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Errbii M, Ernst UR, Lajmi A, Privman E, Gadau J, Schrader L. Evolutionary genomics of socially polymorphic populations of Pogonomyrmex californicus. BMC Biol 2024; 22:109. [PMID: 38735942 PMCID: PMC11089791 DOI: 10.1186/s12915-024-01907-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 04/30/2024] [Indexed: 05/14/2024] Open
Abstract
BACKGROUND Social insects vary considerably in their social organization both between and within species. In the California harvester ant, Pogonomyrmex californicus (Buckley 1867), colonies are commonly founded and headed by a single queen (haplometrosis, primary monogyny). However, in some populations in California (USA), unrelated queens cooperate not only during founding (pleometrosis) but also throughout the life of the colony (primary polygyny). The genetic architecture and evolutionary dynamics of this complex social niche polymorphism (haplometrosis vs pleometrosis) have remained unknown. RESULTS We provide a first analysis of its genomic basis and evolutionary history using population genomics comparing individuals from a haplometrotic population to those from a pleometrotic population. We discovered a recently evolved (< 200 k years), 8-Mb non-recombining region segregating with the observed social niche polymorphism. This region shares several characteristics with supergenes underlying social polymorphisms in other socially polymorphic ant species. However, we also find remarkable differences from previously described social supergenes. Particularly, four additional genomic regions not in linkage with the supergene show signatures of a selective sweep in the pleometrotic population. Within these regions, we find for example genes crucial for epigenetic regulation via histone modification (chameau) and DNA methylation (Dnmt1). CONCLUSIONS Altogether, our results suggest that social morph in this species is a polygenic trait involving a potential young supergene. Further studies targeting haplo- and pleometrotic individuals from a single population are however required to conclusively resolve whether these genetic differences underlie the alternative social phenotypes or have emerged through genetic drift.
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Affiliation(s)
- Mohammed Errbii
- Molecular Evolution and Sociobiology Group, Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, Münster, DE-48149, Germany
| | - Ulrich R Ernst
- Molecular Evolution and Sociobiology Group, Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, Münster, DE-48149, Germany
- Present Address: Apicultural State Institute, University of Hohenheim, Erna-Hruschka-Weg 6, Stuttgart, DE-70599, Germany
- Center for Biodiversity and Integrative Taxonomy (KomBioTa), University of Hohenheim, Stuttgart, DE-70599, Germany
| | - Aparna Lajmi
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
| | - Eyal Privman
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
| | - Jürgen Gadau
- Molecular Evolution and Sociobiology Group, Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, Münster, DE-48149, Germany.
| | - Lukas Schrader
- Molecular Evolution and Sociobiology Group, Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, Münster, DE-48149, Germany.
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2
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Kalotay E, Klugmann M, Housley GD, Fröhlich D. Dominant aminoacyl-tRNA synthetase disorders: lessons learned from in vivo disease models. Front Neurosci 2023; 17:1182845. [PMID: 37274211 PMCID: PMC10234151 DOI: 10.3389/fnins.2023.1182845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/05/2023] [Indexed: 06/06/2023] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) play an essential role in protein synthesis, being responsible for ligating tRNA molecules to their corresponding amino acids in a reaction known as 'tRNA aminoacylation'. Separate ARSs carry out the aminoacylation reaction in the cytosol and in mitochondria, and mutations in almost all ARS genes cause pathophysiology most evident in the nervous system. Dominant mutations in multiple cytosolic ARSs have been linked to forms of peripheral neuropathy including Charcot-Marie-Tooth disease, distal hereditary motor neuropathy, and spinal muscular atrophy. This review provides an overview of approaches that have been employed to model each of these diseases in vivo, followed by a discussion of the existing animal models of dominant ARS disorders and key mechanistic insights that they have provided. In summary, ARS disease models have demonstrated that loss of canonical ARS function alone cannot fully account for the observed disease phenotypes, and that pathogenic ARS variants cause developmental defects within the peripheral nervous system, despite a typically later onset of disease in humans. In addition, aberrant interactions between mutant ARSs and other proteins have been shown to contribute to the disease phenotypes. These findings provide a strong foundation for future research into this group of diseases, providing methodological guidance for studies on ARS disorders that currently lack in vivo models, as well as identifying candidate therapeutic targets.
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Affiliation(s)
- Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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3
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Kalotay E, Klugmann M, Housley GD, Fröhlich D. Recessive aminoacyl-tRNA synthetase disorders: lessons learned from in vivo disease models. Front Neurosci 2023; 17:1182874. [PMID: 37274208 PMCID: PMC10234152 DOI: 10.3389/fnins.2023.1182874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/17/2023] [Indexed: 06/06/2023] Open
Abstract
Protein synthesis is a fundamental process that underpins almost every aspect of cellular functioning. Intriguingly, despite their common function, recessive mutations in aminoacyl-tRNA synthetases (ARSs), the family of enzymes that pair tRNA molecules with amino acids prior to translation on the ribosome, cause a diverse range of multi-system disorders that affect specific groups of tissues. Neurological development is impaired in most ARS-associated disorders. In addition to central nervous system defects, diseases caused by recessive mutations in cytosolic ARSs commonly affect the liver and lungs. Patients with biallelic mutations in mitochondrial ARSs often present with encephalopathies, with variable involvement of peripheral systems. Many of these disorders cause severe disability, and as understanding of their pathogenesis is currently limited, there are no effective treatments available. To address this, accurate in vivo models for most of the recessive ARS diseases are urgently needed. Here, we discuss approaches that have been taken to model recessive ARS diseases in vivo, highlighting some of the challenges that have arisen in this process, as well as key results obtained from these models. Further development and refinement of animal models is essential to facilitate a better understanding of the pathophysiology underlying recessive ARS diseases, and ultimately to enable development and testing of effective therapies.
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Affiliation(s)
- Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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4
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Zheng T, Luo Q, Han C, Zhou J, Gong J, Chun L, Xu XZS, Liu J. Cytoplasmic and mitochondrial aminoacyl-tRNA synthetases differentially regulate lifespan in Caenorhabditis elegans. iScience 2022; 25:105266. [PMID: 36304099 PMCID: PMC9593246 DOI: 10.1016/j.isci.2022.105266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/21/2022] [Accepted: 09/29/2022] [Indexed: 11/12/2022] Open
Abstract
Reducing the rate of translation promotes longevity in multiple organisms, representing a conserved mechanism for lifespan extension. Aminoacyl-tRNA synthetases (ARSs) catalyze the loading of amino acids to their cognate tRNAs, thereby playing an essential role in translation. Mutations in ARS genes are associated with various human diseases. However, little is known about the role of ARSs in aging, particularly whether and how these genes regulate lifespan. Here, using Caenorhabditis elegans as a model, we systematically characterized the role of all three types of ARS genes in lifespan regulation, including mitochondrial, cytoplasmic, and cyto-mito bifunctional ARS genes. We found that, as expected, RNAi knockdown of mitochondrial ARS genes extended lifespan. Surprisingly, knocking down cytoplasmic or cyto-mito bifunctional ARS genes shortened lifespan, though such treatment reduced the rate of translation. These results reveal opposing roles of mitochondrial and cytoplasmic ARSs in lifespan regulation, demonstrating that inhibiting translation may not always extend lifespan. RNAi knockdown of mitochondrial ARS genes extends lifespan via UPRmt RNAi knockdown of cytoplasmic or cyto-mito bifunctional ARS genes shortens lifespan Inhibiting translation may not always extend lifespan
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Affiliation(s)
- Tianlin Zheng
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qiang Luo
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Chengxuan Han
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jiejun Zhou
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jianke Gong
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.,Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lei Chun
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - X Z Shawn Xu
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianfeng Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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5
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The psychiatric risk gene BRD1 modulates mitochondrial bioenergetics by transcriptional regulation. Transl Psychiatry 2022; 12:319. [PMID: 35941107 PMCID: PMC9359996 DOI: 10.1038/s41398-022-02053-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/24/2022] [Accepted: 07/01/2022] [Indexed: 12/03/2022] Open
Abstract
Bromodomain containing 1 (BRD1) encodes an epigenetic regulator that controls the expression of genetic networks linked to mental illness. BRD1 is essential for normal brain development and its role in psychopathology has been demonstrated in genetic and preclinical studies. However, the neurobiology that bridges its molecular and neuropathological effects remains poorly explored. Here, using publicly available datasets, we find that BRD1 targets nuclear genes encoding mitochondrial proteins in cell lines and that modulation of BRD1 expression, irrespective of whether it is downregulation or upregulation of one or the other existing BRD1 isoforms (BRD1-L and BRD1-S), leads to distinct shifts in the expression profile of these genes. We further show that the expression of nuclear genes encoding mitochondrial proteins is negatively correlated with the expression of BRD1 mRNA during human brain development. In accordance, we identify the key gate-keeper of mitochondrial metabolism, Peroxisome proliferator-activated receptor (PPAR) among BRD1's co-transcription factors and provide evidence that BRD1 acts as a co-repressor of PPAR-mediated transcription. Lastly, when using quantitative PCR, mitochondria-targeted fluorescent probes, and the Seahorse XFe96 Analyzer, we demonstrate that modulation of BRD1 expression in cell lines alters mitochondrial physiology (mtDNA content and mitochondrial mass), metabolism (reducing power), and bioenergetics (among others, basal, maximal, and spare respiration) in an expression level- and isoform-dependent manner. Collectively, our data suggest that BRD1 is a transcriptional regulator of nuclear-encoded mitochondrial proteins and that disruption of BRD1's genomic actions alters mitochondrial functions. This may be the mechanism underlying the cellular and atrophic changes of neurons previously associated with BRD1 deficiency and suggests that mitochondrial dysfunction may be a possible link between genetic variation in BRD1 and psychopathology in humans.
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6
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Kumarapuram S, Kunnath AJ, Omelchenko A, Boustany NN, Firestein BL. Glutamate Receptors Mediate Changes to Dendritic Mitochondria in Neurons Grown on Stiff Substrates. Ann Biomed Eng 2022; 50:1116-1133. [PMID: 35652995 DOI: 10.1007/s10439-022-02987-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022]
Abstract
The stiffness of brain tissue changes during development and disease. These changes can affect neuronal morphology, specifically dendritic arborization. We previously reported that N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors regulate dendrite number and branching in a manner that is dependent on substrate stiffness. Since mitochondria affect the shape of dendrites, in this study, we determined whether the stiffness of substrates on which rat hippocampal neurons are grown affects mitochondrial characteristics and if glutamate receptors mediate the effects of substrate stiffness. Dendritic mitochondria are small, short, simple, and scarce in neurons cultured on substrates of 0.5 kPa stiffness. In contrast, dendritic mitochondria are large, long, complex, and low in number in neurons grown on substrates of 4 kPa stiffness. Dendritic mitochondria of neurons cultured on glass are high in number and small with complex shapes. Treatment of neurons grown on the stiffer gels or glass with the NMDA and AMPA receptor antagonists, 2-amino-5-phosphonopentanoic acid and 6-cyano-7-nitroquinoxaline-2,3-dione, respectively, results in mitochondrial characteristics of neurons grown on the softer substrate. These results suggest that glutamate receptors play important roles in regulating both mitochondrial morphology and dendritic arborization in response to substrate stiffness.
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Affiliation(s)
- Siddhant Kumarapuram
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA
| | - Ansley J Kunnath
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA.,Neurosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Nada N Boustany
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA.
