1
|
Xiang D, Xu K, Chen M, Zhang Z, Sun N, Qi Y, Lu J, Wang C, Yang S. A rare homozygous mutation in the YARS2 gene presents with hypertrophic cardiomyopathy, lactic acidosis and anemia in a Chinese infant. Gene 2024; 914:148379. [PMID: 38490507 DOI: 10.1016/j.gene.2024.148379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Affiliation(s)
- Dandan Xiang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Kangkang Xu
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Mei Chen
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Zhongman Zhang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Ningning Sun
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Yuying Qi
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Jie Lu
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Chunli Wang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing 210008, China
| | - Shiwei Yang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing 210008, China.
| |
Collapse
|
2
|
Suo L, Liang X, Zhang W, Gao M, Ma T, Hu D, Song Y, Gao Z. Potential prognostic biomarkers of hepatocellular carcinoma based on 4D label-free quantitative proteomics analysis pilot investigation. Int J Biol Markers 2024; 39:59-69. [PMID: 37956648 DOI: 10.1177/03936155231212925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
BACKGROUND Hepatocellular carcinoma carries a poor prognosis and poses a serious threat to global health. Currently, there are few potential prognostic biomarkers available for the prognosis of hepatocellular carcinoma. METHODS This pilot study used 4D label-free quantitative proteomics to compare the proteomes of hepatocellular carcinoma and adjacent non-tumor tissue. A total of 66,075 peptides, 6363 identified proteins, and 772 differentially expressed proteins were identified in specimens from three hepatocellular carcinoma patients. Through functional enrichment analysis of differentially expressed proteins by Gene Ontology, KEGG pathway, and protein domain, we identified proteins with similar functions. RESULTS Twelve differentially expressed proteins (RPL17, RPL27, RPL27A, RPS5, RPS16, RSL1D1, DDX18, RRP12, TARS2, YARS2, MARS2, and NARS1) were selected for identification and validation by parallel reaction monitoring. Subsequent Western blotting confirmed overexpression of RPL27, RPS16, and TARS2 in hepatocellular carcinoma compared to non-tumor tissue in 16 pairs of clinical samples. Analysis of The Cancer Genome Atlas datasets associated the increased expression of these proteins with poor prognosis. Tissue microarray revealed a negative association between high expression of RPL27 and TARS2 and the prognosis of hepatocellular carcinoma patients, although RPS16 was not significant. CONCLUSIONS These data suggest that RPL27 and TARS2 play an important role in hepatocellular carcinoma progression and may be potential prognostic biomarkers of overall survival in hepatocellular carcinoma patients.
Collapse
Affiliation(s)
- Lida Suo
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Xiangnan Liang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Weibin Zhang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Mingwei Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Taiheng Ma
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Daosheng Hu
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Yilin Song
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Zhenming Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| |
Collapse
|
3
|
Peng GX, Mao XL, Cao Y, Yao SY, Li QR, Chen X, Wang ED, Zhou XL. RNA granule-clustered mitochondrial aminoacyl-tRNA synthetases form multiple complexes with the potential to fine-tune tRNA aminoacylation. Nucleic Acids Res 2022; 50:12951-12968. [PMID: 36503967 PMCID: PMC9825176 DOI: 10.1093/nar/gkac1141] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/23/2022] [Accepted: 11/15/2022] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial RNA metabolism is suggested to occur in identified compartmentalized foci, i.e. mitochondrial RNA granules (MRGs). Mitochondrial aminoacyl-tRNA synthetases (mito aaRSs) catalyze tRNA charging and are key components in mitochondrial gene expression. Mutations of mito aaRSs are associated with various human disorders. However, the suborganelle distribution, interaction network and regulatory mechanism of mito aaRSs remain largely unknown. Here, we found that all mito aaRSs partly colocalize with MRG, and this colocalization is likely facilitated by tRNA-binding capacity. A fraction of human mitochondrial AlaRS (hmtAlaRS) and hmtSerRS formed a direct complex via interaction between catalytic domains in vivo. Aminoacylation activities of both hmtAlaRS and hmtSerRS were fine-tuned upon complex formation in vitro. We further established a full spectrum of interaction networks via immunoprecipitation and mass spectrometry for all mito aaRSs and discovered interactions between hmtSerRS and hmtAsnRS, between hmtSerRS and hmtTyrRS and between hmtThrRS and hmtArgRS. The activity of hmtTyrRS was also influenced by the presence of hmtSerRS. Notably, hmtSerRS utilized the same catalytic domain in mediating several interactions. Altogether, our results systematically analyzed the suborganelle localization and interaction network of mito aaRSs and discovered several mito aaRS-containing complexes, deepening our understanding of the functional and regulatory mechanisms of mito aaRSs.
Collapse
Affiliation(s)
| | | | - Yating Cao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - Shi-Ying Yao
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qing-Run Li
- CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Xin Chen
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen 361102, China
| | - En-Duo Wang
- Correspondence may also be addressed to En-Duo Wang. Tel: +86 21 5492 1241; Fax: +86 21 5492 1011;
| | - Xiao-Long Zhou
- To whom correspondence should be addressed. Tel: +86 21 5492 1247; Fax: +86 21 5492 1011;
| |
Collapse
|
4
|
Two Novel Variants in YARS2 Gene Are Responsible for an Extended MLASA Phenotype with Pancreatic Insufficiency. J Clin Med 2021; 10:jcm10163471. [PMID: 34441767 PMCID: PMC8397107 DOI: 10.3390/jcm10163471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/02/2021] [Indexed: 11/17/2022] Open
Abstract
Pathogenic variants in the mitochondrial tyrosyl-tRNA synthetase gene (YARS2) were associated with myopathy, lactic acidosis, and sideroblastic anemia (MLASA). However, patients can present mitochondrial myopathy, with exercise intolerance and muscle weakness, leading from mild to lethal phenotypes. Genes implicated in mtDNA replication were studied by Next Generation Sequencing (NGS) and whole exome sequence with the TruSeq Rapid Exome kit (Illumina, San Diego, CA, USA). Mitochondrial protein translation was studied following the Sasarman and Shoubridge protocol and oxygen consumption rates with Agilent Seahorse XF24 Analyzer Mitostress Test, (Agilent, Santa Clara, CA, USA). We report two siblings with two novel compound heterozygous pathogenic variants in YARS2 gene: a single nucleotide deletion in exon 1, c.314delG (p.(Gly105Alafs*4)), which creates a premature stop codon in the amino acid 109, and a single nucleotide change in exon 5 c.1391T>C (p.(Ile464Thr)), that cause a missense variant in amino acid 464. We demonstrate the pathogenicity of these new variants associated with reduced YARS2 mRNA transcript, reduced mitochondrial protein translation and dysfunctional organelle function. These pathogenic variants are responsible for late onset MLASA, herein accompanied by pancreatic insufficiency, observed in both brothers, clinically considered as Pearson's syndrome. Molecular study of YARS2 gene should be considered in patients presenting Pearson's syndrome characteristics and MLASA related phenotypes.
Collapse
|
5
|
Jin X, Zhang J, Yi Q, Meng F, Yu J, Ji Y, Mo JQ, Tong Y, Jiang P, Guan MX. Leber's Hereditary Optic Neuropathy Arising From the Synergy Between ND1 3635G>A Mutation and Mitochondrial YARS2 Mutations. Invest Ophthalmol Vis Sci 2021; 62:22. [PMID: 34156427 PMCID: PMC8237128 DOI: 10.1167/iovs.62.7.22] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To investigate the mechanism underlying the synergic interaction between Leber's hereditary optic neuropathy (LHON)-associated ND1 and mitochondrial tyrosyl-tRNA synthetase (YARS2) mutations. Methods Molecular dynamics simulation and differential scanning fluorimetry were used to evaluate the structure and stability of proteins. The impact of ND1 3635G>A and YARS2 p.G191V mutations on the oxidative phosphorylation machinery was evaluated using blue native gel electrophoresis and enzymatic activities assays. Assessment of reactive oxygen species (ROS) production in cell lines was performed by flow cytometry with MitoSOX Red reagent. Analysis of effect of mutations on autophagy was undertaken via flow cytometry for autophagic flux. Results Members of one Chinese family bearing both the YARS2 p.191Gly>Val and m.3635G>A mutations exhibited much higher penetrance of optic neuropathy than those pedigrees carrying only the m.3635G>A mutation. The m.3635G>A (p.Ser110Asn) mutation altered the ND1 structure and function, whereas the p.191Gly>Val mutation affected the stability of YARS2. Lymphoblastoid cell lines harboring both m.3635G>A and p.191Gly>Val mutations revealed more reductions in the levels of mitochondrion-encoding ND1 and CO2 than cells bearing only the m.3635G>A mutation. Strikingly, both m.3635G>A and p.191Gly>Val mutations exhibited decreases in the nucleus-encoding subunits of complex I and IV. These deficiencies manifested greater defects in the stability and activities of complex I and complex IV and overproduction of ROS and promoted greater autophagy in cell lines harboring both m.3635G>A and p.191Gly>Val mutations compared with cells bearing only the m.3635G>A mutation. Conclusions Our findings provide new insights into the pathophysiology of LHON arising from the synergy between ND1 3635G>A mutation and mitochondrial YARS2 mutations.
Collapse
Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Jialing Yu
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California, United States
| | - Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Pingping Jiang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Hangzhou, Zhejiang, China.,Zhejiang University-University of Toronto Joint Institute of Genetics and Genome Medicine, Hangzhou, Zhejiang, China
| |
Collapse
|
6
|
Figuccia S, Degiorgi A, Ceccatelli Berti C, Baruffini E, Dallabona C, Goffrini P. Mitochondrial Aminoacyl-tRNA Synthetase and Disease: The Yeast Contribution for Functional Analysis of Novel Variants. Int J Mol Sci 2021; 22:ijms22094524. [PMID: 33926074 PMCID: PMC8123711 DOI: 10.3390/ijms22094524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/23/2021] [Indexed: 12/28/2022] Open
Abstract
In most eukaryotes, mitochondrial protein synthesis is essential for oxidative phosphorylation (OXPHOS) as some subunits of the respiratory chain complexes are encoded by the mitochondrial DNA (mtDNA). Mutations affecting the mitochondrial translation apparatus have been identified as a major cause of mitochondrial diseases. These mutations include either heteroplasmic mtDNA mutations in genes encoding for the mitochondrial rRNA (mtrRNA) and tRNAs (mttRNAs) or mutations in nuclear genes encoding ribosomal proteins, initiation, elongation and termination factors, tRNA-modifying enzymes, and aminoacyl-tRNA synthetases (mtARSs). Aminoacyl-tRNA synthetases (ARSs) catalyze the attachment of specific amino acids to their cognate tRNAs. Differently from most mttRNAs, which are encoded by mitochondrial genome, mtARSs are encoded by nuclear genes and then imported into the mitochondria after translation in the cytosol. Due to the extensive use of next-generation sequencing (NGS), an increasing number of mtARSs variants associated with large clinical heterogeneity have been identified in recent years. Being most of these variants private or sporadic, it is crucial to assess their causative role in the disease by functional analysis in model systems. This review will focus on the contributions of the yeast Saccharomyces cerevisiae in the functional validation of mutations found in mtARSs genes associated with human disorders.
