1
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Marshall GF, Fasol M, Davies FCJ, Le Seelleur M, Fernandez Alvarez A, Bennett-Ness C, Gonzalez-Sulser A, Abbott CM. Face-valid phenotypes in a mouse model of the most common mutation in EEF1A2-related neurodevelopmental disorder. Dis Model Mech 2024; 17:dmm050501. [PMID: 38179821 PMCID: PMC10855229 DOI: 10.1242/dmm.050501] [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: 09/07/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
De novo heterozygous missense mutations in EEF1A2, encoding neuromuscular translation-elongation factor eEF1A2, are associated with developmental and epileptic encephalopathies. We used CRISPR/Cas9 to recapitulate the most common mutation, E122K, in mice. Although E122K heterozygotes were not observed to have convulsive seizures, they exhibited frequent electrographic seizures and EEG abnormalities, transient early motor deficits and growth defects. Both E122K homozygotes and Eef1a2-null mice developed progressive motor abnormalities, with E122K homozygotes reaching humane endpoints by P31. The null phenotype is driven by progressive spinal neurodegeneration; however, no signs of neurodegeneration were observed in E122K homozygotes. The E122K protein was relatively stable in neurons yet highly unstable in skeletal myocytes, suggesting that the E122K/E122K phenotype is instead driven by loss of function in muscle. Nevertheless, motor abnormalities emerged far earlier in E122K homozygotes than in nulls, suggesting a toxic gain of function and/or a possible dominant-negative effect. This mouse model represents the first animal model of an EEF1A2 missense mutation with face-valid phenotypes and has provided mechanistic insights needed to inform rational treatment design.
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Affiliation(s)
- Grant F. Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Melissa Fasol
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Faith C. J. Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Matthew Le Seelleur
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alejandra Fernandez Alvarez
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Cavan Bennett-Ness
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Catherine M. Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
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2
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Romano F, Haanpää MK, Pomianowski P, Peraino AR, Pollard JR, Di Feo MF, Traverso M, Severino M, Derchi M, Henzen E, Zara F, Faravelli F, Capra V, Scala M. Expanding the phenotype of UPF3B-related disorder: Case reports and literature review. Am J Med Genet A 2024; 194:e63534. [PMID: 38318947 DOI: 10.1002/ajmg.a.63534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 02/07/2024]
Abstract
UPF3B encodes the Regulator of nonsense transcripts 3B protein, a core-member of the nonsense-mediated mRNA decay pathway, protecting the cells from the potentially deleterious actions of transcripts with premature termination codons. Hemizygous variants in the UPF3B gene cause a spectrum of neuropsychiatric issues including intellectual disability, autism spectrum disorder, attention deficit hyperactivity disorder, and schizophrenia/childhood-onset schizophrenia (COS). The number of patients reported to date is very limited, often lacking an extensive phenotypical and neuroradiological description of this ultra-rare syndrome. Here we report three subjects harboring UPF3B variants, presenting with variable clinical pictures, including cognitive impairment, central hypotonia, and syndromic features. Patients 1 and 2 harbored novel UPF3B variants-the p.(Lys207*) and p.(Asp429Serfs*27) ones, respectively-while the p.(Arg225Lysfs*229) variant, identified in Patient 3, was already reported in the literature. Novel features in our patients are represented by microcephaly, midface hypoplasia, and brain malformations. Then, we reviewed pertinent literature and compared previously reported subjects to our cases, providing possible insights into genotype-phenotype correlations in this emerging condition. Overall, the detailed phenotypic description of three patients carrying UPF3B variants is useful not only to expand the genotypic and phenotypic spectrum of UPF3B-related disorders, but also to ameliorate the clinical management of affected individuals.
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Affiliation(s)
- Ferruccio Romano
- Clinical Genomics and Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Maria K Haanpää
- Department of Genomics and Clinical Genetics, Turku University Hospital, Turku, Finland
| | - Pawel Pomianowski
- Center for Medical Genetics and Genomics, Christiana Care Health System, Newark, Delaware, USA
| | - Amanda Rose Peraino
- Center for Medical Genetics and Genomics, Christiana Care Health System, Newark, Delaware, USA
| | - John R Pollard
- Epilepsy Center, Christiana Care Health System, Newark, Delaware, USA
| | - Maria Francesca Di Feo
- Clinical Genomics and Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Genomics and Clinical Genetics, Turku University Hospital, Turku, Finland
- Center for Medical Genetics and Genomics, Christiana Care Health System, Newark, Delaware, USA
- Epilepsy Center, Christiana Care Health System, Newark, Delaware, USA
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Monica Traverso
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | | | - Maria Derchi
- Cardiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Edoardo Henzen
- Genomics Facility, Italian Institute of Technology (IIT), Genoa, Italy
| | - Federico Zara
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Francesca Faravelli
- Clinical Genomics and Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Valeria Capra
- Clinical Genomics and Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Marcello Scala
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
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3
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Lewis SA, Forstrom J, Tavani J, Schafer R, Tiede Z, Padilla-Lopez SR, Kruer MC. eIF2α phosphorylation evokes dystonia-like movements with D2-receptor and cholinergic origin and abnormal neuronal connectivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.594240. [PMID: 38798458 PMCID: PMC11118466 DOI: 10.1101/2024.05.14.594240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Dystonia is the 3rd most common movement disorder. Dystonia is acquired through either injury or genetic mutations, with poorly understood molecular and cellular mechanisms. Eukaryotic initiation factor alpha (eIF2α) controls cell state including neuronal plasticity via protein translation control and expression of ATF4. Dysregulated eIF2α phosphorylation (eIF2α-P) occurs in dystonia patients and models including DYT1, but the consequences are unknown. We increased/decreased eIF2α-P and tested motor control and neuronal properties in a Drosophila model. Bidirectionally altering eIF2α-P produced dystonia-like abnormal posturing and dyskinetic movements in flies. These movements were also observed with expression of the DYT1 risk allele. We identified cholinergic and D2-receptor neuroanatomical origins of these dyskinetic movements caused by genetic manipulations to dystonia molecular candidates eIF2α-P, ATF4, or DYT1, with evidence for decreased cholinergic release. In vivo, increased and decreased eIF2α-P increase synaptic connectivity at the NMJ with increased terminal size and bouton synaptic release sites. Long-term treatment of elevated eIF2α-P with ISRIB restored adult longevity, but not performance in a motor assay. Disrupted eIF2α-P signaling may alter neuronal connectivity, change synaptic release, and drive motor circuit changes in dystonia.