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7
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Ecovoiu AA, Ratiu AC, Micheu MM, Chifiriuc MC. Inter-Species Rescue of Mutant Phenotype—The Standard for Genetic Analysis of Human Genetic Disorders in Drosophila melanogaster Model. Int J Mol Sci 2022; 23:ijms23052613. [PMID: 35269756 PMCID: PMC8909942 DOI: 10.3390/ijms23052613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 11/16/2022] Open
Abstract
Drosophila melanogaster (the fruit fly) is arguably a superstar of genetics, an astonishing versatile experimental model which fueled no less than six Nobel prizes in medicine. Nowadays, an evolving research endeavor is to simulate and investigate human genetic diseases in the powerful D. melanogaster platform. Such a translational experimental strategy is expected to allow scientists not only to understand the molecular mechanisms of the respective disorders but also to alleviate or even cure them. In this regard, functional gene orthology should be initially confirmed in vivo by transferring human or vertebrate orthologous transgenes in specific mutant backgrounds of D. melanogaster. If such a transgene rescues, at least partially, the mutant phenotype, then it qualifies as a strong candidate for modeling the respective genetic disorder in the fruit fly. Herein, we review various examples of inter-species rescue of relevant mutant phenotypes of the fruit fly and discuss how these results recommend several human genes as candidates to study and validate genetic variants associated with human diseases. We also consider that a wider implementation of this evolutionist exploratory approach as a standard for the medicine of genetic disorders would allow this particular field of human health to advance at a faster pace.
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Affiliation(s)
- Alexandru Al. Ecovoiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
| | - Attila Cristian Ratiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
- Correspondence: ; Tel.: +40-722250366
| | - Miruna Mihaela Micheu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, 014461 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- The Research Institute of the University of Bucharest and Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania;
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8
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Niu F, Han P, Zhang J, She Y, Yang L, Yu J, Zhuang M, Tang K, Shi Y, Yang B, Liu C, Peng B, Ji SJ. The m 6A reader YTHDF2 is a negative regulator for dendrite development and maintenance of retinal ganglion cells. eLife 2022; 11:75827. [PMID: 35179492 PMCID: PMC8906807 DOI: 10.7554/elife.75827] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/16/2022] [Indexed: 11/29/2022] Open
Abstract
The precise control of growth and maintenance of the retinal ganglion cell (RGC) dendrite arborization is critical for normal visual functions in mammals. However, the underlying mechanisms remain elusive. Here, we find that the N6-methyladenosine (m6A) reader YTHDF2 is highly expressed in the mouse RGCs. Conditional knockout (cKO) of Ythdf2 in the retina leads to increased RGC dendrite branching, resulting in more synapses in the inner plexiform layer. Interestingly, the Ythdf2 cKO mice show improved visual acuity compared with control mice. We further demonstrate that Ythdf2 cKO in the retina protects RGCs from dendrite degeneration caused by the experimental acute glaucoma model. We identify the m6A-modified YTHDF2 target transcripts which mediate these effects. This study reveals mechanisms by which YTHDF2 restricts RGC dendrite development and maintenance. YTHDF2 and its target mRNAs might be valuable in developing new treatment approaches for glaucomatous eyes.
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Affiliation(s)
- Fugui Niu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Peng Han
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jian Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Yuanchu She
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Lixin Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jun Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Mengru Zhuang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Kezhen Tang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yuwei Shi
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Baisheng Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Chunqiao Liu
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Bo Peng
- Department of Neurosurgery, Fudan University, Shanghai, China
| | - Sheng-Jian Ji
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
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9
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Kamemura K, Moriya H, Ukita Y, Okumura M, Miura M, Chihara T. Endoplasmic reticulum proteins Meigo and Gp93 govern dendrite targeting by regulating Toll-6 localization. Dev Biol 2022; 484:30-39. [DOI: 10.1016/j.ydbio.2022.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/29/2021] [Accepted: 02/02/2022] [Indexed: 12/15/2022]
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10
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Drosophila Models for Charcot-Marie-Tooth Neuropathy Related to Aminoacyl-tRNA Synthetases. Genes (Basel) 2021; 12:genes12101519. [PMID: 34680913 PMCID: PMC8536177 DOI: 10.3390/genes12101519] [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: 08/11/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 11/29/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRS) represent the largest cluster of proteins implicated in Charcot–Marie–Tooth neuropathy (CMT), the most common neuromuscular disorder. Dominant mutations in six aaRS cause different axonal CMT subtypes with common clinical characteristics, including progressive distal muscle weakness and wasting, impaired sensory modalities, gait problems and skeletal deformities. These clinical manifestations are caused by “dying back” axonal degeneration of the longest peripheral sensory and motor neurons. Surprisingly, loss of aminoacylation activity is not a prerequisite for CMT to occur, suggesting a gain-of-function disease mechanism. Here, we present the Drosophila melanogaster disease models that have been developed to understand the molecular pathway(s) underlying GARS1- and YARS1-associated CMT etiology. Expression of dominant CMT mutations in these aaRSs induced comparable neurodegenerative phenotypes, both in larvae and adult animals. Interestingly, recent data suggests that shared molecular pathways, such as dysregulation of global protein synthesis, might play a role in disease pathology. In addition, it has been demonstrated that the important function of nuclear YARS1 in transcriptional regulation and the binding properties of mutant GARS1 are also conserved and can be studied in D. melanogaster in the context of CMT. Taken together, the fly has emerged as a faithful companion model for cellular and molecular studies of aaRS-CMT that also enables in vivo investigation of candidate CMT drugs.
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11
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Nawalpuri B, Sharma A, Chattarji S, Muddashetty RS. Distinct temporal expression of the GW182 paralog TNRC6A in neurons regulates dendritic arborization. J Cell Sci 2021; 134:271120. [PMID: 34328181 DOI: 10.1242/jcs.258465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 07/19/2021] [Indexed: 01/11/2023] Open
Abstract
Precise development of the dendritic architecture is a critical determinant of mature neuronal circuitry. MicroRNA (miRNA)-mediated regulation of protein synthesis plays a crucial role in dendritic morphogenesis, but the role of miRNA-induced silencing complex (miRISC) protein components in this process is less studied. Here, we show an important role of a key miRISC protein, the GW182 paralog TNRC6A, in the regulation of dendritic growth. We identified a distinct brain region-specific spatiotemporal expression pattern of GW182 during rat postnatal development. We found that the window of peak GW182 expression coincides with the period of extensive dendritic growth, both in the hippocampus and cerebellum. Perturbation of GW182 function during a specific temporal window resulted in reduced dendritic growth of cultured hippocampal neurons. Mechanistically, we show that GW182 modulates dendritic growth by regulating global somatodendritic translation and actin cytoskeletal dynamics of developing neurons. Furthermore, we found that GW182 affects dendritic architecture by regulating the expression of actin modulator LIMK1. Taken together, our data reveal a previously undescribed neurodevelopmental expression pattern of GW182 and its role in dendritic morphogenesis, which involves both translational control and actin cytoskeletal rearrangement. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Bharti Nawalpuri
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (InStem), Bangalore 560065, India.,School of Chemical and Biotechnology, Shanmugha Arts, Science, and Technology and Research Academy (SASTRA) University, Thanjavur 613401, India.,Centre for Brain Research, Indian Institute of Science, Bangalore 560012, India
| | - Arpita Sharma
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (InStem), Bangalore 560065, India
| | - Sumantra Chattarji
- National Centre for Biological Sciences, Bangalore 560065, India.,Simons Initiative for the Developing Brain and Centre for Discovery Brain Sciences, University of Edinburgh EH8 9XD, Edinburgh, UK
| | - Ravi S Muddashetty
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (InStem), Bangalore 560065, India.,Centre for Brain Research, Indian Institute of Science, Bangalore 560012, India
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12
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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.
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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.)
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13
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Kamemura K, Chen CA, Okumura M, Miura M, Chihara T. Amyotrophic lateral sclerosis-associated Vap33 is required for maintaining neuronal dendrite morphology and organelle distribution in Drosophila. Genes Cells 2021; 26:230-239. [PMID: 33548103 DOI: 10.1111/gtc.12835] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/23/2021] [Accepted: 02/03/2021] [Indexed: 12/19/2022]
Abstract
VAMP-associated protein (VAP) is an endoplasmic reticulum (ER) membrane protein that functions as a tethering protein at the membrane contact sites between the ER and various intracellular organelles. Mutations such as P56S in human VAPB cause neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). However, VAP functions in neurons are poorly understood. Here, we utilized Drosophila olfactory projection neurons with a mosaic analysis with a repressible cell marker (MARCM) to analyze the neuronal function of Vap33, a Drosophila ortholog of human VAPB. In vap33 null mutant clones, the dendrites of projection neurons exhibited defects in the maintenance of their morphology. The subcellular localization of the Golgi apparatus and mitochondria were also abnormal. These results indicate that Vap33 is required for neuronal morphology and organelle distribution. Additionally, to examine the impact of ALS-associated mutations in neurons, we overexpressed human VAPB-P56S in vap33 null mutant clones (mosaic rescue experiments) and found that, in aged flies, human VAPB-P56S expression caused mislocalization of Bruchpilot, a presynaptic protein. These results implied that synaptic protein localization and ER quality control may be affected by disease mutations. We provide insights into the physiological and pathological functions of VAP in neurons.
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Affiliation(s)
- Kosuke Kamemura
- Program of Biomedical Science and Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Chun-An Chen
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Misako Okumura
- Program of Biomedical Science and Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Takahiro Chihara
- Program of Biomedical Science and Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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14
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Mullen P, Abbott JA, Wellman T, Aktar M, Fjeld C, Demeler B, Ebert AM, Francklyn CS. Neuropathy-associated histidyl-tRNA synthetase variants attenuate protein synthesis in vitro and disrupt axon outgrowth in developing zebrafish. FEBS J 2021; 288:142-159. [PMID: 32543048 PMCID: PMC7736457 DOI: 10.1111/febs.15449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/11/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) encompasses a set of genetically and clinically heterogeneous neuropathies characterized by length-dependent dysfunction of the peripheral nervous system. Mutations in over 80 diverse genes are associated with CMT, and aminoacyl-tRNA synthetases (ARS) constitute a large gene family implicated in the disease. Despite considerable efforts to elucidate the mechanistic link between ARS mutations and the CMT phenotype, the molecular basis of the pathology is unknown. In this work, we investigated the impact of three CMT-associated substitutions (V155G, Y330C, and R137Q) in the cytoplasmic histidyl-tRNA synthetase (HARS1) on neurite outgrowth and peripheral nervous system development. The model systems for this work included a nerve growth factor-stimulated neurite outgrowth model in rat pheochromocytoma cells (PC12), and a zebrafish line with GFP/red fluorescent protein reporters of sensory and motor neuron development. The expression of CMT-HARS1 mutations led to attenuation of protein synthesis and increased phosphorylation of eIF2α in PC12 cells and was accompanied by impaired neurite and axon outgrowth in both models. Notably, these effects were phenocopied by histidinol, a HARS1 inhibitor, and cycloheximide, a protein synthesis inhibitor. The mutant proteins also formed heterodimers with wild-type HARS1, raising the possibility that CMT-HARS1 mutations cause disease through a dominant-negative mechanism. Overall, these findings support the hypothesis that CMT-HARS1 alleles exert their toxic effect in a neuronal context, and lead to dysregulated protein synthesis. These studies demonstrate the value of zebrafish as a model for studying mutant alleles associated with CMT, and for characterizing the processes that lead to peripheral nervous system dysfunction.
