial targeting might be a conserved feature of the RNA import pathway in different organisms.
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Affiliation(s)
- Ali Gowher
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS - Université de Strasbourg, Strasbourg, France
| | - Alexandre Smirnov
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS - Université de Strasbourg, Strasbourg, France
| | - Ivan Tarassov
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS - Université de Strasbourg, Strasbourg, France
| | - Nina Entelis
- Department of Molecular and Cellular Genetics, UMR 7156 Génétique Moléculaire, Génomique, Microbiologie (GMGM), CNRS - Université de Strasbourg, Strasbourg, France
- * E-mail:
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40
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Ro S, Ma HY, Park C, Ortogero N, Song R, Hennig GW, Zheng H, Lin YM, Moro L, Hsieh JT, Yan W. The mitochondrial genome encodes abundant small noncoding RNAs. Cell Res 2013; 23:759-74. [PMID: 23478297 DOI: 10.1038/cr.2013.37] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Small noncoding RNAs identified thus far are all encoded by the nuclear genome. Here, we report that the murine and human mitochondrial genomes encode thousands of small noncoding RNAs, which are predominantly derived from the sense transcripts of the mitochondrial genes (host genes), and we termed these small RNAs mitochondrial genome-encoded small RNAs (mitosRNAs). DICER inactivation affected, but did not completely abolish mitosRNA production. MitosRNAs appear to be products of currently unidentified mitochondrial ribonucleases. Overexpression of mitosRNAs enhanced expression levels of their host genes in vitro, and dysregulated mitosRNA expression was generally associated with aberrant mitochondrial gene expression in vivo. Our data demonstrate that in addition to 37 known mitochondrial genes, the mammalian mitochondrial genome also encodes abundant mitosRNAs, which may play an important regulatory role in the control of mitochondrial gene expression in the cell.
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Affiliation(s)
- Seungil Ro
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
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41
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Vedrenne V, Gowher A, De Lonlay P, Nitschke P, Serre V, Boddaert N, Altuzarra C, Mager-Heckel AM, Chretien F, Entelis N, Munnich A, Tarassov I, Rötig A. Mutation in PNPT1, which encodes a polyribonucleotide nucleotidyltransferase, impairs RNA import into mitochondria and causes respiratory-chain deficiency. Am J Hum Genet 2012; 91:912-8. [PMID: 23084291 DOI: 10.1016/j.ajhg.2012.09.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/10/2012] [Accepted: 09/04/2012] [Indexed: 11/27/2022] Open
Abstract
Multiple-respiratory-chain deficiency represents an important cause of mitochondrial disorders. Hitherto, however, mutations in genes involved in mtDNA maintenance and translation machinery only account for a fraction of cases. Exome sequencing in two siblings, born to consanguineous parents, with severe encephalomyopathy, choreoathetotic movements, and combined respiratory-chain defects allowed us to identify a homozygous PNPT1 missense mutation (c.1160A>G) that encodes the mitochondrial polynucleotide phosphorylase (PNPase). Blue-native polyacrylamide gel electrophoresis showed that no PNPase complex could be detected in subject fibroblasts, confirming that the substitution encoded by c.1160A>G disrupts the trimerization of the protein. PNPase is predominantly localized in the mitochondrial intermembrane space and is implicated in RNA targeting to human mitochondria. Mammalian mitochondria import several small noncoding nuclear RNAs (5S rRNA, MRP RNA, some tRNAs, and miRNAs). By RNA hybridization experiments, we observed a significant decrease in 5S rRNA and MRP-related RNA import into mitochondria in fibroblasts of affected subject 1. Moreover, we found a reproducible decrease in the rate of mitochondrial translation in her fibroblasts. Finally, overexpression of the wild-type PNPT1 cDNA in fibroblasts of subject 1 induced an increase in 5S rRNA import in mitochondria and rescued the mitochondrial-translation deficiency. In conclusion, we report here abnormal RNA import into mitochondria as a cause of respiratory-chain deficiency.
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Sripada L, Tomar D, Singh R. Mitochondria: One of the destinations of miRNAs. Mitochondrion 2012; 12:593-9. [DOI: 10.1016/j.mito.2012.10.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 08/22/2012] [Accepted: 10/09/2012] [Indexed: 01/15/2023]
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Comte C, Tonin Y, Heckel-Mager AM, Boucheham A, Smirnov A, Auré K, Lombès A, Martin RP, Entelis N, Tarassov I. Mitochondrial targeting of recombinant RNAs modulates the level of a heteroplasmic mutation in human mitochondrial DNA associated with Kearns Sayre Syndrome. Nucleic Acids Res 2012; 41:418-33. [PMID: 23087375 PMCID: PMC3592399 DOI: 10.1093/nar/gks965] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial mutations, an important cause of incurable human neuromuscular diseases, are mostly heteroplasmic: mutated mitochondrial DNA is present in cells simultaneously with wild-type genomes, the pathogenic threshold being generally >70% of mutant mtDNA. We studied whether heteroplasmy level could be decreased by specifically designed oligoribonucleotides, targeted into mitochondria by the pathway delivering RNA molecules in vivo. Using mitochondrially imported RNAs as vectors, we demonstrated that oligoribonucleotides complementary to mutant mtDNA region can specifically reduce the proportion of mtDNA bearing a large deletion associated with the Kearns Sayre Syndrome in cultured transmitochondrial cybrid cells. These findings may be relevant to developing of a new tool for therapy of mtDNA associated diseases.