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Affiliation(s)
- Sara A Lewis
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Jacob Forstrom
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Jennifer Tavani
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Robert Schafer
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Zach Tiede
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Sergio R Padilla-Lopez
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Michael C Kruer
- Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
- Departments of Child Health, Cellular & Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
- Programs in Neuroscience, Molecular & Cellular Biology, and Biomedical Informatics, Arizona State University, Tempe, AZ USA
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4
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Minoia M, Quintana-Cordero J, Jetzinger K, Kotan IE, Turnbull KJ, Ciccarelli M, Masser AE, Liebers D, Gouarin E, Czech M, Hauryliuk V, Bukau B, Kramer G, Andréasson C. Chp1 is a dedicated chaperone at the ribosome that safeguards eEF1A biogenesis. Nat Commun 2024; 15:1382. [PMID: 38360885 PMCID: PMC10869706 DOI: 10.1038/s41467-024-45645-w] [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: 06/02/2023] [Accepted: 01/29/2024] [Indexed: 02/17/2024] Open
Abstract
Cotranslational protein folding depends on general chaperones that engage highly diverse nascent chains at the ribosomes. Here we discover a dedicated ribosome-associated chaperone, Chp1, that rewires the cotranslational folding machinery to assist in the challenging biogenesis of abundantly expressed eukaryotic translation elongation factor 1A (eEF1A). Our results indicate that during eEF1A synthesis, Chp1 is recruited to the ribosome with the help of the nascent polypeptide-associated complex (NAC), where it safeguards eEF1A biogenesis. Aberrant eEF1A production in the absence of Chp1 triggers instant proteolysis, widespread protein aggregation, activation of Hsf1 stress transcription and compromises cellular fitness. The expression of pathogenic eEF1A2 variants linked to epileptic-dyskinetic encephalopathy is protected by Chp1. Thus, eEF1A is a difficult-to-fold protein that necessitates a biogenesis pathway starting with dedicated folding factor Chp1 at the ribosome to protect the eukaryotic cell from proteostasis collapse.
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Affiliation(s)
- Melania Minoia
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Jany Quintana-Cordero
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Katharina Jetzinger
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Ilgin Eser Kotan
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kathryn Jane Turnbull
- Department of Clinical Microbiology, Rigshospitalet, 2200, Copenhagen, Denmark
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Michela Ciccarelli
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Anna E Masser
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dorina Liebers
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Eloïse Gouarin
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Marius Czech
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Vasili Hauryliuk
- Science for Life Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, 50411, Tartu, Estonia
| | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
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5
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Paulet A, Bennett-Ness C, Ageorges F, Trost D, Green A, Goudie D, Jewell R, Kraatari-Tiri M, Piard J, Coubes C, Lam W, Lynch SA, Groeschel S, Ramond F, Fluss J, Fagerberg C, Brasch Andersen C, Varvagiannis K, Kleefstra T, Gérard B, Fradin M, Vitobello A, Tenconi R, Denommé-Pichon AS, Vincent-Devulder A, Haack T, Marsh JA, Laulund LW, Grimmel M, Riess A, de Boer E, Padilla-Lopez S, Bakhtiari S, Ostendorf A, Zweier C, Smol T, Willems M, Faivre L, Scala M, Striano P, Bagnasco I, Koboldt D, Iascone M, Suerink M, Kruer MC, Levy J, Verloes A, Abbott CM, Ruaud L. Expansion of the neurodevelopmental phenotype of individuals with EEF1A2 variants and genotype-phenotype study. Eur J Hum Genet 2024:10.1038/s41431-024-01560-8. [PMID: 38355961 DOI: 10.1038/s41431-024-01560-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 01/10/2024] [Accepted: 02/01/2024] [Indexed: 02/16/2024] Open
Abstract
Translation elongation factor eEF1A2 constitutes the alpha subunit of the elongation factor-1 complex, responsible for the enzymatic binding of aminoacyl-tRNA to the ribosome. Since 2012, 21 pathogenic missense variants affecting EEF1A2 have been described in 42 individuals with a severe neurodevelopmental phenotype including epileptic encephalopathy and moderate to profound intellectual disability (ID), with neurological regression in some patients. Through international collaborative call, we collected 26 patients with EEF1A2 variants and compared them to the literature. Our cohort shows a significantly milder phenotype. 83% of the patients are walking (vs. 29% in the literature), and 84% of the patients have language skills (vs. 15%). Three of our patients do not have ID. Epilepsy is present in 63% (vs. 93%). Neurological examination shows a less severe phenotype with significantly less hypotonia (58% vs. 96%), and pyramidal signs (24% vs. 68%). Cognitive regression was noted in 4% (vs. 56% in the literature). Among individuals over 10 years, 56% disclosed neurocognitive regression, with a mean age of onset at 2 years. We describe 8 novel missense variants of EEF1A2. Modeling of the different amino-acid sites shows that the variants associated with a severe phenotype, and the majority of those associated with a moderate phenotype, cluster within the switch II region of the protein and thus may affect GTP exchange. In contrast, variants associated with milder phenotypes may impact secondary functions such as actin binding. We report the largest cohort of individuals with EEF1A2 variants thus far, allowing us to expand the phenotype spectrum and reveal genotype-phenotype correlations.