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Affiliation(s)
- Patrick Mullen
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - Jamie A Abbott
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - Theresa Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mahafuza Aktar
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - Christian Fjeld
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - Borries Demeler
- Department of Chemistry & Biochemistry, University of Lethbridge, Canada
| | - Alicia M Ebert
- Department of Biology, University of Vermont, Burlington, VT, USA
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15
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Zhang H, Zhou ZW, Sun L. Aminoacyl-tRNA synthetases in Charcot-Marie-Tooth disease: A gain or a loss? J Neurochem 2020; 157:351-369. [PMID: 33236345 PMCID: PMC8247414 DOI: 10.1111/jnc.15249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 01/05/2023]
Abstract
Charcot‐Marie‐Tooth disease (CMT) is one of the most common inherited neurodegenerative disorders with an increasing number of CMT‐associated variants identified as causative factors, however, there has been no effective therapy for CMT to date. Aminoacyl‐tRNA synthetases (aaRS) are essential enzymes in translation by charging amino acids onto their cognate tRNAs during protein synthesis. Dominant monoallelic variants of aaRSs have been largely implicated in CMT. Some aaRSs variants affect enzymatic activity, demonstrating a loss‐of‐function property. In contrast, loss of aminoacylation activity is neither necessary nor sufficient for some aaRSs variants to cause CMT. Instead, accumulating evidence from CMT patient samples, animal genetic studies or protein conformational analysis has pinpointed toxic gain‐of‐function of aaRSs variants in CMT, suggesting complicated mechanisms underlying the pathogenesis of CMT. In this review, we summarize the latest advances in studies on CMT‐linked aaRSs, with a particular focus on their functions. The current challenges, future direction and the promising candidates for potential treatment of CMT are also discussed. ![]()
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Affiliation(s)
- Han Zhang
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Zhong-Wei Zhou
- School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Litao Sun
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangzhou, China
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16
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Wang YH, Ding ZY, Cheng YJ, Chien CT, Huang ML. An Efficient Screen for Cell-Intrinsic Factors Identifies the Chaperonin CCT and Multiple Conserved Mechanisms as Mediating Dendrite Morphogenesis. Front Cell Neurosci 2020; 14:577315. [PMID: 33100975 PMCID: PMC7546278 DOI: 10.3389/fncel.2020.577315] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 12/25/2022] Open
Abstract
Dendritic morphology is inextricably linked to neuronal function. Systematic large-scale screens combined with genetic mapping have uncovered several mechanisms underlying dendrite morphogenesis. However, a comprehensive overview of participating molecular mechanisms is still lacking. Here, we conducted an efficient clonal screen using a collection of mapped P-element insertions that were previously shown to cause lethality and eye defects in Drosophila melanogaster. Of 280 mutants, 52 exhibited dendritic defects. Further database analyses, complementation tests, and RNA interference validations verified 40 P-element insertion genes as being responsible for the dendritic defects. Twenty-eight mutants presented severe arbor reduction, and the remainder displayed other abnormalities. The intrinsic regulators encoded by the identified genes participate in multiple conserved mechanisms and pathways, including the protein folding machinery and the chaperonin-containing TCP-1 (CCT) complex that facilitates tubulin folding. Mutant neurons in which expression of CCT4 or CCT5 was depleted exhibited severely retarded dendrite growth. We show that CCT localizes in dendrites and is required for dendritic microtubule organization and tubulin stability, suggesting that CCT-mediated tubulin folding occurs locally within dendrites. Our study also reveals novel mechanisms underlying dendrite morphogenesis. For example, we show that Drosophila Nogo signaling is required for dendrite development and that Mummy and Wech also regulate dendrite morphogenesis, potentially via Dpp- and integrin-independent pathways. Our methodology represents an efficient strategy for identifying intrinsic dendrite regulators, and provides insights into the plethora of molecular mechanisms underlying dendrite morphogenesis.
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Affiliation(s)
- Ying-Hsuan Wang
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Zhao-Ying Ding
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan
| | - Ying-Ju Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | - Min-Lang Huang
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan
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17
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Markovitz R, Ghosh R, Kuo ME, Hong W, Lim J, Bernes S, Manberg S, Crosby K, Tanpaiboon P, Bharucha-Goebel D, Bonnemann C, Mohila CA, Mizerik E, Woodbury S, Bi W, Lotze T, Antonellis A, Xiao R, Potocki L. GARS-related disease in infantile spinal muscular atrophy: Implications for diagnosis and treatment. Am J Med Genet A 2020; 182:1167-1176. [PMID: 32181591 PMCID: PMC8297662 DOI: 10.1002/ajmg.a.61544] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/06/2020] [Accepted: 02/21/2020] [Indexed: 01/05/2023]
Abstract
The majority of patients with spinal muscular atrophy (SMA) identified to date harbor a biallelic exonic deletion of SMN1. However, there have been reports of SMA-like disorders that are independent of SMN1, including those due to pathogenic variants in the glycyl-tRNA synthetase gene (GARS1). We report three unrelated patients with de novo variants in GARS1 that are associated with infantile-onset SMA (iSMA). Patients were ascertained during inpatient hospital evaluations for complications of neuropathy. Evaluations were completed as indicated for clinical care and management and informed consent for publication was obtained. One newly identified, disease-associated GARS1 variant, identified in two out of three patients, was analyzed by functional studies in yeast complementation assays. Genomic analyses by exome and/or gene panel and SMN1 copy number analysis of three patients identified two previously undescribed de novo missense variants in GARS1 and excluded SMN1 as the causative gene. Functional studies in yeast revealed that one of the de novo GARS1 variants results in a loss-of-function effect, consistent with other pathogenic GARS1 alleles. In sum, the patients' clinical presentation, assessments of previously identified GARS1 variants and functional assays in yeast suggest that the GARS1 variants described here cause iSMA. GARS1 variants have been previously associated with Charcot-Marie-Tooth disease (CMT2D) and distal SMA type V (dSMAV). Our findings expand the allelic heterogeneity of GARS-associated disease and support that severe early-onset SMA can be caused by variants in this gene. Distinguishing the SMA phenotype caused by SMN1 variants from that due to pathogenic variants in other genes such as GARS1 significantly alters approaches to treatment.
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Affiliation(s)
- Rebecca Markovitz
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Rajarshi Ghosh
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Molly E. Kuo
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
- Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan
| | - William Hong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
| | - Jaehyung Lim
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
| | - Saunder Bernes
- Division of Child Neurology, Barrow Neurological Institute, Phoenix Children’s Hospital, Phoenix, Arizona
| | - Stephanie Manberg
- Division of Child Neurology, Barrow Neurological Institute, Phoenix Children’s Hospital, Phoenix, Arizona
| | - Kathleen Crosby
- Division of Genetics and Metabolism, Children’s National Hospital, Rare Disease Institute, Washington, District of Columbia
| | - Pranoot Tanpaiboon
- Division of Genetics and Metabolism, Children’s National Hospital, Rare Disease Institute, Washington, District of Columbia
| | - Diana Bharucha-Goebel
- Division of Neurology, Children’s National Hospital, Washington, District of Columbia
- Neuromuscular and Neurogenetic Disorders of Childhood Section, NINDS, National Institutes of Health, Bethesda, Maryland
| | - Carsten Bonnemann
- Division of Neurology, Children’s National Hospital, Washington, District of Columbia
- Neuromuscular and Neurogenetic Disorders of Childhood Section, NINDS, National Institutes of Health, Bethesda, Maryland
| | - Carrie A. Mohila
- Department of Pathology, Texas Children’s Hospital, Houston, Texas
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Elizabeth Mizerik
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
| | - Suzanne Woodbury
- Texas Children’s Hospital, Houston, Texas
- Baylor College of Medicine, Department of Physical Medicine and Rehabilitation, Houston, Texas
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Timothy Lotze
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
| | - Anthony Antonellis
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
- Department of Neurology, University of Michigan, Ann Arbor, Michigan
| | - Rui Xiao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Lorraine Potocki
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
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18
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Martin PB, Hicks AN, Holbrook SE, Cox GA. Overlapping spectrums: The clinicogenetic commonalities between Charcot-Marie-Tooth and other neurodegenerative diseases. Brain Res 2020; 1727:146532. [PMID: 31678418 PMCID: PMC6939129 DOI: 10.1016/j.brainres.2019.146532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/20/2019] [Accepted: 10/22/2019] [Indexed: 12/11/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is a progressive and heterogeneous inherited peripheral neuropathy. A myriad of genetic factors have been identified that contribute to the degeneration of motor and sensory axons in a length-dependent manner. Emerging biological themes underlying disease include defects in axonal trafficking, dysfunction in RNA metabolism and protein homeostasis, as well deficits in the cellular stress response. Moreover, genetic contributions to CMT can have overlap with other neuropathies, motor neuron diseases (MNDs) and neurodegenerative disorders. Recent progress in understanding the molecular biology of CMT and overlapping syndromes aids in the search for necessary therapeutic targets.
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Affiliation(s)
- Paige B Martin
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA
| | - Amy N Hicks
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Sarah E Holbrook
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA
| | - Gregory A Cox
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA.
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19
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Ramirez J, Lectez B, Osinalde N, Sivá M, Elu N, Aloria K, Procházková M, Perez C, Martínez-Hernández J, Barrio R, Šašková KG, Arizmendi JM, Mayor U. Quantitative proteomics reveals neuronal ubiquitination of Rngo/Ddi1 and several proteasomal subunits by Ube3a, accounting for the complexity of Angelman syndrome. Hum Mol Genet 2019; 27:1955-1971. [PMID: 29788202 DOI: 10.1093/hmg/ddy103] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/19/2018] [Indexed: 01/01/2023] Open
Abstract
Angelman syndrome is a complex neurodevelopmental disorder caused by the lack of function in the brain of a single gene, UBE3A. The E3 ligase coded by this gene is known to build K48-linked ubiquitin chains, a modification historically considered to target substrates for degradation by the proteasome. However, a change in protein abundance is not proof that a candidate UBE3A substrate is indeed ubiquitinated by UBE3A. We have here used an unbiased ubiquitin proteomics approach, the bioUb strategy, to identify 79 proteins that appear more ubiquitinated in the Drosophila photoreceptor cells when Ube3a is over-expressed. We found a significantly high number of those proteins to be proteasomal subunits or proteasome-interacting proteins, suggesting a wide proteasomal perturbation in the brain of Angelman patients. We focused on validating the ubiquitination by Ube3a of Rngo, a proteasomal component conserved from yeast (Ddi1) to humans (DDI1 and DDI2), but yet scarcely characterized. Ube3a-mediated Rngo ubiquitination in fly neurons was confirmed by immunoblotting. Using human neuroblastoma SH-SY5Y cells in culture, we also observed that human DDI1 is ubiquitinated by UBE3A, without being targeted for degradation. The novel observation that DDI1 is expressed in the developing mice brain, with a significant peak at E16.5, strongly suggests that DDI1 has biological functions not yet described that could be of relevance for Angelman syndrome clinical research.
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Affiliation(s)
- Juanma Ramirez
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Benoit Lectez
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Nerea Osinalde
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy (UPV/EHU), 01006 Vitoria-Gasteiz, Spain
| | - Monika Sivá
- Department of Genetics and Microbiology, Charles University, 12843 Prague, Czech Republic.,Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 16610 Prague, Czech Republic.,First Faculty of Medicine, Charles University, 12108 Prague, Czech Republic
| | - Nagore Elu
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Kerman Aloria
- Proteomics Core Facility-SGIKER, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Michaela Procházková
- Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Coralia Perez
- Functional Genomics Unit, CIC bioGUNE, 48160 Derio, Spain
| | - Jose Martínez-Hernández
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain.,Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Rosa Barrio
- Functional Genomics Unit, CIC bioGUNE, 48160 Derio, Spain
| | - Klára Grantz Šašková
- Department of Genetics and Microbiology, Charles University, 12843 Prague, Czech Republic.,Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 16610 Prague, Czech Republic
| | - Jesus M Arizmendi
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Ugo Mayor
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain.,Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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20
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Wei N, Zhang Q, Yang XL. Neurodegenerative Charcot-Marie-Tooth disease as a case study to decipher novel functions of aminoacyl-tRNA synthetases. J Biol Chem 2019; 294:5321-5339. [PMID: 30643024 DOI: 10.1074/jbc.rev118.002955] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that catalyze the first reaction in protein biosynthesis, namely the charging of transfer RNAs (tRNAs) with their cognate amino acids. aaRSs have been increasingly implicated in dominantly and recessively inherited human diseases. The most common aaRS-associated monogenic disorder is the incurable neurodegenerative disease Charcot-Marie-Tooth neuropathy (CMT), caused by dominant mono-allelic mutations in aaRSs. With six currently known members (GlyRS, TyrRS, AlaRS, HisRS, TrpRS, and MetRS), aaRSs represent the largest protein family implicated in CMT etiology. After the initial discovery linking aaRSs to CMT, the field has progressed from understanding whether impaired tRNA charging is a critical component of this disease to elucidating the specific pathways affected by CMT-causing mutations in aaRSs. Although many aaRS CMT mutants result in loss of tRNA aminoacylation function, animal genetics studies demonstrated that dominant mutations in GlyRS cause CMT through toxic gain-of-function effects, which also may apply to other aaRS-linked CMT subtypes. The CMT-causing mechanism is likely to be multifactorial and involves multiple cellular compartments, including the nucleus and the extracellular space, where the normal WT enzymes also appear. Thus, the association of aaRSs with neuropathy is relevant to discoveries indicating that aaRSs also have nonenzymatic regulatory functions that coordinate protein synthesis with other biological processes. Through genetic, functional, and structural analyses, commonalities among different mutations and different aaRS-linked CMT subtypes have begun to emerge, providing insights into the nonenzymatic functions of aaRSs and the pathogenesis of aaRS-linked CMT to guide therapeutic development to treat this disease.
