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Aneli S, Ceccatelli Berti C, Gilea AI, Birolo G, Mutti G, Pavesi A, Baruffini E, Goffrini P, Capelli C. Functional characterization of archaic-specific variants in mitonuclear genes: insights from comparative analysis in S. cerevisiae. Hum Mol Genet 2024; 33:1152-1163. [PMID: 38558123 DOI: 10.1093/hmg/ddae057] [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: 01/17/2024] [Revised: 02/29/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024] Open
Abstract
Neanderthal and Denisovan hybridisation with modern humans has generated a non-random genomic distribution of introgressed regions, the result of drift and selection dynamics. Cross-species genomic incompatibility and more efficient removal of slightly deleterious archaic variants have been proposed as selection-based processes involved in the post-hybridisation purge of archaic introgressed regions. Both scenarios require the presence of functionally different alleles across Homo species onto which selection operated differently according to which populations hosted them, but only a few of these variants have been pinpointed so far. In order to identify functionally divergent archaic variants removed in humans, we focused on mitonuclear genes, which are underrepresented in the genomic landscape of archaic humans. We searched for non-synonymous, fixed, archaic-derived variants present in mitonuclear genes, rare or absent in human populations. We then compared the functional impact of archaic and human variants in the model organism Saccharomyces cerevisiae. Notably, a variant within the mitochondrial tyrosyl-tRNA synthetase 2 (YARS2) gene exhibited a significant decrease in respiratory activity and a substantial reduction of Cox2 levels, a proxy for mitochondrial protein biosynthesis, coupled with the accumulation of the YARS2 protein precursor and a lower amount of mature enzyme. Our work suggests that this variant is associated with mitochondrial functionality impairment, thus contributing to the purging of archaic introgression in YARS2. While different molecular mechanisms may have impacted other mitonuclear genes, our approach can be extended to the functional screening of mitonuclear genetic variants present across species and populations.
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Affiliation(s)
- Serena Aneli
- Department of Public Health Sciences and Pediatrics, University of Turin, C.so Galileo Galilei 22, Turin 10126, Italy
| | - Camilla Ceccatelli Berti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
| | - Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
| | - Giovanni Birolo
- Department of Medical Sciences, University of Turin, Via Santena 5, Turin 10126, Italy
| | - Giacomo Mutti
- Barcelona Supercomputing Centre (BSC-CNS), Department of Life Sciences, Plaça Eusebi Güell, 1-3, Barcelona 08034, Spain
- Institute for Research in Biomedicine (IRB Barcelona), Department of Mechanisms of Disease, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain
| | - Angelo Pavesi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
| | - Cristian Capelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, Parma 43124, Italy
- Department of Biology, University of Oxford, 11a Mansfield Rd, Oxford OX1 3SZ, United Kingdom
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Gilea AI, Magistrati M, Notaroberto I, Tiso N, Dallabona C, Baruffini E. The Saccharomyces cerevisiae mitochondrial DNA polymerase and its contribution to the knowledge about human POLG-related disorders. IUBMB Life 2023; 75:983-1002. [PMID: 37470284 DOI: 10.1002/iub.2770] [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: 05/31/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023]
Abstract
Most eukaryotes possess a mitochondrial genome, called mtDNA. In animals and fungi, the replication of mtDNA is entrusted by the DNA polymerase γ, or Pol γ. The yeast Pol γ is composed only of a catalytic subunit encoded by MIP1. In humans, Pol γ is a heterotrimer composed of a catalytic subunit homolog to Mip1, encoded by POLG, and two accessory subunits. In the last 25 years, more than 300 pathological mutations in POLG have been identified as the cause of several mitochondrial diseases, called POLG-related disorders, which are characterized by multiple mtDNA deletions and/or depletion in affected tissues. In this review, at first, we summarize the biochemical properties of yeast Mip1, and how mutations, especially those introduced recently in the N-terminal and C-terminal regions of the enzyme, affect the in vitro activity of the enzyme and the in vivo phenotype connected to the mtDNA stability and to the mtDNA extended and point mutability. Then, we focus on the use of yeast harboring Mip1 mutations equivalent to the human ones to confirm their pathogenicity, identify the phenotypic defects caused by these mutations, and find both mechanisms and molecular compounds able to rescue the detrimental phenotype. A closing chapter will be dedicated to other polymerases found in yeast mitochondria, namely Pol ζ, Rev1 and Pol η, and to their genetic interactions with Mip1 necessary to maintain mtDNA stability and to avoid the accumulation of spontaneous or induced point mutations.
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Affiliation(s)
- Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Martina Magistrati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Ilenia Notaroberto
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Padova, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
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3
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Meyrick J, Stefanetti RJ, Errington L, McFarland R, Gorman GS, Lax NZ. Model systems informing mechanisms and drug discovery: a systematic review of POLG-related disease models. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.18637.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Introduction Pathogenic variants in the gene encoding the catalytic subunit of DNA polymerase gamma (POLG), comprise an important single-gene cause of inherited mitochondrial disorders. Clinical manifestations are now recognised as an array of overlapping clinical features rather than discrete syndromes as originally conceptualised. Animal and cellular models have been used to address numerous scientific questions, from basic science to the development and assessment of novel therapies. Here, we sought to perform a systematic review of the existing models used in mitochondrial research and their effectiveness in recapitulating POLG-related disease. Methods Four databases were searched from inception to May 31, 2022: MEDLINE, Scopus, Web of Science, and Cochrane Review. Original articles available in English, reporting the use of a model system designed to recapitulate POLG-related disease, or related pathogenicity, were eligible for inclusion. Risk of bias and the methodological quality of articles were assessed by an adapted version of the Cochrane Risk of Bias Tool, with the quality of evidence synthesized across each model. Results A total of 55 articles, including seven model organisms (Human, yeast [Saccharomyces cerevisiae and Schizosaccharomyces pombe], Drosophila, Mouse, Nematoda, and Zebrafish) with 258 distinct variants were included. Of these, 66% (N=38) of articles recapitulated mitochondrial DNA (mtDNA) depletion and 42% (N=23) recapitulated POLG-related disease. Thirty-three percent of articles (N=18/55) utilised tissue-specific models of POLG-related dysfunction, while 13% (N=7) investigated the effect of potential therapeutics in POLG-related mitochondrial disorders. Discussion The available evidence supporting the ability of models for POLG-related disease to recapitulate molecular mechanisms and phenotype is limited, inconsistent and of poor methodologic quality. Further success in examining and translating novel therapies into effective treatments will be enhanced by the availability of more robust models that better recapitulate the entire spectrum of POLG-related disease. PROSPERO registration: CRD42021234883
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Wongkittichote P, Magistrati M, Shimony JS, Smyser CD, Fatemi SA, Fine AS, Bellacchio E, Dallabona C, Shinawi M. Functional analysis of missense DARS2 variants in siblings with leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation. Mol Genet Metab 2022; 136:260-267. [PMID: 35820270 DOI: 10.1016/j.ymgme.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/01/2022] [Accepted: 07/02/2022] [Indexed: 11/18/2022]
Abstract
Biallelic pathogenic variants in the nuclear gene DARS2 (MIM# 610956), encoding the mitochondrial enzyme aspartyl-tRNA synthetase (MT-ASPRS) cause leukoencephalopathy with Brain Stem and Spinal Cord Involvement and Lactate Elevation (LBSL) (MIM# 611105), a neurometabolic disorder characterized by progressive ataxia, spasticity, developmental arrest or regression and characteristic brain MRI findings. Most patients exhibit a slowly progressive disease course with motor deterirartion that begins in childhood or adolescence, but can also occasionaly occur in adulthood. More severe LBSL presentations with atypical brain MRI findings have been recently described. Baker's yeast orthologue of DARS2, MSD1, is required for growth on oxidative carbon sources. A yeast with MSD1 knockout (msd1Δ) demonstrated a complete lack of oxidative growth which could be rescued by wild-type MSD1 but not MSD1 with pathogenic variants. Here we reported two siblings who exhibited developmental regression and ataxia with different age of onset and phenotypic severity. Exome sequencing revealed 2 compound heterozygous missense variants in DARS2: c.473A>T (p.Glu158Val) and c.829G>A (p.Glu277Lys); this variant combination has not been previously reported. The msd1Δ yeast transformed with plasmids expressing p.Glu259Lys, equivalent to human p.Glu277Lys, showed complete loss of oxidative growth and oxygen consumption, while the strain carrying p.Gln137Val, equivalent to human p.Glu158Val, showed a significant reduction of oxidative growth, but a residual ability to grow was retained. Structural analysis indicated that p.Glu158Val may interfere with protein binding of tRNAAsp, while p.Glu277Lys may impact both homodimerization and catalysis of MT-ASPRS. Our data illustrate the utility of yeast model and in silico analysis to determine pathogenicity of DARS2 variants, expand the genotypic spectrum and suggest intrafamilial variability in LBSL.
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Affiliation(s)
- Parith Wongkittichote
- Division of Genetics and Genomic Medicine, Department of Pediatrics, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO, USA
| | - Martina Magistrati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Joshua S Shimony
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, USA
| | - Christopher D Smyser
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, USA; Division of Pediatric Neurology, Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - Seyed Ali Fatemi
- Kennedy Krieger Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Amena S Fine
- Kennedy Krieger Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Emanuele Bellacchio
- Genetics and Rare Diseases Research Area, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy.
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO, USA.
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5
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Saccharomyces cerevisiae as a Tool for Studying Mutations in Nuclear Genes Involved in Diseases Caused by Mitochondrial DNA Instability. Genes (Basel) 2021; 12:genes12121866. [PMID: 34946817 PMCID: PMC8701800 DOI: 10.3390/genes12121866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023] Open
Abstract
Mitochondrial DNA (mtDNA) maintenance is critical for oxidative phosphorylation (OXPHOS) since some subunits of the respiratory chain complexes are mitochondrially encoded. Pathological mutations in nuclear genes involved in the mtDNA metabolism may result in a quantitative decrease in mtDNA levels, referred to as mtDNA depletion, or in qualitative defects in mtDNA, especially in multiple deletions. Since, in the last decade, most of the novel mutations have been identified through whole-exome sequencing, it is crucial to confirm the pathogenicity by functional analysis in the appropriate model systems. Among these, the yeast Saccharomyces cerevisiae has proved to be a good model for studying mutations associated with mtDNA instability. This review focuses on the use of yeast for evaluating the pathogenicity of mutations in six genes, MPV17/SYM1, MRM2/MRM2, OPA1/MGM1, POLG/MIP1, RRM2B/RNR2, and SLC25A4/AAC2, all associated with mtDNA depletion or multiple deletions. We highlight the techniques used to construct a specific model and to measure the mtDNA instability as well as the main results obtained. We then report the contribution that yeast has given in understanding the pathogenic mechanisms of the mutant variants, in finding the genetic suppressors of the mitochondrial defects and in the discovery of molecules able to improve the mtDNA stability.