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Affiliation(s)
- Alix Paulet
- Département de Génétique, Hôpital Robert-Debré, Paris, France.
| | - Cavan Bennett-Ness
- Centre for Genomic and Experimental Medicine and Simons Initiative for the Developing Brain, Institute of Genetics and Cancer, Edinburgh, Scotland, UK
| | | | | | - Andrew Green
- UCD School of Medicine and Medical Science Consultant in Clinical Genetics, Dublin, Ireland
| | - David Goudie
- Regional Genetics Service, NHS Tayside, Dundee, Scotland, UK
| | - Rosalyn Jewell
- Yorkshire Regional Genetics Service, Leeds Teaching Hospitals NHS Trust, Leeds, England, UK
| | - Minna Kraatari-Tiri
- Department of Clinical Genetics, Research unit of Clinical Medicine, Medical Research Center Oulu, Oulu, Finland
- Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Juliette Piard
- Centre de Génétique Humaine, CHU Besançon, Besançon, France
| | - Christine Coubes
- Service de Génétique Médicale, CHU de Montpellier, Montpellier, France
| | - Wayne Lam
- South-East of Scotland Clinical Genetics Service, General Hospital, Edinburgh, Scotland, UK
| | - Sally Ann Lynch
- Clinical Genetics, Children's Health Ireland, Dublin, Ireland
| | - Samuel Groeschel
- Department of Neuropediatrics, University Children's Hospital, Tuebingen, Germany
| | - Francis Ramond
- Service de Génétique, CHU Saint-Etienne - Hôpital Nord, Saint-Etienne, France
| | - Joël Fluss
- University Hospitals of Geneva, Geneva, Switzerland
| | - Christina Fagerberg
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | | | | | - Tjitske Kleefstra
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
- Center of Excellence for Neuropsychiatry, Vincent van Gogh Institute for Psychiatry, Venray, The Netherlands
| | | | - Mélanie Fradin
- Service de Génétique Médicale, Hôpital Sud, CHU de Rennes, Rennes, France
| | - Antonio Vitobello
- UMR-Inserm, Génétique des Anomalies du développement, Université de Bourgogne Franche-Comté, Dijon, France
| | - Romano Tenconi
- Servizio di Genetica Medica, Dipartimento di Pediatra, Padova, Italia
| | - Anne-Sophie Denommé-Pichon
- Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | | | - Tobias Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Joseph A Marsh
- MRC Human Genetics Unit, Western General Hospital, University of Edinburgh, Edinburgh, Scotland, UK
| | | | - Mona Grimmel
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Angelika Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Elke de Boer
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Sergio Padilla-Lopez
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Adam Ostendorf
- Steve and Cindy Rasmussen Institute for Genomic Medicine Nationwide Children's Hospital, Colombus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Colombus, USA
| | - Christiane Zweier
- Department of Human Genetics, Inselspital Bern, University of Bern, 3010, Bern, Switzerland
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Thomas Smol
- University of Lille, EA7364-RADEME, Medical Genetics Institute, Chu Lille, Lille, France
| | - Marjolaine Willems
- Medical Genetic Department for Rare Diseases and Personalized Medicine, Reference Center AD SOOR, AnDDI-RARE, Groupe DI, Inserm U1298, INM, Montpellier University, Montpellier, France
- Centre Hospitalier Universitaire de Montpellier, Montpellier, France
| | - Laurence Faivre
- UMR1231 GAD, Inserm, Université de Bourgogne-Franche Comté, Dijon, France
- Centre de Référence Maladies Rares « Anomalies du développement et syndromes malformatifs », Centre de Génétique, FHU-TRANSLAD et Institut GIMI, CHU dijon, Bourgogne, Dijon, France
| | - Marcello Scala
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Irene Bagnasco
- Division of Child Neuropsychiatry, Martini Hospital, Torino, Italy
| | - Daniel Koboldt
- Steve and Cindy Rasmussen Institute for Genomic Medicine Nationwide Children's Hospital, Colombus, Ohio, USA
| | | | - Manon Suerink
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Michael C Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Jonathan Levy
- Département de Génétique, Hôpital Robert-Debré, Paris, France
| | - Alain Verloes
- Département de Génétique, Hôpital Robert-Debré, Paris, France
| | - Catherine M Abbott
- Centre for Genomic and Experimental Medicine and Simons Initiative for the Developing Brain, Institute of Genetics and Cancer, Edinburgh, Scotland, UK
| | - Lyse Ruaud
- Département de Génétique, Hôpital Robert-Debré, Paris, France
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6
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Negrutskii BS, Porubleva LV, Malinowska A, Novosylna OV, Dadlez M, Knudsen CR. Understanding functions of eEF1 translation elongation factors beyond translation. A proteomic approach. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 138:67-99. [PMID: 38220433 DOI: 10.1016/bs.apcsb.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Mammalian translation elongation factors eEF1A1 and eEF1A2 are 92% homologous isoforms whose mutually exclusive tissue-specific expression is regulated during development. The isoforms have similar translation functionality, but show differences in spatial organization and participation in various processes, such as oncogenesis and virus reproduction. The differences may be due to their ability to interact with isoform-specific partner proteins. We used the identified sets of eEF1A1 or eEF1A2 partner proteins to identify cell complexes and/or processes specific to one particular isoform. As a result, we found isoform-specific interactions reflecting the involvement of different eEF1A isoforms in different cellular processes, including actin-related, chromatin-remodeling, ribonuclease H2, adenylyl cyclase, and Cul3-RING ubiquitin ligase complexes as well as initiation of mitochondrial transcription. An essential by-product of our analysis is the elucidation of a number of cellular processes beyond protein biosynthesis, where both isoforms appear to participate such as large ribosomal subunit biogenesis, mRNA splicing, DNA mismatch repair, 26S proteasome activity, P-body and exosomes formation, protein targeting to the membrane. This information suggests that a relatively high content of eEF1A in the cell may be necessary not only to maintain efficient translation, but also to ensure its participation in various cellular processes, where some roles of eEF1A have not yet been described. We believe that the data presented here will be useful for deciphering new auxiliary functions of eEF1A and its isoforms, and provide a new look at the known non-canonical functions of this main component of the human translation-elongation machinery.