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Affiliation(s)
- Na Wei
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Qian Zhang
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Xiang-Lei Yang
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
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21
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Paternoster V, Svanborg M, Edhager AV, Rajkumar AP, Eickhardt EA, Pallesen J, Grove J, Qvist P, Fryland T, Wegener G, Nyengaard JR, Mors O, Palmfeldt J, Børglum AD, Christensen JH. Brain proteome changes in female Brd1 +/- mice unmask dendritic spine pathology and show enrichment for schizophrenia risk. Neurobiol Dis 2018; 124:479-488. [PMID: 30590179 DOI: 10.1016/j.nbd.2018.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 11/23/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022] Open
Abstract
Genetic and molecular studies have implicated the Bromodomain containing 1 (BRD1) gene in the pathogenesis of schizophrenia and bipolar disorder. Accordingly, mice heterozygous for a targeted deletion of Brd1 (Brd1+/- mice) show behavioral phenotypes with broad translational relevance to psychiatric disorders. BRD1 encodes a scaffold protein that affects the expression of many genes through modulation of histone acetylation. BRD1 target genes have been identified in cell lines; however the impact of reduced Brd1 levels on the brain proteome is largely unknown. In this study, we applied label-based quantitative mass spectrometry to profile the frontal cortex, hippocampus and striatum proteome and synaptosomal proteome of female Brd1+/- mice. We successfully quantified between 1537 and 2196 proteins and show widespread changes in protein abundancies and compartmentalization. By integrative analysis of human genetic data, we find that the differentially abundant proteins in frontal cortex and hippocampus are enriched for schizophrenia risk further linking the actions of BRD1 to psychiatric disorders. Affected proteins were further enriched for proteins involved in processes known to influence neuronal and dendritic spine morphology e.g. regulation of cytoskeleton dynamics and mitochondrial function. Directly prompted in these findings, we investigated dendritic spine morphology of pyramidal neurons in anterior cingulate cortex and found them significantly altered, including reduced size of small dendritic spines and decreased number of the mature mushroom type. Collectively, our study describes known as well as new mechanisms related to BRD1 dysfunction and its role in psychiatric disorders, and provides evidence for the molecular and cellular dysfunctions underlying altered neurosignalling and cognition in Brd1+/- mice.
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Affiliation(s)
- Veerle Paternoster
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark.
| | - Maria Svanborg
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Anto P Rajkumar
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark; Mental Health of Older Adults and Dementia Clinical Academic Group, South London and Maudsley NHS Foundation Trust, London, UK; Department of Old Age Psychiatry, Psychology, & Neuroscience, King's College London, Institute of Psychiatry, London, UK
| | - Esben Ahlburg Eickhardt
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jonatan Pallesen
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jakob Grove
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark; Bioinformatics Research Centre, BiRC, Aarhus University, Aarhus, Denmark
| | - Per Qvist
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Tue Fryland
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Gregers Wegener
- Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Stereology and Electron Microscopy Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, Aarhus, Denmark
| | - Ole Mors
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark
| | - Johan Palmfeldt
- Research Unit for Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Anders Dupont Børglum
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jane Hvarregaard Christensen
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
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22
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Friederich MW, Timal S, Powell CA, Dallabona C, Kurolap A, Palacios-Zambrano S, Bratkovic D, Derks TGJ, Bick D, Bouman K, Chatfield KC, Damouny-Naoum N, Dishop MK, Falik-Zaccai TC, Fares F, Fedida A, Ferrero I, Gallagher RC, Garesse R, Gilberti M, González C, Gowan K, Habib C, Halligan RK, Kalfon L, Knight K, Lefeber D, Mamblona L, Mandel H, Mory A, Ottoson J, Paperna T, Pruijn GJM, Rebelo-Guiomar PF, Saada A, Sainz B, Salvemini H, Schoots MH, Smeitink JA, Szukszto MJ, Ter Horst HJ, van den Brandt F, van Spronsen FJ, Veltman JA, Wartchow E, Wintjes LT, Zohar Y, Fernández-Moreno MA, Baris HN, Donnini C, Minczuk M, Rodenburg RJ, Van Hove JLK. Pathogenic variants in glutamyl-tRNA Gln amidotransferase subunits cause a lethal mitochondrial cardiomyopathy disorder. Nat Commun 2018; 9:4065. [PMID: 30283131 PMCID: PMC6170436 DOI: 10.1038/s41467-018-06250-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/23/2018] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial protein synthesis requires charging a mitochondrial tRNA with its amino acid. Here, the authors describe pathogenic variants in the GatCAB protein complex genes required for the generation of glutaminyl-mt-tRNAGln, that impairs mitochondrial translation and presents with cardiomyopathy. Mitochondrial protein synthesis requires charging mt-tRNAs with their cognate amino acids by mitochondrial aminoacyl-tRNA synthetases, with the exception of glutaminyl mt-tRNA (mt-tRNAGln). mt-tRNAGln is indirectly charged by a transamidation reaction involving the GatCAB aminoacyl-tRNA amidotransferase complex. Defects involving the mitochondrial protein synthesis machinery cause a broad spectrum of disorders, with often fatal outcome. Here, we describe nine patients from five families with genetic defects in a GatCAB complex subunit, including QRSL1, GATB, and GATC, each showing a lethal metabolic cardiomyopathy syndrome. Functional studies reveal combined respiratory chain enzyme deficiencies and mitochondrial dysfunction. Aminoacylation of mt-tRNAGln and mitochondrial protein translation are deficient in patients’ fibroblasts cultured in the absence of glutamine but restore in high glutamine. Lentiviral rescue experiments and modeling in S. cerevisiae homologs confirm pathogenicity. Our study completes a decade of investigations on mitochondrial aminoacylation disorders, starting with DARS2 and ending with the GatCAB complex.
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Affiliation(s)
- Marisa W Friederich
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Sharita Timal
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Christopher A Powell
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Alina Kurolap
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Sara Palacios-Zambrano
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Drago Bratkovic
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Terry G J Derks
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - David Bick
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Katelijne Bouman
- Department of Genetics, University Medical Center of Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Kathryn C Chatfield
- Department of Pediatrics, Section of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado, Aurora, CO, 80045, USA
| | - Nadine Damouny-Naoum
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Megan K Dishop
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Tzipora C Falik-Zaccai
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Fuad Fares
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Ayalla Fedida
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Ileana Ferrero
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Renata C Gallagher
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Rafael Garesse
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Micol Gilberti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Cristina González
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Katherine Gowan
- Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO, 80045, USA
| | - Clair Habib
- Department of Pediatrics, Bnai Zion Medical Center, Haifa, 3339419, Israel
| | - Rebecca K Halligan
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Limor Kalfon
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel
| | - Kaz Knight
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Dirk Lefeber
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Laura Mamblona
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hanna Mandel
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel.,Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,Metabolic Unit, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - John Ottoson
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Tamar Paperna
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Ger J M Pruijn
- Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University, Nijmegen, 6500 HB, The Netherlands
| | - Pedro F Rebelo-Guiomar
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom.,Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, Porto, 4200-135, Portugal
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and the Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Bruno Sainz
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Enfermedades Crónicas y Cáncer Area, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, 28034, Spain
| | - Hayley Salvemini
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Mirthe H Schoots
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands
| | - Jan A Smeitink
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Maciej J Szukszto
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Hendrik J Ter Horst
- Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Frans van den Brandt
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Institute of Genetic Medicine, Newcastle University, Newcastle, NE1 3BZ, United Kingdom
| | - Eric Wartchow
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Liesbeth T Wintjes
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Yaniv Zohar
- Institute of Pathology, Rambam Health Care Campus, 3109601, Haifa, Israel
| | - Miguel A Fernández-Moreno
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hagit N Baris
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Michal Minczuk
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Johan L K Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA.
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23
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Prenatal exposure to oxidative phosphorylation xenobiotics and late-onset Parkinson disease. Ageing Res Rev 2018; 45:24-32. [PMID: 29689408 DOI: 10.1016/j.arr.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 12/21/2022]
Abstract
Late-onset Parkinson disease is a multifactorial and multietiological disorder, age being one of the factors implicated. Genetic and/or environmental factors, such as pesticides, can also be involved. Up to 80% of dopaminergic neurons of the substantia nigra are lost before motor features of the disorder begin to appear. In humans, these neurons are only formed a few weeks after fertilization. Therefore, prenatal exposure to pesticides or industrial chemicals during crucial steps of brain development might also alter their proliferation and differentiation. Oxidative phosphorylation is one of the metabolic pathways sensitive to environmental toxicants and it is crucial for neuronal differentiation. Many inhibitors of this biochemical pathway, frequently found as persistent organic pollutants, affect dopaminergic neurogenesis, promote the degeneration of these neurons and increase the risk of suffering late-onset Parkinson disease. Here, we discuss how an early, prenatal, exposure to these oxidative phosphorylation xenobiotics might trigger a late-onset, old age, Parkinson disease.
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24
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Mitochondrial transcription and translation: overview. Essays Biochem 2018; 62:309-320. [PMID: 30030363 PMCID: PMC6056719 DOI: 10.1042/ebc20170102] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
Mitochondria are the major source of ATP in the cell. Five multi-subunit complexes in the inner membrane of the organelle are involved in the oxidative phosphorylation required for ATP production. Thirteen subunits of these complexes are encoded by the mitochondrial genome often referred to as mtDNA. For this reason, the expression of mtDNA is vital for the assembly and functioning of the oxidative phosphorylation complexes. Defects of the mechanisms regulating mtDNA gene expression have been associated with deficiencies in assembly of these complexes, resulting in mitochondrial diseases. Recently, numerous factors involved in these processes have been identified and characterized leading to a deeper understanding of the mechanisms that underlie mitochondrial diseases.
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25
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Preston G, Kirdar F, Kozicz T. The role of suboptimal mitochondrial function in vulnerability to post-traumatic stress disorder. J Inherit Metab Dis 2018; 41:585-596. [PMID: 29594645 DOI: 10.1007/s10545-018-0168-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/28/2018] [Accepted: 03/02/2018] [Indexed: 12/13/2022]
Abstract
Post-traumatic stress disorder remains the most significant psychiatric condition associated with exposure to a traumatic event, though rates of traumatic event exposure far outstrip incidence of PTSD. Mitochondrial dysfunction and suboptimal mitochondrial function have been increasingly implicated in several psychopathologies, and recent genetic studies have similarly suggested a pathogenic role of mitochondria in PTSD. Mitochondria play a central role in several physiologic processes underlying PTSD symptomatology, including abnormal fear learning, brain network activation, synaptic plasticity, steroidogenesis, and inflammation. Here we outline several potential mechanisms by which inherited (genetic) or acquired (environmental) mitochondrial dysfunction or suboptimal mitochondrial function, may contribute to PTSD symptomatology and increase susceptibility to PTSD. The proposed pathogenic role of mitochondria in the pathophysiology of PTSD has important implications for prevention and therapy, as antidepressants commonly prescribed for patients with PTSD have been shown to inhibit mitochondrial function, while alternative therapies shown to improve mitochondrial function may prove more efficacious.