Collapse
Affiliation(s)
| | | | | | | | - Cristina Dallabona
- Correspondence: (C.D.); (P.G.); Tel.: +39-0521-905600 (C.D.); +39-0521-905107 (P.G.)
| | - Paola Goffrini
- Correspondence: (C.D.); (P.G.); Tel.: +39-0521-905600 (C.D.); +39-0521-905107 (P.G.)
| |
Collapse
|
7
|
Jin X, Zhang Z, Nie Z, Wang C, Meng F, Yi Q, Chen M, Sun J, Zou J, Jiang P, Guan MX. An animal model for mitochondrial tyrosyl-tRNA synthetase deficiency reveals links between oxidative phosphorylation and retinal function. J Biol Chem 2021; 296:100437. [PMID: 33610547 PMCID: PMC8010715 DOI: 10.1016/j.jbc.2021.100437] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria maintain a distinct pool of ribosomal machinery, including tRNAs and tRNAs activating enzymes, such as mitochondrial tyrosyl-tRNA synthetase (YARS2). Mutations in YARS2, which typically lead to the impairment of mitochondrial protein synthesis, have been linked to an array of human diseases including optic neuropathy. However, the lack of YARS2 mutation animal model makes us difficult to elucidate the pathophysiology underlying YARS2 deficiency. To explore this system, we generated YARS2 knockout (KO) HeLa cells and zebrafish using CRISPR/Cas9 technology. We observed the aberrant tRNATyr aminoacylation overall and reductions in the levels in mitochondrion- and nucleus-encoding subunits of oxidative phosphorylation system (OXPHOS), which were especially pronounced effects in the subunits of complex I and complex IV. These deficiencies manifested the decreased levels of intact supercomplexes overall. Immunoprecipitation assays showed that YARS2 bound to specific subunits of complex I and complex IV, suggesting the posttranslational stabilization of OXPHOS. Furthermore, YARS2 ablation caused defects in the stability and activities of OXPHOS complexes. These biochemical defects could be rescued by the overexpression of YARS2 cDNA in the YARS2KO cells. In zebrafish, the yars2KO larva conferred deficient COX activities in the retina, abnormal mitochondrial morphology, and numbers in the photoreceptor and retinal ganglion cells. The zebrafish further exhibited the retinal defects affecting both rods and cones. Vision defects in yars2KO zebrafish recapitulated the clinical phenotypes in the optic neuropathy patients carrying the YARS2 mutations. Our findings highlighted the critical role of YARS2 in the stability and activity of OXPHOS and its pathological consequence in vision impairments.
Collapse
Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zengming Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhipeng Nie
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chenghui Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Jiji Sun
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Zou
- Insitute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China.
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
| |
Collapse
|
8
|
Gurtner C, Hug P, Kleiter M, Köhler K, Dietschi E, Jagannathan V, Leeb T. YARS2 Missense Variant in Belgian Shepherd Dogs with Cardiomyopathy and Juvenile Mortality. Genes (Basel) 2020; 11:genes11030313. [PMID: 32183361 PMCID: PMC7140874 DOI: 10.3390/genes11030313] [Citation(s) in RCA: 3] [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: 02/12/2020] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 01/03/2023] Open
Abstract
Dog puppy loss by the age of six to eight weeks after normal development is relatively uncommon. Necropsy findings in two spontaneously deceased Belgian Shepherd puppies indicated an abnormal accumulation of material in several organs. A third deceased puppy exhibited mild signs of an inflammation in the central nervous system and an enteritis. The puppies were closely related, raising the suspicion of a genetic cause. Pedigree analysis suggested a monogenic autosomal recessive inheritance. Combined linkage and homozygosity mapping assigned the most likely position of a potential genetic defect to 13 genome segments totaling 82 Mb. The genome of an affected puppy was sequenced and compared to 645 control genomes. Three private protein changing variants were found in the linked and homozygous regions. Targeted genotyping in 96 Belgian Shepherd dogs excluded two of these variants. The remaining variant, YARS2:1054G>A or p.Glu352Lys, was perfectly associated with the phenotype in a cohort of 474 Belgian Shepherd dogs. YARS2 encodes the mitochondrial tyrosyl-tRNA synthetase 2 and the predicted amino acid change replaces a negatively charged and evolutionary conserved glutamate at the surface of the tRNA binding domain of YARS2 with a positively charged lysine. Human patients with loss-of-function variants in YARS2 suffer from myopathy, lactic acidosis, and sideroblastic anemia 2, a disease with clinical similarities to the phenotype of the studied dogs. The carrier frequency was 27.2% in the tested Belgian Shepherd dogs. Our data suggest YARS2:1054G>A as the candidate causative variant for the observed juvenile mortality.
Collapse
Affiliation(s)
- Corinne Gurtner
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland;
| | - Petra Hug
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (P.H.); (E.D.); (V.J.)
| | - Miriam Kleiter
- Department/Hospital for Companion Animals and Horses, University Clinic for Small Animals, Internal Medicine Small Animals, University of Veterinary Medicine, 1210 Vienna, Austria;
| | - Kernt Köhler
- Institute of Veterinary Pathology, Justus-Liebig-University Giessen, 35392 Giessen, Germany;
| | - Elisabeth Dietschi
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (P.H.); (E.D.); (V.J.)
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (P.H.); (E.D.); (V.J.)
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (P.H.); (E.D.); (V.J.)
- Correspondence: ; Tel.: +41-31-631-23-26
| |
Collapse
|
9
|
Kuo ME, Theil AF, Kievit A, Malicdan MC, Introne WJ, Christian T, Verheijen FW, Smith DEC, Mendes MI, Hussaarts-Odijk L, van der Meijden E, van Slegtenhorst M, Wilke M, Vermeulen W, Raams A, Groden C, Shimada S, Meyer-Schuman R, Hou YM, Gahl WA, Antonellis A, Salomons GS, Mancini GMS. Cysteinyl-tRNA Synthetase Mutations Cause a Multi-System, Recessive Disease That Includes Microcephaly, Developmental Delay, and Brittle Hair and Nails. Am J Hum Genet 2019; 104:520-529. [PMID: 30824121 DOI: 10.1016/j.ajhg.2019.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 01/15/2019] [Indexed: 02/06/2023] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are essential enzymes responsible for charging tRNA molecules with cognate amino acids. Consistent with the essential function and ubiquitous expression of ARSs, mutations in 32 of the 37 ARS-encoding loci cause severe, early-onset recessive phenotypes. Previous genetic and functional data suggest a loss-of-function mechanism; however, our understanding of the allelic and locus heterogeneity of ARS-related disease is incomplete. Cysteinyl-tRNA synthetase (CARS) encodes the enzyme that charges tRNACys with cysteine in the cytoplasm. To date, CARS variants have not been implicated in any human disease phenotype. Here, we report on four subjects from three families with complex syndromes that include microcephaly, developmental delay, and brittle hair and nails. Each affected person carries bi-allelic CARS variants: one individual is compound heterozygous for c.1138C>T (p.Gln380∗) and c.1022G>A (p.Arg341His), two related individuals are compound heterozygous for c.1076C>T (p.Ser359Leu) and c.1199T>A (p.Leu400Gln), and one individual is homozygous for c.2061dup (p.Ser688Glnfs∗2). Measurement of protein abundance, yeast complementation assays, and assessments of tRNA charging indicate that each CARS variant causes a loss-of-function effect. Compared to subjects with previously reported ARS-related diseases, individuals with bi-allelic CARS variants are unique in presenting with a brittle-hair-and-nail phenotype, which most likely reflects the high cysteine content in human keratins. In sum, our efforts implicate CARS variants in human inherited disease, expand the locus and clinical heterogeneity of ARS-related clinical phenotypes, and further support impaired tRNA charging as the primary mechanism of recessive ARS-related disease.
Collapse
Affiliation(s)
- Molly E Kuo
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Arjan F Theil
- Department of Molecular Genetics, Oncode Institute, Erasmus Medical Center, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 CN Rotterdam, the Netherlands
| | - Anneke Kievit
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - May Christine Malicdan
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wendy J Introne
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas Christian
- Department of Biochemistry and Molecular Biochemistry, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Frans W Verheijen
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - Desiree E C Smith
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Center and Amsterdam Gastroenterology and Metabolism, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, 1081 HZ Amsterdam, the Netherlands
| | - Marisa I Mendes
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Center and Amsterdam Gastroenterology and Metabolism, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, 1081 HZ Amsterdam, the Netherlands
| | - Lidia Hussaarts-Odijk
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - Eric van der Meijden
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - Martina Wilke
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| | - Wim Vermeulen
- Department of Molecular Genetics, Oncode Institute, Erasmus Medical Center, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 CN Rotterdam, the Netherlands
| | - Anja Raams
- Department of Molecular Genetics, Oncode Institute, Erasmus Medical Center, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 CN Rotterdam, the Netherlands
| | - Catherine Groden
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shino Shimada
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ya Ming Hou
- Department of Biochemistry and Molecular Biochemistry, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - William A Gahl
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anthony Antonellis
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Center and Amsterdam Gastroenterology and Metabolism, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, 1081 HZ Amsterdam, the Netherlands; Genetic Metabolic Diseases, Amsterdam University Medical Center, University of Amsterdam, 1081 HZ Amsterdam, the Netherlands.
| | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus Medical Center, University Medical Center, 3015 GD Rotterdam, the Netherlands
| |
Collapse
|
10
|
Fujiwara T, Harigae H. Molecular pathophysiology and genetic mutations in congenital sideroblastic anemia. Free Radic Biol Med 2019; 133:179-185. [PMID: 30098397 DOI: 10.1016/j.freeradbiomed.2018.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/02/2018] [Accepted: 08/04/2018] [Indexed: 01/19/2023]
Abstract
Sideroblastic anemia is a heterogeneous congenital and acquired disorder characterized by anemia and the presence of ring sideroblasts in the bone marrow. Congenital sideroblastic anemia (CSA) is a rare disease caused by mutations in genes involved in the heme biosynthesis, iron-sulfur [Fe-S] cluster biosynthesis, and mitochondrial protein synthesis. The most prevalent form of CSA is X-linked sideroblastic anemia, caused by mutations in the erythroid-specific δ-aminolevulinate synthase (ALAS2), which is the first enzyme of the heme biosynthesis pathway in erythroid cells. To date, a remarkable number of genetically undefined CSA cases remain, but a recent application of the next-generation sequencing technology has recognized novel causative genes for CSA. However, in most instances, the detailed molecular mechanisms of how defects of each gene result in the abnormal mitochondrial iron accumulation remain unclear. This review aims to cover the current understanding of the molecular pathophysiology of CSA.
