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Fu Y, Tigano M, Sfeir A. Safeguarding mitochondrial genomes in higher eukaryotes. Nat Struct Mol Biol 2020; 27:687-695. [PMID: 32764737 DOI: 10.1038/s41594-020-0474-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/02/2020] [Indexed: 12/20/2022]
Abstract
Mitochondria respond to DNA damage and preserve their own genetic material in a manner distinct from that of the nucleus but that requires organized mito-nuclear communication. Failure to resolve mtDNA breaks leads to mitochondrial dysfunction and affects host cells and tissues. Here, we review the pathways that safeguard mitochondrial genomes and examine the insights gained from studies of cellular and tissue-wide responses to mtDNA damage and mito-nuclear genome incompatibility.
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Affiliation(s)
- Yi Fu
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA
| | - Marco Tigano
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA
| | - Agnel Sfeir
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA.
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52
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Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer. Nat Commun 2020; 11:3059. [PMID: 32546718 PMCID: PMC7297733 DOI: 10.1038/s41467-020-16765-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 05/26/2020] [Indexed: 01/27/2023] Open
Abstract
Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for 'selfish' traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts. Remarkably, one canine mtDNA haplotype, A1d1a, has repeatedly and recently colonised CTVT cells, recurrently replacing incumbent CTVT haplotypes. An A1d1a control region polymorphism predicted to influence transcription is fixed in the products of an A1d1a recombination event and occurs somatically on other CTVT mtDNA backgrounds. We present a model whereby 'selfish' positive selection acting on a regulatory variant drives repeated fixation of A1d1a within CTVT cells.
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53
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Mitochondrial Inheritance in Phytopathogenic Fungi-Everything Is Known, or Is It? Int J Mol Sci 2020; 21:ijms21113883. [PMID: 32485941 PMCID: PMC7312866 DOI: 10.3390/ijms21113883] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/19/2022] Open
Abstract
Mitochondria are important organelles in eukaryotes that provide energy for cellular processes. Their function is highly conserved and depends on the expression of nuclear encoded genes and genes encoded in the organellar genome. Mitochondrial DNA replication is independent of the replication control of nuclear DNA and as such, mitochondria may behave as selfish elements, so they need to be controlled, maintained and reliably inherited to progeny. Phytopathogenic fungi meet with special environmental challenges within the plant host that might depend on and influence mitochondrial functions and services. We find that this topic is basically unexplored in the literature, so this review largely depends on work published in other systems. In trying to answer elemental questions on mitochondrial functioning, we aim to introduce the aspect of mitochondrial functions and services to the study of plant-microbe-interactions and stimulate phytopathologists to consider research on this important organelle in their future projects.
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54
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Abstract
The double-helical structure of genomic DNA is both elegant and functional in that it serves both to protect vulnerable DNA bases and to facilitate DNA replication and compaction. However, these design advantages come at the cost of having to evolve and maintain a cellular machinery that can manipulate a long polymeric molecule that readily becomes topologically entangled whenever it has to be opened for translation, replication, or repair. If such a machinery fails to eliminate detrimental topological entanglements, utilization of the information stored in the DNA double helix is compromised. As a consequence, the use of B-form DNA as the carrier of genetic information must have co-evolved with a means to manipulate its complex topology. This duty is performed by DNA topoisomerases, which therefore are, unsurprisingly, ubiquitous in all kingdoms of life. In this review, we focus on how DNA topoisomerases catalyze their impressive range of DNA-conjuring tricks, with a particular emphasis on DNA topoisomerase III (TOP3). Once thought to be the most unremarkable of topoisomerases, the many lives of these type IA topoisomerases are now being progressively revealed. This research interest is driven by a realization that their substrate versatility and their ability to engage in intimate collaborations with translocases and other DNA-processing enzymes are far more extensive and impressive than was thought hitherto. This, coupled with the recent associations of TOP3s with developmental and neurological pathologies in humans, is clearly making us reconsider their undeserved reputation as being unexceptional enzymes.
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Affiliation(s)
- Anna H Bizard
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
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55
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Sommerville EW, Dalla Rosa I, Rosenberg MM, Bruni F, Thompson K, Rocha M, Blakely EL, He L, Falkous G, Schaefer AM, Yu‐Wai‐Man P, Chinnery PF, Hedstrom L, Spinazzola A, Taylor RW, Gorman GS. Identification of a novel heterozygous guanosine monophosphate reductase (GMPR) variant in a patient with a late-onset disorder of mitochondrial DNA maintenance. Clin Genet 2020; 97:276-286. [PMID: 31600844 PMCID: PMC7004030 DOI: 10.1111/cge.13652] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/18/2019] [Accepted: 09/27/2019] [Indexed: 12/18/2022]
Abstract
Autosomal dominant progressive external ophthalmoplegia (adPEO) is a late-onset, Mendelian mitochondrial disorder characterised by paresis of the extraocular muscles, ptosis, and skeletal-muscle restricted multiple mitochondrial DNA (mtDNA) deletions. Although dominantly inherited, pathogenic variants in POLG, TWNK and RRM2B are among the most common genetic defects of adPEO, identification of novel candidate genes and the underlying pathomechanisms remains challenging. We report the clinical, genetic and molecular investigations of a patient who presented in the seventh decade of life with PEO. Oxidative histochemistry revealed cytochrome c oxidase-deficient fibres and occasional ragged red fibres showing subsarcolemmal mitochondrial accumulation in skeletal muscle, while molecular studies identified the presence of multiple mtDNA deletions. Negative candidate screening of known nuclear genes associated with PEO prompted diagnostic exome sequencing, leading to the prioritisation of a novel heterozygous c.547G>C variant in GMPR (NM_006877.3) encoding guanosine monophosphate reductase, a cytosolic enzyme required for maintaining the cellular balance of adenine and guanine nucleotides. We show that the novel c.547G>C variant causes aberrant splicing, decreased GMPR protein levels in patient skeletal muscle, proliferating and quiescent cells, and is associated with subtle changes in nucleotide homeostasis protein levels and evidence of disturbed mtDNA maintenance in skeletal muscle. Despite confirmation of GMPR deficiency, demonstrating marked defects of mtDNA replication or nucleotide homeostasis in patient cells proved challenging. Our study proposes that GMPR is the 19th locus for PEO and highlights the complexities of uncovering disease mechanisms in late-onset PEO phenotypes.