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di Punzio G, Gilberti M, Baruffini E, Lodi T, Donnini C, Dallabona C. A Yeast-Based Repurposing Approach for the Treatment of Mitochondrial DNA Depletion Syndromes Led to the Identification of Molecules Able to Modulate the dNTP Pool. Int J Mol Sci 2021; 22:ijms222212223. [PMID: 34830106 PMCID: PMC8621932 DOI: 10.3390/ijms222212223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial DNA depletion syndromes (MDS) are clinically heterogenous and often severe diseases, characterized by a reduction of the number of copies of mitochondrial DNA (mtDNA) in affected tissues. In the context of MDS, yeast has proved to be both an excellent model for the study of the mechanisms underlying mitochondrial pathologies and for the discovery of new therapies via high-throughput assays. Among the several genes involved in MDS, it has been shown that recessive mutations in MPV17 cause a hepatocerebral form of MDS and Navajo neurohepatopathy. MPV17 encodes a non selective channel in the inner mitochondrial membrane, but its physiological role and the nature of its cargo remains elusive. In this study we identify ten drugs active against MPV17 disorder, modelled in yeast using the homologous gene SYM1. All ten of the identified molecules cause a concomitant increase of both the mitochondrial deoxyribonucleoside triphosphate (mtdNTP) pool and mtDNA stability, which suggests that the reduced availability of DNA synthesis precursors is the cause for the mtDNA deletion and depletion associated with Sym1 deficiency. We finally evaluated the effect of these molecules on mtDNA stability in two other MDS yeast models, extending the potential use of these drugs to a wider range of MDS patients.
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7
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Cappuccio G, Ceccatelli Berti C, Baruffini E, Sullivan J, Shashi V, Jewett T, Stamper T, Maitz S, Canonico F, Revah-Politi A, Kupchik GS, Anyane-Yeboa K, Aggarwal V, Benneche A, Bratland E, Berland S, D'Arco F, Alves CA, Vanderver A, Longo D, Bertini E, Torella A, Nigro V, D'Amico A, van der Knaap MS, Goffrini P, Brunetti-Pierri N. Bi-allelic KARS1 pathogenic variants affecting functions of cytosolic and mitochondrial isoforms are associated with a progressive and multisystem disease. Hum Mutat 2021; 42:745-761. [PMID: 33942428 PMCID: PMC8251883 DOI: 10.1002/humu.24210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/10/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022]
Abstract
KARS1 encodes a lysyl‐transfer RNA synthetase (LysRS) that links lysine to its cognate transfer RNA. Two different KARS1 isoforms exert functional effects in cytosol and mitochondria. Bi‐allelic pathogenic variants in KARS1 have been associated to sensorineural hearing and visual loss, neuropathy, seizures, and leukodystrophy. We report the clinical, biochemical, and neuroradiological features of nine individuals with KARS1‐related disorder carrying 12 different variants with nine of them being novel. The consequences of these variants on the cytosol and/or mitochondrial LysRS were functionally validated in yeast mutants. Most cases presented with severe neurological features including congenital and progressive microcephaly, seizures, developmental delay/intellectual disability, and cerebral atrophy. Oculo‐motor dysfunction and immuno‐hematological problems were present in six and three cases, respectively. A yeast growth defect of variable severity was detected for most variants on both cytosolic and mitochondrial isoforms. The detrimental effects of two variants on yeast growth were partially rescued by lysine supplementation. Congenital progressive microcephaly, oculo‐motor dysfunction, and immuno‐hematological problems are emerging phenotypes in KARS1‐related disorder. The data in yeast emphasize the role of both mitochondrial and cytosolic isoforms in the pathogenesis of KARS1‐related disorder and supports the therapeutic potential of lysine supplementation at least in a subset of patients.
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Affiliation(s)
- Gerarda Cappuccio
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
| | - Camilla Ceccatelli Berti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Jennifer Sullivan
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Vandana Shashi
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Tamison Jewett
- Department of Pediatrics, Section on Medical Genetics, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Tara Stamper
- Department of Pediatrics, Section on Medical Genetics, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Silvia Maitz
- Clinical Pediatric Genetics Unit, Pediatrics Clinics, MBBM Foundation, Hospital San Gerardo, Monza, Italy
| | - Francesco Canonico
- Department of Neuroradiology, San Gerardo Hospital, ASST di Monza, Università degli Studi di Milano Bicocca, Monza, Italy
| | - Anya Revah-Politi
- Department of Pathology and Cell Biology, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Gabriel S Kupchik
- Division of Medical Genetics, Maimonides Children's Hospital of Brooklyn at Maimonides Medical Center, Downstate Medical Center, State University of New York, New York, New York, USA
| | - Kwame Anyane-Yeboa
- Department of Pediatrics, Institute for Genomic Medicine Columbia University Medical Center, New York, New York, USA
| | - Vimla Aggarwal
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA
| | - Andreas Benneche
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Eirik Bratland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Siren Berland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Felice D'Arco
- Department of Paediatric Neuroradiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Cesar A Alves
- Division of Neuroradiology, Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniela Longo
- Department of Diagnostic Imaging, Pediatric Hospital Bambino Gesù, Rome, Italy
| | - Enrico Bertini
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Annalaura Torella
- Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy.,Department of Precision Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy.,Department of Precision Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | | | - Alessandra D'Amico
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Nicola Brunetti-Pierri
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
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8
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A Yeast-Based Screening Unravels Potential Therapeutic Molecules for Mitochondrial Diseases Associated with Dominant ANT1 Mutations. Int J Mol Sci 2021; 22:ijms22094461. [PMID: 33923309 PMCID: PMC8123201 DOI: 10.3390/ijms22094461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/15/2021] [Accepted: 04/22/2021] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial diseases result from inherited or spontaneous mutations in mitochondrial or nuclear DNA, leading to an impairment of the oxidative phosphorylation responsible for the synthesis of ATP. To date, there are no effective pharmacological therapies for these pathologies. We performed a yeast-based screening to search for therapeutic drugs to be used for treating mitochondrial diseases associated with dominant mutations in the nuclear ANT1 gene, which encodes for the mitochondrial ADP/ATP carrier. Dominant ANT1 mutations are involved in several degenerative mitochondrial pathologies characterized by the presence of multiple deletions or depletion of mitochondrial DNA in tissues of affected patients. Thanks to the presence in yeast of the AAC2 gene, orthologue of human ANT1, a yeast mutant strain carrying the M114P substitution equivalent to adPEO-associated L98P mutation was created. Five molecules were identified for their ability to suppress the defective respiratory growth phenotype of the haploid aac2M114P. Furthermore, these molecules rescued the mtDNA mutability in the heteroallelic AAC2/aac2M114P strain, which mimics the human heterozygous condition of adPEO patients. The drugs were effective in reducing mtDNA instability also in the heteroallelic strain carrying the R96H mutation equivalent to the more severe de novo dominant missense mutation R80H, suggesting a general therapeutic effect on diseases associated with dominant ANT1 mutations.
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9
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Ceccatelli Berti C, di Punzio G, Dallabona C, Baruffini E, Goffrini P, Lodi T, Donnini C. The Power of Yeast in Modelling Human Nuclear Mutations Associated with Mitochondrial Diseases. Genes (Basel) 2021; 12:300. [PMID: 33672627 PMCID: PMC7924180 DOI: 10.3390/genes12020300] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/17/2022] Open
Abstract
The increasing application of next generation sequencing approaches to the analysis of human exome and whole genome data has enabled the identification of novel variants and new genes involved in mitochondrial diseases. The ability of surviving in the absence of oxidative phosphorylation (OXPHOS) and mitochondrial genome makes the yeast Saccharomyces cerevisiae an excellent model system for investigating the role of these new variants in mitochondrial-related conditions and dissecting the molecular mechanisms associated with these diseases. The aim of this review was to highlight the main advantages offered by this model for the study of mitochondrial diseases, from the validation and characterisation of novel mutations to the dissection of the role played by genes in mitochondrial functionality and the discovery of potential therapeutic molecules. The review also provides a summary of the main contributions to the understanding of mitochondrial diseases emerged from the study of this simple eukaryotic organism.
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Affiliation(s)
| | | | | | | | | | | | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy; (C.C.B.); (G.d.P.); (C.D.); (E.B.); (P.G.); (T.L.)
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10
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Exploring Yeast as a Study Model of Pantothenate Kinase-Associated Neurodegeneration and for the Identification of Therapeutic Compounds. Int J Mol Sci 2020; 22:ijms22010293. [PMID: 33396642 PMCID: PMC7795310 DOI: 10.3390/ijms22010293] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
Mutations in the pantothenate kinase 2 gene (PANK2) are the cause of pantothenate kinase-associated neurodegeneration (PKAN), the most common form of neurodegeneration with brain iron accumulation. Although different disease models have been created to investigate the pathogenic mechanism of PKAN, the cascade of molecular events resulting from CoA synthesis impairment is not completely understood. Moreover, for PKAN disease, only symptomatic treatments are available. Despite the lack of a neural system, Saccharomyces cerevisiae has been successfully used to decipher molecular mechanisms of many human disorders including neurodegenerative diseases as well as iron-related disorders. To gain insights into the molecular basis of PKAN, a yeast model of this disease was developed: a yeast strain with the unique gene encoding pantothenate kinase CAB1 deleted, and expressing a pathological variant of this enzyme. A detailed functional characterization demonstrated that this model recapitulates the main phenotypes associated with human disease: mitochondrial dysfunction, altered lipid metabolism, iron overload, and oxidative damage suggesting that the yeast model could represent a tool to provide information on pathophysiology of PKAN. Taking advantage of the impaired oxidative growth of this mutant strain, a screening for molecules able to rescue this phenotype was performed. Two molecules in particular were able to restore the multiple defects associated with PKAN deficiency and the rescue was not allele-specific. Furthermore, the construction and characterization of a set of mutant alleles, allowing a quick evaluation of the biochemical consequences of pantothenate kinase (PANK) protein variants could be a tool to predict genotype/phenotype correlation.
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11
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Aleo SJ, Del Dotto V, Fogazza M, Maresca A, Lodi T, Goffrini P, Ghelli A, Rugolo M, Carelli V, Baruffini E, Zanna C. Drug repositioning as a therapeutic strategy for neurodegenerations associated with OPA1 mutations. Hum Mol Genet 2020; 29:3631-3645. [PMID: 33231680 PMCID: PMC7823107 DOI: 10.1093/hmg/ddaa244] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/19/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
OPA1 mutations are the major cause of dominant optic atrophy (DOA) and the syndromic form DOA plus, pathologies for which there is no established cure. We used a ‘drug repurposing’ approach to identify FDA-approved molecules able to rescue the mitochondrial dysfunctions induced by OPA1 mutations. We screened two different chemical libraries by using two yeast strains carrying the mgm1I322M and the chim3P646L mutations, identifying 26 drugs able to rescue their oxidative growth phenotype. Six of them, able to reduce the mitochondrial DNA instability in yeast, have been then tested in Opa1 deleted mouse embryonic fibroblasts expressing the human OPA1 isoform 1 bearing the R445H and D603H mutations. Some of these molecules were able to ameliorate the energetic functions and/or the mitochondrial network morphology, depending on the type of OPA1 mutation. The final validation has been performed in patients’ fibroblasts, allowing to select the most effective molecules. Our current results are instrumental to rapidly translating the findings of this drug repurposing approach into clinical trial for DOA and other neurodegenerations caused by OPA1 mutations.