Collapse
Affiliation(s)
- Tohru Fujiwara
- Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Hideo Harigae
- Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan.
| |
Collapse
|
11
|
Vona B, Maroofian R, Bellacchio E, Najafi M, Thompson K, Alahmad A, He L, Ahangari N, Rad A, Shahrokhzadeh S, Bahena P, Mittag F, Traub F, Movaffagh J, Amiri N, Doosti M, Boostani R, Shirzadeh E, Haaf T, Diodato D, Schmidts M, Taylor RW, Karimiani EG. Expanding the clinical phenotype of IARS2-related mitochondrial disease. BMC MEDICAL GENETICS 2018; 19:196. [PMID: 30419932 PMCID: PMC6233262 DOI: 10.1186/s12881-018-0709-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 10/25/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND IARS2 encodes a mitochondrial isoleucyl-tRNA synthetase, a highly conserved nuclear-encoded enzyme required for the charging of tRNAs with their cognate amino acid for translation. Recently, pathogenic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes with autosomal recessive inheritance. These phenotypes range from Leigh and West syndrome to a new syndrome abbreviated CAGSSS that is characterised by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, as well as cataract with no additional anomalies. METHODS Genomic DNA from Iranian probands from two families with consanguineous parental background and overlapping CAGSSS features were subjected to exome sequencing and bioinformatics analysis. RESULTS Exome sequencing and data analysis revealed a novel homozygous missense variant (c.2625C > T, p.Pro909Ser, NM_018060.3) within a 14.3 Mb run of homozygosity in proband 1 and a novel homozygous missense variant (c.2282A > G, p.His761Arg) residing in an ~ 8 Mb region of homozygosity in a proband of the second family. Patient-derived fibroblasts from proband 1 showed normal respiratory chain enzyme activity, as well as unchanged oxidative phosphorylation protein subunits and IARS2 levels. Homology modelling of the known and novel amino acid residue substitutions in IARS2 provided insight into the possible consequence of these variants on function and structure of the protein. CONCLUSIONS This study further expands the phenotypic spectrum of IARS2 pathogenic variants to include two patients (patients 2 and 3) with cataract and skeletal dysplasia and no other features of CAGSSS to the possible presentation of the defects in IARS2. Additionally, this study suggests that adult patients with CAGSSS may manifest central adrenal insufficiency and type II esophageal achalasia and proposes that a variable sensorineural hearing loss onset, proportionate short stature, polyneuropathy, and mild dysmorphic features are possible, as seen in patient 1. Our findings support that even though biallelic IARS2 pathogenic variants can result in a distinctive, clinically recognisable phenotype in humans, it can also show a wide range of clinical presentation from severe pediatric neurological disorders of Leigh and West syndrome to both non-syndromic cataract and cataract accompanied by skeletal dysplasia.
Collapse
Affiliation(s)
- Barbara Vona
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre (THRC), Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Reza Maroofian
- Genetics and Molecular Cell Sciences Research Centre, St George’s, University of London, Cranmer Terrace, London, SW17 0RE UK
| | - Emanuele Bellacchio
- Genetics and Rare Diseases, Research Division, ‘Bambino Gesù’ Children Hospital, Rome, Italy
| | - Maryam Najafi
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Ahmad Alahmad
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Najmeh Ahangari
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Next Generation Genetic Clinic, Mashhad, Iran
| | - Abolfazl Rad
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands
- Cellular and Molecular Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | | | - Paulina Bahena
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Falk Mittag
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany
| | - Frank Traub
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany
| | - Jebrail Movaffagh
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, University of Medical Sciences, Mashhad, Iran
| | - Nafise Amiri
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, University of Medical Sciences, Mashhad, Iran
| | | | - Reza Boostani
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Thomas Haaf
- Institute of Human Genetics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Daria Diodato
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, ‘Bambino Gesu’ Children’s Research Hospital, Rome, Italy
| | - Miriam Schmidts
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Faculty of Medicine, Mathildenstrasse 1, 79112 Freiburg, Germany
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Ehsan Ghayoor Karimiani
- Genetics and Molecular Cell Sciences Research Centre, St George’s, University of London, Cranmer Terrace, London, SW17 0RE UK
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
12
|
Mitochondrial DNA transcription and translation: clinical syndromes. Essays Biochem 2018; 62:321-340. [PMID: 29980628 PMCID: PMC6056718 DOI: 10.1042/ebc20170103] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 01/15/2023]
Abstract
Diagnosing primary mitochondrial diseases is challenging in clinical practice. Although, defective oxidative phosphorylation (OXPHOS) is the common final pathway, it is unknown why different mtDNA or nuclear mutations result in largely heterogeneous and often tissue -specific clinical presentations. Mitochondrial tRNA (mt-tRNA) mutations are frequent causes of mitochondrial diseases both in children and adults. However numerous nuclear mutations involved in mitochondrial protein synthesis affecting ubiquitously expressed genes have been reported in association with very tissue specific clinical manifestations suggesting that there are so far unknown factors determining the tissue specificity in mitochondrial translation. Most of these gene defects result in histological abnormalities and multiple respiratory chain defects in the affected organs. The clinical phenotypes are usually early-onset, severe, and often fatal, implying the importance of mitochondrial translation from birth. However, some rare, reversible infantile mitochondrial diseases are caused by very specific defects of mitochondrial translation. An unbiased genetic approach (whole exome sequencing, RNA sequencing) combined with proteomics and functional studies revealed novel factors involved in mitochondrial translation which contribute to the clinical manifestation and recovery in these rare reversible mitochondrial conditions.
Collapse
|
13
|
Riley LG, Heeney MM, Rudinger-Thirion J, Frugier M, Campagna DR, Zhou R, Hale GA, Hilliard LM, Kaplan JA, Kwiatkowski JL, Sieff CA, Steensma DP, Rennings AJ, Simons A, Schaap N, Roodenburg RJ, Kleefstra T, Arenillas L, Fita-Torró J, Ahmed R, Abboud M, Bechara E, Farah R, Tamminga RYJ, Bottomley SS, Sanchez M, Huls G, Swinkels DW, Christodoulou J, Fleming MD. The phenotypic spectrum of germline YARS2 variants: from isolated sideroblastic anemia to mitochondrial myopathy, lactic acidosis and sideroblastic anemia 2. Haematologica 2018; 103:2008-2015. [PMID: 30026338 PMCID: PMC6269294 DOI: 10.3324/haematol.2017.182659] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 07/12/2018] [Indexed: 01/19/2023] Open
Abstract
YARS2 variants have previously been described in patients with myopathy, lactic acidosis and sideroblastic anemia 2 (MLASA2). YARS2 encodes the mitochondrial tyrosyl-tRNA synthetase, which is responsible for conjugating tyrosine to its cognate mt-tRNA for mitochondrial protein synthesis. Here we describe 14 individuals from 11 families presenting with sideroblastic anemia and YARS2 variants that we identified using a sideroblastic anemia gene panel or exome sequencing. The phenotype of these patients ranged from MLASA to isolated congenital sideroblastic anemia. As in previous cases, inter- and intra-familial phenotypic variability was observed, however, this report includes the first cases with isolated sideroblastic anemia and patients with biallelic YARS2 variants that have no clinically ascertainable phenotype. We identified ten novel YARS2 variants and three previously reported variants. In vitro amino-acylation assays of five novel missense variants showed that three had less effect on the catalytic activity of YARS2 than the most commonly reported variant, p.(Phe52Leu), associated with MLASA2, which may explain the milder phenotypes in patients with these variants. However, the other two missense variants had a more severe effect on YARS2 catalytic efficiency. Several patients carried the common YARS2 c.572 G>T, p.(Gly191Val) variant (minor allele frequency =0.1259) in trans with a rare deleterious YARS2 variant. We have previously shown that the p.(Gly191Val) variant reduces YARS2 catalytic activity. Consequently, we suggest that biallelic YARS2 variants, including severe loss-of-function alleles in trans of the common p.(Gly191Val) variant, should be considered as a cause of isolated congenital sideroblastic anemia, as well as the MLASA syndromic phenotype.
Collapse
Affiliation(s)
- Lisa G Riley
- Genetic Metabolic Disorders Research Unit, Kids Research Institute, Children's Hospital at Westmead, Sydney, Australia.,Discipline of Child & Adolescent Health, Sydney Medical School, University of Sydney, Australia
| | - Matthew M Heeney
- Dana Farber-Boston Children's Center for Cancer and Blood Disorders, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Joëlle Rudinger-Thirion
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Magali Frugier
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Dean R Campagna
- Department of Pathology, Boston Children's Hospital, Boston, MA, USA
| | - Ronghao Zhou
- Dana Farber-Boston Children's Center for Cancer and Blood Disorders, Boston, MA, USA
| | - Gregory A Hale
- Johns Hopkins All Children's Hospital, St. Petersburg, FL, USA
| | - Lee M Hilliard
- Division of Pediatric Hematology Oncology, University of Alabama at Birmingham, AL, USA
| | | | - Janet L Kwiatkowski
- The Children's Hospital of Philadelphia, Division of Hematology, Philadelphia, PA, USA.,University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Colin A Sieff
- Dana Farber-Boston Children's Center for Cancer and Blood Disorders, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - David P Steensma
- Adult Leukemia Program, Dana-Farber Cancer Institute, Boston, MA, USA.,Harvard Medical School, Boston, MA USA
| | - Alexander J Rennings
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Annet Simons
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Nicolaas Schaap
- Department of Hematology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Richard J Roodenburg
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Leonor Arenillas
- Laboratorio Citología Hematológica, Servicio Patología, GRETNHE, IMIM Hospital del Mar Research Institute, Hospital del Mar, Barcelona, Spain
| | - Josep Fita-Torró
- Iron metabolism: regulation and disease group, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-Germans Trias i Pujol, Campus Can Ruti, Carretera de Can Ruti, Cami de les Escoles, Badalona, Spain
| | - Rasha Ahmed
- Department of Pediatrics and Adolescents, American University of Beirut Medical Center, Beirut, Lebanon
| | - Miguel Abboud
- Department of Pediatrics and Adolescents, American University of Beirut Medical Center, Beirut, Lebanon
| | - Elie Bechara
- Department of Pediatrics, Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Roula Farah
- Department of Pediatrics, Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Rienk Y J Tamminga
- Beatrix Children's Hospital, Department of Pediatric Hematology, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Sylvia S Bottomley
- Department of Medicine, University of Oklahoma College of Medicine, Oklahoma City, OK, USA
| | - Mayka Sanchez
- Iron metabolism: regulation and disease group, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-Germans Trias i Pujol, Campus Can Ruti, Carretera de Can Ruti, Cami de les Escoles, Badalona, Spain.,Programme of Predictive and Personalized Medicine of Cancer, Germans Trias i Pujol Research Institute (PMPPC-IGTP), Badalona, Spain.,BloodGenetics, S.L., Esplugues de Llobregat, Barcelona, Spain
| | - Gerwin Huls
- Department of Hematology, University Medical Center Groningen, the Netherlands
| | - Dorine W Swinkels
- Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - John Christodoulou
- Genetic Metabolic Disorders Research Unit, Kids Research Institute, Children's Hospital at Westmead, Sydney, Australia .,Discipline of Child & Adolescent Health, Sydney Medical School, University of Sydney, Australia.,Neurodevelopmental Genomics Research Group, Murdoch Childrens Research Institute, Melbourne, Australia.,Department of Paediatrics, Melbourne Medical School, University of Melbourne, Australia
| | - Mark D Fleming
- Dana Farber-Boston Children's Center for Cancer and Blood Disorders, Boston, MA, USA.,Department of Pathology, Boston Children's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA USA
| |
Collapse
|
14
|
Smith F, Hopton S, Dallabona C, Gilberti M, Falkous G, Norwood F, Donnini C, Gorman GS, Clark B, Taylor RW, Kulasekararaj AG. Sideroblastic anemia with myopathy secondary to novel, pathogenic missense variants in the YARS2 gene. Haematologica 2018; 103:e564-e566. [PMID: 29976739 DOI: 10.3324/haematol.2018.194464] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Frances Smith
- Molecular Pathology, Viapath at King's College Hospital, London, UK
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy
| | - Micol Gilberti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Fiona Norwood
- Department of Neurology, King's College Hospital, London, UK
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Barnaby Clark
- Department of Haematological Medicine, King's College Hospital, London, UK.,Molecular Haematology, King's College London, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | | |
Collapse
|
15
|
Aminoacyl-tRNA synthetases: Structure, function, and drug discovery. Int J Biol Macromol 2018; 111:400-414. [PMID: 29305884 DOI: 10.1016/j.ijbiomac.2017.12.157] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 01/02/2023]
Abstract
Aminoacyl-tRNA synthetases (AARSs) are the enzymes that catalyze the aminoacylation reaction by covalently linking an amino acid to its cognate tRNA in the first step of protein translation. Beyond this classical function, these enzymes are also known to have a role in several metabolic and signaling pathways that are important for cell viability. Study of these enzymes is of great interest to the researchers due to its pivotal role in the growth and survival of an organism. Further, unfolding the interesting structural and functional aspects of these enzymes in the last few years has qualified them as a potential drug target against various diseases. Here we review the classification, function, and the conserved as well the appended structural architecture of these enzymes in detail, including its association with multi-synthetase complexes. We also considered their role in human diseases in terms of mutations and autoantibodies against AARSs. Finally, we have discussed the available inhibitors against AARSs. This review offers comprehensive information on AARSs under a single canopy that would be a good inventory for researchers working in this area.