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Affiliation(s)
- Ewen W. Sommerville
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Queens Square Institute of Neurology, Royal Free CampusUniversity College LondonLondonUK
| | | | - Francesco Bruni
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- Department of Biosciences, Biotechnologies and BiopharmaceuticsUniversity of Bari “ldo Moro”BariItaly
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Mariana Rocha
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Andrew M. Schaefer
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Patrick Yu‐Wai‐Man
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of OphthalmologyLondonUK
- MRC Mitochondrial Biology UnitUniversity of CambridgeCambridgeUK
- Cambridge Centre for Brain Repair, Department of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Patrick F. Chinnery
- Department of Clinical Neuroscience & Medical Research Council Mitochondrial Biology UnitSchool of Clinical Medicine, University of CambridgeCambridgeUK
| | - Lizbeth Hedstrom
- Department of BiologyBrandeis UniversityWalthamMA
- Department of ChemistryBrandeis University, 415 South St.WalthamMA
| | - Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Queens Square Institute of Neurology, Royal Free CampusUniversity College LondonLondonUK
- MRC Centre for Neuromuscular DiseasesUCL Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondonUK
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Gráinne S. Gorman
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
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56
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Abstract
The POLG gene encodes the mitochondrial DNA polymerase that is responsible for replication of the mitochondrial genome. Mutations in POLG can cause early childhood mitochondrial DNA (mtDNA) depletion syndromes or later-onset syndromes arising from mtDNA deletions. POLG mutations are the most common cause of inherited mitochondrial disorders, with as many as 2% of the population carrying these mutations. POLG-related disorders comprise a continuum of overlapping phenotypes with onset from infancy to late adulthood. The six leading disorders caused by POLG mutations are Alpers-Huttenlocher syndrome, which is one of the most severe phenotypes; childhood myocerebrohepatopathy spectrum, which presents within the first 3 years of life; myoclonic epilepsy myopathy sensory ataxia; ataxia neuropathy spectrum; autosomal recessive progressive external ophthalmoplegia; and autosomal dominant progressive external ophthalmoplegia. This Review describes the clinical features, pathophysiology, natural history and treatment of POLG-related disorders, focusing particularly on the neurological manifestations of these conditions.
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57
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Matkarimov BT, Saparbaev MK. DNA Repair and Mutagenesis in Vertebrate Mitochondria: Evidence for Asymmetric DNA Strand Inheritance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1241:77-100. [DOI: 10.1007/978-3-030-41283-8_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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58
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Thompson K, Collier JJ, Glasgow RIC, Robertson FM, Pyle A, Blakely EL, Alston CL, Oláhová M, McFarland R, Taylor RW. Recent advances in understanding the molecular genetic basis of mitochondrial disease. J Inherit Metab Dis 2020; 43:36-50. [PMID: 31021000 PMCID: PMC7041634 DOI: 10.1002/jimd.12104] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/03/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022]
Abstract
Mitochondrial disease is hugely diverse with respect to associated clinical presentations and underlying genetic causes, with pathogenic variants in over 300 disease genes currently described. Approximately half of these have been discovered in the last decade due to the increasingly widespread application of next generation sequencing technologies, in particular unbiased, whole exome-and latterly, whole genome sequencing. These technologies allow more genetic data to be collected from patients with mitochondrial disorders, continually improving the diagnostic success rate in a clinical setting. Despite these significant advances, some patients still remain without a definitive genetic diagnosis. Large datasets containing many variants of unknown significance have become a major challenge with next generation sequencing strategies and these require significant functional validation to confirm pathogenicity. This interface between diagnostics and research is critical in continuing to expand the list of known pathogenic variants and concomitantly enhance our knowledge of mitochondrial biology. The increasing use of whole exome sequencing, whole genome sequencing and other "omics" techniques such as transcriptomics and proteomics will generate even more data and allow further interrogation and validation of genetic causes, including those outside of coding regions. This will improve diagnostic yields still further and emphasizes the integral role that functional assessment of variant causality plays in this process-the overarching focus of this review.
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Affiliation(s)
- Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Jack J. Collier
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Ruth I. C. Glasgow
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Fiona M. Robertson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
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59
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Abstract
DNA replication in human mitochondria has been studied for several decades; however, its mechanism still remains unclear. During the last 15 years, many new experimental data on the mitochondrial replication have appeared, although extremely contradictory. Two asynchronous (strand displacement and RITOLS) and one synchronous (strand-coupled) replication models have been proposed. In the asynchronous models, replication from the origin in the H-chain starts earlier, so that the replication of the two chains ends at different times. The synchronous model is more traditional and implies two replication forks with leading and lagging strands initiated at the same origin. For each of the three models, both confirming and contradicting experimental data exist. Most likely, there is no single model of mitochondrial replication. It is possible that the unique mitochondrial replication machinery that has originated as a results of endosymbiosis has an unexpected variety of replication strategies to maintain the mitochondrial genome. An unusual combination of enzymes of different origin (phage, bacterial, eukaryotic) and unique features of the mitochondrial genome (existance of heavy and light chains, insertions of ribonucleotides, a variety of origins) can allow replication through different mechanisms. In human mitochondria, asynchronous replication seems to dominate; however, synchronous replication is also possible under certain conditions. In the human heart mitochondria, circular mitochondrial DNA (mtDNA) molecules can rearrange in a network of rapidly replicating linear genomes, thereby suggesting possible existence of a wide range of replication mechanisms in the mitochondria. The review describes the main stages of mtDNA replication and enzymes involved in this process, as well as discusses the prospects of mitochondrial replication studies.
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Affiliation(s)
- L A Zinovkina
- Lomonosov Moscow State University, Faculty of Bioengineering and Bioinformatics, Moscow, 119234, Russia.
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60
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Li Z, Fu J, Li Z, Tang Y, Hua Q, Liu L, Zhao J. Air pollution and placental mitochondrial DNA copy number: Mechanistic insights and epidemiological challenges. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113266. [PMID: 31557557 DOI: 10.1016/j.envpol.2019.113266] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
During embryogenesis and embryo implantation, the copy number of mtDNA is elaborately regulated to meet the cellular demand for division, growth and differentiation. With large numbers of mitochondria for energy production, placental cells possess strong endocrine functionalities and capacities for efficient signaling communication. Recently, several environmental epidemiological studies have shown an association between mitochondrial DNA copy number, adverse birth outcomes and maternal exposure to air pollution, which has shed light on the possible effect of pollutants on placental molecular events. Because the mtDNA replication is thought to be a direct drive of mtDNA change, we tried to highlight the essential factors involved in the process of mtDNA replication. Then we traced the mtDNA change in the formation of placenta during embryogenesis, and evaluated the importance of mitochondrial genome maintenance during gestation. The possible mechanism from the epidemiological and experimental studies were reviewed and summarized, and recommendations were proposed for future studies to improve the precision of the estimated difference. The issue will be well-understood if the integrated profiles, such as familial genetic tendency, maternal genetic information, identification of mitochondrial DNA copy number in each placental cell type, and total personal exposure assessment, are considered in the future study.