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Affiliation(s)
- Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Anna Ghelli
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
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12
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Chin HL, Goh DLM, Wang FS, Tay SKH, Heng CK, Donnini C, Baruffini E, Pines O. A combination of two novel VARS2 variants causes a mitochondrial disorder associated with failure to thrive and pulmonary hypertension. J Mol Med (Berl) 2019; 97:1557-1566. [PMID: 31529142 DOI: 10.1007/s00109-019-01834-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 07/29/2019] [Accepted: 08/13/2019] [Indexed: 01/30/2023]
Abstract
The VARS2 gene encodes a mitochondrial valyl-transfer RNA synthetase which is used in mitochondrial translation. To date, several patients with VARS2 pathogenic variants have been described in the literature. These patients have features of lactic acidosis with encephalomyopathy. We present a case of an infant with lactic acidosis, failure to thrive, and severe primary pulmonary hypertension who was found to be a compound heterozygote for two novel VARS2 variants (c.1940C>T, p.(Thr647Met) and c.2318G>A, p.(Arg773Gln)). The patient was treated with vitamin supplements and a carbohydrate-restricted diet. The lactic acidosis and failure to thrive resolved, and he showed good growth and development. Functional studies and molecular analysis employed a yeast model system and the VAS1 gene (yeast homolog of VARS2). VAS1 genes harboring either one of two mutations corresponding to the two novel variants in the VARS2 gene, exhibited partially reduced function in haploid yeast strains. A combination of both VAS1 variant alleles in a diploid yeast cell exhibited a more significant decrease in oxidative metabolism-dependent growth and in the oxygen consumption rate (reminiscent of the patient who carries two mutant VARS2 alleles). Our results demonstrate the pathogenicity of the biallellic novel VARS2 variants. KEY MESSAGES: • A case of an infant who is a compound heterozygote for two novel VARS2 variants. • This infant displayed lactic acidosis, failure to thrive, and pulmonary hypertension. • Treatment of the patient with a carbohydrate-restricted diet resulted in good growth and development. • Studies with the homologous yeast VAS1 gene showed reduced function of corresponding single mutant in haploid yeast strains. • A combination of both VAS1 variant alleles in diploid yeast exhibited a more significant decrease in function, thereby confirming the pathogenicity of the biallellic novel VARS2 variants.
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Affiliation(s)
- Hui-Lin Chin
- Khoo Teck Puat-National University Children's Medical Institute, National University Health Systems (NUHS), Singapore, Singapore. .,Department of Pediatrics, Yong Loo Lin School of Medicine, National University Hospital, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore.
| | - Denise Li-Meng Goh
- Khoo Teck Puat-National University Children's Medical Institute, National University Health Systems (NUHS), Singapore, Singapore.,Department of Pediatrics, Yong Loo Lin School of Medicine, National University Hospital, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Furene Sijia Wang
- Khoo Teck Puat-National University Children's Medical Institute, National University Health Systems (NUHS), Singapore, Singapore.,Department of Pediatrics, Yong Loo Lin School of Medicine, National University Hospital, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Stacey Kiat Hong Tay
- Khoo Teck Puat-National University Children's Medical Institute, National University Health Systems (NUHS), Singapore, Singapore.,Department of Pediatrics, Yong Loo Lin School of Medicine, National University Hospital, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Chew Kiat Heng
- Khoo Teck Puat-National University Children's Medical Institute, National University Health Systems (NUHS), Singapore, Singapore.,Department of Pediatrics, Yong Loo Lin School of Medicine, National University Hospital, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124, Parma, Italy.
| | - Ophry Pines
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,NUS-HUJ-CREATE Program and the Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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13
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Amino and carboxy-terminal extensions of yeast mitochondrial DNA polymerase assemble both the polymerization and exonuclease active sites. Mitochondrion 2019; 49:166-177. [PMID: 31445096 DOI: 10.1016/j.mito.2019.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/11/2019] [Accepted: 08/19/2019] [Indexed: 11/24/2022]
Abstract
Human and yeast mitochondrial DNA polymerases (DNAPs), POLG and Mip1, are related by evolution to bacteriophage DNAPs. However, mitochondrial DNAPs contain unique amino and carboxyl-terminal extensions that physically interact. Here we describe that N-terminal deletions in Mip1 polymerases abolish polymerization and decrease exonucleolytic degradation, whereas moderate C-terminal deletions reduce polymerization. Similarly, to the N-terminal deletions, an extended C-terminal deletion of 298 amino acids is deficient in nucleotide addition and exonucleolytic degradation of double and single-stranded DNA. The latter observation suggests that the physical interaction between the amino and carboxyl-terminal regions of Mip1 may be related to the spread of pathogenic POLG mutant along its primary sequence.
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14
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Dallabona C, Pioli M, Spadola G, Orsoni N, Bisceglie F, Lodi T, Pelosi G, Restivo FM, Degola F. Sabotage at the Powerhouse? Unraveling the Molecular Target of 2-Isopropylbenzaldehyde Thiosemicarbazone, a Specific Inhibitor of Aflatoxin Biosynthesis and Sclerotia Development in Aspergillus flavus, Using Yeast as a Model System. Molecules 2019; 24:molecules24162971. [PMID: 31426298 PMCID: PMC6719062 DOI: 10.3390/molecules24162971] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/11/2019] [Accepted: 08/14/2019] [Indexed: 11/16/2022] Open
Abstract
Amongst the various approaches to contain aflatoxin contamination of feed and food commodities, the use of inhibitors of fungal growth and/or toxin biosynthesis is showing great promise for the implementation or the replacement of conventional pesticide-based strategies. Several inhibition mechanisms were found taking place at different levels in the biology of the aflatoxin-producing fungal species such as Aspergillus flavus: compounds that influence aflatoxin production may block the biosynthetic pathway through the direct control of genes belonging to the aflatoxin gene cluster, or interfere with one or more of the several steps involved in the aflatoxin metabolism upstream. Recent findings pointed to mitochondrial functionality as one of the potential targets of some aflatoxin inhibitors. Additionally, we have recently reported that the effect of a compound belonging to the class of thiosemicarbazones might be related to the energy generation/carbon flow and redox homeostasis control by the fungal cell. Here, we report our investigation about a putative molecular target of the 3-isopropylbenzaldehyde thiosemicarbazone (mHtcum), using the yeast Saccharomyces cerevisiae as model system, to demonstrate how the compound can actually interfere with the mitochondrial respiratory chain.
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Affiliation(s)
- Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Marianna Pioli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Giorgio Spadola
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Nicolò Orsoni
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Franco Bisceglie
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Giorgio Pelosi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Francesco Maria Restivo
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy
| | - Francesca Degola
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43123 Parma, Italy.
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15
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Maffezzini C, Laine I, Dallabona C, Clemente P, Calvo-Garrido J, Wibom R, Naess K, Barbaro M, Falk A, Donnini C, Freyer C, Wredenberg A, Wedell A. Mutations in the mitochondrial tryptophanyl-tRNA synthetase cause growth retardation and progressive leukoencephalopathy. Mol Genet Genomic Med 2019; 7:e654. [PMID: 30920170 PMCID: PMC6565557 DOI: 10.1002/mgg3.654] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/23/2019] [Accepted: 03/04/2019] [Indexed: 01/02/2023] Open
Abstract
Background Mutations in mitochondrial aminoacyl tRNA synthetases form a subgroup of mitochondrial disorders often only perturbing brain function by affecting mitochondrial translation. Here we report two siblings with mitochondrial disease, due to compound heterozygous mutations in the mitochondrial tryptophanyl‐tRNA synthetase (WARS2) gene, presenting with severe neurological symptoms but normal mitochondrial function in skeletal muscle biopsies and cultured skin fibroblasts. Methods Whole exome sequencing on genomic DNA samples from both subjects and their parents identified two compound heterozygous variants c.833T>G (p.Val278Gly) and c.938A>T (p.Lys313Met) in the WARS2 gene as potential disease‐causing variants. We generated patient‐derived neuroepithelial stem cells and modeled the disease in yeast and Drosophila melanogaster to confirm pathogenicity. Results Biochemical analysis of patient‐derived neuroepithelial stem cells revealed a mild combined complex I and IV defect, while modeling the disease in yeast demonstrated that the reported aminoacylation defect severely affects respiration and viability. Furthermore, silencing of wild type WARS2 in Drosophila melanogaster showed that a partial defect in aminoacylation is enough to cause lethality. Conclusions Our results establish the identified WARS2 variants as disease‐causing and highlight the benefit of including human neuronal models, when investigating mutations specifically affecting the nervous system.
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Affiliation(s)
- Camilla Maffezzini
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Isabelle Laine
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Paula Clemente
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Javier Calvo-Garrido
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Rolf Wibom
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Karin Naess
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Michela Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Christoph Freyer
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Wredenberg
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Wedell
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
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16
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Verrigni D, Di Nottia M, Ardissone A, Baruffini E, Nasca A, Legati A, Bellacchio E, Fagiolari G, Martinelli D, Fusco L, Battaglia D, Trani G, Versienti G, Marchet S, Torraco A, Rizza T, Verardo M, D'Amico A, Diodato D, Moroni I, Lamperti C, Petrini S, Moggio M, Goffrini P, Ghezzi D, Carrozzo R, Bertini E. Clinical-genetic features and peculiar muscle histopathology in infantile DNM1L-related mitochondrial epileptic encephalopathy. Hum Mutat 2019; 40:601-618. [PMID: 30801875 DOI: 10.1002/humu.23729] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/31/2019] [Accepted: 02/05/2019] [Indexed: 11/09/2022]
Abstract
Mitochondria are highly dynamic organelles, undergoing continuous fission and fusion. The DNM1L (dynamin-1 like) gene encodes for the DRP1 protein, an evolutionary conserved member of the dynamin family, responsible for fission of mitochondria, and having a role in the division of peroxisomes, as well. DRP1 impairment is implicated in several neurological disorders and associated with either de novo dominant or compound heterozygous mutations. In five patients presenting with severe epileptic encephalopathy, we identified five de novo dominant DNM1L variants, the pathogenicity of which was validated in a yeast model. Fluorescence microscopy revealed abnormally elongated mitochondria and aberrant peroxisomes in mutant fibroblasts, indicating impaired fission of these organelles. Moreover, a very peculiar finding in our cohort of patients was the presence, in muscle biopsy, of core like areas with oxidative enzyme alterations, suggesting an abnormal distribution of mitochondria in the muscle tissue.