Collapse
|
16
|
Meyer-Schuman R, Antonellis A. Emerging mechanisms of aminoacyl-tRNA synthetase mutations in recessive and dominant human disease. Hum Mol Genet 2017; 26:R114-R127. [PMID: 28633377 PMCID: PMC5886470 DOI: 10.1093/hmg/ddx231] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 12/29/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are responsible for charging amino acids to cognate tRNA molecules, which is the essential first step of protein translation. Interestingly, mutations in genes encoding ARS enzymes have been implicated in a broad spectrum of human inherited diseases. Bi-allelic mutations in ARSs typically cause severe, early-onset, recessive diseases that affect a wide range of tissues. The vast majority of these mutations show loss-of-function effects and impair protein translation. However, it is not clear how a subset cause tissue-specific phenotypes. In contrast, dominant ARS-mediated diseases specifically affect the peripheral nervous system-most commonly causing axonal peripheral neuropathy-and usually manifest later in life. These neuropathies are linked to heterozygosity for missense mutations in five ARS genes, which points to a shared mechanism of disease. However, it is not clear if a loss-of-function mechanism or a toxic gain-of-function mechanism is responsible for ARS-mediated neuropathy, or if a combination of these mechanisms operate on a mutation-specific basis. Here, we review our current understanding of recessive and dominant ARS-mediated disease. We also propose future directions for defining the molecular mechanisms of ARS mutations toward designing therapies for affected patient populations.
Collapse
Affiliation(s)
- Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| |
Collapse
|
17
|
Sommerville EW, Ng YS, Alston CL, Dallabona C, Gilberti M, He L, Knowles C, Chin SL, Schaefer AM, Falkous G, Murdoch D, Longman C, de Visser M, Bindoff LA, Rawles JM, Dean JCS, Petty RK, Farrugia ME, Haack TB, Prokisch H, McFarland R, Turnbull DM, Donnini C, Taylor RW, Gorman GS. Clinical Features, Molecular Heterogeneity, and Prognostic Implications in YARS2-Related Mitochondrial Myopathy. JAMA Neurol 2017; 74:686-694. [PMID: 28395030 PMCID: PMC5822212 DOI: 10.1001/jamaneurol.2016.4357] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/25/2016] [Indexed: 01/09/2023]
Abstract
Importance YARS2 mutations have been associated with a clinical triad of myopathy, lactic acidosis, and sideroblastic anemia in predominantly Middle Eastern populations. However, the identification of new patients expands the clinical and molecular spectrum of mitochondrial disorders. Objectives To review the clinical, molecular, and genetic features of YARS2-related mitochondrial disease and to demonstrate a new Scottish founder variant. Design, Setting, and Participants An observational case series study was conducted at a national diagnostic center for mitochondrial disease in Newcastle upon Tyne, England, and review of cases published in the literature. Six adults in a well-defined mitochondrial disease cohort and 11 additional cases described in the literature were identified with YARS2 variants between January 1, 2000, and January 31, 2015. Main Outcome and Measures The spectrum of clinical features and disease progression in unreported and reported patients with pathogenic YARS2 variants. Results Seventeen patients (median [interquartile range] age at onset, 1.5 [9.8] years) with YARS2-related mitochondrial myopathy were identified. Fifteen individuals (88%) exhibited an elevated blood lactate level accompanied by generalized myopathy; only 12 patients (71%) manifested with sideroblastic anemia. Hypertrophic cardiomyopathy (9 [53%]) and respiratory insufficiency (8 [47%]) were also prominent clinical features. Central nervous system involvement was rare. Muscle studies showed global cytochrome-c oxidase deficiency in all patients tested and severe, combined respiratory chain complex activity deficiencies. Microsatellite genotyping demonstrated a common founder effect shared between 3 Scottish patients with a p.Leu392Ser variant. Immunoblotting from fibroblasts and myoblasts of an affected Scottish patient showed normal YARS2 protein levels and mild respiratory chain complex defects. Yeast modeling of novel missense YARS2 variants closely correlated with the severity of clinical phenotypes. Conclusions and Relevance The p.Leu392Ser variant is likely a newly identified founder YARS2 mutation. Testing for pathogenic YARS2 variants should be considered in patients presenting with mitochondrial myopathy, characterized by exercise intolerance and muscle weakness even in the absence of sideroblastic anemia irrespective of ethnicity. Regular surveillance and early treatment for cardiomyopathy and respiratory muscle weakness is advocated because early treatment may mitigate the significant morbidity and mortality associated with this genetic disorder.
Collapse
Affiliation(s)
- Ewen W. Sommerville
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Yi Shiau Ng
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Charlotte L. Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | | | - Micol Gilberti
- Department of Life Sciences, University of Parma, Parma, Italy
| | - Langping He
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Charlotte Knowles
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Sophie L. Chin
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Andrew M. Schaefer
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Gavin Falkous
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - David Murdoch
- Department of Cardiology, Queen Elizabeth University Hospital, Glasgow, Scotland
| | - Cheryl Longman
- West of Scotland Regional Genetics Service, Queen Elizabeth University Hospital, Glasgow, Scotland
| | - Marianne de Visser
- Department of Neurology, Academic Medical Centre, Amsterdam, the Netherlands
| | - Laurence A. Bindoff
- Department of Clinical Medicine, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - John M. Rawles
- Department of Medicine, University of Aberdeen, Aberdeen, Scotland (retired)
| | - John C. S. Dean
- Department of Medical Genetics, Medical School Building, University of Aberdeen, Aberdeen, Scotland
| | - Richard K. Petty
- Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, Scotland
| | - Maria E. Farrugia
- Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, Scotland
| | - Tobias B. Haack
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Douglass M. Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Claudia Donnini
- Department of Life Sciences, University of Parma, Parma, Italy
| | - Robert W. Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| | - Gráinne S. Gorman
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, England
| |
Collapse
|
18
|
Abstract
INTRODUCTION This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. METHODS The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as 'definite', 'probable' or 'possible' according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. RESULTS A total of 46 patients ('definite' = 5; 'probable' = 9; 'possible' = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. CONCLUSION MID should be considered if a patient's abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem.
Collapse
Affiliation(s)
| | - Marlies Frank
- First Medical Department, Krankenanstalt Rudolfstiftung, Austria
| |
Collapse
|
19
|
Oprescu SN, Griffin LB, Beg AA, Antonellis A. Predicting the pathogenicity of aminoacyl-tRNA synthetase mutations. Methods 2016; 113:139-151. [PMID: 27876679 DOI: 10.1016/j.ymeth.2016.11.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 11/12/2016] [Accepted: 11/18/2016] [Indexed: 10/24/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed, essential enzymes responsible for charging tRNA with cognate amino acids-the first step in protein synthesis. ARSs are required for protein translation in the cytoplasm and mitochondria of all cells. Surprisingly, mutations in 28 of the 37 nuclear-encoded human ARS genes have been linked to a variety of recessive and dominant tissue-specific disorders. Current data indicate that impaired enzyme function is a robust predictor of the pathogenicity of ARS mutations. However, experimental model systems that distinguish between pathogenic and non-pathogenic ARS variants are required for implicating newly identified ARS mutations in disease. Here, we outline strategies to assist in predicting the pathogenicity of ARS variants and urge cautious evaluation of genetic and functional data prior to linking an ARS mutation to a human disease phenotype.
Collapse
Affiliation(s)
- Stephanie N Oprescu
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Laurie B Griffin
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States; Medical Scientist Training Program, and University of Michigan Medical School, Ann Arbor, MI, United States
| | - Asim A Beg
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, United States; Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, United States.
| |
Collapse
|
20
|
Wedatilake Y, Niazi R, Fassone E, Powell CA, Pearce S, Plagnol V, Saldanha JW, Kleta R, Chong WK, Footitt E, Mills PB, Taanman JW, Minczuk M, Clayton PT, Rahman S. TRNT1 deficiency: clinical, biochemical and molecular genetic features. Orphanet J Rare Dis 2016; 11:90. [PMID: 27370603 PMCID: PMC4930608 DOI: 10.1186/s13023-016-0477-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/24/2016] [Indexed: 11/10/2022] Open
Abstract
Background TRNT1 (CCA-adding transfer RNA nucleotidyl transferase) enzyme deficiency is a new metabolic disease caused by defective post-transcriptional modification of mitochondrial and cytosolic transfer RNAs (tRNAs). Results We investigated four patients from two families with infantile-onset cyclical, aseptic febrile episodes with vomiting and diarrhoea, global electrolyte imbalance during these episodes, sideroblastic anaemia, B lymphocyte immunodeficiency, retinitis pigmentosa, hepatosplenomegaly, exocrine pancreatic insufficiency and renal tubulopathy. Other clinical features found in children include sensorineural deafness, cerebellar atrophy, brittle hair, partial villous atrophy and nephrocalcinosis. Whole exome sequencing and bioinformatic filtering were utilised to identify recessive compound heterozygous TRNT1 mutations (missense mutation c.668T>C, p.Ile223Thr and a novel splice mutation c.342+5G>T) segregating with disease in the first family. The second family was found to have a homozygous TRNT1 mutation (c.569G>T), p.Arg190Ile, (previously published). We found normal mitochondrial translation products using passage matched controls and functional perturbation of 3’ CCA addition to mitochondrial tRNAs (tRNACys, tRNALeuUUR and tRNAHis) in fibroblasts from two patients, demonstrating a pathomechanism affecting the CCA addition to mt-tRNAs. Acute management of these patients included transfusion for anaemia, fluid and electrolyte replacement and immunoglobulin therapy. We also describe three-year follow-up findings after treatment by bone marrow transplantation in one patient, with resolution of fever and reversal of the abnormal metabolic profile. Conclusions Our report highlights that TRNT1 mutations cause a spectrum of disease ranging from a childhood-onset complex disease with manifestations in most organs to an adult-onset isolated retinitis pigmentosa presentation. Systematic review of all TRNT1 cases and mutations reported to date revealed a distinctive phenotypic spectrum and metabolic and other investigative findings, which will facilitate rapid clinical recognition of future cases.