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Affiliation(s)
- Boris S Negrutskii
- Institute of Molecular Biology and Genetics, Kyiv, Ukraine; Aarhus Institute of Advanced Sciences, Høegh-Guldbergs, Aarhus C, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen, Aarhus C, Denmark.
| | | | - Agata Malinowska
- Institute of Biochemistry and Biophysics, PAN, Pawinskiego, Warsaw, Poland
| | | | - Michal Dadlez
- Institute of Biochemistry and Biophysics, PAN, Pawinskiego, Warsaw, Poland
| | - Charlotte R Knudsen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen, Aarhus C, Denmark
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7
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Desai J, Singh E. Intrafamilial Phenotypic Overlap With Distinct Genotypes. Pediatr Neurol 2023; 148:172. [PMID: 37738884 DOI: 10.1016/j.pediatrneurol.2023.08.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/24/2023]
Affiliation(s)
- Jay Desai
- Division of Neurology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California.
| | - Eesha Singh
- University of Southern California, Los Angeles, California
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8
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Mohamed MS, Klann E. Autism- and epilepsy-associated EEF1A2 mutations lead to translational dysfunction and altered actin bundling. Proc Natl Acad Sci U S A 2023; 120:e2307704120. [PMID: 37695913 PMCID: PMC10515156 DOI: 10.1073/pnas.2307704120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/28/2023] [Indexed: 09/13/2023] Open
Abstract
Protein synthesis is a fundamental cellular process in neurons that is essential for synaptic plasticity and memory consolidation. Here, we describe our investigations of a neuron- and muscle-specific translation factor, eukaryotic Elongation Factor 1a2 (eEF1A2), which when mutated in patients results in autism, epilepsy, and intellectual disability. We characterize three EEF1A2 patient mutations, G70S, E122K, and D252H, and demonstrate that all three mutations decrease de novo protein synthesis and elongation rates in HEK293 cells. In mouse cortical neurons, the EEF1A2 mutations not only decrease de novo protein synthesis but also alter neuronal morphology, regardless of endogenous levels of eEF1A2, indicating that the mutations act via a toxic gain of function. We also show that eEF1A2 mutant proteins display increased tRNA binding and decreased actin-bundling activity, suggesting that these mutations disrupt neuronal function by decreasing tRNA availability and altering the actin cytoskeleton. More broadly, our findings are consistent with the idea that eEF1A2 acts as a bridge between translation and the actin cytoskeleton, which is essential for proper neuron development and function.
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Affiliation(s)
- Muhaned S. Mohamed
- Center for Neural Science, New York University, New York, NY10003
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY10016
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY10003
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY10016
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9
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Davies FCJ, Marshall GF, Pegram E, Gadd D, Abbott CM. Endogenous epitope tagging of eEF1A2 in mice reveals early embryonic expression of eEF1A2 and subcellular compartmentalisation of neuronal eEF1A1 and eEF1A2. Mol Cell Neurosci 2023; 126:103879. [PMID: 37429391 DOI: 10.1016/j.mcn.2023.103879] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023] Open
Abstract
All vertebrate species express two independently-encoded forms of translation elongation factor eEF1A. In humans and mice eEF1A1 and eEF1A2 are 92 % identical at the amino acid level, but the well conserved developmental switch between the two variants in specific tissues suggests the existence of important functional differences. Heterozygous mutations in eEF1A2 result in neurodevelopmental disorders in humans; the mechanism of pathogenicity is unclear, but one hypothesis is that there is a dominant negative effect on eEF1A1 during development. The high degree of similarity between the eEF1A proteins has complicated expression analysis in the past; here we describe a gene edited mouse line in which we have introduced a V5 tag in the gene encoding eEF1A2. Expression analysis using anti-V5 and anti-eEF1A1 antibodies demonstrates that, in contrast to the prevailing view that eEF1A2 is only expressed postnatally, it is expressed from as early as E11.5 in the developing neural tube. Two colour immunofluorescence also reveals coordinated switching between eEF1A1 and eEF1A2 in different regions of postnatal brain. Completely reciprocal expression of the two variants is seen in post-weaning mouse brain with eEF1A1 expressed in oligodendrocytes and astrocytes and eEF1A2 in neuronal soma. Although eEF1A1 is absent from neuronal cell bodies after development, it is widely expressed in axons. This expression does not appear to coincide with myelin sheaths originating from oligodendrocytes but rather results from localised translation within the axon, suggesting that both variants are transcribed in neurons but show completely distinct subcellular localisation at the protein level. These findings will form an underlying framework for understanding how missense mutations in eEF1A2 result in neurodevelopmental disorders.