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Affiliation(s)
- Daniela Verrigni
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Michela Di Nottia
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Anna Ardissone
- Department of Clinical Neurosciences, Child Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Molecular and Translational Medicine DIMET, University of Milan-Bicocca, Milan, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Alessia Nasca
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Legati
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Emanuele Bellacchio
- Genetics and Rare Diseases, Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Gigliola Fagiolari
- Dino Ferrari Centre, Unit of Neuromuscular and Rare Disorders, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università of Milano, Milan, Italy
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Lucia Fusco
- Neurophysiology Unit, Department of Neuroscience, Bambino Gesu' Children's Hospital, Rome, Italy
| | - Domenica Battaglia
- Department of Child Neurology and Psychiatry, Catholic University, Rome, Italy
| | - Giulia Trani
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Gianmarco Versienti
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvia Marchet
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessandra Torraco
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Teresa Rizza
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Margherita Verardo
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Adele D'Amico
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Daria Diodato
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Isabella Moroni
- Department of Clinical Neurosciences, Child Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Costanza Lamperti
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stefania Petrini
- Scientific Direction, Research Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maurizio Moggio
- Dino Ferrari Centre, Unit of Neuromuscular and Rare Disorders, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università of Milano, Milan, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Daniele Ghezzi
- Department of Molecular Neurogenetics, Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Rosalba Carrozzo
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Enrico Bertini
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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17
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Friederich MW, Timal S, Powell CA, Dallabona C, Kurolap A, Palacios-Zambrano S, Bratkovic D, Derks TGJ, Bick D, Bouman K, Chatfield KC, Damouny-Naoum N, Dishop MK, Falik-Zaccai TC, Fares F, Fedida A, Ferrero I, Gallagher RC, Garesse R, Gilberti M, González C, Gowan K, Habib C, Halligan RK, Kalfon L, Knight K, Lefeber D, Mamblona L, Mandel H, Mory A, Ottoson J, Paperna T, Pruijn GJM, Rebelo-Guiomar PF, Saada A, Sainz B, Salvemini H, Schoots MH, Smeitink JA, Szukszto MJ, Ter Horst HJ, van den Brandt F, van Spronsen FJ, Veltman JA, Wartchow E, Wintjes LT, Zohar Y, Fernández-Moreno MA, Baris HN, Donnini C, Minczuk M, Rodenburg RJ, Van Hove JLK. Pathogenic variants in glutamyl-tRNA Gln amidotransferase subunits cause a lethal mitochondrial cardiomyopathy disorder. Nat Commun 2018; 9:4065. [PMID: 30283131 PMCID: PMC6170436 DOI: 10.1038/s41467-018-06250-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/23/2018] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial protein synthesis requires charging a mitochondrial tRNA with its amino acid. Here, the authors describe pathogenic variants in the GatCAB protein complex genes required for the generation of glutaminyl-mt-tRNAGln, that impairs mitochondrial translation and presents with cardiomyopathy. Mitochondrial protein synthesis requires charging mt-tRNAs with their cognate amino acids by mitochondrial aminoacyl-tRNA synthetases, with the exception of glutaminyl mt-tRNA (mt-tRNAGln). mt-tRNAGln is indirectly charged by a transamidation reaction involving the GatCAB aminoacyl-tRNA amidotransferase complex. Defects involving the mitochondrial protein synthesis machinery cause a broad spectrum of disorders, with often fatal outcome. Here, we describe nine patients from five families with genetic defects in a GatCAB complex subunit, including QRSL1, GATB, and GATC, each showing a lethal metabolic cardiomyopathy syndrome. Functional studies reveal combined respiratory chain enzyme deficiencies and mitochondrial dysfunction. Aminoacylation of mt-tRNAGln and mitochondrial protein translation are deficient in patients’ fibroblasts cultured in the absence of glutamine but restore in high glutamine. Lentiviral rescue experiments and modeling in S. cerevisiae homologs confirm pathogenicity. Our study completes a decade of investigations on mitochondrial aminoacylation disorders, starting with DARS2 and ending with the GatCAB complex.
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Affiliation(s)
- Marisa W Friederich
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Sharita Timal
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Christopher A Powell
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Alina Kurolap
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Sara Palacios-Zambrano
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Drago Bratkovic
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Terry G J Derks
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - David Bick
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Katelijne Bouman
- Department of Genetics, University Medical Center of Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Kathryn C Chatfield
- Department of Pediatrics, Section of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado, Aurora, CO, 80045, USA
| | - Nadine Damouny-Naoum
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Megan K Dishop
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Tzipora C Falik-Zaccai
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Fuad Fares
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Ayalla Fedida
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Ileana Ferrero
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Renata C Gallagher
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Rafael Garesse
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Micol Gilberti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Cristina González
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Katherine Gowan
- Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO, 80045, USA
| | - Clair Habib
- Department of Pediatrics, Bnai Zion Medical Center, Haifa, 3339419, Israel
| | - Rebecca K Halligan
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Limor Kalfon
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel
| | - Kaz Knight
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Dirk Lefeber
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Laura Mamblona
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hanna Mandel
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel.,Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,Metabolic Unit, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - John Ottoson
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Tamar Paperna
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Ger J M Pruijn
- Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University, Nijmegen, 6500 HB, The Netherlands
| | - Pedro F Rebelo-Guiomar
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom.,Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, Porto, 4200-135, Portugal
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and the Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Bruno Sainz
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Enfermedades Crónicas y Cáncer Area, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, 28034, Spain
| | - Hayley Salvemini
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Mirthe H Schoots
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands
| | - Jan A Smeitink
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Maciej J Szukszto
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Hendrik J Ter Horst
- Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Frans van den Brandt
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Institute of Genetic Medicine, Newcastle University, Newcastle, NE1 3BZ, United Kingdom
| | - Eric Wartchow
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Liesbeth T Wintjes
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Yaniv Zohar
- Institute of Pathology, Rambam Health Care Campus, 3109601, Haifa, Israel
| | - Miguel A Fernández-Moreno
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hagit N Baris
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Michal Minczuk
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Johan L K Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA.
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18
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Gilberti M, Baruffini E, Donnini C, Dallabona C. Pathological alleles of MPV17 modeled in the yeast Saccharomyces cerevisiae orthologous gene SYM1 reveal their inability to take part in a high molecular weight complex. PLoS One 2018; 13:e0205014. [PMID: 30273399 PMCID: PMC6166979 DOI: 10.1371/journal.pone.0205014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/18/2018] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial DNA depletion syndromes (MDDS) are a genetically and clinically heterogeneous group of human diseases caused by mutations in nuclear genes and characterized by a severe reduction in mitochondrial DNA (mtDNA) copy number leading to impaired energy production in affected tissues and organs. Mutations in the MPV17 gene, whose role is still elusive, were described as cause of the hepatocerebral form of MDDS and Navajo neuro-hepathopathy. The high degree of conservation observed between MPV17 and its yeast homolog SYM1 made the latter a good model for the study of the pathology. Here, we used Saccharomyces cerevisiae to elucidate the molecular consequences of seven MPV17 missense mutations identified in patients and localized in different protein domains. The phenotypic analysis of the appropriate sym1 mutant strains created demonstrated deleterious effect for all mutations regarding OXPHOS metabolism and mtDNA stability. We deepened the pathogenic effect of the mutations by investigating whether they prevented the correct protein localization into the mitochondria or affected the stability of the proteins. All the Sym1 mutant proteins correctly localized into the mitochondria and only one mutation predominantly affects protein stability. All the other mutations compromised the formation of the high molecular weight complex of unknown composition, previously identified both in yeast, cell cultures and mouse tissues, as demonstrated by the consistent fraction of the Sym1 mutant proteins found free or in not fully assembled complex, strengthening its role as protein forming part of a high molecular weight complex.
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Affiliation(s)
- Micol Gilberti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
- * E-mail:
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
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19
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Molon M, Panek A, Molestak E, Skoneczny M, Tchorzewski M, Wnuk M. Daughters of the budding yeast from old mothers have shorter replicative lifespans but not total lifespans. Are DNA damage and rDNA instability the factors that determine longevity? Cell Cycle 2018; 17:1173-1187. [PMID: 29895191 DOI: 10.1080/15384101.2018.1464846] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although a lot of effort has been put into the search for factors responsible for aging in yeast mother cells, our knowledge of cellular changes in daughter cells originating from old mothers is still very limited. It has been shown that an old mother is not able to compensate for all negative changes within its cell and therefore transfers them to the bud. In this paper, we show for the first time that daughter cells of an old mother have a reset lifespan expressed in units of time despite drastic reduction of their budding lifespan, which suggests that a single yeast cell has a fixed programmed longevity regardless of the time point at which it was originated. Moreover, in our study we found that longevity parameters are not correlated with the rDNA level, DNA damage, chromosome structure or aging parameters (budding lifespan and total lifespan).
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Affiliation(s)
- Mateusz Molon
- a Department of Biochemistry and Cell Biology , University of Rzeszow , Rzeszow , Poland
| | - Anita Panek
- b Department of Genetics , University of Rzeszow , Rzeszow , Poland
| | - Eliza Molestak
- c Department of Molecular Biology , Maria Curie-Sklodowska University , Lublin , Poland
| | - Marek Skoneczny
- d Department of Genetics , Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Warsaw , Poland
| | - Marek Tchorzewski
- c Department of Molecular Biology , Maria Curie-Sklodowska University , Lublin , Poland
| | - Maciej Wnuk
- b Department of Genetics , University of Rzeszow , Rzeszow , Poland
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20
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Weidberg H, Amon A. MitoCPR-A surveillance pathway that protects mitochondria in response to protein import stress. Science 2018; 360:360/6385/eaan4146. [PMID: 29650645 DOI: 10.1126/science.aan4146] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 12/19/2017] [Accepted: 02/19/2018] [Indexed: 12/13/2022]
Abstract
Mitochondrial functions are essential for cell viability and rely on protein import into the organelle. Various disease and stress conditions can lead to mitochondrial import defects. We found that inhibition of mitochondrial import in budding yeast activated a surveillance mechanism, mitoCPR, that improved mitochondrial import and protected mitochondria during import stress. mitoCPR induced expression of Cis1, which associated with the mitochondrial translocase to reduce the accumulation of mitochondrial precursor proteins at the mitochondrial translocase. Clearance of precursor proteins depended on the Cis1-interacting AAA+ adenosine triphosphatase Msp1 and the proteasome, suggesting that Cis1 facilitates degradation of unimported proteins. mitoCPR was required for maintaining mitochondrial functions when protein import was compromised, demonstrating the importance of mitoCPR in protecting the mitochondrial compartment.
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Affiliation(s)
- Hilla Weidberg
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Angelika Amon
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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21
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Ribonucleotides incorporated by the yeast mitochondrial DNA polymerase are not repaired. Proc Natl Acad Sci U S A 2017; 114:12466-12471. [PMID: 29109257 DOI: 10.1073/pnas.1713085114] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Incorporation of ribonucleotides into DNA during genome replication is a significant source of genomic instability. The frequency of ribonucleotides in DNA is determined by deoxyribonucleoside triphosphate/ribonucleoside triphosphate (dNTP/rNTP) ratios, by the ability of DNA polymerases to discriminate against ribonucleotides, and by the capacity of repair mechanisms to remove incorporated ribonucleotides. To simultaneously compare how the nuclear and mitochondrial genomes incorporate and remove ribonucleotides, we challenged these processes by changing the balance of cellular dNTPs. Using a collection of yeast strains with altered dNTP pools, we discovered an inverse relationship between the concentration of individual dNTPs and the amount of the corresponding ribonucleotides incorporated in mitochondrial DNA, while in nuclear DNA the ribonucleotide pattern was only altered in the absence of ribonucleotide excision repair. Our analysis uncovers major differences in ribonucleotide repair between the two genomes and provides concrete evidence that yeast mitochondria lack mechanisms for removal of ribonucleotides incorporated by the mtDNA polymerase. Furthermore, as cytosolic dNTP pool imbalances were transmitted equally well into the nucleus and the mitochondria, our results support a view of the cytosolic and mitochondrial dNTP pools in frequent exchange.