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Affiliation(s)
- Graeme Preston
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA, 70112, USA.
| | - Faisal Kirdar
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA, 70112, USA
| | - Tamas Kozicz
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA, 70112, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
- Department of Anatomy, Radboud University Medical Center, Nijmegen, Netherlands
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26
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Şentürk M, Bellen HJ. Genetic strategies to tackle neurological diseases in fruit flies. Curr Opin Neurobiol 2018; 50:24-32. [PMID: 29128849 PMCID: PMC5940587 DOI: 10.1016/j.conb.2017.10.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/13/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
Drosophila melanogaster is a genetic model organism that has contributed to the discovery of numerous genes whose human homologues are associated with diseases. The development of sophisticated genetic tools to manipulate its genome accelerates the discovery of the genetic basis of undiagnosed human diseases and the elucidation of molecular pathogenic events of known and novel diseases. Here, we discuss various approaches used in flies to assess the function of the fly homologues of disease-associated genes. We highlight how systematic and combinatorial approaches based on recently established methods provide us with integrated tool sets that can be applied to the study of neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Mümine Şentürk
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston TX 77030, USA; Department of Neuroscience, BCM, Houston TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston TX 77030, USA; Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA.
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27
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Grice SJ, Sleigh JN, Zameel Cader M. Plexin-Semaphorin Signaling Modifies Neuromuscular Defects in a Drosophila Model of Peripheral Neuropathy. Front Mol Neurosci 2018. [PMID: 29520219 PMCID: PMC5827687 DOI: 10.3389/fnmol.2018.00055] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Dominant mutations in GARS, encoding the ubiquitous enzyme glycyl-tRNA synthetase (GlyRS), cause peripheral nerve degeneration and Charcot-Marie-Tooth disease type 2D (CMT2D). This genetic disorder exemplifies a recurring paradigm in neurodegeneration, in which mutations in essential genes cause selective degeneration of the nervous system. Recent evidence suggests that the mechanism underlying CMT2D involves extracellular neomorphic binding of mutant GlyRS to neuronally-expressed proteins. Consistent with this, our previous studies indicate a non-cell autonomous mechanism, whereby mutant GlyRS is secreted and interacts with the neuromuscular junction (NMJ). In this Drosophila model for CMT2D, we have previously shown that mutant gars expression decreases viability and larval motor function, and causes a concurrent build-up of mutant GlyRS at the larval neuromuscular presynapse. Here, we report additional phenotypes that closely mimic the axonal branching defects of Drosophila plexin transmembrane receptor mutants, implying interference of plexin signaling in gars mutants. Individual dosage reduction of two Drosophila Plexins, plexin A (plexA) and B (plexB) enhances and represses the viability and larval motor defects caused by mutant GlyRS, respectively. However, we find plexB levels, but not plexA levels, modify mutant GlyRS association with the presynaptic membrane. Furthermore, increasing availability of the plexB ligand, Semaphorin-2a (Sema2a), alleviates the pathology and the build-up of mutant GlyRS, suggesting competition for plexB binding may be occurring between these two ligands. This toxic gain-of-function and subversion of neurodevelopmental processes indicate that signaling pathways governing axonal guidance could be integral to neuropathology and may underlie the non-cell autonomous CMT2D mechanism.
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Affiliation(s)
- Stuart J Grice
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - James N Sleigh
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom
| | - M Zameel Cader
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.,MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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28
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Boczonadi V, Jennings MJ, Horvath R. The role of tRNA synthetases in neurological and neuromuscular disorders. FEBS Lett 2018; 592:703-717. [PMID: 29288497 PMCID: PMC5873386 DOI: 10.1002/1873-3468.12962] [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: 10/27/2017] [Revised: 12/06/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
Aminoacyl‐tRNA synthetases (ARSs) are ubiquitously expressed enzymes responsible for charging tRNAs with their cognate amino acids, therefore essential for the first step in protein synthesis. Although the majority of protein synthesis happens in the cytosol, an additional translation apparatus is required to translate the 13 mitochondrial DNA‐encoded proteins important for oxidative phosphorylation. Most ARS genes in these cellular compartments are distinct, but two genes are common, encoding aminoacyl‐tRNA synthetases of glycine (GARS) and lysine (KARS) in both mitochondria and the cytosol. Mutations in the majority 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 could explain the pathogenicity, however not all pathogenic ARSs mutations result in deficient catalytic function; thus, the consequences of mutations may arise from other molecular mechanisms. The peripheral nerves are frequently affected, as illustrated by the high number of mutations in cytosolic and bifunctional tRNA synthetases causing Charcot–Marie–Tooth disease (CMT). Here we provide insights on the pathomechanisms of CMT‐causing tRNA synthetases with specific focus on the two bifunctional tRNA synthetases (GARS, KARS).
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Affiliation(s)
- Veronika Boczonadi
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew J Jennings
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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29
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Beckervordersandforth R. Mitochondrial Metabolism-Mediated Regulation of Adult Neurogenesis. Brain Plast 2017; 3:73-87. [PMID: 29765861 PMCID: PMC5928529 DOI: 10.3233/bpl-170044] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The life-long generation of new neurons from radial glia-like neural stem cells (NSCs) is achieved through a stereotypic developmental sequence that requires precise regulatory mechanisms to prevent exhaustion or uncontrolled growth of the stem cell pool. Cellular metabolism is the new kid on the block of adult neurogenesis research and the identity of stage-specific metabolic programs and their impact on neurogenesis turns out to be an emerging research topic in the field. Mitochondrial metabolism is best known for energy production but it contains a great deal more. Mitochondria are key players in a variety of cellular processes including ATP synthesis through functional coupling of the electron transport chain and oxidative phosphorylation, recycling of hydrogen carriers, biosynthesis of cellular building blocks, and generation of reactive oxygen species that can modulate signaling pathways in a redox-dependent fashion. In this review, I will discuss recent findings describing stage-specific modulations of mitochondrial metabolism within the adult NSC lineage, emphasizing its importance for NSC self-renewal, proliferation of neural stem and progenitor cells (NSPCs), cell fate decisions, and differentiation and maturation of newborn neurons. I will furthermore summarize the important role of mitochondrial dysfunction in tissue regeneration and ageing, suggesting it as a potential therapeutic target for regenerative medicine practice.
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Affiliation(s)
- Ruth Beckervordersandforth
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
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30
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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.
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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
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31
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Wong HHW, Lin JQ, Ströhl F, Roque CG, Cioni JM, Cagnetta R, Turner-Bridger B, Laine RF, Harris WA, Kaminski CF, Holt CE. RNA Docking and Local Translation Regulate Site-Specific Axon Remodeling In Vivo. Neuron 2017; 95:852-868.e8. [PMID: 28781168 PMCID: PMC5563073 DOI: 10.1016/j.neuron.2017.07.016] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 06/09/2017] [Accepted: 07/14/2017] [Indexed: 12/03/2022]
Abstract
Nascent proteins can be positioned rapidly at precise subcellular locations by local protein synthesis (LPS) to facilitate localized growth responses. Axon arbor architecture, a major determinant of synaptic connectivity, is shaped by localized growth responses, but it is unknown whether LPS influences these responses in vivo. Using high-resolution live imaging, we examined the spatiotemporal dynamics of RNA and LPS in retinal axons during arborization in vivo. Endogenous RNA tracking reveals that RNA granules dock at sites of branch emergence and invade stabilized branches. Live translation reporter analysis reveals that de novo β-actin hotspots colocalize with docked RNA granules at the bases and tips of new branches. Inhibition of axonal β-actin mRNA translation disrupts arbor dynamics primarily by reducing new branch emergence and leads to impoverished terminal arbors. The results demonstrate a requirement for LPS in building arbor complexity and suggest a key role for pre-synaptic LPS in assembling neural circuits. Tracking endogenous RNA shows that RNA docking predicts axon branch emergence in vivo Axon arbor complexity in vivo depends on local protein synthesis Axonal β-actin synthesis regulates branching by increased branch initiation Live imaging reveals de novo synthesis of β-actin hotspots during branch formation
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Affiliation(s)
- Hovy Ho-Wai Wong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Julie Qiaojin Lin
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Florian Ströhl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Cláudio Gouveia Roque
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Jean-Michel Cioni
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Roberta Cagnetta
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Benita Turner-Bridger
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Romain F Laine
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
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32
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Oprescu SN, Chepa-Lotrea X, Takase R, Golas G, Markello TC, Adams DR, Toro C, Gropman AL, Hou YM, Malicdan MCV, Gahl WA, Tifft CJ, Antonellis A. Compound heterozygosity for loss-of-function GARS variants results in a multisystem developmental syndrome that includes severe growth retardation. Hum Mutat 2017; 38:1412-1420. [PMID: 28675565 DOI: 10.1002/humu.23287] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/17/2017] [Accepted: 06/16/2017] [Indexed: 01/25/2023]
Abstract
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed enzymes that ligate amino acids onto tRNA molecules. Genes encoding ARSs have been implicated in myriad dominant and recessive disease phenotypes. Glycyl-tRNA synthetase (GARS) is a bifunctional ARS that charges tRNAGly in the cytoplasm and mitochondria. GARS variants have been associated with dominant Charcot-Marie-Tooth disease but have not been convincingly implicated in recessive phenotypes. Here, we describe a patient from the NIH Undiagnosed Diseases Program with a multisystem, developmental phenotype. Whole-exome sequence analysis revealed that the patient is compound heterozygous for one frameshift (p.Glu83Ilefs*6) and one missense (p.Arg310Gln) GARS variant. Using in vitro and in vivo functional studies, we show that both GARS variants cause a loss-of-function effect: the frameshift variant results in depleted protein levels and the missense variant reduces GARS tRNA charging activity. In support of GARS variant pathogenicity, our patient shows striking phenotypic overlap with other patients having ARS-related recessive diseases, including features associated with variants in both cytoplasmic and mitochondrial ARSs; this observation is consistent with the essential function of GARS in both cellular locations. In summary, our clinical, genetic, and functional analyses expand the phenotypic spectrum associated with GARS variants.
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Affiliation(s)
| | - Xenia Chepa-Lotrea
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Ryuichi Takase
- Department of Biochemistry and Molecular Biochemistry, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Gretchen Golas
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Thomas C Markello
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - David R Adams
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Camilo Toro
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Andrea L Gropman
- Division of Neurogenetics and Developmental Pediatrics, Children's National Medical Center, Washington, District of Columbia
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biochemistry, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - May Christine V Malicdan
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Gahl
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Cynthia J Tifft
- NIH, Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan.,Department of Neurology, University of Michigan, Ann Arbor, Michigan
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33
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Ognjenović J, Simonović M. Human aminoacyl-tRNA synthetases in diseases of the nervous system. RNA Biol 2017; 15:623-634. [PMID: 28534666 PMCID: PMC6103678 DOI: 10.1080/15476286.2017.1330245] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 12/21/2022] Open
Abstract
Aminoacyl-tRNA synthetases (AaRSs) are ubiquitously expressed enzymes that ensure accurate translation of the genetic information into functional proteins. These enzymes also execute a variety of non-canonical functions that are significant for regulation of diverse cellular processes and that reside outside the realm of protein synthesis. Associations between faults in AaRS-mediated processes and human diseases have been long recognized. Most recent research findings strongly argue that 10 cytosolic and 14 mitochondrial AaRSs are implicated in some form of pathology of the human nervous system. The advent of modern whole-exome sequencing makes it all but certain that similar associations between the remaining 15 ARS genes and neurologic illnesses will be defined in future. It is not surprising that an intense scientific debate about the role of translational machinery, in general, and AaRSs, in particular, in the development and maintenance of the healthy human neural cell types and the brain is sparked. Herein, we summarize the current knowledge about causative links between mutations in human AaRSs and diseases of the nervous system and briefly discuss future directions.