Collapse
Affiliation(s)
- Yehani Wedatilake
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - Rojeen Niazi
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - Elisa Fassone
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | | | | | | | - José W Saldanha
- Division of Mathematical Biology, National Institute for Medical Research, Mill Hill, London, UK
| | - Robert Kleta
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK.,UCL Genetics Institute, London, UK.,Division of Medicine, UCL, London, UK
| | - W Kling Chong
- Radiology Department, Great Ormond Street Hospital, London, UK
| | - Emma Footitt
- Metabolic medicine department, Great Ormond Street Hospital, London, UK
| | - Philippa B Mills
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - Jan-Willem Taanman
- Department of Clinical Neurosciences, UCL Institute of Neurology, London, UK
| | | | - Peter T Clayton
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - Shamima Rahman
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK. .,Mitochondrial Research Group, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, 30, Guilford Street, London, WC1N 1EH, UK.
| |
Collapse
|
21
|
Pseudouridine synthase 1 deficient mice, a model for Mitochondrial Myopathy with Sideroblastic Anemia, exhibit muscle morphology and physiology alterations. Sci Rep 2016; 6:26202. [PMID: 27197761 PMCID: PMC4873756 DOI: 10.1038/srep26202] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/28/2016] [Indexed: 01/02/2023] Open
Abstract
Mitochondrial myopathy with lactic acidosis and sideroblastic anemia (MLASA) is an oxidative phosphorylation disorder, with primary clinical manifestations of myopathic exercise intolerance and a macrocytic sideroblastic anemia. One cause of MLASA is recessive mutations in PUS1, which encodes pseudouridine (Ψ) synthase 1 (Pus1p). Here we describe a mouse model of MLASA due to mutations in PUS1. As expected, certain Ψ modifications were missing in cytoplasmic and mitochondrial tRNAs from Pus1−/− animals. Pus1−/− mice were born at the expected Mendelian frequency and were non-dysmorphic. At 14 weeks the mutants displayed reduced exercise capacity. Examination of tibialis anterior (TA) muscle morphology and histochemistry demonstrated an increase in the cross sectional area and proportion of myosin heavy chain (MHC) IIB and low succinate dehydrogenase (SDH) expressing myofibers, without a change in the size of MHC IIA positive or high SDH myofibers. Cytochrome c oxidase activity was significantly reduced in extracts from red gastrocnemius muscle from Pus1−/− mice. Transmission electron microscopy on red gastrocnemius muscle demonstrated that Pus1−/− mice also had lower intermyofibrillar mitochondrial density and smaller mitochondria. Collectively, these results suggest that alterations in muscle metabolism related to mitochondrial content and oxidative capacity may account for the reduced exercise capacity in Pus1−/− mice.
Collapse
|
22
|
Rouault TA. Mitochondrial iron overload: causes and consequences. Curr Opin Genet Dev 2016; 38:31-37. [PMID: 27026139 DOI: 10.1016/j.gde.2016.02.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/08/2016] [Accepted: 02/21/2016] [Indexed: 02/07/2023]
Abstract
Pathological overload of iron in the mitochondrial matrix has been observed in numerous diseases, including sideroblastic anemias, which have many causes, and in genetic diseases that affect iron-sulfur cluster biogenesis, heme synthesis, and mitochondrial protein translation and its products. Although high expression of the mitochondrial iron importer, mitoferrin, appears to be an underlying common feature, it is unclear what drives high mitoferrin expression and what other proteins are involved in trapping excess toxic iron in the mitochondrial matrix. Numerous examples of human diseases and model systems suggest that mitochondrial iron homeostasis is coordinated through transcriptional remodeling. A cytosolic/nuclear molecule may affect a transcriptional factor to coordinate the events that lead to iron accumulation, but no candidates for this role have yet been identified.
Collapse
Affiliation(s)
- Tracey A Rouault
- Eunice Kennedy Shriver, National Institute of Child Health and Human Development, Bethesda, MD 20892, United States.
| |
Collapse
|
23
|
Khan NA, Govindaraj P, Meena AK, Thangaraj K. Mitochondrial disorders: challenges in diagnosis & treatment. Indian J Med Res 2016; 141:13-26. [PMID: 25857492 PMCID: PMC4405934 DOI: 10.4103/0971-5916.154489] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial dysfunctions are known to be responsible for a number of heterogenous clinical presentations with multi-systemic involvement. Impaired oxidative phosphorylation leading to a decrease in cellular energy (ATP) production is the most important cause underlying these disorders. Despite significant progress made in the field of mitochondrial medicine during the last two decades, the molecular mechanisms underlying these disorders are not fully understood. Since the identification of first mitochondrial DNA (mtDNA) mutation in 1988, there has been an exponential rise in the identification of mtDNA and nuclear DNA mutations that are responsible for mitochondrial dysfunction and disease. Genetic complexity together with ever widening clinical spectrum associated with mitochondrial dysfunction poses a major challenge in diagnosis and treatment. Effective therapy has remained elusive till date and is mostly efficient in relieving symptoms. In this review, we discuss the important clinical and genetic features of mitochondrials disorders with special emphasis on diagnosis and treatment.
Collapse
Affiliation(s)
| | | | | | - Kumarasamy Thangaraj
- CSIR-Centre for Cellular & Molecular Biology, Nizam's Institute of Medical Sciences, Hyderabad, India
| |
Collapse
|
24
|
Fang P, Guo M. Evolutionary Limitation and Opportunities for Developing tRNA Synthetase Inhibitors with 5-Binding-Mode Classification. Life (Basel) 2015; 5:1703-25. [PMID: 26670257 PMCID: PMC4695845 DOI: 10.3390/life5041703] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 11/24/2015] [Accepted: 11/25/2015] [Indexed: 12/30/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are enzymes that catalyze the transfer of amino acids to their cognate tRNAs as building blocks for translation. Each of the aaRS families plays a pivotal role in protein biosynthesis and is indispensable for cell growth and survival. In addition, aaRSs in higher species have evolved important non-translational functions. These translational and non-translational functions of aaRS are attractive for developing antibacterial, antifungal, and antiparasitic agents and for treating other human diseases. The interplay between amino acids, tRNA, ATP, EF-Tu and non-canonical binding partners, had shaped each family with distinct pattern of key sites for regulation, with characters varying among species across the path of evolution. These sporadic variations in the aaRSs offer great opportunity to target these essential enzymes for therapy. Up to this day, growing numbers of aaRS inhibitors have been discovered and developed. Here, we summarize the latest developments and structural studies of aaRS inhibitors, and classify them with distinct binding modes into five categories.
Collapse
Affiliation(s)
- Pengfei Fang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Min Guo
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA.
| |
Collapse
|
25
|
Jiang P, Jin X, Peng Y, Wang M, Liu H, Liu X, Zhang Z, Ji Y, Zhang J, Liang M, Zhao F, Sun YH, Zhang M, Zhou X, Chen Y, Mo JQ, Huang T, Qu J, Guan MX. The exome sequencing identified the mutation in YARS2 encoding the mitochondrial tyrosyl-tRNA synthetase as a nuclear modifier for the phenotypic manifestation of Leber's hereditary optic neuropathy-associated mitochondrial DNA mutation. Hum Mol Genet 2015; 25:584-96. [PMID: 26647310 DOI: 10.1093/hmg/ddv498] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/01/2015] [Indexed: 01/18/2023] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is the most common mitochondrial disorder. Nuclear modifier genes are proposed to modify the phenotypic expression of LHON-associated mitochondrial DNA (mtDNA) mutations. By using an exome sequencing approach, we identified a LHON susceptibility allele (c.572G>T, p.191Gly>Val) in YARS2 gene encoding mitochondrial tyrosyl-tRNA synthetase, which interacts with m.11778G>A mutation to cause visual failure. We performed functional assays by using lymphoblastoid cell lines derived from members of Chinese families (asymptomatic individuals carrying m.11778G>A mutation, or both m.11778G>A and heterozygous p.191Gly>Val mutations and symptomatic subjects harboring m.11778G>A and homozygous p.191Gly>Val mutations) and controls lacking these mutations. The 191Gly>Val mutation reduced the YARS2 protein level in the mutant cells. The aminoacylated efficiency and steady-state level of tRNA(Tyr) were markedly decreased in the cell lines derived from patients both carrying homozygous YARS2 p.191Gly>Val and m.11778G>A mutations. The failure in tRNA(Tyr) metabolism impaired mitochondrial translation, especially for polypeptides with high content of tyrosine codon such as ND4, ND5, ND6 and COX2 in cells lines carrying homozygous YARS2 p.191Gly>Val and m.11778G>A mutations. The YARS2 p.191Gly>Val mutation worsened the respiratory phenotypes associated with m.11778G>A mutation, especially reducing activities of complexes I and IV. The respiratory deficiency altered the efficiency of mitochondrial ATP synthesis and increased the production of reactive oxygen species. Thus, mutated YARS2 aggravates mitochondrial dysfunctions associated with the m.11778G>A mutation, exceeding the threshold for the expression of blindness phenotype. Our findings provided new insights into the pathophysiology of LHON that were manifested by interaction between mtDNA mutation and mutated nuclear-modifier YARS2.
Collapse
Affiliation(s)
- Pingping Jiang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Xiaofen Jin
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Yanyan Peng
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Meng Wang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Hao Liu
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Zengjun Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min Liang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Fuxin Zhao
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yan-Hong Sun
- Department of Ophthalmology, Beijing University of Chinese Medicine and Pharmacology, Beijing, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China and
| | - Xiangtian Zhou
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Ye Chen
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Jun Qin Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, CA, USA
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China,
| |
Collapse
|
26
|
Cao M, Donà M, Valentino ML, Valentino L, Semplicini C, Maresca A, Cassina M, Torraco A, Galletta E, Manfioli V, Sorarù G, Carelli V, Stramare R, Bertini E, Carrozzo R, Salviati L, Pegoraro E. Clinical and molecular study in a long-surviving patient with MLASA syndrome due to novel PUS1 mutations. Neurogenetics 2015; 17:65-70. [PMID: 26556812 DOI: 10.1007/s10048-015-0465-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/12/2015] [Indexed: 02/08/2023]
Abstract
Myopathy-lactic acidosis-sideroblastic anemia (MLASA) syndrome is a rare autosomal recessive disease. We studied a 43-year-old female presenting since childhood with mild cognitive impairment and sideroblastic anemia. She later developed hepatopathy, cardiomyopathy, and insulin-dependent diabetes. Muscle weakness appeared in adolescence and, at age 43, she was unable to walk. Two novel different mutations in the PUS1 gene were identified: c.487delA (p.I163Lfs*4) and c.884 G>A (p.R295Q). Quantitative analysis of DNA from skeletal muscle biopsies showed a significant increase in mitochondrial DNA (mtDNA) content in the patient compared to controls. Clinical and molecular findings of this patient widen the genotype-phenotype spectrum in MLASA syndrome.
Collapse
Affiliation(s)
| | - Marta Donà
- Department of Women's and Children's Health, University of Padova, Padua, Italy
| | - M Lucia Valentino
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Lucia Valentino
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Institute of Neurological Sciences, Bellaria Hospital, Bologna, Italy
| | | | - Alessandra Maresca
- IRCCS Institute of Neurological Sciences, Bellaria Hospital, Bologna, Italy
| | - Matteo Cassina
- Department of Women's and Children's Health, University of Padova, Padua, Italy
| | - Alessandra Torraco
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Children's Research Hospital "Bambino Gesù", IRCCS, Rome, Italy
| | - Eva Galletta
- Department of Neuroscience, University of Padova, Padua, Italy
| | | | - Gianni Sorarù
- Department of Neuroscience, University of Padova, Padua, Italy
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Institute of Neurological Sciences, Bellaria Hospital, Bologna, Italy
| | - Roberto Stramare
- Section of Radiology, Department of Medicine, University of Padova, Padua, Italy
| | - Enrico Bertini
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Children's Research Hospital "Bambino Gesù", IRCCS, Rome, Italy
| | - Rosalba Carrozzo
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Children's Research Hospital "Bambino Gesù", IRCCS, Rome, Italy
| | - Leonardo Salviati
- Department of Women's and Children's Health, University of Padova, Padua, Italy
| | - Elena Pegoraro
- Department of Neuroscience, University of Padova, Padua, Italy. .,Department of Neurosciences, University of Padova, via Giustiniani, 5, 35128, Padua, Italy.
| |
Collapse
|
27
|
Abstract
YARS2 encodes the mitochondrial tyrosyl-tRNA synthetase that catalyzes the covalent binding of tyrosine to its cognate mt-tRNA. Mutations in YARS2 have been identified in patients with myopathy, lactic acidosis, and sideroblastic anemia type 2 (MLASA2). We report here on two siblings with a novel mutation and a review of literature. The older patient presented at 2 months with marked anemia and lactic acidemia. He required periodic blood transfusions until 14 months of age. Cognitive and motor development was normal. His younger sister was diagnosed at birth, presenting with anemia and lactic acidosis at 1 month of age requiring periodical transfusions. She is now 14 months old and doing well. For both our patients, there was no clinical evidence of muscle involvement. We found a new homozygous mutation in YARS2, located in the α-anticodon-binding (αACB) domain, involved in the interaction with the anticodon of the cognate mt-tRNA(Tyr).Our study confirms that MLASA must be considered in patients with congenital sideroblastic anemia and underlines the importance of early diagnosis and supportive therapy in order to prevent severe complications. Clinical severity is variable among YARS2-reported patients: our review of the literature suggests a possible phenotype-genotype correlation, although this should be confirmed in a larger population.