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22
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Dallabona C, Baruffini E, Goffrini P, Lodi T. Dominance of yeast aac2 R96H and aac2 R252G mutations, equivalent to pathological mutations in ant1, is due to gain of function. Biochem Biophys Res Commun 2017; 493:909-913. [PMID: 28947214 DOI: 10.1016/j.bbrc.2017.09.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 09/21/2017] [Indexed: 01/20/2023]
Abstract
The mitochondrial ADP/ATP carrier is a nuclear encoded protein, which catalyzes the exchange of ATP generated in mitochondria with ADP produced in the cytosol. In humans, mutations in the major ADP/ATP carrier gene, ANT1, are involved in several degenerative mitochondrial pathologies, leading to instability of mitochondrial DNA. Recessive mutations have been associated with mitochondrial myopathy and cardiomyopathy whereas dominant mutations have been associated with autosomal dominant Progressive External Ophtalmoplegia (adPEO). Recently, two de novo dominant mutations, R80H and R235G, leading to extremely severe symptoms, have been identified. In order to evaluate if the dominance is due to haploinsufficiency or to a gain of function, the two mutations have been introduced in the equivalent positions of the AAC2 gene, the yeast orthologue of human ANT1, and their dominant effect has been studied in heteroallelic strains, containing both one copy of wild type AAC2 and one copy of mutant aac2 allele. Through phenotypic characterization of these yeast models we showed that the OXPHOS phenotypes in the heteroallelic strains were more affected than in the hemiallelic strain indicating that the dominant trait of the two mutations is due to gain of function.
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Affiliation(s)
- Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
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23
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Structural modification of cuminaldehyde thiosemicarbazone increases inhibition specificity toward aflatoxin biosynthesis and sclerotia development in Aspergillus flavus. Appl Microbiol Biotechnol 2017; 101:6683-6696. [PMID: 28725928 DOI: 10.1007/s00253-017-8426-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/29/2017] [Accepted: 07/02/2017] [Indexed: 01/18/2023]
Abstract
Aspergillus flavus is an opportunistic mold that represents a serious threat for human and animal health due to its ability to synthesize and release, on food and feed commodities, different toxic secondary metabolites. Among them, aflatoxin B1 is one of the most dangerous since it is provided with a strong cancerogenic and mutagenic activity. Controlling fungal contamination on the different crops that may host A. flavus is considered a priority by sanitary authorities of an increasing number of countries due also to the fact that, owing to global temperature increase, the geographic areas that are expected to be prone to experience sudden A. flavus outbreaks are widening. Among the different pre- and post-harvest strategies that may be put forward in order to prevent fungal and/or mycotoxin contamination, fungicides are still considered a prominent weapon. We have here analyzed different structural modifications of a natural-derived compound (cuminaldehyde thiosemicarbazone) for their fungistatic and anti-aflatoxigenic activity. In particular, we have focused our attention on one of the compound that presented a prominent anti-aflatoxin specificity, and performed a set of physiological and molecular analyses, taking also advantage of yeast (Saccharomyces cerevisiae) cell as an experimental model.
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24
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Activation of Dun1 in response to nuclear DNA instability accounts for the increase in mitochondrial point mutations in Rad27/FEN1 deficient S. cerevisiae. PLoS One 2017; 12:e0180153. [PMID: 28678842 PMCID: PMC5497989 DOI: 10.1371/journal.pone.0180153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/09/2017] [Indexed: 11/25/2022] Open
Abstract
Rad27/FEN1 nuclease that plays important roles in the maintenance of DNA stability in the nucleus has recently been shown to reside in mitochondria. Accordingly, it has been established that Rad27 deficiency causes increased mutagenesis, but decreased microsatellite instability and homologous recombination in mitochondria. Our current analysis of mutations leading to erythromycin resistance indicates that only some of them arise in mitochondrial DNA and that the GC→AT transition is a hallmark of the mitochondrial mutagenesis in rad27 null background. We also show that the mitochondrial mutator phenotype resulting from Rad27 deficiency entirely depends on the DNA damage checkpoint kinase Dun1. DUN1 inactivation suppresses the mitochondrial mutator phenotype caused by Rad27 deficiency and this suppression is eliminated at least in part by subsequent deletion of SML1 encoding a repressor of ribonucleotide reductase. We conclude that Rad27 deficiency causes a mitochondrial mutator phenotype via activation of DNA damage checkpoint kinase Dun1 and that a Dun1-mediated increase of dNTP pools contributes to this phenomenon. These results point to the nuclear DNA instability as the source of mitochondrial mutagenesis. Consistently, we show that mitochondrial mutations occurring more frequently in yeast devoid of Rrm3, a DNA helicase involved in rDNA replication, are also dependent on Dun1. In addition, we have established that overproduction of Exo1, which suppresses DNA damage sensitivity and replication stress in nuclei of Rad27 deficient cells, but does not enter mitochondria, suppresses the mitochondrial mutagenesis. Exo1 overproduction restores also a great part of allelic recombination and microsatellite instability in mitochondria of Rad27 deficient cells. In contrast, the overproduction of Exo1 does not influence mitochondrial direct-repeat mediated deletions in rad27 null background, pointing to this homologous recombination pathway as the direct target of Rad27 activity in mitochondria.
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25
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Thompson K, Majd H, Dallabona C, Reinson K, King MS, Alston CL, He L, Lodi T, Jones SA, Fattal-Valevski A, Fraenkel ND, Saada A, Haham A, Isohanni P, Vara R, Barbosa IA, Simpson MA, Deshpande C, Puusepp S, Bonnen PE, Rodenburg RJ, Suomalainen A, Õunap K, Elpeleg O, Ferrero I, McFarland R, Kunji ERS, Taylor RW. Recurrent De Novo Dominant Mutations in SLC25A4 Cause Severe Early-Onset Mitochondrial Disease and Loss of Mitochondrial DNA Copy Number. Am J Hum Genet 2016; 99:860-876. [PMID: 27693233 PMCID: PMC5065686 DOI: 10.1016/j.ajhg.2016.08.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/18/2016] [Indexed: 11/26/2022] Open
Abstract
Mutations in SLC25A4 encoding the mitochondrial ADP/ATP carrier AAC1 are well-recognized causes of mitochondrial disease. Several heterozygous SLC25A4 mutations cause adult-onset autosomal-dominant progressive external ophthalmoplegia associated with multiple mitochondrial DNA deletions, whereas recessive SLC25A4 mutations cause childhood-onset mitochondrial myopathy and cardiomyopathy. Here, we describe the identification by whole-exome sequencing of seven probands harboring dominant, de novo SLC25A4 mutations. All affected individuals presented at birth, were ventilator dependent and, where tested, revealed severe combined mitochondrial respiratory chain deficiencies associated with a marked loss of mitochondrial DNA copy number in skeletal muscle. Strikingly, an identical c.239G>A (p.Arg80His) mutation was present in four of the seven subjects, and the other three case subjects harbored the same c.703C>G (p.Arg235Gly) mutation. Analysis of skeletal muscle revealed a marked decrease of AAC1 protein levels and loss of respiratory chain complexes containing mitochondrial DNA-encoded subunits. We show that both recombinant AAC1 mutant proteins are severely impaired in ADP/ATP transport, affecting most likely the substrate binding and mechanics of the carrier, respectively. This highly reduced capacity for transport probably affects mitochondrial DNA maintenance and in turn respiration, causing a severe energy crisis. The confirmation of the pathogenicity of these de novo SLC25A4 mutations highlights a third distinct clinical phenotype associated with mutation of this gene and demonstrates that early-onset mitochondrial disease can be caused by recurrent de novo mutations, which has significant implications for the application and analysis of whole-exome sequencing data in mitochondrial disease.
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Affiliation(s)
- Kyle Thompson
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Homa Majd
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Cristina Dallabona
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Karit Reinson
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Martin S King
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Langping He
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Simon A Jones
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, St Marys Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Aviva Fattal-Valevski
- Paediatric Neurology Unit, "Dana" Children Hospital, Tel Aviv Sourasky Medical Centre, Sackler Faculty of Medicine, Tel Aviv University, 64239 Tel Aviv, Israel
| | - Nitay D Fraenkel
- Department of Respiratory Rehabilitation, Alyn Hospital, Jerusalem 91090, Israel
| | - Ann Saada
- Metabolic Laboratory Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Alon Haham
- Neonatal Intensive Care Unit, "Lis" Maternity Hospital, Tel Aviv Sourasky Medical Centre, 64239 Tel Aviv, Israel
| | - Pirjo Isohanni
- Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, University of Helsinki, 00290 Helsinki, Finland; Department of Pediatric Neurology, Children's Hospital, Helsinki University Hospital and University of Helsinki, 00290 Helsinki, Finland
| | - Roshni Vara
- Department of Paediatric Inherited Metabolic Diseases, Evelina Children's Hospital, London SE1 7EH, UK
| | - Inês A Barbosa
- Division of Genetics and Molecular Medicine, King's College London School of Medicine, London SE1 9RY, UK
| | - Michael A Simpson
- Division of Genetics and Molecular Medicine, King's College London School of Medicine, London SE1 9RY, UK
| | - Charu Deshpande
- Clinical Genetics Unit, Guys and St Thomas' NHS Foundation Trust, London SE1 9RT, UK
| | - Sanna Puusepp
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Penelope E Bonnen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Department of Paediatrics, Translational Metabolic Laboratory, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Anu Suomalainen
- Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, University of Helsinki, 00290 Helsinki, Finland; Department of Neurosciences, Helsinki University Hospital and University of Helsinki, 00290 Helsinki, Finland
| | - Katrin Õunap
- Department of Pediatrics, Institute of Clinical Medicine, University of Tartu, 51014 Tartu, Estonia; Department of Genetics, United Laboratories, Tartu University Hospital, 51014 Tartu, Estonia
| | - Orly Elpeleg
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Ileana Ferrero
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Edmund R S Kunji
- The Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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26
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Dallabona C, Abbink TEM, Carrozzo R, Torraco A, Legati A, van Berkel CGM, Niceta M, Langella T, Verrigni D, Rizza T, Diodato D, Piemonte F, Lamantea E, Fang M, Zhang J, Martinelli D, Bevivino E, Dionisi-Vici C, Vanderver A, Philip SG, Kurian MA, Verma IC, Bijarnia-Mahay S, Jacinto S, Furtado F, Accorsi P, Ardissone A, Moroni I, Ferrero I, Tartaglia M, Goffrini P, Ghezzi D, van der Knaap MS, Bertini E. LYRM7mutations cause a multifocal cavitating leukoencephalopathy with distinct MRI appearance. Brain 2016; 139:782-94. [DOI: 10.1093/brain/awv392] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022] Open
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27
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Nolli C, Goffrini P, Lazzaretti M, Zanna C, Vitale R, Lodi T, Baruffini E. Validation of a MGM1/OPA1 chimeric gene for functional analysis in yeast of mutations associated with dominant optic atrophy. Mitochondrion 2015; 25:38-48. [PMID: 26455272 DOI: 10.1016/j.mito.2015.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/24/2015] [Accepted: 10/01/2015] [Indexed: 01/08/2023]
Abstract
Mutations in OPA1 are associated with DOA or DOA plus. Novel mutations in OPA1 are periodically identified, but often the causative effect of the mutation is not demonstrated. A chimeric protein containing the N-terminal region of Mgm1, the yeast orthologue of OPA1, and the C-terminal region of OPA1 was constructed. This chimeric construct can be exploited to evaluate the pathogenicity of most of the missense mutations in OPA1 as well as to determine whether the dominance of the mutation is due to haploinsufficiency or to gain of function.
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Affiliation(s)
- Cecilia Nolli
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Mirca Lazzaretti
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Via Altura 3, 40139 Bologna, Italy
| | - Rita Vitale
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy.