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Affiliation(s)
- Jana Ognjenović
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, Chicago, IL, USA
| | - Miljan Simonović
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, Chicago, IL, USA
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34
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Völgyi K, Gulyássy P, Todorov MI, Puska G, Badics K, Hlatky D, Kékesi KA, Nyitrai G, Czurkó A, Drahos L, Dobolyi A. Chronic Cerebral Hypoperfusion Induced Synaptic Proteome Changes in the rat Cerebral Cortex. Mol Neurobiol 2017; 55:4253-4266. [PMID: 28620701 DOI: 10.1007/s12035-017-0641-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/29/2017] [Indexed: 12/23/2022]
Abstract
Chronic cerebral hypoperfusion (CCH) evokes mild cognitive impairment (MCI) and contributes to the progression of vascular dementia and Alzheimer's disease (AD). How CCH induces these neurodegenerative processes that may spread along the synaptic network and whether they are detectable at the synaptic proteome level of the cerebral cortex remains to be established. In the present study, we report the synaptic protein changes in the cerebral cortex after stepwise bilateral common carotid artery occlusion (BCCAO) induced CCH in the rat. The occlusions were confirmed with magnetic resonance angiography 5 weeks after the surgery. Synaptosome fractions were prepared using sucrose gradient centrifugation from cerebral cortex dissected 7 weeks after the occlusion. The synaptic protein differences between the sham operated and CCH groups were analyzed with label-free nanoUHPLC-MS/MS. We identified 46 proteins showing altered abundance due to CCH. In particular, synaptic protein and lipid metabolism, as well as GABA shunt-related proteins showed increased while neurotransmission and synaptic assembly-related proteins showed decreased protein level changes in CCH rats. Protein network analysis of CCH-induced protein alterations suggested the importance of increased synaptic apolipoprotein E (APOE) level as a consequence of CCH. Therefore, the change in APOE level was confirmed with Western blotting. The identified synaptic protein changes would precede the onset of dementia-like symptoms in the CCH model, suggesting their importance in the development of vascular dementia.
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Affiliation(s)
- Katalin Völgyi
- MTA-ELTE NAP B Laboratory of Molecular and Systems Neurobiology, Institute of Biology, Hungarian Academy of Sciences and Eötvös Loránd University, Pázmány Péter sétány 1C, Budapest, H-1117, Hungary.
| | - Péter Gulyássy
- MTA-TTK NAP B MS Neuroproteomics Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Mihail Ivilinov Todorov
- MTA-ELTE NAP B Laboratory of Molecular and Systems Neurobiology, Institute of Biology, Hungarian Academy of Sciences and Eötvös Loránd University, Pázmány Péter sétány 1C, Budapest, H-1117, Hungary.,Laboratory of Proteomics, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gina Puska
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Kata Badics
- Laboratory of Proteomics, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Dávid Hlatky
- Preclinical Imaging and Biomarker Laboratory, Pharmacology and Drug Safety Research, Richter Gedeon Plc, Budapest, Hungary
| | - Katalin Adrienna Kékesi
- MTA-TTK NAP B MS Neuroproteomics Research Group, Hungarian Academy of Sciences, Budapest, Hungary.,Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Gabriella Nyitrai
- Preclinical Imaging and Biomarker Laboratory, Pharmacology and Drug Safety Research, Richter Gedeon Plc, Budapest, Hungary
| | - András Czurkó
- Preclinical Imaging and Biomarker Laboratory, Pharmacology and Drug Safety Research, Richter Gedeon Plc, Budapest, Hungary
| | - László Drahos
- MTA-TTK NAP B MS Neuroproteomics Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Arpád Dobolyi
- MTA-ELTE NAP B Laboratory of Molecular and Systems Neurobiology, Institute of Biology, Hungarian Academy of Sciences and Eötvös Loránd University, Pázmány Péter sétány 1C, Budapest, H-1117, Hungary
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35
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Lopes S, Teplytska L, Vaz-Silva J, Dioli C, Trindade R, Morais M, Webhofer C, Maccarrone G, Almeida OFX, Turck CW, Sousa N, Sotiropoulos I, Filiou MD. Tau Deletion Prevents Stress-Induced Dendritic Atrophy in Prefrontal Cortex: Role of Synaptic Mitochondria. Cereb Cortex 2017; 27:2580-2591. [PMID: 27073221 DOI: 10.1093/cercor/bhw057] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Tau protein in dendrites and synapses has been recently implicated in synaptic degeneration and neuronal malfunction. Chronic stress, a well-known inducer of neuronal/synaptic atrophy, triggers hyperphosphorylation of Tau protein and cognitive deficits. However, the cause-effect relationship between these events remains to be established. To test the involvement of Tau in stress-induced impairments of cognition, we investigated the impact of stress on cognitive behavior, neuronal structure, and the synaptic proteome in the prefrontal cortex (PFC) of Tau knock-out (Tau-KO) and wild-type (WT) mice. Whereas exposure to chronic stress resulted in atrophy of apical dendrites and spine loss in PFC neurons as well as significant impairments in working memory in WT mice, such changes were absent in Tau-KO animals. Quantitative proteomic analysis of PFC synaptosomal fractions, combined with transmission electron microscopy analysis, suggested a prominent role for mitochondria in the regulation of the effects of stress. Specifically, chronically stressed animals exhibit Tau-dependent alterations in the levels of proteins involved in mitochondrial transport and oxidative phosphorylation as well as in the synaptic localization of mitochondria in PFC. These findings provide evidence for a causal role of Tau in mediating stress-elicited neuronal atrophy and cognitive impairment and indicate that Tau may exert its effects through synaptic mitochondria.
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Affiliation(s)
- Sofia Lopes
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | | | - Joao Vaz-Silva
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Chrysoula Dioli
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Rita Trindade
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Monica Morais
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Christian Webhofer
- Max Planck Institute of Psychiatry, 80804 Munich, Germany.,Current address: Sandoz Biopharmaceuticals, 82041 Oberhaching, Germany
| | | | | | | | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Ioannis Sotiropoulos
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
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36
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Tsuyama T, Tsubouchi A, Usui T, Imamura H, Uemura T. Mitochondrial dysfunction induces dendritic loss via eIF2α phosphorylation. J Cell Biol 2017; 216:815-834. [PMID: 28209644 PMCID: PMC5346966 DOI: 10.1083/jcb.201604065] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 11/30/2016] [Accepted: 01/19/2017] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial dysfunction is associated with neuropathological events, but how it mediates loss of specific neuronal subtypes is unclear. Tsuyama et al. show that mitochondrial dysfunction triggers selective dendritic loss in class IV arborization neurons in a manner dependent on eIF2α phosphorylation and translation inhibition. Mitochondria are key contributors to the etiology of diseases associated with neuromuscular defects or neurodegeneration. How changes in cellular metabolism specifically impact neuronal intracellular processes and cause neuropathological events is still unclear. We here dissect the molecular mechanism by which mitochondrial dysfunction induced by Prel aberrant function mediates selective dendritic loss in Drosophila melanogaster class IV dendritic arborization neurons. Using in vivo ATP imaging, we found that neuronal cellular ATP levels during development are not correlated with the progression of dendritic loss. We searched for mitochondrial stress signaling pathways that induce dendritic loss and found that mitochondrial dysfunction is associated with increased eIF2α phosphorylation, which is sufficient to induce dendritic pathology in class IV arborization neurons. We also observed that eIF2α phosphorylation mediates dendritic loss when mitochondrial dysfunction results from other genetic perturbations. Furthermore, mitochondrial dysfunction induces translation repression in class IV neurons in an eIF2α phosphorylation-dependent manner, suggesting that differential translation attenuation among neuron subtypes is a determinant of preferential vulnerability.
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Affiliation(s)
- Taiichi Tsuyama
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Asako Tsubouchi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Tadao Usui
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Hiromi Imamura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
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37
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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.
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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.
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38
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Abstract
Aminoacyl-tRNA synthetases (aaRSs) ligate amino acids to their cognate tRNAs, allowing them to decode the triplet code during translation. Through different mechanisms aaRSs also perform several non-canonical functions in transcription, translation, apoptosis, angiogenesis and inflammation. Drosophila has become a preferred system to model human diseases caused by mutations in aaRS genes, to dissect effects of reduced translation or non-canonical activities, and to study aminoacylation and translational fidelity. However, the lack of a systematic annotation of this gene family has hampered such studies. Here, we report the identification of the entire set of aaRS genes in the fly genome and we predict their roles based on experimental evidence and/or orthology. Further, we propose a new, systematic and logical nomenclature for aaRSs. We also review the research conducted on Drosophila aaRSs to date. Together, our work provides the foundation for further research in the fly aaRS field.
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Affiliation(s)
- Jiongming Lu
- a Institute of Cell Biology; University of Bern ; Bern , Switzerland
| | - Steven J Marygold
- b FlyBase; Department of Genetics; University of Cambridge ; Cambridge , UK
| | - Walid H Gharib
- c Interfaculty Bioinformatics Unit; University of Bern ; Bern , Switzerland
| | - Beat Suter
- a Institute of Cell Biology; University of Bern ; Bern , Switzerland
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39
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Storkebaum E. Peripheral neuropathy via mutant tRNA synthetases: Inhibition of protein translation provides a possible explanation. Bioessays 2016; 38:818-29. [PMID: 27352040 PMCID: PMC5094542 DOI: 10.1002/bies.201600052] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent evidence indicates that inhibition of protein translation may be a common pathogenic mechanism for peripheral neuropathy associated with mutant tRNA synthetases (aaRSs). aaRSs are enzymes that ligate amino acids to their cognate tRNA, thus catalyzing the first step of translation. Dominant mutations in five distinct aaRSs cause Charcot‐Marie‐Tooth (CMT) peripheral neuropathy, characterized by length‐dependent degeneration of peripheral motor and sensory axons. Surprisingly, loss of aminoacylation activity is not required for mutant aaRSs to cause CMT. Rather, at least for some mutations, a toxic‐gain‐of‐function mechanism underlies CMT‐aaRS. Interestingly, several mutations in two distinct aaRSs were recently shown to inhibit global protein translation in Drosophila models of CMT‐aaRS, by a mechanism independent of aminoacylation, suggesting inhibition of translation as a common pathogenic mechanism. Future research aimed at elucidating the molecular mechanisms underlying the translation defect induced by CMT‐mutant aaRSs should provide novel insight into the molecular pathogenesis of these incurable diseases.
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Affiliation(s)
- Erik Storkebaum
- Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Faculty of Medicine, University of Münster, Münster, Germany
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40
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Malissovas N, Griffin LB, Antonellis A, Beis D. Dimerization is required for GARS-mediated neurotoxicity in dominant CMT disease. Hum Mol Genet 2016; 25:1528-42. [PMID: 27008886 DOI: 10.1093/hmg/ddw031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 02/01/2016] [Indexed: 01/25/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a genetically heterogeneous group of peripheral neuropathies. Mutations in several aminoacyl-tRNA synthetase (ARS) genes have been implicated in inherited CMT disease. There are 12 reported CMT-causing mutations dispersed throughout the primary sequence of the human glycyl-tRNA synthetase (GARS). While there is strong genetic evidence linking GARS mutations to CMT disease, the molecular pathology underlying the neuromuscular and sensory phenotypes is still not fully understood. In particular, it is unclear whether the mutations result in a toxic gain of function, a partial loss of activity related to translation, or a combination of these mechanisms. We identified a zebrafish allele of gars (gars(s266)). Homozygous mutant embryos carry a C->A transversion, that changes a threonine to a lysine, in a residue next to a CMT-associated human mutation. We show that the neuromuscular phenotype observed in animals homozygous for T209K Gars (T130K in GARS) is due to a loss of dimerization of the mutated protein. Furthermore, we show that the loss of function, dimer-deficient and human disease-associated G319R Gars (G240R in GARS) mutant protein is unable to rescue the above phenotype. Finally, we demonstrate that another human disease-associated mutant G605R Gars (G526 in GARS) dimerizes with the remaining wild-type protein in animals heterozygous for the T209K Gars and reduces the function enough to elicit a neuromuscular phenotype. Our data indicate that dimerization is required for the dominant neurotoxicity of disease-associated GARS mutations and provide a rapid, tractable model for studying newly identified GARS variants for a role in human disease.