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Affiliation(s)
- Faith C J Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Grant F Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Eleanor Pegram
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Danni Gadd
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Catherine M Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.
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10
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Mohamed MS, Klann E. Autism- and epilepsy-associated EEF1A2 mutations lead to translational dysfunction and altered actin bundling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.06.543912. [PMID: 37333416 PMCID: PMC10274670 DOI: 10.1101/2023.06.06.543912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Protein synthesis is a fundamental cellular process in neurons that is essential for synaptic plasticity and memory consolidation. Here, we describe our investigations of a neuron- and muscle-specific translation factor, e ukaryotic E longation F actor 1a2 (eEF1A2), which when mutated in patients results in autism, epilepsy, and intellectual disability. We characterize three most common EEF1A2 patient mutations, G70S, E122K, and D252H, and demonstrate that all three mutations decrease de novo protein synthesis and elongation rates in HEK293 cells. In mouse cortical neurons, the EEF1A2 mutations not only decrease de novo protein synthesis, but also alter neuronal morphology, regardless of endogenous levels of eEF1A2, indicating that the mutations act via a toxic gain of function. We also show that eEF1A2 mutant proteins display increased tRNA binding and decreased actin bundling activity, suggesting that these mutations disrupt neuronal function by decreasing tRNA availability and altering the actin cytoskeleton. More broadly, our findings are consistent with the idea that eEF1A2 acts as a bridge between translation and the actin skeleton, which is essential for proper neuron development and function. Significance Statement E ukaryotic E longation F actor 1A2 (eEF1A2) is a muscle- and neuron-specific translation factor responsible for bringing charge tRNAs to the elongating ribosome. Why neurons express this unique translation factor is unclear; however, it is known that mutations in EEF1A2 cause severe drug-resistant epilepsy, autism and neurodevelopmental delay. Here, we characterize the impact of three common disease-causing mutations in EEF1A2 and demonstrate that they cause decreased protein synthesis via reduced translation elongation, increased tRNA binding, decreased actin bundling activity, as well as altered neuronal morphology. We posit that eEF1A2 serves as a bridge between translation and the actin cytoskeleton, linking these two processes that are essential for neuronal function and plasticity.
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11
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Vogt LM, Lorenzo M, B Prendergast D, Jobling R, Gill PJ. EEF1A2 pathogenic variant presenting in an infant with failure to thrive and frequent apneas requiring respiratory support. Am J Med Genet A 2022; 188:3106-3109. [PMID: 35938194 DOI: 10.1002/ajmg.a.62932] [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: 12/20/2021] [Revised: 05/16/2022] [Accepted: 06/02/2022] [Indexed: 01/31/2023]
Abstract
EEF1A2 is a gene whose protein product, eukaryotic translation elongation factor 1 alpha 2 (eEF1A2), plays an important role in neurodevelopment. Reports of individuals with pathogenic variants in EEF1A2 are rare, with less than 40 individuals reported world-wide, however a common feature is the association of the variant with developmental and epileptic encephalopathy. Thus far, there have been limited reports of other organ systems or body functions affected by variants in this gene. Here, we present a case of a child with EEF1A2-related disorder who presented at 3 months of age with hypotonia, microcephaly, failure to thrive, and respiratory insufficiency with central apneas requiring respiratory support. Our case highlights the notion that the respiratory system may be highly implicated in EEF1A2-related disorder, allowing for better phenotypic characterization of the disorder.
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Affiliation(s)
- Lindsey M Vogt
- Division of Paediatric Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Melissa Lorenzo
- Division of Emergency Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - D'Arcy B Prendergast
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rebekah Jobling
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Peter J Gill
- Division of Paediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
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12
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Modelling the Human Blood-Brain Barrier in Huntington Disease. Int J Mol Sci 2022; 23:ijms23147813. [PMID: 35887162 PMCID: PMC9321930 DOI: 10.3390/ijms23147813] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 02/05/2023] Open
Abstract
While blood–brain barrier (BBB) dysfunction has been described in neurological disorders, including Huntington’s disease (HD), it is not known if endothelial cells themselves are functionally compromised when promoting BBB dysfunction. Furthermore, the underlying mechanisms of BBB dysfunction remain elusive given the limitations with mouse models and post mortem tissue to identify primary deficits. We established models of BBB and undertook a transcriptome and functional analysis of human induced pluripotent stem cell (iPSC)-derived brain-like microvascular endothelial cells (iBMEC) from HD patients or unaffected controls. We demonstrated that HD-iBMECs have abnormalities in barrier properties, as well as in specific BBB functions such as receptor-mediated transcytosis.