Collapse
|
28
|
Datt M, Sharma A. Evolutionary and structural annotation of disease-associated mutations in human aminoacyl-tRNA synthetases. BMC Genomics 2014; 15:1063. [PMID: 25476837 PMCID: PMC4298046 DOI: 10.1186/1471-2164-15-1063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 11/20/2014] [Indexed: 11/10/2022] Open
Abstract
Background Mutation(s) in proteins are a natural byproduct of evolution but can also cause serious diseases. Aminoacyl-tRNA synthetases (aaRSs) are indispensable components of all cellular protein translational machineries, and in humans they drive translation in both cytoplasm and mitochondria. Mutations in aaRSs have been implicated in a plethora of diseases including neurological conditions, metabolic disorders and cancer. Results We have developed an algorithmic approach for genome-wide analyses of sequence substitutions that combines evolutionary, structural and functional information. This pipeline enabled us to super-annotate human aaRS mutations and analyze their linkage to health disorders. Our data suggest that in some but not all cases, aaRS mutations occur in functional and structural sectors where they can manifest their pathological effects by altering enzyme activity or causing structural instability. Further, mutations appear in both solvent exposed and buried regions of aaRSs indicating that these alterations could lead to dysfunctional enzymes resulting in abnormal protein translation routines by affecting inter-molecular interactions or by disruption of non-bonded interactions. Overall, the prevalence of mutations is much higher in mitochondrial aaRSs, and the two most often mutated aaRSs are mitochondrial glutamyl-tRNA synthetase and dual localized glycyl-tRNA synthetase. Out of 63 mutations annotated in this work, only 12 (~20%) were observed in regions that could directly affect aminoacylation activity via either binding to ATP/amino-acid, tRNA or by involvement in dimerization. Mutations in structural cores or at potential biomolecular interfaces account for ~55% mutations while remaining mutations (~25%) remain structurally un-annotated. Conclusion This work provides a comprehensive structural framework within which most defective human aaRSs have been structurally analyzed. The methodology described here could be employed to annotate mutations in other protein families in a high-throughput manner. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1063) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Amit Sharma
- Structural and Computational Biology group, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India.
| |
Collapse
|
29
|
Burrage LC, Tang S, Wang J, Donti TR, Walkiewicz M, Luchak JM, Chen LC, Schmitt ES, Niu Z, Erana R, Hunter JV, Graham BH, Wong LJ, Scaglia F. Mitochondrial myopathy, lactic acidosis, and sideroblastic anemia (MLASA) plus associated with a novel de novo mutation (m.8969G>A) in the mitochondrial encoded ATP6 gene. Mol Genet Metab 2014; 113:207-12. [PMID: 25037980 PMCID: PMC4253070 DOI: 10.1016/j.ymgme.2014.06.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 06/24/2014] [Accepted: 06/24/2014] [Indexed: 11/18/2022]
Abstract
Mitochondrial myopathy, lactic acidosis and sideroblastic anemia (MLASA) is a rare mitochondrial disorder that has previously been associated with mutations in PUS1 and YARS2. In the present report, we describe a 6-year old male with an MLASA plus phenotype. This patient had features of MLASA in the setting of developmental delay, sensorineural hearing loss, epilepsy, agenesis of the corpus callosum, failure to thrive, and stroke-like episodes. Sequencing of the mitochondrial genome identified a novel de novo, heteroplasmic mutation in the mitochondrial DNA (mtDNA) encoded ATP6 gene (m.8969G>A, p.S148N). Whole exome sequencing did not identify mutations or variants in PUS1 or YARS2 or any known nuclear genes that could affect mitochondrial function and explain this phenotype. Studies of fibroblasts derived from the patient revealed a decrease in oligomycin-sensitive respiration, a finding which is consistent with a complex V defect. Thus, this mutation in MT-ATP6 may represent the first mtDNA point mutation associated with the MLASA phenotype.
Collapse
Affiliation(s)
- Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Jing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Taraka R Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Magdalena Walkiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - J Michael Luchak
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Li-Chieh Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Eric S Schmitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Zhiyv Niu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Rodrigo Erana
- Department of Pediatrics, Division of Hematology and Oncology, Baylor College of Medicine, Houston, TX, USA.
| | - Jill V Hunter
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA.
| | - Brett H Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
30
|
Diodato D, Melchionda L, Haack TB, Dallabona C, Baruffini E, Donnini C, Granata T, Ragona F, Balestri P, Margollicci M, Lamantea E, Nasca A, Powell CA, Minczuk M, Strom TM, Meitinger T, Prokisch H, Lamperti C, Zeviani M, Ghezzi D. VARS2 and TARS2 mutations in patients with mitochondrial encephalomyopathies. Hum Mutat 2014; 35:983-9. [PMID: 24827421 PMCID: PMC4140549 DOI: 10.1002/humu.22590] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 04/29/2014] [Indexed: 01/14/2023]
Abstract
By way of whole-exome sequencing, we identified a homozygous missense mutation in VARS2 in one subject with microcephaly and epilepsy associated with isolated deficiency of the mitochondrial respiratory chain (MRC) complex I and compound heterozygous mutations in TARS2 in two siblings presenting with axial hypotonia and severe psychomotor delay associated with multiple MRC defects. The nucleotide variants segregated within the families, were absent in Single Nucleotide Polymorphism (SNP) databases and are predicted to be deleterious. The amount of VARS2 and TARS2 proteins and valyl-tRNA and threonyl-tRNA levels were decreased in samples of afflicted patients according to the genetic defect. Expression of the corresponding wild-type transcripts in immortalized mutant fibroblasts rescued the biochemical impairment of mitochondrial respiration and yeast modeling of the VARS2 mutation confirmed its pathogenic role. Taken together, these data demonstrate the role of the identified mutations for these mitochondriopathies. Our study reports the first mutations in the VARS2 and TARS2 genes, which encode two mitochondrial aminoacyl-tRNA synthetases, as causes of clinically distinct, early-onset mitochondrial encephalopathies.
Collapse
MESH Headings
- Cell Line
- Child
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Electron Transport Complex I/genetics
- Electron Transport Complex I/metabolism
- Fibroblasts/cytology
- Fibroblasts/metabolism
- HLA Antigens/genetics
- HLA Antigens/metabolism
- Heterozygote
- Homozygote
- Humans
- Infant
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Male
- Mitochondria/enzymology
- Mitochondria/genetics
- Mitochondria/pathology
- Mitochondrial Encephalomyopathies/enzymology
- Mitochondrial Encephalomyopathies/genetics
- Mitochondrial Encephalomyopathies/pathology
- Mutation
- Polymorphism, Genetic
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Transfer, Thr/genetics
- RNA, Transfer, Thr/metabolism
- RNA, Transfer, Val/genetics
- RNA, Transfer, Val/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Threonine-tRNA Ligase/genetics
- Threonine-tRNA Ligase/metabolism
- Valine-tRNA Ligase/genetics
- Valine-tRNA Ligase/metabolism
Collapse
Affiliation(s)
- Daria Diodato
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Laura Melchionda
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Tobias B Haack
- Institute of Human Genetics, Helmholtz Zentrum MünchenNeuherberg, Germany
- Institute of Human Genetics, Technische Universitat MünchenMunich, Germany
| | | | | | - Claudia Donnini
- Department of Life Sciences, University of ParmaParma, Italy
| | - Tiziana Granata
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Francesca Ragona
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Paolo Balestri
- Department of Pediatrics, University of SienaSiena, Italy
| | | | - Eleonora Lamantea
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Alessia Nasca
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| | | | | | - Tim M Strom
- Institute of Human Genetics, Helmholtz Zentrum MünchenNeuherberg, Germany
- Institute of Human Genetics, Technische Universitat MünchenMunich, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum MünchenNeuherberg, Germany
- Institute of Human Genetics, Technische Universitat MünchenMunich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum MünchenNeuherberg, Germany
- Institute of Human Genetics, Technische Universitat MünchenMunich, Germany
| | - Costanza Lamperti
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| | - Massimo Zeviani
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
- MRC Mitochondrial Biology UnitCambridge, United Kingdom
| | - Daniele Ghezzi
- Unit of Molecular Neurogenetics, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) Istituto Neurologico “Carlo Besta”Milan, Italy
| |
Collapse
|
31
|
Abstract
Sideroblastic anemias (SAs) may be acquired or congenital and share the features of disrupted utilization of iron in the erythroblast, ineffective erythropoiesis, and variable systemic iron overload. Congenital forms can have associated syndromic features or be nonsyndromic, and many of them have mutations in genes encoding proteins involved in heme biosynthesis, iron-sulfur cluster biogenesis, or mitochondrial protein synthesis. The mechanism(s) for the acquired clonal SA is undefined and is under intense study. Precise diagnosis of these disorders rests on careful clinical and laboratory evaluation, including molecular analysis. Supportive treatments usually provide for a favorable prognosis and often for normal survival.
Collapse
Affiliation(s)
- Sylvia S Bottomley
- Department of Medicine, University of Oklahoma College of Medicine, 755 Research Park, Suite 427, Oklahoma City, OK 73104, USA.
| | - Mark D Fleming
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Bader 124.1, Boston, MA 02115, USA
| |
Collapse
|
32
|
McMillan HJ, Schwartzentruber J, Smith A, Lee S, Chakraborty P, Bulman DE, Beaulieu CL, Majewski J, Boycott KM, Geraghty MT. Compound heterozygous mutations in glycyl-tRNA synthetase are a proposed cause of systemic mitochondrial disease. BMC MEDICAL GENETICS 2014; 15:36. [PMID: 24669931 PMCID: PMC3973608 DOI: 10.1186/1471-2350-15-36] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 03/12/2014] [Indexed: 12/31/2022]
Abstract
Background Glycyl-tRNA synthetase (GARS) is an aminoacyl-tRNA synthetase (ARS) that links the amino acid glycine to its corresponding tRNA prior to protein translation and is one of three bifunctional ARS that are active within both the cytoplasm and mitochondria. Dominant mutations in GARS cause rare forms of Charcot-Marie-Tooth disease and distal spinal muscular atrophy. Case presentation We report a 12-year old girl who presented with clinical and biochemical features of a systemic mitochondrial disease including exercise-induced myalgia, non-compaction cardiomyopathy, persistent elevation of blood lactate and alanine and MRI evidence of mild periventricular leukomalacia. Using exome sequencing she was found to harbor compound heterozygous mutations within the glycyl-tRNA synthetase (GARS) gene; c.1904C > T; p.Ser635Leu and c.1787G > A; p.Arg596Gln. Each mutation occurred at a highly conserved site within the anticodon binding domain. Conclusion Our findings suggest that recessive mutations in GARS may cause systemic mitochondrial disease. This phenotype is distinct from patients with previously reported dominant mutations in this gene, thereby expanding the spectrum of disease associated with GARS dysregulation.