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Affiliation(s)
- Nikos Malissovas
- Developmental Biology, Biomedical Research Foundation Academy of Athens, Soranou Ephessiou 4, 11527 Athens, Greece, Medical School, University of Crete, Greece
| | - Laurie B Griffin
- Cellular and Molecular Biology Program, Medical Scientist Training Program
| | - Anthony Antonellis
- Cellular and Molecular Biology Program, Department of Human Genetics, and Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Dimitris Beis
- Developmental Biology, Biomedical Research Foundation Academy of Athens, Soranou Ephessiou 4, 11527 Athens, Greece,
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41
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Niehues S, Bussmann J, Steffes G, Erdmann I, Köhrer C, Sun L, Wagner M, Schäfer K, Wang G, Koerdt SN, Stum M, Jaiswal S, RajBhandary UL, Thomas U, Aberle H, Burgess RW, Yang XL, Dieterich D, Storkebaum E. Impaired protein translation in Drosophila models for Charcot-Marie-Tooth neuropathy caused by mutant tRNA synthetases. Nat Commun 2015; 6:7520. [PMID: 26138142 PMCID: PMC4506996 DOI: 10.1038/ncomms8520] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 05/16/2015] [Indexed: 01/06/2023] Open
Abstract
Dominant mutations in five tRNA synthetases cause Charcot-Marie-Tooth (CMT) neuropathy, suggesting that altered aminoacylation function underlies the disease. However, previous studies showed that loss of aminoacylation activity is not required to cause CMT. Here we present a Drosophila model for CMT with mutations in glycyl-tRNA synthetase (GARS). Expression of three CMT-mutant GARS proteins induces defects in motor performance and motor and sensory neuron morphology, and shortens lifespan. Mutant GARS proteins display normal subcellular localization but markedly reduce global protein synthesis in motor and sensory neurons, or when ubiquitously expressed in adults, as revealed by FUNCAT and BONCAT. Translational slowdown is not attributable to altered tRNA(Gly) aminoacylation, and cannot be rescued by Drosophila Gars overexpression, indicating a gain-of-toxic-function mechanism. Expression of CMT-mutant tyrosyl-tRNA synthetase also impairs translation, suggesting a common pathogenic mechanism. Finally, genetic reduction of translation is sufficient to induce CMT-like phenotypes, indicating a causal contribution of translational slowdown to CMT.
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Affiliation(s)
- Sven Niehues
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Julia Bussmann
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Georg Steffes
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Ines Erdmann
- 1] Research Group Neuralomics, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany [2] Institute for Pharmacology and Toxicology, Otto-von-Guericke-University, 39120 Magdeburg, Germany
| | - Caroline Köhrer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Litao Sun
- The Scripps Research Institute, La Jolla, California 92037, USA
| | - Marina Wagner
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Kerstin Schäfer
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Guangxia Wang
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Sophia N Koerdt
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
| | - Morgane Stum
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA
| | | | - Uttam L RajBhandary
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Ulrich Thomas
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Hermann Aberle
- Functional Cell Morphology Lab, Heinrich Heine University, 40225 Düsseldorf, Germany
| | | | - Xiang-Lei Yang
- The Scripps Research Institute, La Jolla, California 92037, USA
| | - Daniela Dieterich
- 1] Research Group Neuralomics, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany [2] Institute for Pharmacology and Toxicology, Otto-von-Guericke-University, 39120 Magdeburg, Germany
| | - Erik Storkebaum
- 1] Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany [2] Faculty of Medicine, University of Münster, 48149 Münster, Germany
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42
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Griffin LB, Sakaguchi R, McGuigan D, Gonzalez MA, Searby C, Züchner S, Hou YM, Antonellis A. Impaired function is a common feature of neuropathy-associated glycyl-tRNA synthetase mutations. Hum Mutat 2015; 35:1363-71. [PMID: 25168514 DOI: 10.1002/humu.22681] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/20/2014] [Indexed: 11/09/2022]
Abstract
Charcot-Marie-Tooth disease type 2D (CMT2D) is an autosomal-dominant axonal peripheral neuropathy characterized by impaired motor and sensory function in the distal extremities. Mutations in the glycyl-tRNA synthetase (GARS) gene cause CMT2D. GARS is a member of the ubiquitously expressed aminoacyl-tRNA synthetase (ARS) family and is responsible for charging tRNA with glycine. To date, 13 GARS mutations have been identified in patients with CMT disease. While functional studies have revealed loss-of-function characteristics, only four GARS mutations have been rigorously studied. Here, we report the functional evaluation of nine CMT-associated GARS mutations in tRNA charging, yeast complementation, and subcellular localization assays. Our results demonstrate that impaired function is a common characteristic of CMT-associated GARS mutations. Additionally, one mutation previously associated with CMT disease (p.Ser581Leu) does not demonstrate impaired function, was identified in the general population, and failed to segregate with disease in two newly identified families with CMT disease. Thus, we propose that this variant is not a disease-causing mutation. Together, our data indicate that impaired function is a key component of GARS-mediated CMT disease and emphasize the need for careful genetic and functional evaluation before implicating a variant in disease onset.
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Affiliation(s)
- Laurie B Griffin
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan; Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, Michigan
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Grice SJ, Sleigh JN, Motley WW, Liu JL, Burgess RW, Talbot K, Cader MZ. Dominant, toxic gain-of-function mutations in gars lead to non-cell autonomous neuropathology. Hum Mol Genet 2015; 24:4397-406. [PMID: 25972375 PMCID: PMC4492401 DOI: 10.1093/hmg/ddv176] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/06/2015] [Indexed: 12/15/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are collectively the most common hereditary neurological condition and a major health burden for society. Dominant mutations in the gene GARS, encoding the ubiquitous enzyme, glycyl-tRNA synthetase (GlyRS), cause peripheral nerve degeneration and lead to CMT disease type 2D. This genetic disorder exemplifies a recurring motif in neurodegeneration, whereby mutations in essential, widely expressed genes have selective deleterious consequences for the nervous system. Here, using novel Drosophila models, we show a potential solution to this phenomenon. Ubiquitous expression of mutant GlyRS leads to motor deficits, progressive neuromuscular junction (NMJ) denervation and pre-synaptic build-up of mutant GlyRS. Intriguingly, neuronal toxicity is, at least in part, non-cell autonomous, as expression of mutant GlyRS in mesoderm or muscle alone results in similar pathology. This mutant GlyRS toxic gain-of-function, which is WHEP domain-dependent, coincides with abnormal NMJ assembly, leading to synaptic degeneration, and, ultimately, reduced viability. Our findings suggest that mutant GlyRS gains access to ectopic sub-compartments of the motor neuron, providing a possible explanation for the selective neuropathology caused by mutations in a widely expressed gene.
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Affiliation(s)
- Stuart J Grice
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, UK
| | - James N Sleigh
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK, The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - William W Motley
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA and
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, UK
| | | | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - M Zameel Cader
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK, The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK,
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Simon M, Richard EM, Wang X, Shahzad M, Huang VH, Qaiser TA, Potluri P, Mahl SE, Davila A, Nazli S, Hancock S, Yu M, Gargus J, Chang R, Al-sheqaih N, Newman WG, Abdenur J, Starr A, Hegde R, Dorn T, Busch A, Park E, Wu J, Schwenzer H, Flierl A, Florentz C, Sissler M, Khan SN, Li R, Guan MX, Friedman TB, Wu DK, Procaccio V, Riazuddin S, Wallace DC, Ahmed ZM, Huang T, Riazuddin S. Mutations of human NARS2, encoding the mitochondrial asparaginyl-tRNA synthetase, cause nonsyndromic deafness and Leigh syndrome. PLoS Genet 2015; 11:e1005097. [PMID: 25807530 PMCID: PMC4373692 DOI: 10.1371/journal.pgen.1005097] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 02/23/2015] [Indexed: 12/31/2022] Open
Abstract
Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome. Mitochondrial respiratory chain (MRC) disease represents a large and heterogeneous group of energy deficiency disorders. Here we report three mutations in NARS2, a mitochondrial asparaginyl-tRNA synthetase, associated with non-syndromic hearing loss (NSHL) and Leigh syndrome in two independent families. Located in the predicted catalytic domain of the protein, missense mutation p.(Val213Phe) results in NSHL (DFNB94) while compound heterozygous mutation (p.Tyr323*; p.Asn381Ser) is leading to Leigh syndrome with auditory neuropathy. In vivo analysis deemed p.Tyr323* mutant protein to be unstable. Co-immunoprecipitation assays show that p.Asn381Ser mutant disrupts the dimerization ability of NARS2. Leigh syndrome patient fibroblasts exhibit a decreased steady-state level of mt-tRNAAsn. In addition, in these cells, the mitochondrial respiratory chain is deficient, including significantly decreased oxygen consumption rates and electron transport chain activities. These functions can be partially restored with over-expression of wild-type NARS2 but not with p.Val213Phe mutant protein. Our study provides new insights into the genes that are necessary for the function of brain and inner ear sensory cells in humans.
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Affiliation(s)
- Mariella Simon
- Department of Developmental and Cellular Biology, School of Biological Sciences, University of California, Irvine, Irvine, California, United States of America
- CHOC Childrens’, Division of Metabolics, Orange, California, United States of America
| | - Elodie M. Richard
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Xinjian Wang
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Mohsin Shahzad
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Vincent H. Huang
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Tanveer A. Qaiser
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Prasanth Potluri
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sarah E. Mahl
- Division of Pediatric Otolaryngology Head & Neck Surgery, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Antonio Davila
- Smilow Center for Translational Research, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sabiha Nazli
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Saege Hancock
- Trovagene, San Diego, California, United States of America
| | - Margret Yu
- Marshall B Ketchum University, Fullerton, California, United States of America
| | - Jay Gargus
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California, United States of America
| | - Richard Chang
- CHOC Childrens’, Division of Metabolics, Orange, California, United States of America
| | - Nada Al-sheqaih
- Manchester Centre for Genomic Medicine, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre (MAHSC), Manchester, United Kingdom
| | - William G. Newman
- Manchester Centre for Genomic Medicine, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre (MAHSC), Manchester, United Kingdom
| | - Jose Abdenur
- CHOC Childrens’, Division of Metabolics, Orange, California, United States of America
| | - Arnold Starr
- Department of Neurology and Neurobiology, University of California, Irvine, Irvine, California, United States of America
| | - Rashmi Hegde
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | | | - Anke Busch
- Institute of Molecular Biology, Mainz, Germany
| | - Eddie Park
- Department of Developmental and Cellular Biology, School of Biological Sciences, University of California, Irvine, Irvine, California, United States of America
| | - Jie Wu
- Institute for Genomics and Bioinformatics, University of California, Irvine, Irvine, California, United States of America
| | - Hagen Schwenzer
- Architecture et Réactivité de l’ARN, CNRS, University of Strasbourg, IBMC, Strasbourg, France
| | - Adrian Flierl
- Parkinson’s Institute and Clinical Center, Sunnyvale, California, United States of America
| | - Catherine Florentz
- Architecture et Réactivité de l’ARN, CNRS, University of Strasbourg, IBMC, Strasbourg, France
| | - Marie Sissler
- Architecture et Réactivité de l’ARN, CNRS, University of Strasbourg, IBMC, Strasbourg, France
| | - Shaheen N. Khan
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Ronghua Li
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Min-Xin Guan
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Doris K. Wu
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Vincent Procaccio
- Biochemistry and Genetics Department, UMR CNRS 6214–INSERM U1083, CHU Angers, Angers, France
| | - Sheikh Riazuddin
- Jinnah Hospital Complex, Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
- University of Lahore, Lahore, Pakistan
- Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zubair M. Ahmed
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- * E-mail: (TH); (SR)
| | - Saima Riazuddin
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- * E-mail: (TH); (SR)
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Sakuma C, Kawauchi T, Haraguchi S, Shikanai M, Yamaguchi Y, Gelfand VI, Luo L, Miura M, Chihara T. Drosophila Strip serves as a platform for early endosome organization during axon elongation. Nat Commun 2014; 5:5180. [PMID: 25312435 PMCID: PMC4197811 DOI: 10.1038/ncomms6180] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/05/2014] [Indexed: 12/19/2022] Open
Abstract
Early endosomes are essential for regulating cell signalling and controlling the amount of cell surface molecules during neuronal morphogenesis. Early endosomes undergo retrograde transport (clustering) before their homotypic fusion. Small GTPase Rab5 is known to promote early endosomal fusion, but the mechanism linking the transport/clustering with Rab5 activity is unclear. Here we show that Drosophila Strip is a key regulator for neuronal morphogenesis. strip knockdown disturbs the early endosome clustering and Rab5-positive early endosomes become smaller and scattered. Strip genetically and biochemically interacts with both Glued (the regulator of dynein-dependent transport) and Sprint (the guanine nucleotide exchange factor for Rab5), suggesting that Strip is a molecular linker between retrograde transport and Rab5 activation. Overexpression of an active form of Rab5 in strip mutant neurons suppresses the axon elongation defects. Thus, Strip acts as a molecular platform for the early endosome organization that plays important roles in neuronal morphogenesis.