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13
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Xiao T, Chen X, Xu Y, Chen H, Dong X, Yang L, Wu B, Chen L, Li L, Zhuang D, Chen D, Zhou Y, Wang H, Zhou W. Clinical Study of 30 Novel KCNQ2 Variants/Deletions in KCNQ2-Related Disorders. Front Mol Neurosci 2022; 15:809810. [PMID: 35557555 PMCID: PMC9088225 DOI: 10.3389/fnmol.2022.809810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/02/2022] [Indexed: 11/24/2022] Open
Abstract
Background KCNQ2-related disorder is typically characterized as neonatal onset seizure and epileptic encephalopathy. The relationship between its phenotype and genotype is still elusive. This study aims to provide clinical features, management, and prognosis of patients with novel candidate variants of the KCNQ2 gene. Methods We enrolled patients with novel variants in the KCNQ2 gene from the China Neonatal Genomes Project between January 2018 and January 2021. All patients underwent next-generation sequencing tests and genetic data were analyzed by an in-house pipeline. The pathogenicity of variants was classified according to the guideline of the American College of Medical Genetics. Each case was evaluated by two geneticists back to back. Patients' information was acquired from clinical records. Results A total of 30 unrelated patients with novel variants in the KCNQ2 gene were identified, including 19 patients with single-nucleotide variants (SNVs) and 11 patients with copy number variants (CNVs). For the 19 SNVs, 12 missense variants and 7 truncating variants were identified. Of them, 36.8% (7/19) of the KCNQ2 variants were located in C-terminal regions, 15.7% (3/19) in segment S2, and 15.7% (3/19) in segment S4. Among them, 18 of 19 patients experienced seizures in the early neonatal period. However, one patient presented neurodevelopmental delay (NDD) as initial phenotype when he was 2 months old, and he had severe NDD when he was 3 years old. This patient did not present seizure but had abnormal electrographic background activity and brain imaging. Moreover, for the 11 patients with CNVs, 20q13.3 deletions involving EEF1A2, KCNQ2, and CHRNA4 genes were detected. All of them presented neonatal-onset seizures, responded to antiepileptic drugs, and had normal neurological development. Conclusion In this study, patients with novel KCNQ2 variants have variable phenotypes, whereas patients with 20q13.3 deletion involving EEF1A2, KCNQ2, and CHRNA4 genes tend to have normal neurological development.
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Affiliation(s)
- Tiantian Xiao
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Xiang Chen
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Yan Xu
- Division of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Huiyao Chen
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Xinran Dong
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Lin Yang
- Department of Endocrinology and Inherited Metabolic Diseases, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Bingbing Wu
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Liping Chen
- Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Long Li
- Department of Neonatology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | | | - Dongmei Chen
- Quanzhou Women and Children's Hospital, Quanzhou, China
| | - Yuanfeng Zhou
- Division of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- *Correspondence: Yuanfeng Zhou
| | - Huijun Wang
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- Huijun Wang
| | - Wenhao Zhou
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
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14
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Tian M, Chen J, Li J, Pan H, Lei W, Shu X. Damaging novel mutations in PIGN cause developmental epileptic-dyskinetic encephalopathy: a case report. BMC Pediatr 2022; 22:222. [PMID: 35468813 PMCID: PMC9036787 DOI: 10.1186/s12887-022-03246-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/27/2022] [Indexed: 11/10/2022] Open
Abstract
Background Mutations in PIGN, resulting in a glycosylphosphatidylinositol (GPI) anchor deficiency, typically leads to multiple congenital anomalies-hypotonia-seizures syndrome. However, the link between PIGN and epilepsy or paroxysmal non-kinesigenic dyskinesia (PNKD) is not well-described. This study reported a patient with PIGN mutation leading to developmental and epileptic encephalopathy and PNKD, to expand upon the genotype–phenotype correlation of PIGN. Case presentation During the first 10 days of life, a girl exhibited paroxysmal staring episodes with durations that ranged from several minutes to hours. These episodes occurred 2–5 times daily and always occurred during wakefulness. Ictal electroencephalography revealed no abnormalities, and PNKD was diagnosed. The patient also exhibited severely delayed psychomotor development and generalized seizures at the age of 4 months. Results of brain magnetic resonance imaging and metabolic screenings were normal, but trio-based whole-exome sequencing identified two novel compound heterozygous PIGN mutations (NM_176787; c.163C > T [p.R55 > X] and c.283C > T [p.R95W]). Flow cytometry analysis of the patient’s granulocytes revealed dramatically reduced expression of GPI-anchored proteins. This indicated that the mutations compromised GPI functions. The patient got seizure-free for 1 year, and her dyskinesia episodes reduced significantly (1–2 times/month) after treatment with levetiracetam (600 mg/day) and clonazepam (1.5 mg/day). No progress was observed with respect to psychomotor development; however, no craniofacial dysmorphic features, cleft lip/palate, brachytelephalangy with nail hypoplasia, and internal malformations have been observed until now (6 years of age). Conclusion This is the first study to document developmental and epileptic encephalopathy with PNKD in a human with PIGN mutations. This report expanded our understanding of the genotype–phenotype correlation of PIGN, and PIGN may be considered a potentially relevant gene when investigating cases of epilepsy or PNKD.
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Affiliation(s)
- Maoqiang Tian
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical University, No. 143 Dalian Road, Zunyi, 563003, China.
| | - Jing Chen
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical University, No. 143 Dalian Road, Zunyi, 563003, China
| | - Juan Li
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical University, No. 143 Dalian Road, Zunyi, 563003, China
| | - Hong Pan
- Department of Cosmetic Skin Laser, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, China
| | - Wenting Lei
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical University, No. 143 Dalian Road, Zunyi, 563003, China
| | - Xiaomei Shu
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical University, No. 143 Dalian Road, Zunyi, 563003, China
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15
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The Physiological Roles of the Exon Junction Complex in Development and Diseases. Cells 2022; 11:cells11071192. [PMID: 35406756 PMCID: PMC8997533 DOI: 10.3390/cells11071192] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/19/2022] [Accepted: 03/24/2022] [Indexed: 01/12/2023] Open
Abstract
The exon junction complex (EJC) becomes an increasingly important regulator of early gene expression in the central nervous system (CNS) and other tissues. The EJC is comprised of three core proteins: RNA-binding motif 8A (RBM8A), Mago homolog (MAGOH), eukaryotic initiation factor 4A3 (EIF4A3), and a peripheral EJC factor, metastatic lymph node 51 (MLN51), together with various auxiliary factors. The EJC is assembled specifically at exon-exon junctions on mRNAs, hence the name of the complex. The EJC regulates multiple levels of gene expression, from splicing to translation and mRNA degradation. The functional roles of the EJC have been established as crucial to the normal progress of embryonic and neurological development, with wide ranging implications on molecular, cellular, and organism level function. Dysfunction of the EJC has been implicated in multiple developmental and neurological diseases. In this review, we discuss recent progress on the EJC’s physiological roles.