Collapse
Affiliation(s)
- Hugh J McMillan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, 401 Smyth Rd, Ottawa, ON K1H 8 L1, Canada.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Tissue-specific loss of DARS2 activates stress responses independently of respiratory chain deficiency in the heart. Cell Metab 2014; 19:458-69. [PMID: 24606902 DOI: 10.1016/j.cmet.2014.02.004] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 10/08/2013] [Accepted: 01/27/2014] [Indexed: 01/27/2023]
Abstract
Adaptive stress responses activated upon mitochondrial dysfunction are assumed to arise in order to counteract respiratory chain deficiency. Here, we demonstrate that loss of DARS2 (mitochondrial aspartyl-tRNA synthetase) leads to the activation of various stress responses in a tissue-specific manner independently of respiratory chain deficiency. DARS2 depletion in heart and skeletal muscle leads to the severe deregulation of mitochondrial protein synthesis followed by a strong respiratory chain deficit in both tissues, yet the activation of adaptive responses is observed predominantly in cardiomyocytes. We show that the impairment of mitochondrial proteostasis in the heart activates the expression of mitokine FGF21, which acts as a signal for cell-autonomous and systemic metabolic changes. Conversely, skeletal muscle has an intrinsic mechanism relying on the slow turnover of mitochondrial transcripts and higher proteostatic buffering capacity. Our results show that mitochondrial dysfunction is sensed independently of respiratory chain deficiency, questioning the current view on the role of stress responses in mitochondrial diseases.
Collapse
|
34
|
The Mitochondrial Aminoacyl tRNA Synthetases: Genes and Syndromes. Int J Cell Biol 2014; 2014:787956. [PMID: 24639874 PMCID: PMC3932222 DOI: 10.1155/2014/787956] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/01/2013] [Indexed: 02/05/2023] Open
Abstract
Mitochondrial respiratory chain (RC) disorders are a group of genetically and clinically heterogeneous diseases. This is because protein components of the RC are encoded by both mitochondrial and nuclear genomes and are essential in all cells. In addition, the biogenesis and maintenance of mitochondria, including mitochondrial DNA (mtDNA) replication, transcription, and translation, require nuclear-encoded genes. In the past decade, a growing number of syndromes associated with dysfunction of mtDNA translation have been reported. This paper reviews the current knowledge of mutations affecting mitochondrial aminoacyl tRNAs synthetases and their role in the pathogenic mechanisms underlying the different clinical presentations.
Collapse
|
35
|
Nakajima J, Eminoglu TF, Vatansever G, Nakashima M, Tsurusaki Y, Saitsu H, Kawashima H, Matsumoto N, Miyake N. A novel homozygous YARS2 mutation causes severe myopathy, lactic acidosis, and sideroblastic anemia 2. J Hum Genet 2014; 59:229-32. [PMID: 24430573 DOI: 10.1038/jhg.2013.143] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/17/2013] [Accepted: 12/17/2013] [Indexed: 11/09/2022]
Abstract
Mitochondrial diseases are associated with defects of adenosine triphosphate production and energy supply to organs as a result of dysfunctions of the mitochondrial respiratory chain. Biallelic mutations in the YARS2 gene encoding mitochondrial tyrosyl-tRNA synthetase cause myopathy, lactic acidosis, and sideroblastic anemia 2 (MLASA2), a type of mitochondrial disease. Here, we report a consanguineous Turkish family with two siblings showing severe metabolic decompensation including recurrent hypoglycemia, lactic acidosis, and transfusion-dependent anemia. Using whole-exome sequencing of the proband and his parents, we identified a novel YARS2 mutation (c.1303A>G, p.Ser435Gly) that was homozygous in the patient and heterozygous in his parents. This mutation is located at the ribosomal protein S4-like domain of the gene, while other reported YARS2 mutations are all within the catalytic domain. Interestingly, the proband showed more severe symptoms and an earlier onset than previously reported patients, suggesting the functional importance of the S4-like domain in tyrosyl-tRNA synthetase.
Collapse
Affiliation(s)
- Junya Nakajima
- 1] Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan [2] Department of Pediatrics, Tokyo Medical University, Shinjuku, Japan
| | - Tuba F Eminoglu
- Department of Pediatric Metabolism, Ankara University School of Medicine, Ankara, Turkey
| | - Goksel Vatansever
- Department of Pediatrics, Ankara University School of Medicine, Ankara, Turkey
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshinori Tsurusaki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | | | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| |
Collapse
|
36
|
Almalki A, Alston CL, Parker A, Simonic I, Mehta SG, He L, Reza M, Oliveira JM, Lightowlers RN, McFarland R, Taylor RW, Chrzanowska-Lightowlers ZM. Mutation of the human mitochondrial phenylalanine-tRNA synthetase causes infantile-onset epilepsy and cytochrome c oxidase deficiency. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1842:56-64. [PMID: 24161539 PMCID: PMC3898479 DOI: 10.1016/j.bbadis.2013.10.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/30/2013] [Accepted: 10/17/2013] [Indexed: 11/24/2022]
Abstract
Mitochondrial aminoacyl-tRNA synthetases (aaRSs) are essential enzymes in protein synthesis since they charge tRNAs with their cognate amino acids. Mutations in the genes encoding mitochondrial aaRSs have been associated with a wide spectrum of human mitochondrial diseases. Here we report the identification of pathogenic mutations (a partial genomic deletion and a highly conserved p. Asp325Tyr missense variant) in FARS2, the gene encoding mitochondrial phenylalanyl-tRNA synthetase, in a patient with early-onset epilepsy and isolated complex IV deficiency in muscle. The biochemical defect was expressed in myoblasts but not in fibroblasts and associated with decreased steady state levels of COXI and COXII protein and reduced steady state levels of the mt-tRNA(Phe) transcript. Functional analysis of the recombinant mutant p. Asp325Tyr FARS2 protein showed an inability to bind ATP and consequently undetectable aminoacylation activity using either bacterial tRNA or human mt-tRNA(Phe) as substrates. Lentiviral transduction of cells with wildtype FARS2 restored complex IV protein levels, confirming that the p.Asp325Tyr mutation is pathogenic, causing respiratory chain deficiency and neurological deficits on account of defective aminoacylation of mt-tRNA(Phe).
Collapse
Affiliation(s)
- Abdulraheem Almalki
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Charlotte L. Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Alasdair Parker
- Child Development Centre, Addenbrooke's Hospital, Cambridge, UK
| | - Ingrid Simonic
- Medical Genetics Laboratories, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Sarju G. Mehta
- Department of Medical Genetics, Addenbrookes Hospital, Cambridge, UK
| | - Langping He
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Mojgan Reza
- Biobank, Institute for Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Jorge M.A. Oliveira
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Robert N. Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Robert W. Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Zofia M.A. Chrzanowska-Lightowlers
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| |
Collapse
|
37
|
Riley LG, Menezes MJ, Rudinger-Thirion J, Duff R, de Lonlay P, Rotig A, Tchan MC, Davis M, Cooper ST, Christodoulou J. Phenotypic variability and identification of novel YARS2 mutations in YARS2 mitochondrial myopathy, lactic acidosis and sideroblastic anaemia. Orphanet J Rare Dis 2013; 8:193. [PMID: 24344687 PMCID: PMC3878580 DOI: 10.1186/1750-1172-8-193] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/13/2013] [Indexed: 12/21/2022] Open
Abstract
Background Mutations in the mitochondrial tyrosyl-tRNA synthetase (YARS2) gene have previously been identified as a cause of the tissue specific mitochondrial respiratory chain (RC) disorder, Myopathy, Lactic Acidosis, Sideroblastic Anaemia (MLASA). In this study, a cohort of patients with a mitochondrial RC disorder for who anaemia was a feature, were screened for mutations in YARS2. Methods Twelve patients were screened for YARS2 mutations by Sanger sequencing. Clinical data were compared. Functional assays were performed to confirm the pathogenicity of the novel mutations and to investigate tissue specific effects. Results PathogenicYARS2 mutations were identified in three of twelve patients screened. Two patients were found to be homozygous for the previously reported p.Phe52Leu mutation, one severely and one mildly affected. These patients had different mtDNA haplogroups which may contribute to the observed phenotypic variability. A mildly affected patient was a compound heterozygote for two novel YARS2 mutations, p.Gly191Asp and p.Arg360X. The p.Gly191Asp mutation resulted in a 38-fold loss in YARS2 catalytic efficiency and the p.Arg360X mutation did not produce a stable protein. The p.Phe52Leu and p.Gly191Asp/p.Arg360X mutations resulted in more severe RC deficiency of complexes I, III and IV in muscle cells compared to fibroblasts, but had relatively normal YARS2 protein levels. The muscle-specific RC deficiency can be related to the increased requirement for RC complexes in muscle. There was also a failure of mtDNA proliferation upon myogenesis in patient cells which may compound the RC defect. Patient muscle had increased levels of PGC1-α and TFAM suggesting mitochondrial biogenesis was activated as a potential compensatory mechanism. Conclusion In this study we have identified novel YARS2 mutations and noted marked phenotypic variability among YARS2 MLASA patients, with phenotypes ranging from mild to lethal, and we suggest that the background mtDNA haplotype may be contributing to the phenotypic variability. These findings have implications for diagnosis and prognostication of the MLASA and related phenotypes.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - John Christodoulou
- Genetic Metabolic Disorders Research Unit, Kids Research Institute, Children's Hospital at Westmead 2145, Sydney, Australia.
| |
Collapse
|
38
|
Fujiwara T, Harigae H. Pathophysiology and genetic mutations in congenital sideroblastic anemia. Pediatr Int 2013; 55:675-9. [PMID: 24003969 DOI: 10.1111/ped.12217] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 08/28/2013] [Indexed: 01/23/2023]
Abstract
Sideroblastic anemias are heterogeneous congenital and acquired disorders characterized by anemia and the presence of ringed sideroblasts in the bone marrow. Congenital sideroblastic anemia (CSA) is a rare disease caused by mutations of genes involved in heme biosynthesis, iron-sulfur [Fe-S] cluster biosynthesis, and mitochondrial protein synthesis. The most common form is X-linked sideroblastic anemia, due to mutations in the erythroid-specific δ-aminolevulinate synthase (ALAS2), which is the first enzyme of the heme biosynthesis pathway in erythroid cells. Other known etiologies include mutations in the erythroid specific mitochondrial transporter (SLC25A38), adenosine triphosphate (ATP) binding cassette B7 (ABCB7), glutaredoxin 5 (GLRX5), thiamine transporter SLC19A2, the RNA-modifying enzyme pseudouridine synthase (PUS1), and mitochondrial tyrosyl-tRNA synthase (YARS2), as well as mitochondrial DNA deletions. Due to its rarity, however, there have been few systematic pathophysiological and genetic investigations focusing on sideroblastic anemia. Therefore, a nationwide survey of sideroblastic anemia was conducted in Japan to investigate the epidemiology and pathogenesis of this disease. This review will cover the findings of this recent survey and summarize the current understanding of the pathophysiology and genetic mutations involved in CSA.