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28
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Tigano M, Ruotolo R, Dallabona C, Fontanesi F, Barrientos A, Donnini C, Ottonello S. Elongator-dependent modification of cytoplasmic tRNALysUUU is required for mitochondrial function under stress conditions. Nucleic Acids Res 2015; 43:8368-80. [PMID: 26240381 PMCID: PMC4787798 DOI: 10.1093/nar/gkv765] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 07/15/2015] [Indexed: 11/12/2022] Open
Abstract
To gain a wider view of the pathways that regulate mitochondrial function, we combined the effect of heat stress on respiratory capacity with the discovery potential of a genome-wide screen in Saccharomyces cerevisiae. We identified 105 new genes whose deletion impairs respiratory growth at 37°C by interfering with processes such as transcriptional regulation, ubiquitination and cytosolic tRNA wobble uridine modification via 5-methoxycarbonylmethyl-2-thiouridine formation. The latter process, specifically required for efficient decoding of AA-ending codons under stress conditions, was covered by multiple genes belonging to the Elongator (e.g. ELP3) and urmylation (e.g., NCS6) pathways. ELP3 or NCS6 deletants had impaired mitochondrial protein synthesis. Their respiratory deficiency was selectively rescued by overexpression of tRNA(Lys) UUU as well by overexpression of genes (BCK1 and HFM1) with a strong bias for the AAA codon read by this tRNA. These data extend the mitochondrial regulome, demonstrate that heat stress can impair respiration by disturbing cytoplasmic translation of proteins critically involved in mitochondrial function and document, for the first time, the involvement in such process of the Elongator and urmylation pathways. Given the conservation of these pathways, the present findings may pave the way to a better understanding of the human mitochondrial regulome in health and disease.
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Affiliation(s)
- Marco Tigano
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Roberta Ruotolo
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | | | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Antoni Barrientos
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Claudia Donnini
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Simone Ottonello
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
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Skoneczna A, Kaniak A, Skoneczny M. Genetic instability in budding and fission yeast-sources and mechanisms. FEMS Microbiol Rev 2015; 39:917-67. [PMID: 26109598 PMCID: PMC4608483 DOI: 10.1093/femsre/fuv028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2015] [Indexed: 12/17/2022] Open
Abstract
Cells are constantly confronted with endogenous and exogenous factors that affect their genomes. Eons of evolution have allowed the cellular mechanisms responsible for preserving the genome to adjust for achieving contradictory objectives: to maintain the genome unchanged and to acquire mutations that allow adaptation to environmental changes. One evolutionary mechanism that has been refined for survival is genetic variation. In this review, we describe the mechanisms responsible for two biological processes: genome maintenance and mutation tolerance involved in generations of genetic variations in mitotic cells of both Saccharomyces cerevisiae and Schizosaccharomyces pombe. These processes encompass mechanisms that ensure the fidelity of replication, DNA lesion sensing and DNA damage response pathways, as well as mechanisms that ensure precision in chromosome segregation during cell division. We discuss various factors that may influence genome stability, such as cellular ploidy, the phase of the cell cycle, transcriptional activity of a particular region of DNA, the proficiency of DNA quality control systems, the metabolic stage of the cell and its respiratory potential, and finally potential exposure to endogenous or environmental stress. The stability of budding and fission yeast genomes is influenced by two contradictory factors: (1) the need to be fully functional, which is ensured through the replication fidelity pathways of nuclear and mitochondrial genomes through sensing and repairing DNA damage, through precise chromosome segregation during cell division; and (2) the need to acquire changes for adaptation to environmental challenges.
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Affiliation(s)
- Adrianna Skoneczna
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| | - Aneta Kaniak
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
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Biallelic Mutations of Methionyl-tRNA Synthetase Cause a Specific Type of Pulmonary Alveolar Proteinosis Prevalent on Réunion Island. Am J Hum Genet 2015; 96:826-31. [PMID: 25913036 DOI: 10.1016/j.ajhg.2015.03.010] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 03/19/2015] [Indexed: 12/25/2022] Open
Abstract
Methionyl-tRNA synthetase (MARS) catalyzes the ligation of methionine to tRNA and is critical for protein biosynthesis. We identified biallelic missense mutations in MARS in a specific form of pediatric pulmonary alveolar proteinosis (PAP), a severe lung disorder that is prevalent on the island of Réunion and the molecular basis of which is unresolved. Mutations were found in 26 individuals from Réunion and nearby islands and in two families from other countries. Functional consequences of the mutated alleles were assessed by growth of wild-type and mutant strains and methionine-incorporation assays in yeast. Enzyme activity was attenuated in a liquid medium without methionine but could be restored by methionine supplementation. In summary, identification of a founder mutation in MARS led to the molecular definition of a specific type of PAP and will enable carrier screening in the affected community and possibly open new treatment opportunities.
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31
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Kaniak-Golik A, Skoneczna A. Mitochondria-nucleus network for genome stability. Free Radic Biol Med 2015; 82:73-104. [PMID: 25640729 DOI: 10.1016/j.freeradbiomed.2015.01.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 11/25/2014] [Accepted: 01/13/2015] [Indexed: 12/21/2022]
Abstract
The proper functioning of the cell depends on preserving the cellular genome. In yeast cells, a limited number of genes are located on mitochondrial DNA. Although the mechanisms underlying nuclear genome maintenance are well understood, much less is known about the mechanisms that ensure mitochondrial genome stability. Mitochondria influence the stability of the nuclear genome and vice versa. Little is known about the two-way communication and mutual influence of the nuclear and mitochondrial genomes. Although the mitochondrial genome replicates independent of the nuclear genome and is organized by a distinct set of mitochondrial nucleoid proteins, nearly all genome stability mechanisms responsible for maintaining the nuclear genome, such as mismatch repair, base excision repair, and double-strand break repair via homologous recombination or the nonhomologous end-joining pathway, also act to protect mitochondrial DNA. In addition to mitochondria-specific DNA polymerase γ, the polymerases α, η, ζ, and Rev1 have been found in this organelle. A nuclear genome instability phenotype results from a failure of various mitochondrial functions, such as an electron transport chain activity breakdown leading to a decrease in ATP production, a reduction in the mitochondrial membrane potential (ΔΨ), and a block in nucleotide and amino acid biosynthesis. The loss of ΔΨ inhibits the production of iron-sulfur prosthetic groups, which impairs the assembly of Fe-S proteins, including those that mediate DNA transactions; disturbs iron homeostasis; leads to oxidative stress; and perturbs wobble tRNA modification and ribosome assembly, thereby affecting translation and leading to proteotoxic stress. In this review, we present the current knowledge of the mechanisms that govern mitochondrial genome maintenance and demonstrate ways in which the impairment of mitochondrial function can affect nuclear genome stability.
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Affiliation(s)
- Aneta Kaniak-Golik
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| | - Adrianna Skoneczna
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland.
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Lodi T, Dallabona C, Nolli C, Goffrini P, Donnini C, Baruffini E. DNA polymerase γ and disease: what we have learned from yeast. Front Genet 2015; 6:106. [PMID: 25852747 PMCID: PMC4362329 DOI: 10.3389/fgene.2015.00106] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Mip1 is the Saccharomyces cerevisiae DNA polymerase γ (Pol γ), which is responsible for the replication of mitochondrial DNA (mtDNA). It belongs to the family A of the DNA polymerases and it is orthologs to human POLGA. In humans, mutations in POLG(1) cause many mitochondrial pathologies, such as progressive external ophthalmoplegia (PEO), Alpers' syndrome, and ataxia-neuropathy syndrome, all of which present instability of mtDNA, which results in impaired mitochondrial function in several tissues with variable degrees of severity. In this review, we summarize the genetic and biochemical knowledge published on yeast mitochondrial DNA polymerase from 1989, when the MIP1 gene was first cloned, up until now. The role of yeast is particularly emphasized in (i) validating the pathological mutations found in human POLG and modeled in MIP1, (ii) determining the molecular defects caused by these mutations and (iii) finding the correlation between mutations/polymorphisms in POLGA and mtDNA toxicity induced by specific drugs. We also describe recent findings regarding the discovery of molecules able to rescue the phenotypic defects caused by pathological mutations in Mip1, and the construction of a model system in which the human Pol γ holoenzyme is expressed in yeast and complements the loss of Mip1.
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Affiliation(s)
- Tiziana Lodi
- Department of Life Sciences, University of Parma Parma, Italy
| | | | - Cecilia Nolli
- Department of Life Sciences, University of Parma Parma, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma Parma, Italy
| | - Claudia Donnini
- Department of Life Sciences, University of Parma Parma, Italy
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Polymorphisms in DNA polymerase γ affect the mtDNA stability and the NRTI-induced mitochondrial toxicity in Saccharomyces cerevisiae. Mitochondrion 2014; 20:52-63. [PMID: 25462018 PMCID: PMC4309887 DOI: 10.1016/j.mito.2014.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/23/2022]
Abstract
Several pathological mutations have been identified in human POLG gene, encoding for the catalytic subunit of Pol γ, the solely mitochondrial replicase in animals and fungi. However, little is known regarding non-pathological polymorphisms found in this gene. Here we studied, in the yeast model Saccharomyces cerevisiae, eight human polymorphisms. We found that most of them are not neutral but enhanced both mtDNA extended mutability and the accumulation of mtDNA point mutations, either alone or in combination with a pathological mutation. In addition, we found that the presence of some SNPs increased the stavudine and/or zalcitabine-induced mtDNA mutability and instability. We studied the effects of 8 human polymorphisms in Pol γ in the model system yeast. Most polymorphisms increase mtDNA extended and point mutability. Treatment with NRTIs determines mtDNA instability in wt and mutant strains. Some polymorphisms make Mip1 more sensitive to NRTIs-induced mtDNA toxicity.
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Stumpf JD, Copeland WC. MMS exposure promotes increased MtDNA mutagenesis in the presence of replication-defective disease-associated DNA polymerase γ variants. PLoS Genet 2014; 10:e1004748. [PMID: 25340760 PMCID: PMC4207668 DOI: 10.1371/journal.pgen.1004748] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 09/11/2014] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial DNA (mtDNA) encodes proteins essential for ATP production. Mutant variants of the mtDNA polymerase cause mutagenesis that contributes to aging, genetic diseases, and sensitivity to environmental agents. We interrogated mtDNA replication in Saccharomyces cerevisiae strains with disease-associated mutations affecting conserved regions of the mtDNA polymerase, Mip1, in the presence of the wild type Mip1. Mutant frequency arising from mtDNA base substitutions that confer erythromycin resistance and deletions between 21-nucleotide direct repeats was determined. Previously, increased mutagenesis was observed in strains encoding mutant variants that were insufficient to maintain mtDNA and that were not expected to reduce polymerase fidelity or exonuclease proofreading. Increased mutagenesis could be explained by mutant variants stalling the replication fork, thereby predisposing the template DNA to irreparable damage that is bypassed with poor fidelity. This hypothesis suggests that the exogenous base-alkylating agent, methyl methanesulfonate (MMS), would further increase mtDNA mutagenesis. Mitochondrial mutagenesis associated with MMS exposure was increased up to 30-fold in mip1 mutants containing disease-associated alterations that affect polymerase activity. Disrupting exonuclease activity of mutant variants was not associated with increased spontaneous mutagenesis compared with exonuclease-proficient alleles, suggesting that most or all of the mtDNA was replicated by wild type Mip1. A novel subset of C to G transversions was responsible for about half of the mutants arising after MMS exposure implicating error-prone bypass of methylated cytosines as the predominant mutational mechanism. Exposure to MMS does not disrupt exonuclease activity that suppresses deletions between 21-nucleotide direct repeats, suggesting the MMS-induce mutagenesis is not explained by inactivated exonuclease activity. Further, trace amounts of CdCl2 inhibit mtDNA replication but suppresses MMS-induced mutagenesis. These results suggest a novel mechanism wherein mutations that lead to hypermutation by DNA base-damaging agents and associate with mitochondrial disease may contribute to previously unexplained phenomena, such as the wide variation of age of disease onset and acquired mitochondrial toxicities. Thousands of mitochondrial DNA (mtDNA) per cell are necessary to maintain energy required for cellular survival in humans. Interfering with the mtDNA polymerase can result in mitochondrial diseases and mitochondrial toxicity. Therefore, it is important to explore new genetic and environmental mechanisms that alter the effectiveness and accuracy of mtDNA replication. This genetic study uses the budding yeast to demonstrate that heterozygous strains harboring disease-associated mutations in the mtDNA polymerase gene in the presence of a wild type copy of the mtDNA polymerase are associated with increased mtDNA point mutagenesis in the presence of methane methylsulfonate, a known base damaging agent. Further observations suggest that the inability of disease-associated variants to replicate mtDNA resulted in increased vulnerability to irreparable base damage that was likely to result in mutations when replicated. Also, this study showed that trace amounts of the environmental contaminant cadmium chloride impairs mtDNA replication but eliminates damage-induced mutagenesis in the remaining functional mitochondria. This interplay between disease-associated variant and wild type polymerase offers new insights on possible disease variation and implicates novel environmental consequences for compound heterozygous patients.