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Affiliation(s)
- Zhen Li
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China.
| | - Jianfei Fu
- Department of Medical Records and Statistics, Ningbo First Hospital, Ningbo, Zhejiang Province 315010, People's Republic of China
| | - Zhou Li
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China
| | - Yuqing Tang
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China
| | - Qihang Hua
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China
| | - Liya Liu
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China
| | - Jinshun Zhao
- Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, Medicine School of Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang Province 315211, People's Republic of China
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61
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Holt IJ. The mitochondrial R-loop. Nucleic Acids Res 2019; 47:5480-5489. [PMID: 31045202 PMCID: PMC6582354 DOI: 10.1093/nar/gkz277] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/11/2019] [Accepted: 04/29/2019] [Indexed: 12/18/2022] Open
Abstract
The DNA in mitochondria contributes essential components of the organelle’s energy producing machinery that is essential for life. In 1971, many mitochondrial DNA molecules were found to have a third strand of DNA that maps to a region containing critical regulatory elements for transcription and replication. Forty-five years later, a third strand of RNA in the same region has been reported. This mitochondrial R-loop is present on thousands of copies of mitochondrial DNA per cell making it potentially the most abundant R-loop in nature. Here, I assess the discovery of the mitochondrial R-loop, discuss why it remained unrecognized for almost half a century and propose for it central roles in the replication, organization and expression of mitochondrial DNA, which if compromised can lead to disease states.
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Affiliation(s)
- Ian J Holt
- Biodonostia Health Research Institute, 20014 San Sebastián, Spain & IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.,Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK.,CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), Madrid, Spain
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62
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Billard P, Poncet DA. Replication Stress at Telomeric and Mitochondrial DNA: Common Origins and Consequences on Ageing. Int J Mol Sci 2019; 20:ijms20194959. [PMID: 31597307 PMCID: PMC6801922 DOI: 10.3390/ijms20194959] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/12/2022] Open
Abstract
Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing.
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Affiliation(s)
- Pauline Billard
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| | - Delphine A Poncet
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
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63
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Abstract
DNA topoisomerases are enzymes that catalyze changes in the torsional and flexural strain of DNA molecules. Earlier studies implicated these enzymes in a variety of processes in both prokaryotes and eukaryotes, including DNA replication, transcription, recombination, and chromosome segregation. Studies performed over the past 3 years have provided new insight into the roles of various topoisomerases in maintaining eukaryotic chromosome structure and facilitating the decatenation of daughter chromosomes at cell division. In addition, recent studies have demonstrated that the incorporation of ribonucleotides into DNA results in trapping of topoisomerase I (TOP1)–DNA covalent complexes during aborted ribonucleotide removal. Importantly, such trapped TOP1–DNA covalent complexes, formed either during ribonucleotide removal or as a consequence of drug action, activate several repair processes, including processes involving the recently described nuclear proteases SPARTAN and GCNA-1. A variety of new TOP1 inhibitors and formulations, including antibody–drug conjugates and PEGylated complexes, exert their anticancer effects by also trapping these TOP1–DNA covalent complexes. Here we review recent developments and identify further questions raised by these new findings.
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Affiliation(s)
- Mary-Ann Bjornsti
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294-0019, USA
| | - Scott H Kaufmann
- Departments of Oncology and Molecular Pharmacolgy & Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
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64
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Mitochondria in the signaling pathways that control longevity and health span. Ageing Res Rev 2019; 54:100940. [PMID: 31415807 PMCID: PMC7479635 DOI: 10.1016/j.arr.2019.100940] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/09/2019] [Accepted: 08/06/2019] [Indexed: 12/26/2022]
Abstract
Genetic and pharmacological intervention studies have identified evolutionarily conserved and functionally interconnected networks of cellular energy homeostasis, nutrient-sensing, and genome damage response signaling pathways, as prominent regulators of longevity and health span in various species. Mitochondria are the primary sites of ATP production and are key players in several other important cellular processes. Mitochondrial dysfunction diminishes tissue and organ functional performance and is a commonly considered feature of the aging process. Here we review the evidence that through reciprocal and multilevel functional interactions, mitochondria are implicated in the lifespan modulation function of these pathways, which altogether constitute a highly dynamic and complex system that controls the aging process. An important characteristic of these pathways is their extensive crosstalk and apparent malleability to modification by non-invasive pharmacological, dietary, and lifestyle interventions, with promising effects on lifespan and health span in animal models and potentially also in humans.
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65
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The natural history of infantile mitochondrial DNA depletion syndrome due to RRM2B deficiency. Genet Med 2019; 22:199-209. [DOI: 10.1038/s41436-019-0613-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/09/2019] [Indexed: 01/21/2023] Open
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66
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Sabouny R, Wong R, Lee-Glover L, Greenway SC, Sinasac DS, Khan A, Shutt TE. Characterization of the C584R variant in the mtDNA depletion syndrome gene FBXL4, reveals a novel role for FBXL4 as a regulator of mitochondrial fusion. Biochim Biophys Acta Mol Basis Dis 2019; 1865:165536. [PMID: 31442532 DOI: 10.1016/j.bbadis.2019.165536] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/16/2019] [Accepted: 08/18/2019] [Indexed: 12/16/2022]
Abstract
Mutations in FBXL4 (F-Box and Leucine rich repeat protein 4), a nuclear-encoded mitochondrial protein with an unknown function, cause mitochondrial DNA depletion syndrome. We report two siblings, from consanguineous parents, harbouring a previously uncharacterized homozygous variant in FBXL4 (c.1750 T > C; p.Cys584Arg). Both patients presented with encephalomyopathy, lactic acidosis and cardiac hypertrophy, which are reported features of FBXL4 impairment. Remarkably, dichloroacetate (DCA) administration to the younger sibling improved metabolic acidosis and reversed cardiac hypertrophy. Characterization of FBXL4 patient fibroblasts revealed severe bioenergetic defects, mtDNA depletion, fragmentation of mitochondrial networks, and abnormalities in mtDNA nucleoids. These phenotypes, observed with other pathogenic FBXL4 variants, confirm the pathogenicity of the p.Cys584Arg variant. Although treating FBXL4 fibroblasts with DCA improved extracellular acidification, in line with reduced lactate levels in patients, DCA treatment did not improve any of the other mitochondrial functions. Nonetheless, we highlight DCA as a potentially effective drug for the management of elevated lactate and cardiomyopathy in patients with pathogenic FBXL4 variants. Finally, as the exact mechanism through which FBXL4 mutations lead to mtDNA depletion was unknown, we tested the hypothesis that FBXL4 promotes mitochondrial fusion. Using a photo-activatable GFP fusion assay, we found reduced mitochondrial fusion rates in cells harbouring a pathogenic FBXL4 variant. Meanwhile, overexpression of wildtype FBXL4, but not the p.Cys584Arg variant, promoted mitochondrial hyperfusion. Thus, we have uncovered a novel function for FBXL4 in promoting mitochondrial fusion, providing important mechanistic insights into the pathogenic mechanism underlying FBXL4 dysfunction.