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Affiliation(s)
- Chisako Sakuma
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takeshi Kawauchi
- 1] Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Shuka Haraguchi
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mima Shikanai
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Yoshifumi Yamaguchi
- 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Liqun Luo
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - Masayuki Miura
- 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] CREST, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Takahiro Chihara
- 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan [3] CREST, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
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Abstract
Precise connections established between pre- and postsynaptic partners during development are essential for the proper function of the nervous system. The olfactory system detects a wide variety of odorants and processes the information in a precisely connected neural circuit. A common feature of the olfactory systems from insects to mammals is that the olfactory receptor neurons (ORNs) expressing the same odorant receptor make one-to-one connections with a single class of second-order olfactory projection neurons (PNs). This represents one of the most striking examples of targeting specificity in developmental neurobiology. Recent studies have uncovered central roles of transmembrane and secreted proteins in organizing this one-to-one connection specificity in the olfactory system. Here, we review recent advances in the understanding of how this wiring specificity is genetically controlled and focus on the mechanisms by which transmembrane and secreted proteins regulate different stages of the Drosophila olfactory circuit assembly in a coordinated manner. We also discuss how combinatorial coding, redundancy, and error-correcting ability could contribute to constructing a complex neural circuit in general.
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López Del Amo V, Seco-Cervera M, García-Giménez JL, Whitworth AJ, Pallardó FV, Galindo MI. Mitochondrial defects and neuromuscular degeneration caused by altered expression of Drosophila Gdap1: implications for the Charcot-Marie-Tooth neuropathy. Hum Mol Genet 2014; 24:21-36. [PMID: 25122658 DOI: 10.1093/hmg/ddu416] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
One of the genes involved in Charcot-Marie-Tooth (CMT) disease, an inherited peripheral neuropathy, is GDAP1. In this work, we show that there is a true ortholog of this gene in Drosophila, which we have named Gdap1. By up- and down-regulation of Gdap1 in a tissue-specific manner, we show that altering its levels of expression produces changes in mitochondrial size, morphology and distribution, and neuronal and muscular degeneration. Interestingly, muscular degeneration is tissue-autonomous and not dependent on innervation. Metabolic analyses of our experimental genotypes suggest that alterations in oxidative stress are not a primary cause of the neuromuscular degeneration but a long-term consequence of the underlying mitochondrial dysfunction. Our results contribute to a better understanding of the role of mitochondria in CMT disease and pave the way to generate clinically relevant disease models to study the relationship between mitochondrial dynamics and peripheral neurodegeneration.
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Affiliation(s)
- Víctor López Del Amo
- Program of Rare and Genetic Diseases, Centro de Investigación Príncipe Felipe, Valencia, Spain Center for Biomedical Network Research on Rare Diseases (CIBERER), Valencia, Spain
| | - Marta Seco-Cervera
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Valencia, Spain Department of Physiology, School of Medicine and Dentistry, Universitat de València, INCLIVA Biomedical Research Institute, Valencia, Spain and
| | - José Luís García-Giménez
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Valencia, Spain Department of Physiology, School of Medicine and Dentistry, Universitat de València, INCLIVA Biomedical Research Institute, Valencia, Spain and
| | | | - Federico V Pallardó
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Valencia, Spain Department of Physiology, School of Medicine and Dentistry, Universitat de València, INCLIVA Biomedical Research Institute, Valencia, Spain and
| | - Máximo Ibo Galindo
- Program of Rare and Genetic Diseases, Centro de Investigación Príncipe Felipe, Valencia, Spain Center for Biomedical Network Research on Rare Diseases (CIBERER), Valencia, Spain
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48
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Abbott JA, Francklyn CS, Robey-Bond SM. Transfer RNA and human disease. Front Genet 2014; 5:158. [PMID: 24917879 PMCID: PMC4042891 DOI: 10.3389/fgene.2014.00158] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/14/2014] [Indexed: 12/25/2022] Open
Abstract
Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA) genes are “hotspots” for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase), mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers), and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing). Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.
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Affiliation(s)
- Jamie A Abbott
- Department of Biochemistry, College of Medicine, University of Vermont Burlington, VT, USA
| | | | - Susan M Robey-Bond
- Department of Biochemistry, College of Medicine, University of Vermont Burlington, VT, USA
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Ermanoska B, Motley WW, Leitão-Gonçalves R, Asselbergh B, Lee LH, De Rijk P, Sleegers K, Ooms T, Godenschwege TA, Timmerman V, Fischbeck KH, Jordanova A. CMT-associated mutations in glycyl- and tyrosyl-tRNA synthetases exhibit similar pattern of toxicity and share common genetic modifiers in Drosophila. Neurobiol Dis 2014; 68:180-9. [PMID: 24807208 DOI: 10.1016/j.nbd.2014.04.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 04/17/2014] [Accepted: 04/27/2014] [Indexed: 01/29/2023] Open
Abstract
Aminoacyl-tRNA synthetases are ubiquitously expressed proteins that charge tRNAs with their cognate amino acids. By ensuring the fidelity of protein synthesis, these enzymes are essential for the viability of every cell. Yet, mutations in six tRNA synthetases specifically affect the peripheral nerves and cause Charcot-Marie-Tooth (CMT) disease. The CMT-causing mutations in tyrosyl- and glycyl-tRNA synthetases (YARS and GARS, respectively) alter the activity of the proteins in a range of ways (some mutations do not impact charging function, while others abrogate it), making a loss of function in tRNA charging unlikely to be the cause of disease pathology. It is currently unknown which cellular mechanisms are triggered by the mutant enzymes and how this leads to neurodegeneration. Here, by expressing two pathogenic mutations (G240R, P234KY) in Drosophila, we generated a model for GARS-associated neuropathy. We observed compromised viability, and behavioral, electrophysiological and morphological impairment in flies expressing the cytoplasmic isoform of mutant GARS. Their features recapitulated several hallmarks of CMT pathophysiology and were similar to the phenotypes identified in our previously described Drosophila model of YARS-associated neuropathy. Furthermore, CG8316 and CG15599 - genes identified in a retinal degeneration screen to modify mutant YARS, also modified the mutant GARS phenotypes. Our study presents genetic evidence for common mutant-specific interactions between two CMT-associated aminoacyl-tRNA synthetases, lending support for a shared mechanism responsible for the synthetase-induced peripheral neuropathies.
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Affiliation(s)
- Biljana Ermanoska
- Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium; Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium
| | - William W Motley
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ricardo Leitão-Gonçalves
- Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium; Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium; Peripheral Neuropathy Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium
| | - Bob Asselbergh
- Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium; Centralized Service Facility, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium
| | - LaTasha H Lee
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Peter De Rijk
- Applied Molecular Genomics Unit, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium
| | - Kristel Sleegers
- Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium; Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium
| | - Tinne Ooms
- Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium; Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium
| | - Tanja A Godenschwege
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Vincent Timmerman
- Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium; Peripheral Neuropathy Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium
| | - Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Albena Jordanova
- Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerp 2610, Belgium; Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium.
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50
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Zhang X, Ling J, Barcia G, Jing L, Wu J, Barry BJ, Mochida GH, Hill RS, Weimer JM, Stein Q, Poduri A, Partlow JN, Ville D, Dulac O, Yu TW, Lam ATN, Servattalab S, Rodriguez J, Boddaert N, Munnich A, Colleaux L, Zon LI, Söll D, Walsh CA, Nabbout R. Mutations in QARS, encoding glutaminyl-tRNA synthetase, cause progressive microcephaly, cerebral-cerebellar atrophy, and intractable seizures. Am J Hum Genet 2014; 94:547-58. [PMID: 24656866 DOI: 10.1016/j.ajhg.2014.03.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/05/2014] [Indexed: 01/30/2023] Open
Abstract
Progressive microcephaly is a heterogeneous condition with causes including mutations in genes encoding regulators of neuronal survival. Here, we report the identification of mutations in QARS (encoding glutaminyl-tRNA synthetase [QARS]) as the causative variants in two unrelated families affected by progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres. Whole-exome sequencing of individuals from each family independently identified compound-heterozygous mutations in QARS as the only candidate causative variants. QARS was highly expressed in the developing fetal human cerebral cortex in many cell types. The four QARS mutations altered highly conserved amino acids, and the aminoacylation activity of QARS was significantly impaired in mutant cell lines. Variants p.Gly45Val and p.Tyr57His were located in the N-terminal domain required for QARS interaction with proteins in the multisynthetase complex and potentially with glutamine tRNA, and recombinant QARS proteins bearing either substitution showed an over 10-fold reduction in aminoacylation activity. Conversely, variants p.Arg403Trp and p.Arg515Trp, each occurring in a different family, were located in the catalytic core and completely disrupted QARS aminoacylation activity in vitro. Furthermore, p.Arg403Trp and p.Arg515Trp rendered QARS less soluble, and p.Arg403Trp disrupted QARS-RARS (arginyl-tRNA synthetase 1) interaction. In zebrafish, homozygous qars loss of function caused decreased brain and eye size and extensive cell death in the brain. Our results highlight the importance of QARS during brain development and that epilepsy due to impairment of QARS activity is unusually severe in comparison to other aminoacyl-tRNA synthetase disorders.
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Affiliation(s)
- Xiaochang Zhang
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jiqiang Ling
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA; Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Giulia Barcia
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France
| | - Lili Jing
- Howard Hughes Medical Institute; Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jiang Wu
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Brenda J Barry
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Ganeshwaran H Mochida
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, MA 02115, USA; Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - R Sean Hill
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jill M Weimer
- Sanford Children's Health Research Center, Sanford Research, 2301 East 60(th) Street North, Sioux Falls, SD 57104, USA
| | - Quinn Stein
- Departments of Pediatrics and Ob/Gyn, Sanford School of Medicine, Sioux Falls, SD 57105, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Jennifer N Partlow
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Dorothée Ville
- Department of Pediatric Neurology, Centre Hospitalier Universitaire de Lyon, 69007 Lyon, France
| | - Olivier Dulac
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France
| | - Tim W Yu
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Anh-Thu N Lam
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Sarah Servattalab
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jacqueline Rodriguez
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Nathalie Boddaert
- Institut National de la Santé et de la Recherche Médicale U781, Department of Pediatric Radiology, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Arnold Munnich
- Institut National de la Santé et de la Recherche Médicale U781, Department of Genetics, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Laurence Colleaux
- Institut National de la Santé et de la Recherche Médicale U781, Department of Genetics, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Leonard I Zon
- Howard Hughes Medical Institute; Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute; Department of Pediatrics, Harvard Medical School, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Rima Nabbout
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France.
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