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Affiliation(s)
- Jeffrey D. Stumpf
- Mitochondrial DNA Replication Group, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, United States of America
| | - William C. Copeland
- Mitochondrial DNA Replication Group, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, United States of America
- * E-mail:
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35
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Boczonadi V, Müller JS, Pyle A, Munkley J, Dor T, Quartararo J, Ferrero I, Karcagi V, Giunta M, Polvikoski T, Birchall D, Princzinger A, Cinnamon Y, Lützkendorf S, Piko H, Reza M, Florez L, Santibanez-Koref M, Griffin H, Schuelke M, Elpeleg O, Kalaydjieva L, Lochmüller H, Elliott DJ, Chinnery PF, Edvardson S, Horvath R. EXOSC8 mutations alter mRNA metabolism and cause hypomyelination with spinal muscular atrophy and cerebellar hypoplasia. Nat Commun 2014; 5:4287. [PMID: 24989451 PMCID: PMC4102769 DOI: 10.1038/ncomms5287] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 06/03/2014] [Indexed: 12/21/2022] Open
Abstract
The exosome is a multi-protein complex, required for the degradation of AU-rich element (ARE) containing messenger RNAs (mRNAs). EXOSC8 is an essential protein of the exosome core, as its depletion causes a severe growth defect in yeast. Here we show that homozygous missense mutations in EXOSC8 cause progressive and lethal neurological disease in 22 infants from three independent pedigrees. Affected individuals have cerebellar and corpus callosum hypoplasia, abnormal myelination of the central nervous system or spinal motor neuron disease. Experimental downregulation of EXOSC8 in human oligodendroglia cells and in zebrafish induce a specific increase in ARE mRNAs encoding myelin proteins, showing that the imbalanced supply of myelin proteins causes the disruption of myelin, and explaining the clinical presentation. These findings show the central role of the exosomal pathway in neurodegenerative disease. The exosome is responsible for mRNA degradation, which is an important step in the regulation of gene expression. Here the authors report that homozygous missense mutations in the exosome subunit, EXOSC8, may cause neurodegenerative disease in infants through the dysregulation of myelin expression.
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Affiliation(s)
- Veronika Boczonadi
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Juliane S Müller
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Angela Pyle
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Jennifer Munkley
- 1] Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK [2]
| | - Talya Dor
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Jade Quartararo
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Ileana Ferrero
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11A, Parma 43124, Italy
| | - Veronika Karcagi
- Department of Molecular Genetics and Diagnostics, NIEH, Albert Florian ut 2-6, Budapest 1097, Hungary
| | - Michele Giunta
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Tuomo Polvikoski
- Department of Pathology, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Daniel Birchall
- Neuroradiology Department, Regional Neurosciences Centre, Queen Victoria Road, Newcastle upon Tyne NE1 4PL, UK
| | - Agota Princzinger
- Department of Paediatrics, Josa Andras Hospital, Szent Istvan utca 6, Nyiregyhaza 4400, Hungary
| | - Yuval Cinnamon
- 1] The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel [2] Department of Poultry and Aquaculture Sciences, Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.Box 6, Bet Dagan 50250, Israel
| | - Susanne Lützkendorf
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité-Universitätsmedizin, Charité-Platz 1, 10117 Berlin, Germany
| | - Henriett Piko
- Department of Molecular Genetics and Diagnostics, NIEH, Albert Florian ut 2-6, Budapest 1097, Hungary
| | - Mojgan Reza
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Laura Florez
- Western Australian Institute for Medical Research/Centre for Medical Research, The University of Western Australia, 35 Stirling Highway Crawley, Western Australia 6009 Perth, Australia
| | - Mauro Santibanez-Koref
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Helen Griffin
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité-Universitätsmedizin, Charité-Platz 1, 10117 Berlin, Germany
| | - Orly Elpeleg
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Luba Kalaydjieva
- Western Australian Institute for Medical Research/Centre for Medical Research, The University of Western Australia, 35 Stirling Highway Crawley, Western Australia 6009 Perth, Australia
| | - Hanns Lochmüller
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - David J Elliott
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Patrick F Chinnery
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Shimon Edvardson
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Rita Horvath
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
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Vandenbosch D, De Canck E, Dhondt I, Rigole P, Nelis HJ, Coenye T. Genomewide screening for genes involved in biofilm formation and miconazole susceptibility inSaccharomyces cerevisiae. FEMS Yeast Res 2013; 13:720-30. [DOI: 10.1111/1567-1364.12071] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/19/2013] [Accepted: 08/19/2013] [Indexed: 11/29/2022] Open
Affiliation(s)
- Davy Vandenbosch
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
| | - Evelien De Canck
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
| | - Inne Dhondt
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
| | - Petra Rigole
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
| | - Hans J. Nelis
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology; Ghent University; Ghent Belgium
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Invernizzi F, Tigano M, Dallabona C, Donnini C, Ferrero I, Cremonte M, Ghezzi D, Lamperti C, Zeviani M. A homozygous mutation in LYRM7/MZM1L associated with early onset encephalopathy, lactic acidosis, and severe reduction of mitochondrial complex III activity. Hum Mutat 2013; 34:1619-22. [PMID: 24014394 PMCID: PMC4028993 DOI: 10.1002/humu.22441] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 08/29/2013] [Indexed: 11/11/2022]
Abstract
Mutations in nuclear genes associated with defective complex III (cIII) of the mitochondrial respiratory chain are rare, having been found in only two cIII assembly factors and, as private changes in single families, three cIII structural subunits. Recently, human LYRM7/MZM1L, the ortholog of yeast MZM1, has been identified as a new assembly factor for cIII. In a baby patient with early onset, severe encephalopathy, lactic acidosis and profound, isolated cIII deficiency in skeletal muscle, we identified a disease-segregating homozygous mutation (c.73G>A) in LYRM7/MZM1L, predicting a drastic change in a highly conserved amino-acid residue (p.Asp25Asn). In a mzm1Δ yeast strain, the expression of a mzm1(D25N) mutant allele caused temperature-sensitive respiratory growth defect, decreased oxygen consumption, impaired maturation/stabilization of the Rieske Fe-S protein, and reduced complex III activity and amount. LYRM7/MZM1L is a novel disease gene, causing cIII-defective, early onset, severe mitochondrial encephalopathy.
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Affiliation(s)
- Federica Invernizzi
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico "Carlo Besta", Milan, Italy
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38
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Haack T, Kopajtich R, Freisinger P, Wieland T, Rorbach J, Nicholls T, Baruffini E, Walther A, Danhauser K, Zimmermann F, Husain R, Schum J, Mundy H, Ferrero I, Strom T, Meitinger T, Taylor R, Minczuk M, Mayr J, Prokisch H. ELAC2 mutations cause a mitochondrial RNA processing defect associated with hypertrophic cardiomyopathy. Am J Hum Genet 2013; 93:211-23. [PMID: 23849775 PMCID: PMC3738821 DOI: 10.1016/j.ajhg.2013.06.006] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/22/2013] [Accepted: 06/05/2013] [Indexed: 11/16/2022] Open
Abstract
The human mitochondrial genome encodes RNA components of its own translational machinery to produce the 13 mitochondrial-encoded subunits of the respiratory chain. Nuclear-encoded gene products are essential for all processes within the organelle, including RNA processing. Transcription of the mitochondrial genome generates large polycistronic transcripts punctuated by the 22 mitochondrial (mt) tRNAs that are conventionally cleaved by the RNase P-complex and the RNase Z activity of ELAC2 at 5' and 3' ends, respectively. We report the identification of mutations in ELAC2 in five individuals with infantile hypertrophic cardiomyopathy and complex I deficiency. We observed accumulated mtRNA precursors in affected individuals muscle and fibroblasts. Although mature mt-tRNA, mt-mRNA, and mt-rRNA levels were not decreased in fibroblasts, the processing defect was associated with impaired mitochondrial translation. Complementation experiments in mutant cell lines restored RNA processing and a yeast model provided additional evidence for the disease-causal role of defective ELAC2, thereby linking mtRNA processing to human disease.