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Affiliation(s)
- Rasha Sabouny
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
| | - Rachel Wong
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Laurie Lee-Glover
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Steven C Greenway
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
| | - David S Sinasac
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | | | - Aneal Khan
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Timothy E Shutt
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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67
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Baechler SA, Dalla Rosa I, Spinazzola A, Pommier Y. Beyond the unwinding: role of TOP1MT in mitochondrial translation. Cell Cycle 2019; 18:2377-2384. [PMID: 31345095 DOI: 10.1080/15384101.2019.1646563] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mitochondria contain their own genome (mtDNA), encoding 13 proteins of the enzyme complexes of the oxidative phosphorylation. Synthesis of these 13 mitochondrial proteins requires a specific translation machinery, the mitoribosomes whose RNA components are encoded by the mtDNA, whereas more than 80 proteins are encoded by nuclear genes. It has been well established that mitochondrial topoisomerase I (TOP1MT) is important for mtDNA integrity and mitochondrial transcription as it prevents excessive mtDNA negative supercoiling and releases topological stress during mtDNA replication and transcription. We recently showed that TOP1MT also supports mitochondrial protein synthesis, and thus is critical for promoting tumor growth. Impaired mitochondrial protein synthesis leads to activation of the mitonuclear stress response through the transcription factor ATF4, and induces cytoprotective genes in order to prevent mitochondrial and cellular dysfunction. In this perspective, we highlight the novel role of TOP1MT in mitochondrial protein synthesis and as potential target for chemotherapy.
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Affiliation(s)
- Simone A Baechler
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, NIH , Bethesda , MD , USA
| | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology , London , UK
| | - Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology , London , UK
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, NIH , Bethesda , MD , USA
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68
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Abstract
Perturbed mitochondrial bioenergetics constitute a core pillar of cancer-associated metabolic dysfunction. While mitochondrial dysfunction in cancer may result from myriad biochemical causes, a historically neglected source is that of the mitochondrial genome. Recent large-scale sequencing efforts and clinical studies have highlighted the prevalence of mutations in mitochondrial DNA (mtDNA) in human tumours and their potential roles in cancer progression. In this review we discuss the biology of the mitochondrial genome, sources of mtDNA mutations, and experimental evidence of a role for mtDNA mutations in cancer. We also propose a ‘metabolic licensing’ model for mtDNA mutation-derived dysfunction in cancer initiation and progression.
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Affiliation(s)
- Payam A Gammage
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK. .,CRUK Beatson Institute for Cancer Research, Glasgow, UK.
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69
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Abstract
Replication stalling has been associated with the formation of pathological mitochondrial DNA (mtDNA) rearrangements. Yet, almost nothing is known about the fate of stalled replication intermediates in mitochondria. We show here that replication stalling in mitochondria leads to replication fork regression and mtDNA double-strand breaks. The resulting mtDNA fragments are normally degraded by a mechanism involving the mitochondrial exonuclease MGME1, and the loss of this enzyme results in accumulation of linear and recombining mtDNA species. Additionally, replication stress promotes the initiation of alternative replication origins as an apparent means of rescue by fork convergence. Besides demonstrating an interplay between two major mechanisms rescuing stalled replication forks – mtDNA degradation and homology-dependent repair – our data provide evidence that mitochondria employ similar mechanisms to cope with replication stress as known from other genetic systems.
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70
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Silva Ramos E, Motori E, Brüser C, Kühl I, Yeroslaviz A, Ruzzenente B, Kauppila JHK, Busch JD, Hultenby K, Habermann BH, Jakobs S, Larsson NG, Mourier A. Mitochondrial fusion is required for regulation of mitochondrial DNA replication. PLoS Genet 2019; 15:e1008085. [PMID: 31170154 PMCID: PMC6553695 DOI: 10.1371/journal.pgen.1008085] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/11/2019] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial dynamics is an essential physiological process controlling mitochondrial content mixing and mobility to ensure proper function and localization of mitochondria at intracellular sites of high-energy demand. Intriguingly, for yet unknown reasons, severe impairment of mitochondrial fusion drastically affects mtDNA copy number. To decipher the link between mitochondrial dynamics and mtDNA maintenance, we studied mouse embryonic fibroblasts (MEFs) and mouse cardiomyocytes with disruption of mitochondrial fusion. Super-resolution microscopy revealed that loss of outer mitochondrial membrane (OMM) fusion, but not inner mitochondrial membrane (IMM) fusion, leads to nucleoid clustering. Remarkably, fluorescence in situ hybridization (FISH), bromouridine labeling in MEFs and assessment of mitochondrial transcription in tissue homogenates revealed that abolished OMM fusion does not affect transcription. Furthermore, the profound mtDNA depletion in mouse hearts lacking OMM fusion is not caused by defective integrity or increased mutagenesis of mtDNA, but instead we show that mitochondrial fusion is necessary to maintain the stoichiometry of the protein components of the mtDNA replisome. OMM fusion is necessary for proliferating MEFs to recover from mtDNA depletion and for the marked increase of mtDNA copy number during postnatal heart development. Our findings thus link OMM fusion to replication and distribution of mtDNA. Mammalian mitochondria contain multiple copies of the mitochondrial genome (mtDNA), which encodes genes that are essential for the oxidative phosphorylation system. An important feature of mtDNA is that it is evenly distributed throughout the mitochondrial network. Dynamin-related GTPase proteins help control the size and shape of mitochondria by fusion and fission events and are intimately linked to maintenance and distribution of mtDNA. Certain human mutations in mitofusin 2 (MFN2) and optic atrophy protein 1 (OPA1) cause disease phenotypes, such as peripheral neuropathy and optic atrophy, which are often also associated with mtDNA depletion. However, the mechanism whereby MFNs and OPA1 are involved in maintenance of mtDNA is unclear. In this study, we demonstrate that rapid mtDNA synthesis in proliferating tissue-culture cells or cardiomyocytes during post-natal heart development requires mitochondrial fusion. However, the absence of mitochondrial fusion in mouse heart is not associated with mtDNA integrity defects but instead affects the replication of mtDNA. These findings provide direct evidence for the importance of mitochondrial fusion in maintaining mtDNA replication.