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Affiliation(s)
- Caroline Comte
- Department of Molecular and Cellular Genetics, UMR Génétique Moléculaire, Génomique, Microbiologie, CNRS, Université de Strasbourg, Strasbourg, France
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44
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Niazi AK, Mileshina D, Cosset A, Val R, Weber-Lotfi F, Dietrich A. Targeting nucleic acids into mitochondria: progress and prospects. Mitochondrion 2012; 13:548-58. [PMID: 22609422 DOI: 10.1016/j.mito.2012.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 05/14/2012] [Indexed: 12/18/2022]
Abstract
Given the essential functions of these organelles in cell homeostasis, their involvement in incurable diseases and their potential in biotechnological applications, genetic transformation of mitochondria has been a long pursued goal that has only been reached in a couple of unicellular organisms. The challenge led scientists to explore a wealth of different strategies for mitochondrial delivery of DNA or RNA in living cells. These are the subject of the present review. Targeting DNA into the organelles currently shows promise but remarkably a number of alternative approaches based on RNA trafficking were also established and will bring as well major contributions.
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Affiliation(s)
- Adnan Khan Niazi
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
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Sepuri NBV, Gorla M, King MP. Mitochondrial lysyl-tRNA synthetase independent import of tRNA lysine into yeast mitochondria. PLoS One 2012; 7:e35321. [PMID: 22539966 PMCID: PMC3335127 DOI: 10.1371/journal.pone.0035321] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/15/2012] [Indexed: 11/25/2022] Open
Abstract
Aminoacyl tRNA synthetases play a central role in protein synthesis by charging tRNAs with amino acids. Yeast mitochondrial lysyl tRNA synthetase (Msk1), in addition to the aminoacylation of mitochondrial tRNA, also functions as a chaperone to facilitate the import of cytosolic lysyl tRNA. In this report, we show that human mitochondrial Kars (lysyl tRNA synthetase) can complement the growth defect associated with the loss of yeast Msk1 and can additionally facilitate the in vitro import of tRNA into mitochondria. Surprisingly, the import of lysyl tRNA can occur independent of Msk1 in vivo. This suggests that an alternative mechanism is present for the import of lysyl tRNA in yeast.
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Affiliation(s)
- Naresh Babu V. Sepuri
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
- Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (NBVS); (MK)
| | - Madhavi Gorla
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Michael P. King
- Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (NBVS); (MK)
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46
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An overlapping genetic code for frameshifted overlapping genes in Drosophila mitochondria: Antisense antitermination tRNAs UAR insert serine. J Theor Biol 2012; 298:51-76. [DOI: 10.1016/j.jtbi.2011.12.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 12/19/2011] [Accepted: 12/22/2011] [Indexed: 01/27/2023]
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47
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Seidman D, Johnson D, Gerbasi V, Golden D, Orlando R, Hajduk S. Mitochondrial membrane complex that contains proteins necessary for tRNA import in Trypanosoma brucei. J Biol Chem 2012; 287:8892-903. [PMID: 22267727 DOI: 10.1074/jbc.m111.300186] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial genome of Trypanosoma brucei does not contain genes encoding tRNAs; instead this protozoan parasite must import nuclear-encoded tRNAs from the cytosol for mitochondrial translation. Previously, it has been shown that mitochondrial tRNA import requires ATP hydrolysis and a proteinaceous mitochondrial membrane component. However, little is known about the mitochondrial membrane proteins involved in tRNA binding and translocation into the mitochondrion. Here we report the purification of a mitochondrial membrane complex using tRNA affinity purification and have identified several protein components of the putative tRNA translocon by mass spectrometry. Using an in vivo tRNA import assay in combination with RNA interference, we have verified that two of these proteins, Tb11.01.4590 and Tb09.v1.0420, are involved in mitochondrial tRNA import. Using Protein C Epitope -Tobacco Etch Virus-Protein A Epitope (PTP)-tagged Tb11.01.4590, additional associated proteins were identified including Tim17 and other mitochondrial proteins necessary for mitochondrial protein import. Results presented here identify and validate two novel protein components of the putative tRNA translocon and provide additional evidence that mitochondrial tRNA and protein import have shared components in trypanosomes.