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MESH Headings
- Amino Acid Sequence
- Cardiomyopathy, Hypertrophic/genetics
- Cardiomyopathy, Hypertrophic/metabolism
- Cardiomyopathy, Hypertrophic/pathology
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- Electron Transport/genetics
- Endoribonucleases/genetics
- Endoribonucleases/metabolism
- Female
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Genetic Complementation Test
- Humans
- Infant
- Male
- Mitochondria/genetics
- Mitochondria/metabolism
- Molecular Sequence Data
- Muscles/metabolism
- Muscles/pathology
- Mutation
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Pedigree
- RNA Processing, Post-Transcriptional
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Mitochondrial
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- Tobias B. Haack
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Peter Freisinger
- Department of Pediatrics, Klinikum Reutlingen, 72764 Reutlingen, Germany
| | - Thomas Wieland
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Joanna Rorbach
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | | | - Enrico Baruffini
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Anett Walther
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Katharina Danhauser
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Franz A. Zimmermann
- Department of Pediatrics, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria
| | - Ralf A. Husain
- Department of Neuropediatrics, Jena University Hospital, 07740 Jena, Germany
| | - Jessica Schum
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Helen Mundy
- Centre for Inherited Metabolic Disease, Evelina Children’s Hospital, Guys and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK
| | - Ileana Ferrero
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Tim M. Strom
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich, 81675 Munich, Germany
- Munich Heart Alliance, 80802 Munich, Germany
| | - Robert W. Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Johannes A. Mayr
- Department of Pediatrics, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria
| | - Holger Prokisch
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
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Alston CL, Davison JE, Meloni F, van der Westhuizen FH, He L, Hornig-Do HT, Peet AC, Gissen P, Goffrini P, Ferrero I, Wassmer E, McFarland R, Taylor RW. Recessive germline SDHA and SDHB mutations causing leukodystrophy and isolated mitochondrial complex II deficiency. J Med Genet 2013; 49:569-77. [PMID: 22972948 PMCID: PMC3500770 DOI: 10.1136/jmedgenet-2012-101146] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background Isolated complex II deficiency is a rare form of mitochondrial disease, accounting for approximately 2% of all respiratory chain deficiency diagnoses. The succinate dehydrogenase (SDH) genes (SDHA, SDHB, SDHC and SDHD) are autosomally-encoded and transcribe the conjugated heterotetramers of complex II via the action of two known assembly factors (SDHAF1 and SDHAF2). Only a handful of reports describe inherited SDH gene defects as a cause of paediatric mitochondrial disease, involving either SDHA (Leigh syndrome, cardiomyopathy) or SDHAF1 (infantile leukoencephalopathy). However, all four SDH genes, together with SDHAF2, have known tumour suppressor functions, with numerous germline and somatic mutations reported in association with hereditary cancer syndromes, including paraganglioma and pheochromocytoma. Methods and results Here, we report the clinical and molecular investigations of two patients with histochemical and biochemical evidence of a severe, isolated complex II deficiency due to novel SDH gene mutations; the first patient presented with cardiomyopathy and leukodystrophy due to compound heterozygous p.Thr508Ile and p.Ser509Leu SDHA mutations, while the second patient presented with hypotonia and leukodystrophy with elevated brain succinate demonstrated by MR spectroscopy due to a novel, homozygous p.Asp48Val SDHB mutation. Western blotting and BN-PAGE studies confirmed decreased steady-state levels of the relevant SDH subunits and impairment of complex II assembly. Evidence from yeast complementation studies provided additional support for pathogenicity of the SDHB mutation. Conclusions Our report represents the first example of SDHB mutation as a cause of inherited mitochondrial respiratory chain disease and extends the SDHA mutation spectrum in patients with isolated complex II deficiency.
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Affiliation(s)
- Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Medical School, Newcastle University, Newcastle upon Tyne, UK
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Panizza E, Ercolino T, Mori L, Rapizzi E, Castellano M, Opocher G, Ferrero I, Neumann HPH, Mannelli M, Goffrini P. Yeast model for evaluating the pathogenic significance of SDHB, SDHC and SDHD mutations in PHEO-PGL syndrome. Hum Mol Genet 2012; 22:804-15. [PMID: 23175444 DOI: 10.1093/hmg/dds487] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
SDH genes, encoding succinate dehydrogenase, act as tumour suppressor genes, linking mitochondrial dysfunction with tumourigenesis. Heterozygous germline mutations in SDHA, SDHB, SDHC, SDHD and in the assembly factor encoding gene SDHAF2 have all been shown to predispose to heritable endocrine neoplasias such as pheochromocytomas (PHEO) and paragangliomas (PGLs) called 'PHEO-PGL syndrome'. SDH genes mutations, in addition to deletions or truncations which are most likely pathogenic, often include missense substitutions which can be of uncertain significance. Unclassified missense substitutions may be difficult to interpret unless the cause-effect link between mutation and the disease is established by functional and in silico studies or by the familial segregation with the phenotype. Using the yeast model, here, we report functional investigations on several missense SDH mutations found in patients affected by pheochromocytomas or paragangliomas. The aim of this study was to evaluate whether and to which extent the yeast model may be useful for establishing the pathological significance of missense SDH mutations in humans. The results of our study demonstrate that the yeast is a good functional model to validate the pathogenic significance of SDHB missense mutations while, for missense mutations in SDHC and SDHD genes, the model can be informative only when the variation involves a conserved residue in a conserved domain.
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Affiliation(s)
- Elena Panizza
- Department of Life Sciences, University of Parma, Parma 43124, Italy
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41
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Overexpression of DNA polymerase zeta reduces the mitochondrial mutability caused by pathological mutations in DNA polymerase gamma in yeast. PLoS One 2012; 7:e34322. [PMID: 22470557 PMCID: PMC3314619 DOI: 10.1371/journal.pone.0034322] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 02/28/2012] [Indexed: 12/27/2022] Open
Abstract
In yeast, DNA polymerase zeta (Rev3 and Rev7) and Rev1, involved in the error-prone translesion synthesis during replication of nuclear DNA, localize also in mitochondria. We show that overexpression of Rev3 reduced the mtDNA extended mutability caused by a subclass of pathological mutations in Mip1, the yeast mitochondrial DNA polymerase orthologous to human Pol gamma. This beneficial effect was synergistic with the effect achieved by increasing the dNTPs pools. Since overexpression of Rev3 is detrimental for nuclear DNA mutability, we constructed a mutant Rev3 isoform unable to migrate into the nucleus: its overexpression reduced mtDNA mutability without increasing the nuclear one.
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Foury F, Szczepanowska K. Antimutator alleles of yeast DNA polymerase gamma modulate the balance between DNA synthesis and excision. PLoS One 2011; 6:e27847. [PMID: 22114710 PMCID: PMC3218072 DOI: 10.1371/journal.pone.0027847] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 10/26/2011] [Indexed: 11/25/2022] Open
Abstract
Mutations in mitochondrial DNA (mtDNA) are an important cause of disease and perhaps aging in human. DNA polymerase gamma (pol γ ), the unique replicase inside mitochondria, plays a key role in the fidelity of mtDNA replication through selection of the correct nucleotide and 3′-5′ exonuclease proofreading. For the first time, we have isolated and characterized antimutator alleles in the yeast pol γ (Mip1). These mip1 mutations, localised in the 3′-5′ exonuclease and polymerase domains, elicit a 2–15 fold decrease in the frequency of mtDNA point mutations in an msh1-1 strain which is partially deficient in mtDNA mismatch-repair. In vitro experiments show that in all mutants the balance between DNA synthesis and exonucleolysis is shifted towards excision when compared to wild-type, suggesting that in vivo more opportunity is given to the editing function for removing the replicative errors. This results in partial compensation for the mismatch-repair defects and a decrease in mtDNA point mutation rate. However, in all mutants but one the antimutator trait is lost in the wild-type MSH1 background. Accordingly, the polymerases of selected mutants show reduced oligonucleotide primed M13 ssDNA synthesis and to a lesser extent DNA binding affinity, suggesting that in mismatch-repair proficient cells efficient DNA synthesis is required to reach optimal accuracy. In contrast, the Mip1-A256T polymerase, which displays wild-type like DNA synthesis activity, increases mtDNA replication fidelity in both MSH1 and msh1-1 backgrounds. Altogether, our data show that accuracy of wild-type Mip1 is probably not optimal and can be improved by specific (often conservative) amino acid substitutions that define a pol γ area including a loop of the palm subdomain, two residues near the ExoII motif and an exonuclease helix-coil-helix module in close vicinity to the polymerase domain. These elements modulate in a subtle manner the balance between DNA polymerization and excision.
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Affiliation(s)
- Françoise Foury
- Institut des Sciences de la Vie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
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Rinaldi T, Dallabona C, Ferrero I, Frontali L, Bolotin-Fukuhara M. Mitochondrial diseases and the role of the yeast models. FEMS Yeast Res 2010; 10:1006-22. [PMID: 20946356 DOI: 10.1111/j.1567-1364.2010.00685.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nowadays, mitochondrial diseases are recognized and studied with much attention and they cannot be considered anymore as 'rare diseases'. Yeast has been an instrumental organism to understand the genetic and molecular aspects of the many roles of mitochondria within the cells. Thanks to the general conservation of mitochondrial genes and pathways between human and yeast, it can also be used to model some diseases. In this review, we focus on the most recent topics, exemplifying those for which yeast models have been especially valuable.
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Affiliation(s)
- Teresa Rinaldi
- Department of Cell and Developmental Biology, Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
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Mitochondrial DNA replication and disease: insights from DNA polymerase γ mutations. Cell Mol Life Sci 2010; 68:219-33. [PMID: 20927567 DOI: 10.1007/s00018-010-0530-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 08/31/2010] [Accepted: 09/02/2010] [Indexed: 10/19/2022]
Abstract
DNA polymerase γ (pol γ), encoded by POLG, is responsible for replicating human mitochondrial DNA. About 150 mutations in the human POLG have been identified in patients with mitochondrial diseases such as Alpers syndrome, progressive external ophthalmoplegia, and ataxia-neuropathy syndromes. Because many of the mutations are described in single citations with no genotypic family history, it is important to ascertain which mutations cause or contribute to mitochondrial disease. The vast majority of data about POLG mutations has been generated from biochemical characterizations of recombinant pol γ. However, recently, the study of mitochondrial dysfunction in Saccharomyces cerevisiae and mouse models provides important in vivo evidence for the role of POLG mutations in disease. Also, the published 3D-structure of the human pol γ assists in explaining some of the biochemical and genetic properties of the mutants. This review summarizes the current evidence that identifies and explains disease-causing POLG mutations.
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Predicting the contribution of novel POLG mutations to human disease through analysis in yeast model. Mitochondrion 2010; 11:182-90. [PMID: 20883824 DOI: 10.1016/j.mito.2010.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 09/17/2010] [Accepted: 09/20/2010] [Indexed: 11/24/2022]
Abstract
The yeast Saccharomyces cerevisiae was used to validate the pathogenic significance of eight human mutations in the gene encoding for the mitochondrial DNA polymerase gamma, namely G303R, S305R, R386H, R574W, P625R, D930N, K947R and P1073L, among which three are novel and four are of unclear pathological significance. Mitochondrial DNA extended and point mutability as well as dominance/recessivity of each mutation has been evaluated. The analysis in yeast revealed that two mutations, S305R and R386H, cannot be the sole cause of pathology observed in patients. These data led us to search for a second mutation in compound with S305R and we found a mutation, P1073L, missed in the first genetic analysis. Finally, a significant rescue of extended mutability has been observed for several dominant mutations by treatment with mitochondrial antioxidants.
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Szczepanowska K, Foury F. A cluster of pathogenic mutations in the 3'-5' exonuclease domain of DNA polymerase gamma defines a novel module coupling DNA synthesis and degradation. Hum Mol Genet 2010; 19:3516-29. [PMID: 20601675 DOI: 10.1093/hmg/ddq267] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in DNA polymerase gamma (pol g), the unique replicase inside mitochondria, cause a broad and complex spectrum of diseases in human. We have used Mip1, the yeast pol g, as a model enzyme to characterize six pathogenic pol g mutations. Four mutations clustered in a highly conserved 3'-5' exonuclease module are localized in the DNA-binding channel in close vicinity to the polymerase domain. They result in an increased frequency of point mutations and high instability of the mitochondrial DNA (mtDNA) in yeast cells, and unexpectedly for mutator mutations in the exonuclease domain, they favour exonucleolysis versus polymerization. This trait is associated with highly decreased DNA-binding affinity and poorly processive DNA synthesis. Our data show for the first time that a 3'-5' exonuclease module of pol g plays a crucial role in the coordination of the polymerase and exonuclease functions and they strongly suggest that in patients the disease is not caused by defective proofreading but results from poor mtDNA replication generated by a severe imbalance between DNA synthesis and degradation.
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Affiliation(s)
- Karolina Szczepanowska
- Institute of Life Sciences, Croix du Sud 4/15, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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