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Affiliation(s)
- Eduardo Silva Ramos
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Elisa Motori
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Christian Brüser
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Inge Kühl
- Institute of Integrative Biology of the Cell (I2BC) UMR9198, CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Assa Yeroslaviz
- Computational Systems Biochemistry, Bioinformatics Core Facility, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Benedetta Ruzzenente
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Johanna H. K. Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Jakob D. Busch
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Kjell Hultenby
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (NGL); (AM)
| | - Arnaud Mourier
- Université de Bordeaux, IBGC UMR 5095, Bordeaux, France
- CNRS, IBGC CNRS UMR 5095, Bordeaux, France
- * E-mail: (NGL); (AM)
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71
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Organization of DNA in Mammalian Mitochondria. Int J Mol Sci 2019; 20:ijms20112770. [PMID: 31195723 PMCID: PMC6600607 DOI: 10.3390/ijms20112770] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 12/22/2022] Open
Abstract
As with all organisms that must organize and condense their DNA to fit within the limited volume of a cell or a nucleus, mammalian mitochondrial DNA (mtDNA) is packaged into nucleoprotein structures called nucleoids. In this study, we first introduce the general modes of DNA compaction, especially the role of the nucleoid-associated proteins (NAPs) that structure the bacterial chromosome. We then present the mitochondrial nucleoid and the main factors responsible for packaging of mtDNA: ARS- (autonomously replicating sequence-) binding factor 2 protein (Abf2p) in yeast and mitochondrial transcription factor A (TFAM) in mammals. We summarize the single-molecule manipulation experiments on mtDNA compaction and visualization of mitochondrial nucleoids that have led to our current knowledge on mtDNA compaction. Lastly, we discuss the possible regulatory role of DNA packaging by TFAM in DNA transactions such as mtDNA replication and transcription.
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72
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Durigon R, Mitchell AL, Jones AW, Manole A, Mennuni M, Hirst EM, Houlden H, Maragni G, Lattante S, Doronzio PN, Dalla Rosa I, Zollino M, Holt IJ, Spinazzola A. LETM1 couples mitochondrial DNA metabolism and nutrient preference. EMBO Mol Med 2019; 10:emmm.201708550. [PMID: 30012579 PMCID: PMC6127893 DOI: 10.15252/emmm.201708550] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The diverse clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) are the result of haploinsufficiency of several genes, one of which, LETM1, encodes a protein of the mitochondrial inner membrane of uncertain function. Here, we show that LETM1 is associated with mitochondrial ribosomes, is required for mitochondrial DNA distribution and expression, and regulates the activity of an ancillary metabolic enzyme, pyruvate dehydrogenase. LETM1 deficiency in WHS alters mitochondrial morphology and DNA organization, as does substituting ketone bodies for glucose in control cells. While this change in nutrient availability leads to the death of fibroblasts with normal amounts of LETM1, WHS‐derived fibroblasts survive on ketone bodies, which can be attributed to their reduced dependence on glucose oxidation. Thus, remodeling of mitochondrial nucleoprotein complexes results from the inability of mitochondria to use specific substrates for energy production and is indicative of mitochondrial dysfunction. However, the dysfunction could be mitigated by a modified diet—for WHS, one high in lipids and low in carbohydrates.
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Affiliation(s)
- Romina Durigon
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Alice L Mitchell
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Aleck We Jones
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Andreea Manole
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Mara Mennuni
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | | | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | - Serena Lattante
- Institute of Genomic Medicine, Catholic University, Rome, Italy
| | | | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | | | - Ian J Holt
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK.,Biodonostia Health Research Institute, San Sebastián, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK .,MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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73
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Twist and Turn-Topoisomerase Functions in Mitochondrial DNA Maintenance. Int J Mol Sci 2019; 20:ijms20082041. [PMID: 31027213 PMCID: PMC6514783 DOI: 10.3390/ijms20082041] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 12/15/2022] Open
Abstract
Like any genome, mitochondrial DNA (mtDNA) also requires the action of topoisomerases to resolve topological problems in its maintenance, but for a long time, little was known about mitochondrial topoisomerases. The last years have brought a closer insight into the function of these fascinating enzymes in mtDNA topology regulation, replication, transcription, and segregation. Here, we summarize the current knowledge about mitochondrial topoisomerases, paying special attention to mammalian mitochondrial genome maintenance. We also discuss the open gaps in the existing knowledge of mtDNA topology control and the potential involvement of mitochondrial topoisomerases in human pathologies. While Top1mt, the only exclusively mitochondrial topoisomerase in mammals, has been studied intensively for nearly a decade, only recent studies have shed some light onto the mitochondrial function of Top2β and Top3α, enzymes that are shared between nucleus and mitochondria. Top3α mediates the segregation of freshly replicated mtDNA molecules, and its dysfunction leads to mtDNA aggregation and copy number depletion in patients. Top2β, in contrast, regulates mitochondrial DNA replication and transcription through the alteration of mtDNA topology, a fact that should be acknowledged due to the frequent use of Topoisomerase 2 inhibitors in medical therapy.