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Affiliation(s)
- David Seidman
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602-7229, USA
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Faure E, Delaye L, Tribolo S, Levasseur A, Seligmann H, Barthélémy RM. Probable presence of an ubiquitous cryptic mitochondrial gene on the antisense strand of the cytochrome oxidase I gene. Biol Direct 2011; 6:56. [PMID: 22024028 PMCID: PMC3214167 DOI: 10.1186/1745-6150-6-56] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 10/24/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mitochondria mediate most of the energy production that occurs in the majority of eukaryotic organisms. These subcellular organelles contain a genome that differs from the nuclear genome and is referred to as mitochondrial DNA (mtDNA). Despite a disparity in gene content, all mtDNAs encode at least two components of the mitochondrial electron transport chain, including cytochrome c oxidase I (Cox1). PRESENTATION OF THE HYPOTHESIS A positionally conserved ORF has been found on the complementary strand of the cox1 genes of both eukaryotic mitochondria (protist, plant, fungal and animal) and alpha-proteobacteria. This putative gene has been named gau for gene antisense ubiquitous in mtDNAs. The length of the deduced protein is approximately 100 amino acids. In vertebrates, several stop codons have been found in the mt gau region, and potentially functional gau regions have been found in nuclear genomes. However, a recent bioinformatics study showed that several hypothetical overlapping mt genes could be predicted, including gau; this involves the possible import of the cytosolic AGR tRNA into the mitochondria and/or the expression of mt antisense tRNAs with anticodons recognizing AGR codons according to an alternative genetic code that is induced by the presence of suppressor tRNAs. Despite an evolutionary distance of at least 1.5 to 2.0 billion years, the deduced Gau proteins share some conserved amino acid signatures and structure, which suggests a possible conserved function. Moreover, BLAST analysis identified rare, sense-oriented ESTs with poly(A) tails that include the entire gau region. Immunohistochemical analyses using an anti-Gau monoclonal antibody revealed strict co-localization of Gau proteins and a mitochondrial marker. TESTING THE HYPOTHESIS This hypothesis could be tested by purifying the gau gene product and determining its sequence. Cell biological experiments are needed to determine the physiological role of this protein. IMPLICATIONS OF THE HYPOTHESIS Studies of the gau ORF will shed light on the origin of novel genes and their functions in organelles and could also have medical implications for human diseases that are caused by mitochondrial dysfunction. Moreover, this strengthens evidence for mitochondrial genes coded according to an overlapping genetic code.
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Affiliation(s)
- Eric Faure
- Université de Provence, Marseille cedex 3, France.
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Wang G, Shimada E, Koehler CM, Teitell MA. PNPASE and RNA trafficking into mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:998-1007. [PMID: 22023881 DOI: 10.1016/j.bbagrm.2011.10.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 09/26/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
Abstract
The mitochondrial genome encodes a very small fraction of the macromolecular components that are required to generate functional mitochondria. Therefore, most components are encoded within the nuclear genome and are imported into mitochondria from the cytosol. Understanding how mitochondria are assembled, function, and dysfunction in diseases requires detailed knowledge of mitochondrial import mechanisms and pathways. The import of nucleus-encoded RNAs is required for mitochondrial biogenesis and function, but unlike pre-protein import, the pathways and cellular machineries of RNA import are poorly defined, especially in mammals. Recent studies have shown that mammalian polynucleotide phosphorylase (PNPASE) localizes in the mitochondrial intermembrane space (IMS) to regulate the import of RNA. The identification of PNPASE as the first component of the RNA import pathway, along with a growing list of nucleus-encoded RNAs that are imported and newly developed assay systems for RNA import studies, suggest a unique opportunity is emerging to identify the factors and mechanisms that regulate RNA import into mammalian mitochondria. Here we summarize what is known in this fascinating area of mitochondrial biogenesis, identify areas that require further investigation, and speculate on the impact unraveling RNA import mechanisms and pathways will have for the field going forward. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Geng Wang
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
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Abstract
The mitochondrial genomes of most eukaryotes lack a variable number of tRNA genes. This lack is compensated for by import of a small fraction of the corresponding cytosolic tRNAs. There are two broad mechanisms for the import of tRNAs into mitochondria. In the first one, the tRNA is coimported together with a mitochondrial precursor protein along the protein import pathway. It applies to the yeast tRNA(Lys) and has been elucidated in great detail. In the second more vaguely defined mechanism, which is mainly found in plants and protozoa, tRNAs are directly imported independent of cytosolic factors. However, results in plants indicate that direct import of tRNAs may nevertheless require some components of the protein import machinery. All imported tRNAs in all systems are of the eukaryotic type but need to be functionally integrated into the mitochondrial translation system of bacterial descent. For some tRNAs, this is not trivial and requires unique evolutionary adaptations.
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Affiliation(s)
- André Schneider
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland.
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