Collapse
Affiliation(s)
- Tohru Fujiwara
- Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, Sendai, Japan; Molecular Hematology/Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | |
Collapse
|
39
|
Kildey K, Flower RL, Tran TV, Tunningley R, Harris J, Dean MM. Characterization of ENU-induced Mutations in Red Blood Cell Structural Proteins. Comput Struct Biotechnol J 2013; 6:e201303012. [PMID: 24688720 PMCID: PMC3962129 DOI: 10.5936/csbj.201303012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/05/2013] [Accepted: 09/08/2013] [Indexed: 12/25/2022] Open
Abstract
Murine models with modified gene function as a result of N-ethyl-N-nitrosourea (ENU) mutagenesis have been used to study phenotypes resulting from genetic change. This study investigated genetic factors associated with red blood cell (RBC) physiology and structural integrity that may impact on blood component storage and transfusion outcome. Forward and reverse genetic approaches were employed with pedigrees of ENU-treated mice using a homozygous recessive breeding strategy. In a "forward genetic" approach, pedigree selection was based upon identification of an altered phenotype followed by exome sequencing to identify a causative mutation. In a second strategy, a "reverse genetic" approach based on selection of pedigrees with mutations in genes of interest was utilised and, following breeding to homozygosity, phenotype assessed. Thirty-three pedigrees were screened by the forward genetic approach. One pedigree demonstrated reticulocytosis, microcytic anaemia and thrombocytosis. Exome sequencing revealed a novel single nucleotide variation (SNV) in Ank1 encoding the RBC structural protein ankyrin-1 and the pedigree was designated Ank1(EX34). The reticulocytosis and microcytic anaemia observed in the Ank1(EX34) pedigree were similar to clinical features of hereditary spherocytosis in humans. For the reverse genetic approach three pedigrees with different point mutations in Spnb1 encoding RBC protein spectrin-1β, and one pedigree with a mutation in Epb4.1, encoding band 4.1 were selected for study. When bred to homozygosity two of the spectrin-1β pedigrees (a, b) demonstrated increased RBC count, haemoglobin (Hb) and haematocrit (HCT). The third Spnb1 mutation (spectrin-1β c) and mutation in Epb4.1 (band 4.1) did not significantly affect the haematological phenotype, despite these two mutations having a PolyPhen score predicting the mutation may be damaging. Exome sequencing allows rapid identification of causative mutations and development of databases of mutations predicted to be disruptive. These tools require further refinement but provide new approaches to the study of genetically defined changes that may impact on blood component storage and transfusion outcome.
Collapse
Affiliation(s)
- Katrina Kildey
- Research and Development, Australian Red Cross Blood Service, Brisbane, Australia ; Queensland University of Technology, Brisbane, Australia
| | - Robert L Flower
- Research and Development, Australian Red Cross Blood Service, Brisbane, Australia ; Queensland University of Technology, Brisbane, Australia
| | - Thu V Tran
- Research and Development, Australian Red Cross Blood Service, Brisbane, Australia
| | | | | | - Melinda M Dean
- Research and Development, Australian Red Cross Blood Service, Brisbane, Australia
| |
Collapse
|
40
|
Shahni R, Wedatilake Y, Cleary MA, Lindley KJ, Sibson KR, Rahman S. A distinct mitochondrial myopathy, lactic acidosis and sideroblastic anemia (MLASA) phenotype associates with YARS2 mutations. Am J Med Genet A 2013; 161A:2334-8. [PMID: 23918765 PMCID: PMC3884767 DOI: 10.1002/ajmg.a.36065] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/02/2013] [Indexed: 01/19/2023]
Abstract
Nuclear-encoded disorders of mitochondrial translation are clinically and genetically heterogeneous. Genetic causes include defects of mitochondrial aminoacyl-tRNA synthetases, and factors required for initiation, elongation and termination of protein synthesis as well as ribosome recycling. We report on a new case of myopathy, lactic acidosis and sideroblastic anemia (MLASA) syndrome caused by defective mitochondrial tyrosyl aminoacylation. The patient presented at 1 year with anemia initially attributed to iron deficiency. Bone marrow aspirate at 5 years revealed ringed sideroblasts but transfusion dependency did not occur until 11 years. Other clinical features included lactic acidosis, poor weight gain, hypertrophic cardiomyopathy and severe myopathy leading to respiratory failure necessitating ventilatory support. Long-range PCR excluded mitochondrial DNA rearrangements. Clinical diagnosis of MLASA prompted direct sequence analysis of the YARS2 gene encoding the mitochondrial tyrosyl-tRNA synthetase, which revealed homozygosity for a known pathogenic mutation, c.156C>G;p.F52L. Comparison with four previously reported cases demonstrated remarkable clinical homogeneity. First line investigation of MLASA should include direct sequence analysis of YARS2 and PUS1 (encoding a tRNA modification factor) rather than muscle biopsy. Early genetic diagnosis is essential for counseling and to facilitate appropriate supportive therapy. Reasons for segregation of specific clinical phenotypes with particular mitochondrial aminoacyl tRNA-synthetase defects remain unknown. © 2013 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Rojeen Shahni
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
| | - Yehani Wedatilake
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
| | | | - Keith J Lindley
- Gastroenterology Unit, Great Ormond Street HospitalLondon, UK
| | - Keith R Sibson
- Haematology Unit, Great Ormond Street HospitalLondon, UK
| | - Shamima Rahman
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child HealthLondon, UK
- Metabolic Unit, Great Ormond Street HospitalLondon, UK
- *Correspondence to:, Dr. Shamima Rahman, Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK., E-mail:
| |
Collapse
|
41
|
Konovalova S, Tyynismaa H. Mitochondrial aminoacyl-tRNA synthetases in human disease. Mol Genet Metab 2013; 108:206-11. [PMID: 23433712 DOI: 10.1016/j.ymgme.2013.01.010] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/20/2013] [Accepted: 01/20/2013] [Indexed: 01/15/2023]
Abstract
Mitochondrial aminoacyl-tRNA synthetases (mtARSs) are essential in the process of transferring genetic information from mitochondrial DNA to the complexes of the oxidative phosphorylation system. These synthetases perform an integral step in the initiation of mitochondrial protein synthesis by charging tRNAs with their cognate amino acids. All mtARSs are encoded by nuclear genes, nine of which have recently been described as disease genes for mitochondrial disorders. Unexpectedly, the clinical presentations of these diseases are highly specific to the affected synthetase. Encephalopathy is the most common manifestation but again with gene-specific outcomes. Other clinical presentations include myopathy with anemia, cardiomyopathy, tubulopathy and hearing loss with female ovarian dysgenesis. Here we review the described mutation types and the associated patient phenotypes. The identified mutation spectrum suggests that only mutation types that allow some residual tRNA-charging activity can result in the described mtARS diseases but the molecular mechanisms behind the selective tissue involvement are not currently understood.
Collapse
Affiliation(s)
- Svetlana Konovalova
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki and Department of Medical Genetics, Haartman Institute, University of Helsinki, 00014 Helsinki, Finland
| | | |
Collapse
|
42
|
Yao P, Fox PL. Aminoacyl-tRNA synthetases in medicine and disease. EMBO Mol Med 2013; 5:332-43. [PMID: 23427196 PMCID: PMC3598075 DOI: 10.1002/emmm.201100626] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/30/2012] [Accepted: 01/15/2013] [Indexed: 12/12/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are essential and ubiquitous 'house-keeping' enzymes responsible for charging amino acids to their cognate tRNAs and providing the substrates for global protein synthesis. Recent studies have revealed a role of multiple ARSs in pathology, and their potential use as pharmacological targets and therapeutic reagents. The ongoing discovery of genetic mutations in human ARSs is increasing exponentially and can be considered an important determinant of disease etiology. Several chemical compounds target bacterial, fungal and human ARSs as antibiotics or disease-targeting medicines. Remarkably, ongoing exploration of noncanonical functions of ARSs has shown important contributions to control of angiogenesis, inflammation, tumourigenesis and other important physiopathological processes. Here, we summarize the roles of ARSs in human diseases and medicine, focusing on the most recent and exciting discoveries.
Collapse
Affiliation(s)
- Peng Yao
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | | |
Collapse
|
43
|
Schwenzer H, Zoll J, Florentz C, Sissler M. Pathogenic implications of human mitochondrial aminoacyl-tRNA synthetases. Top Curr Chem (Cham) 2013; 344:247-92. [PMID: 23824528 DOI: 10.1007/128_2013_457] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mitochondria are considered as the powerhouse of eukaryotic cells. They host several central metabolic processes fueling the oxidative phosphorylation pathway (OXPHOS) that produces ATP from its precursors ADP and inorganic phosphate Pi (PPi). The respiratory chain complexes responsible for the OXPHOS pathway are formed from complementary sets of protein subunits encoded by the nuclear genome and the mitochondrial genome, respectively. The expression of the mitochondrial genome requires a specific and fully active translation machinery from which aminoacyl-tRNA synthetases (aaRSs) are key actors. Whilst the macromolecules involved in mammalian mitochondrial translation have been under investigation for many years, there has been an explosion of interest in human mitochondrial aaRSs (mt-aaRSs) since the discovery of a large (and growing) number of mutations in these genes that are linked to a variety of neurodegenerative disorders. Herein we will review the present knowledge on mt-aaRSs in terms of their biogenesis, their connection to mitochondrial respiration, i.e., the respiratory chain (RC) complexes, and to the mitochondrial translation machinery. The pathology-related mutations detected so far are described, with special attention given to their impact on mt-aaRSs biogenesis, functioning, and/or subsequent activities. The collected data to date shed light on the diverse routes that are linking primary molecular possible impact of a mutation to its phenotypic expression. It is envisioned that a variety of mechanisms, inside and outside the translation machinery, would play a role on the heterogeneous manifestations of mitochondrial disorders.
Collapse
Affiliation(s)
- Hagen Schwenzer
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, IBMC, 15 rue René Descartes, 67084, Strasbourg Cedex, France,
| | | | | | | |
Collapse
|
44
|
Defective valyl-tRNA synthetase hampers the mitochondrial respiratory chain in Neurospora crassa. Biochem J 2012; 448:297-306. [PMID: 22957697 DOI: 10.1042/bj20120963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Respiratory chain deficiency can result from alterations in mitochondrial and/or cytosolic protein synthesis due to the dual genetic origin of mitochondrial oxidative phosphorylation. In the present paper we report a point mutation (D750G) in the bifunctional VARS (valyl-tRNA synthetase) of the fungus Neurospora crassa, associated with a temperature-sensitive phenotype. Analysis of the mutant strain revealed decreased steady-state levels of VARS and a clear reduction in the rate of mitochondrial protein synthesis. We observed a robust induction of the mitochondrial alternative oxidase with a concomitant decrease in the canonical respiratory pathway, namely in cytochrome b and aa3 content. Furthermore, the mutant strain accumulates the peripheral arm of complex I and depicts decreased levels of complexes III and IV, consistent with severe impairment of the mitochondrial respiratory chain. The phenotypic alterations of the mutant strain are observed at the permissive growth temperature and exacerbated upon increase of the temperature. Surprisingly, glucose-6-phosphate dehydrogenase activities were similar in the wild-type and mutant strains, whereas mitochondrial activities for succinate dehydrogenase and alternative NADH dehydrogenases were increased in the mutant strain, suggesting that the VARSD-G mutation does not affect overall cytosolic protein synthesis. Expression of the wild-type vars gene rescues all of the mutant phenotypes, indicating that the VARSD-G mutation is a loss-of-function mutation that results in a combined respiratory chain deficiency.
Collapse
|