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74
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Persson Ö, Muthukumar Y, Basu S, Jenninger L, Uhler JP, Berglund AK, McFarland R, Taylor RW, Gustafsson CM, Larsson E, Falkenberg M. Copy-choice recombination during mitochondrial L-strand synthesis causes DNA deletions. Nat Commun 2019; 10:759. [PMID: 30770810 PMCID: PMC6377680 DOI: 10.1038/s41467-019-08673-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/21/2019] [Indexed: 11/08/2022] Open
Abstract
Mitochondrial DNA (mtDNA) deletions are associated with mitochondrial disease, and also accumulate during normal human ageing. The mechanisms underlying mtDNA deletions remain unknown although several models have been proposed. Here we use deep sequencing to characterize abundant mtDNA deletions in patients with mutations in mitochondrial DNA replication factors, and show that these have distinct directionality and repeat characteristics. Furthermore, we recreate the deletion formation process in vitro using only purified mitochondrial proteins and defined DNA templates. Based on our in vivo and in vitro findings, we conclude that mtDNA deletion formation involves copy-choice recombination during replication of the mtDNA light strand.
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Affiliation(s)
- Örjan Persson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Yazh Muthukumar
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Swaraj Basu
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Louise Jenninger
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Jay P Uhler
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Anna-Karin Berglund
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden
| | - Erik Larsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden.
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Gothenburg, SE-405 30, Sweden.
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75
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Mitochondrial DNA Integrity: Role in Health and Disease. Cells 2019; 8:cells8020100. [PMID: 30700008 PMCID: PMC6406942 DOI: 10.3390/cells8020100] [Citation(s) in RCA: 131] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 01/06/2023] Open
Abstract
As the primary cellular location for respiration and energy production, mitochondria serve in a critical capacity to the cell. Yet, by virtue of this very function of respiration, mitochondria are subject to constant oxidative stress that can damage one of the unique features of this organelle, its distinct genome. Damage to mitochondrial DNA (mtDNA) and loss of mitochondrial genome integrity is increasingly understood to play a role in the development of both severe early-onset maladies and chronic age-related diseases. In this article, we review the processes by which mtDNA integrity is maintained, with an emphasis on the repair of oxidative DNA lesions, and the cellular consequences of diminished mitochondrial genome stability.
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76
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Baechler SA, Factor VM, Dalla Rosa I, Ravji A, Becker D, Khiati S, Miller Jenkins LM, Lang M, Sourbier C, Michaels SA, Neckers LM, Zhang HL, Spinazzola A, Huang SN, Marquardt JU, Pommier Y. The mitochondrial type IB topoisomerase drives mitochondrial translation and carcinogenesis. Nat Commun 2019; 10:83. [PMID: 30622257 PMCID: PMC6325124 DOI: 10.1038/s41467-018-07922-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/28/2018] [Indexed: 01/23/2023] Open
Abstract
Mitochondrial topoisomerase IB (TOP1MT) is a nuclear-encoded topoisomerase, exclusively localized to mitochondria, which resolves topological stress generated during mtDNA replication and transcription. Here, we report that TOP1MT is overexpressed in cancer tissues and demonstrate that TOP1MT deficiency attenuates tumor growth in human and mouse models of colon and liver cancer. Due to their mitochondrial dysfunction, TOP1MT-KO cells become addicted to glycolysis, which limits synthetic building blocks and energy supply required for the proliferation of cancer cells in a nutrient-deprived tumor microenvironment. Mechanistically, we show that TOP1MT associates with mitoribosomal subunits, ensuring optimal mitochondrial translation and assembly of oxidative phosphorylation complexes that are critical for sustaining tumor growth. The TOP1MT genomic signature profile, based on Top1mt-KO liver cancers, is correlated with enhanced survival of hepatocellular carcinoma patients. Our results highlight the importance of TOP1MT for tumor development, providing a potential rationale to develop TOP1MT-targeted drugs as anticancer therapies.
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MESH Headings
- Animals
- Carcinogenesis/pathology
- Carcinogens/toxicity
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/mortality
- Carcinoma, Hepatocellular/pathology
- Cell Nucleus/metabolism
- Cell Proliferation
- DNA Topoisomerases, Type I/genetics
- DNA Topoisomerases, Type I/metabolism
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/isolation & purification
- Datasets as Topic
- Energy Metabolism
- Female
- Fibroblasts
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Glycolysis
- HCT116 Cells
- Humans
- Liver/cytology
- Liver/metabolism
- Liver/pathology
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Liver Neoplasms/mortality
- Liver Neoplasms/pathology
- Liver Neoplasms, Experimental/chemically induced
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/metabolism
- Liver Neoplasms, Experimental/pathology
- Male
- Mice
- Mice, Knockout
- Mice, Nude
- Mitochondria/metabolism
- Mitochondria/pathology
- Prognosis
- Protein Biosynthesis
- Survival Analysis
- Xenograft Model Antitumor Assays
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Affiliation(s)
- S A Baechler
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - V M Factor
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - I Dalla Rosa
- Department of Clinical and Movement Neurosciences, Institute of Neurology, Royal Free Campus, University College London, London, NW3 2PF, UK
| | - A Ravji
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - D Becker
- Department of Medicine I, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany
| | - S Khiati
- Equipe MitoLab, Institut MitoVasc, UMR CNRS 6015, INSERM U1083, Universite d'Angers, 49933, Angers, France
| | - L M Miller Jenkins
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - M Lang
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MA, 20892, USA
| | - C Sourbier
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MA, 20892, USA
- Laboratory of Molecular Oncology, Division of Biotechnology Review and Research I, Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - S A Michaels
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - L M Neckers
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MA, 20892, USA
| | - H L Zhang
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - A Spinazzola
- Department of Clinical and Movement Neurosciences, Institute of Neurology, Royal Free Campus, University College London, London, NW3 2PF, UK
| | - S N Huang
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - J U Marquardt
- Department of Medicine I, Johannes Gutenberg University, Langenbeckstrasse 1, 55131, Mainz, Germany
| | - Y Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, NIH, National Cancer Institute, Bethesda, Maryland, 20892, USA.