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16
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Gorman KM, Peters CH, Lynch B, Jones L, Bassett DS, King MD, Ruben PC, Rosch RE. Persistent sodium currents in SCN1A developmental and degenerative epileptic dyskinetic encephalopathy. Brain Commun 2021; 3:fcab235. [PMID: 34755109 PMCID: PMC8568850 DOI: 10.1093/braincomms/fcab235] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/15/2021] [Accepted: 06/21/2021] [Indexed: 11/14/2022] Open
Abstract
Pathogenic variants in the voltage-gated sodium channel gene (SCN1A) are amongst the most common genetic causes of childhood epilepsies. There is considerable heterogeneity in both the types of causative variants and associated phenotypes; a recent expansion of the phenotypic spectrum of SCN1A associated epilepsies now includes an early onset severe developmental and epileptic encephalopathy with regression and a hyperkinetic movement disorder. Herein, we report a female with a developmental and degenerative epileptic-dyskinetic encephalopathy, distinct and more severe than classic Dravet syndrome. Clinical diagnostics indicated a paternally inherited c.5053G>T; p. A1685S variant of uncertain significance in SCN1A. Whole-exome sequencing detected a second de novo mosaic (18%) c.2345G>A; p. T782I likely pathogenic variant in SCN1A (maternal allele). Biophysical characterization of both mutant channels in a heterologous expression system identified gain-of-function effects in both, with a milder shift in fast inactivation of the p. A1685S channels; and a more severe persistent sodium current in the p. T782I. Using computational models, we show that large persistent sodium currents induce hyper-excitability in individual cortical neurons, thus relating the severe phenotype to the empirically quantified sodium channel dysfunction. These findings further broaden the phenotypic spectrum of SCN1A associated epilepsies and highlight the importance of testing for mosaicism in epileptic encephalopathies. Detailed biophysical evaluation and computational modelling further highlight the role of gain-of-function variants in the pathophysiology of the most severe phenotypes associated with SCN1A.
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Affiliation(s)
- Kathleen M Gorman
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Colin H Peters
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.,Department of Physiology and Biophysics, University of Colorado, Denver, CO, USA
| | - Bryan Lynch
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Laura Jones
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Dani S Bassett
- Departments of Bioengineering, Electrical & Systems Engineering, Physics & Astronomy, Neurology, and Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.,Santa Fe Institute, Santa Fe, NM, USA
| | - Mary D King
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Richard E Rosch
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.,MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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17
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Mills A, Gago F. On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits. Int J Mol Sci 2021; 22:6973. [PMID: 34203525 PMCID: PMC8268798 DOI: 10.3390/ijms22136973] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023] Open
Abstract
eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.
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Affiliation(s)
| | - Federico Gago
- Department of Biomedical Sciences & “Unidad Asociada IQM-CSIC”, School of Medicine and Health Sciences, University of Alcalá, E-28805 Alcalá de Henares, Spain;
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18
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Jeffrey JS, Leathem J, King C, Mefford HC, Ross K, Sadleir LG. Developmental and epileptic encephalopathy: Personal utility of a genetic diagnosis for families. Epilepsia Open 2021; 6:149-159. [PMID: 33681658 PMCID: PMC7918330 DOI: 10.1002/epi4.12458] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/22/2020] [Accepted: 11/30/2020] [Indexed: 11/11/2022] Open
Abstract
Objectives Identifying genetic pathogenic variants improves clinical outcomes for children with developmental and epileptic encephalopathy (DEE) by directing therapy and enabling accurate reproductive and prognostic information for families. We aimed to explore the additional personal utility of receiving a genetic diagnosis for families. Methods Semi-structured interviews were conducted with fifteen families of children with a DEE who had received a genetic diagnosis. The interviews stimulated discussion focusing on the impact of receiving a genetic diagnosis for the family. Interview transcripts were analyzed using the six-step systematic process of interpretative phenomenological analysis (IPA). Results Three key themes were identified: "Importance of the label," "Relief to end the diagnostic journey," and "Factors that influence personal utility." Families reported that receiving a genetic label improved their knowledge about the likely trajectory of the DEE, increased their hope for the future, and helped them communicate with others. The relief of finally having an answer for the cause of their child's DEE alleviated parental guilt and self-blame as well as helped families to process their grief and move forward. Delay in receipt of a genetic diagnosis diluted its psychological impact. Significance To date, the factors associated with the personal utility of a genetic diagnosis for DEEs have been under appreciated. This study demonstrates that identifying a genetic diagnosis for a child's DEE can be a psychological turning point for families. A genetic result has the potential to set these families on an adaptive path toward better quality of life through increased understanding, social connection, and support. Early access to genetic testing is important as it not only increases clinical utility, but also increases personal utility with early mitigation of family stress, trauma, and negative experiences.