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77
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Posse V, Al-Behadili A, Uhler JP, Clausen AR, Reyes A, Zeviani M, Falkenberg M, Gustafsson CM. RNase H1 directs origin-specific initiation of DNA replication in human mitochondria. PLoS Genet 2019; 15:e1007781. [PMID: 30605451 PMCID: PMC6317783 DOI: 10.1371/journal.pgen.1007781] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/23/2018] [Indexed: 11/21/2022] Open
Abstract
Human mitochondrial DNA (mtDNA) replication is first initiated at the origin of H-strand replication. The initiation depends on RNA primers generated by transcription from an upstream promoter (LSP). Here we reconstitute this process in vitro using purified transcription and replication factors. The majority of all transcription events from LSP are prematurely terminated after ~120 nucleotides, forming stable R-loops. These nascent R-loops cannot directly prime mtDNA synthesis, but must first be processed by RNase H1 to generate 3′-ends that can be used by DNA polymerase γ to initiate DNA synthesis. Our findings are consistent with recent studies of a knockout mouse model, which demonstrated that RNase H1 is required for R-loop processing and mtDNA maintenance in vivo. Both R-loop formation and DNA replication initiation are stimulated by the mitochondrial single-stranded DNA binding protein. In an RNase H1 deficient patient cell line, the precise initiation of mtDNA replication is lost and DNA synthesis is initiated from multiple sites throughout the mitochondrial control region. In combination with previously published in vivo data, the findings presented here suggest a model, in which R-loop processing by RNase H1 directs origin-specific initiation of DNA replication in human mitochondria. Human mitochondria contain a double-stranded DNA genome that codes for key components of the oxidative phosphorylation system. The mitochondrial DNA (mtDNA) is replicated by a replication machinery distinct from that operating in the nucleus and mutations affecting individual replication factors have been associated with an array of rare, human diseases. In the present work, we demonstrate that RNase H1 directs origin-specific initiation of DNA replication in human mitochondria and that disease-causing mutations may impair this process. A unique feature of mtDNA replication is that primers required for initiation of leading-strand DNA replication are produced by the mitochondrial transcription machinery. A substantial fraction of all transcription events is prematurely terminated about 120 nucleotides downstream of the promoter and the RNA remains firmly associated with the genome, forming R-loops. Interestingly, the free 3′-end of these R-loops cannot directly prime initiation of DNA synthesis, but must first be processed by RNase H1. The process is stimulated by the mitochondrial single-stranded DNA binding protein and faithfully reconstitutes replication events mapped in vivo. In combination with mapping of replication events in fibroblasts derived from patients with mutations in RNASEH1, our findings point to a possible model for replication initiation in human mitochondria similar to that previously described in the E. coli plasmid, ColE1.
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Affiliation(s)
- Viktor Posse
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ali Al-Behadili
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jay P Uhler
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anders R Clausen
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Aurelio Reyes
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
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78
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Hangas A, Aasumets K, Kekäläinen NJ, Paloheinä M, Pohjoismäki JL, Gerhold JM, Goffart S. Ciprofloxacin impairs mitochondrial DNA replication initiation through inhibition of Topoisomerase 2. Nucleic Acids Res 2018; 46:9625-9636. [PMID: 30169847 PMCID: PMC6182158 DOI: 10.1093/nar/gky793] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/21/2018] [Accepted: 08/23/2018] [Indexed: 11/17/2022] Open
Abstract
Maintenance of topological homeostasis is vital for gene expression and genome replication in all organisms. Similar to other circular genomes, also mitochondrial DNA (mtDNA) is known to exist in various different topological forms, although their functional significance remains unknown. We report here that both known type II topoisomerases Top2α and Top2β are present in mammalian mitochondria, with especially Top2β regulating the supercoiling state of mtDNA. Loss of Top2β or its inhibition by ciprofloxacin results in accumulation of positively supercoiled mtDNA, followed by cessation of mitochondrial transcription and replication initiation, causing depletion of mtDNA copy number. These mitochondrial effects block both cell proliferation and differentiation, possibly explaining some of the side effects associated with fluoroquinolone antibiotics. Our results show for the first time the importance of topology for maintenance of mtDNA homeostasis and provide novel insight into the mitochondrial effects of fluoroquinolones.
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Affiliation(s)
- Anu Hangas
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Koit Aasumets
- Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Nina J Kekäläinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Mika Paloheinä
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Jaakko L Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Joachim M Gerhold
- Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
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79
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Yasukawa T, Kang D. An overview of mammalian mitochondrial DNA replication mechanisms. J Biochem 2018; 164:183-193. [PMID: 29931097 PMCID: PMC6094444 DOI: 10.1093/jb/mvy058] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/15/2018] [Indexed: 11/14/2022] Open
Abstract
While the majority of DNA is enclosed within the nucleus, the mitochondria also contain their own, separate DNA, the mitochondrial DNA (mtDNA). Mutations in mtDNA are associated with various human diseases, demonstrating the importance of mtDNA. Intensive studies over the last 18 years have demonstrated the presence of two distinct classes of mtDNA replication intermediates in mammals. One involves leading-strand DNA synthesis in the absence of synchronous lagging-strand DNA synthesis. Currently there are competing models in which the lagging-strand template is either systematically hybridized to processed mitochondrial transcripts, or coated with protein, until the lagging-strand DNA synthesis takes place. The other class of mtDNA replication intermediates has many properties of conventional, coupled leading- and lagging-strand DNA synthesis. Additionally, the highly unusual arrangement of DNA in human heart mitochondria suggests a third mechanism of replication. These findings indicate that the mtDNA replication systems of humans and other mammals are far more complex than previously thought, and thereby will require further research to understand the full picture of mtDNA replication.
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Affiliation(s)
- Takehiro Yasukawa
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Dongchon Kang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
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80
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Nicholls TJ, Gustafsson CM. Separating and Segregating the Human Mitochondrial Genome. Trends Biochem Sci 2018; 43:869-881. [PMID: 30224181 DOI: 10.1016/j.tibs.2018.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 12/17/2022]
Abstract
Cells contain thousands of copies of the mitochondrial genome. These genomes are distributed within the tubular mitochondrial network, which is itself spread across the cytosol of the cell. Mitochondrial DNA (mtDNA) replication occurs throughout the cell cycle and ensures that cells maintain a sufficient number of mtDNA copies. At replication termination the genomes must be resolved and segregated within the mitochondrial network. Defects in mtDNA replication and segregation are a cause of human mitochondrial disease associated with failure of cellular energy production. This review focuses upon recent developments on how mitochondrial genomes are physically separated at the end of DNA replication, and how these genomes are subsequently segregated and distributed around the mitochondrial network.
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Affiliation(s)
- Thomas J Nicholls
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, SE-405 30 Gothenburg, Sweden.
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, SE-405 30 Gothenburg, Sweden
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81
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Martin CA, Sarlós K, Logan CV, Thakur RS, Parry DA, Bizard AH, Leitch A, Cleal L, Ali NS, Al-Owain MA, Allen W, Altmüller J, Aza-Carmona M, Barakat BAY, Barraza-García J, Begtrup A, Bogliolo M, Cho MT, Cruz-Rojo J, Dhahrabi HAM, Elcioglu NH, Gorman GS, Jobling R, Kesterton I, Kishita Y, Kohda M, Le Quesne Stabej P, Malallah AJ, Nürnberg P, Ohtake A, Okazaki Y, Pujol R, Ramirez MJ, Revah-Politi A, Shimura M, Stevens P, Taylor RW, Turner L, Williams H, Wilson C, Yigit G, Zahavich L, Alkuraya FS, Surralles J, Iglesias A, Murayama K, Wollnik B, Dattani M, Heath KE, Hickson ID, Jackson AP. Mutations in TOP3A Cause a Bloom Syndrome-like Disorder. Am J Hum Genet 2018; 103:221-231. [PMID: 30057030 PMCID: PMC6080766 DOI: 10.1016/j.ajhg.2018.07.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/29/2018] [Indexed: 11/21/2022] Open
Abstract
Bloom syndrome, caused by biallelic mutations in BLM, is characterized by prenatal-onset growth deficiency, short stature, an erythematous photosensitive malar rash, and increased cancer predisposition. Diagnostically, a hallmark feature is the presence of increased sister chromatid exchanges (SCEs) on cytogenetic testing. Here, we describe biallelic mutations in TOP3A in ten individuals with prenatal-onset growth restriction and microcephaly. TOP3A encodes topoisomerase III alpha (TopIIIα), which binds to BLM as part of the BTRR complex, and promotes dissolution of double Holliday junctions arising during homologous recombination. We also identify a homozygous truncating variant in RMI1, which encodes another component of the BTRR complex, in two individuals with microcephalic dwarfism. The TOP3A mutations substantially reduce cellular levels of TopIIIα, and consequently subjects' cells demonstrate elevated rates of SCE. Unresolved DNA recombination and/or replication intermediates persist into mitosis, leading to chromosome segregation defects and genome instability that most likely explain the growth restriction seen in these subjects and in Bloom syndrome. Clinical features of mitochondrial dysfunction are evident in several individuals with biallelic TOP3A mutations, consistent with the recently reported additional function of TopIIIα in mitochondrial DNA decatenation. In summary, our findings establish TOP3A mutations as an additional cause of prenatal-onset short stature with increased cytogenetic SCEs and implicate the decatenation activity of the BTRR complex in their pathogenesis.
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Affiliation(s)
- Carol-Anne Martin
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Kata Sarlós
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Clare V Logan
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Roshan Singh Thakur
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - David A Parry
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Anna H Bizard
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Andrea Leitch
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Louise Cleal
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | | | - Mohammed A Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | | | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Miriam Aza-Carmona
- Institute of Medical and Molecular Genetics and Skeletal dysplasia multidisciplinary Unit, Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPaz, Madrid 28046, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain
| | | | - Jimena Barraza-García
- Institute of Medical and Molecular Genetics and Skeletal dysplasia multidisciplinary Unit, Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPaz, Madrid 28046, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain
| | - Amber Begtrup
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Massimo Bogliolo
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain; Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Megan T Cho
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Jaime Cruz-Rojo
- Department of Pediatric Endocrinology & Dysmorphology, Hospital 12 Octubre, Madrid 28041, Spain
| | | | - Nursel H Elcioglu
- Department of Pediatric Genetics, Marmara University Medical School, Istanbul 34722, Turkey
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, School of Medical Education, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | | | - Ian Kesterton
- Cytogenetics Department, Viapath Analytics, Guy's Hospital, London SE1 9RT, UK
| | - Yoshihito Kishita
- Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Masakazu Kohda
- Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | | | | | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Akira Ohtake
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan
| | - Yasushi Okazaki
- Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Roser Pujol
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain; Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Maria José Ramirez
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain; Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Anya Revah-Politi
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Masaru Shimura
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1, Heta-cho, Midori-ku, Chiba 266-0007, Japan
| | - Paul Stevens
- Cytogenetics Department, Viapath Analytics, Guy's Hospital, London SE1 9RT, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, School of Medical Education, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Lesley Turner
- Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Hywel Williams
- UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | | | - Gökhan Yigit
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Laura Zahavich
- The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Jordi Surralles
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain; Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain; Department of Genetics and Biomedical Research Institute Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona 08041, Spain
| | - Alejandro Iglesias
- Department of Pediatrics, Division of Clinical Genetics, Columbia University Medical Center, New York, NY 10032, USA
| | - Kei Murayama
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1, Heta-cho, Midori-ku, Chiba 266-0007, Japan
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Mehul Dattani
- UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Karen E Heath
- Institute of Medical and Molecular Genetics and Skeletal dysplasia multidisciplinary Unit, Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPaz, Madrid 28046, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid 28029, Spain
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
| | - Andrew P Jackson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
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82
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Mitochondrial DNA replication in mammalian cells: overview of the pathway. Essays Biochem 2018; 62:287-296. [PMID: 29880722 PMCID: PMC6056714 DOI: 10.1042/ebc20170100] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/18/2018] [Accepted: 05/21/2018] [Indexed: 12/27/2022]
Abstract
Mammalian mitochondria contain multiple copies of a circular, double-stranded DNA genome and a dedicated DNA replication machinery is required for its maintenance. Many disease-causing mutations affect mitochondrial replication factors and a detailed understanding of the replication process may help to explain the pathogenic mechanisms underlying a number of mitochondrial diseases. We here give a brief overview of DNA replication in mammalian mitochondria, describing our current understanding of this process and some unanswered questions remaining.
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83
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Pohjoismäki JLO, Forslund JME, Goffart S, Torregrosa-Muñumer R, Wanrooij S. Known Unknowns of Mammalian Mitochondrial DNA Maintenance. Bioessays 2018; 40:e1800102. [DOI: 10.1002/bies.201800102] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/18/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Jaakko L. O. Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland; 80101 Joensuu Finland
| | | | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland; 80101 Joensuu Finland
| | - Rubén Torregrosa-Muñumer
- Department of Environmental and Biological Sciences, University of Eastern Finland; 80101 Joensuu Finland
| | - Sjoerd Wanrooij
- Department of Medical Biochemistry and Biophysics, Umeå University; 90187 Umeå Sweden
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