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Affiliation(s)
| | - Janet Leathem
- School of PsychologyMassey UniversityWellingtonNew Zealand
| | - Chontelle King
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
| | - Heather C. Mefford
- Department of PediatricsDivision of Genetic MedicineUniversity of WashingtonSeattleWAUSA
| | - Kirsty Ross
- School of PsychologyMassey UniversityWellingtonNew Zealand
| | - Lynette G. Sadleir
- Department of Paediatrics and Child HealthUniversity of OtagoWellingtonNew Zealand
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19
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Yang J, Tang J, Li J, Cen Y, Chen J, Dai G. Effect of activation of the Akt/mTOR signaling pathway by EEF1A2 on the biological behavior of osteosarcoma. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:158. [PMID: 33569460 PMCID: PMC7867884 DOI: 10.21037/atm-20-7974] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Background Osteosarcoma (OS) is a common bone cancer in children and adolescents which causes a large number of cancer-related deaths. Eukaryotic Translation Elongation Factor 1 Alpha 2 (EEF1A2) has been revealed to have carcinogenic properties and promote tumor progression in many cancers. We want to investigate the biological function and mechanism of EEF1A2 in OS. Methods The expression of EEF1A2 in OS was investigated using the Gene Expression Omnibus (GEO) database and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The biological function of EEF1A2 in OS was studied using cell counting kit-8 (CCK8) assay, 5-ethynyl-2’-deoxyuridine (EdU) assay, Transwell assay, and OS of xenograft nude mice model. Real-time fluorescence quantitative PCR was used to detect the expression level of EEF1A2 mRNA in OS tissues and cell lines. Western blot was used to detect the phosphorylation level of Akt and mTOR Results There was high expression of EEF1A2 in OS, which was closely related to the Enneking stage and tumor size of OS. In vitro, EEF1A2 promoted the proliferation, migration, and invasion of OS cells; in vivo, EEF1A2 promoted the growth of OS tumors. The mechanism study showed that EEF1A2 can promote protein kinase B (Akt) and mammalian target of rapamycin (mTOR) phosphorylation, thereby activating the Akt/mTOR signaling pathway in OS. Conclusion There is high expression of EEF1A2 in OS, which can promote the proliferation, migration, and invasion of OS cells in vitro and the growth of OS tumors in vivo via activation of the Akt/mTOR signaling pathway.
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Affiliation(s)
- Jianing Yang
- Department of Burns and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, China.,Department of Dermatology, Sichuan Provincial People's Hospital, Chengdu, China
| | - Jun Tang
- Department of Burns and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Juan Li
- Department of Dermatology, Sichuan Provincial People's Hospital, Chengdu, China
| | - Ying Cen
- Department of Burns and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Junjie Chen
- Department of Burns and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Gengwu Dai
- Department of Dermatology, Sichuan Provincial People's Hospital, Chengdu, China
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Dilated cardiomyopathy in a patient with autosomal dominant EEF1A2-related neurodevelopmental disorder. Eur J Med Genet 2020; 64:104121. [PMID: 33307280 DOI: 10.1016/j.ejmg.2020.104121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 10/28/2020] [Accepted: 12/03/2020] [Indexed: 12/27/2022]
Abstract
The EEF1A2 gene encodes eukaryotic translation elongation factor 1α2, an integral component of the elongation factor complex. Heterozygous pathogenic variants in EEF1A2 are associated with neurodevelopmental disorders characterized by epilepsy, global developmental delay, and autism. To date, dilated cardiomyopathy has only been reported in two siblings with neurodevelopmental phenotypes and a homozygous missense variant in EEF1A2. This report describes a nine-year-old female patient who presented with neurodevelopmental phenotypes and dilated cardiomyopathy. Analysis of 193 epilepsy genes by focused exome sequencing revealed a novel heterozygous variant c.46G > C (p.Val16Leu; NM_001958.3) in EEF1A2. The variant was not detected in either parent, confirming its de novo origin. No additional variants that explain the patient's phenotypes were found by subsequent whole exome analysis. Copy number analysis of the exome data and exon-level microarray excluded a deletion in the other allele of EEF1A2. We present the first patient with a heterozygous pathogenic EEF1A2 variant who had dilated cardiomyopathy as well as neurodevelopmental phenotypes, suggesting that this cardiac phenotype may be associated with the autosomal dominant form of the EEF1A2-related disorder.
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21
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Gene constraint and genotype-phenotype correlations in neurodevelopmental disorders. Curr Opin Genet Dev 2020; 65:69-75. [PMID: 32599522 DOI: 10.1016/j.gde.2020.05.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 05/24/2020] [Indexed: 11/24/2022]
Abstract
With the advent and widespread adoption of high-throughput DNA sequencing, genetic discoveries in neurodevelopmental disorders (NDDs) are advancing very rapidly. The identification of novel NDD genes and of rare, highly penetrant pathogenic variants is leading to improved understanding of genotype-phenotype correlations. Here we emphasize the importance of large-scale, reference databases such as gnomAD to determine gene and variant level constraints and facilitate gene discovery, variant interpretation, and genotype-phenotype correlations. While the majority of dominant NDD genes are highly intolerant to variation, some apparent exceptions in reference databases are related to the presence of variants in transcripts that are not brain expressed and/or genes that show acquired somatic mosaicism in blood. Multiple NDD genes are being identified where varying phenotypes depend on the mode of inheritance (e.g., dominant or recessive), the nature (e.g., missense or truncating), or location of the mutation. Ongoing genome-wide analyses and targeted functional studies provide enhancements to the annotation of genes, gene products and variants, which will continue to facilitate gene and variant discovery and variant interpretation.
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