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Tarum J, Ball G, Gustafsson T, Altun M, Santos L. Artificial neural network inference analysis identified novel genes and gene interactions associated with skeletal muscle aging. J Cachexia Sarcopenia Muscle 2024; 15:2143-2155. [PMID: 39210538 PMCID: PMC11446686 DOI: 10.1002/jcsm.13562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 07/01/2024] [Accepted: 07/15/2024] [Indexed: 09/04/2024] Open
Abstract
BACKGROUND Sarcopenia is an age-related muscle disease that increases the risk of falls, disabilities, and death. It is associated with increased muscle protein degradation driven by molecular signalling pathways including Akt and FOXO1. This study aims to identify genes, gene interactions, and molecular pathways and processes associated with muscle aging and exercise in older adults that remained undiscovered until now leveraging on an artificial intelligence approach called artificial neural network inference (ANNi). METHODS Four datasets reporting the profile of muscle transcriptome obtained by RNA-seq of young (21-43 years) and older adults (63-79 years) were selected and retrieved from the Gene Expression Omnibus (GEO) data repository. Two datasets contained the transcriptome profiles associated to muscle aging and two the transcriptome linked to resistant exercise in older adults, the latter before and after 6 months of exercise training. Each dataset was individually analysed by ANNi based on a swarm neural network approach integrated into a deep learning model (Intelligent Omics). This allowed us to identify top 200 genes influencing (drivers) or being influenced (targets) by aging or exercise and the strongest interactions between such genes. Downstream gene ontology (GO) analysis of these 200 genes was performed using Metacore (Clarivate™) and the open-source software, Metascape. To confirm the differential expression of the genes showing the strongest interactions, real-time quantitative PCR (RT-qPCR) was employed on human muscle biopsies obtained from eight young (25 ± 4 years) and eight older men (78 ± 7.6 years), partaking in a 6-month resistance exercise training programme. RESULTS CHAD, ZDBF2, USP54, and JAK2 were identified as the genes with the strongest interactions predicting aging, while SCFD1, KDM5D, EIF4A2, and NIPAL3 were the main interacting genes associated with long-term exercise in older adults. RT-qPCR confirmed significant upregulation of USP54 (P = 0.005), CHAD (P = 0.03), and ZDBF2 (P = 0.008) in the aging muscle, while exercise-related genes were not differentially expressed (EIF4A2 P = 0.99, NIPAL3 P = 0.94, SCFD1 P = 0.94, and KDM5D P = 0.64). GO analysis related to skeletal muscle aging suggests enrichment of pathways linked to bone development (adj P-value 0.006), immune response (adj P-value <0.001), and apoptosis (adj P-value 0.01). In older exercising adults, these were ECM remodelling (adj P-value <0.001), protein folding (adj P-value <0.001), and proteolysis (adj P-value <0.001). CONCLUSIONS Using ANNi and RT-qPCR, we identified three strongly interacting genes predicting muscle aging, ZDBF2, USP54, and CHAD. These findings can help to inform the design of nonpharmacological and pharmacological interventions that prevent or mitigate sarcopenia.
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Affiliation(s)
- Janelle Tarum
- Department of Sport Science, Sport, Health and Performance Enhancement Research Centre (SHAPE), School of Science and TechnologyNottingham Trent UniversityNottinghamUK
| | - Graham Ball
- Medical Technology Research CentreAnglia Ruskin UniversityEssexUK
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Section of Clinical PhysiologyKarolinska Institutet HuddingeHuddingeSweden
- Department of Clinical PhysiologyKarolinska University HospitalHuddingeSweden
| | - Mikael Altun
- Department of Laboratory Medicine, Section of Clinical PhysiologyKarolinska Institutet HuddingeHuddingeSweden
- Department of Clinical PhysiologyKarolinska University HospitalHuddingeSweden
| | - Lívia Santos
- Department of Sport Science, Sport, Health and Performance Enhancement Research Centre (SHAPE), School of Science and TechnologyNottingham Trent UniversityNottinghamUK
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Screen M, Matheson LS, Howden AJ, Strathdee D, Willis AE, Bushell M, Sansom O, Turner M. RNA helicase EIF4A1-mediated translation is essential for the GC response. Life Sci Alliance 2024; 7:e202302301. [PMID: 38011999 PMCID: PMC10681908 DOI: 10.26508/lsa.202302301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
EIF4A1 and cofactors EIF4B and EIF4H have been well characterised in cancers, including B cell malignancies, for their ability to promote the translation of oncogenes with structured 5' untranslated regions. However, very little is known of their roles in nonmalignant cells. Using mouse models to delete Eif4a1, Eif4b or Eif4h in B cells, we show that EIF4A1, but not EIF4B or EIF4H, is essential for B cell development and the germinal centre response. After B cell activation in vitro, EIF4A1 facilitates an increased rate of protein synthesis, MYC expression, and expression of cell cycle regulators. However, EIF4A1-deficient cells remain viable, whereas inhibition of EIF4A1 and EIF4A2 by Hippuristanol treatment induces cell death.
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Affiliation(s)
- Michael Screen
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, UK
| | - Louise S Matheson
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, UK
| | - Andrew Jm Howden
- Cell Signalling and Immunology, University of Dundee, Dundee, UK
| | | | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Martin Bushell
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Owen Sansom
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Martin Turner
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, UK
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Schmidt T, Dabrowska A, Waldron JA, Hodge K, Koulouras G, Gabrielsen M, Munro J, Tack DC, Harris G, McGhee E, Scott D, Carlin L, Huang D, Le Quesne J, Zanivan S, Wilczynska A, Bushell M. eIF4A1-dependent mRNAs employ purine-rich 5'UTR sequences to activate localised eIF4A1-unwinding through eIF4A1-multimerisation to facilitate translation. Nucleic Acids Res 2023; 51:1859-1879. [PMID: 36727461 PMCID: PMC9976904 DOI: 10.1093/nar/gkad030] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/20/2022] [Accepted: 01/11/2023] [Indexed: 02/03/2023] Open
Abstract
Altered eIF4A1 activity promotes translation of highly structured, eIF4A1-dependent oncogene mRNAs at root of oncogenic translational programmes. It remains unclear how these mRNAs recruit and activate eIF4A1 unwinding specifically to facilitate their preferential translation. Here, we show that single-stranded RNA sequence motifs specifically activate eIF4A1 unwinding allowing local RNA structural rearrangement and translation of eIF4A1-dependent mRNAs in cells. Our data demonstrate that eIF4A1-dependent mRNAs contain AG-rich motifs within their 5'UTR which specifically activate eIF4A1 unwinding of local RNA structure to facilitate translation. This mode of eIF4A1 regulation is used by mRNAs encoding components of mTORC-signalling and cell cycle progression, and renders these mRNAs particularly sensitive to eIF4A1-inhibition. Mechanistically, we show that binding of eIF4A1 to AG-rich sequences leads to multimerization of eIF4A1 with eIF4A1 subunits performing distinct enzymatic activities. Our structural data suggest that RNA-binding of multimeric eIF4A1 induces conformational changes in the RNA resulting in an optimal positioning of eIF4A1 proximal to the RNA duplex enabling efficient unwinding. Our data proposes a model in which AG-motifs in the 5'UTR of eIF4A1-dependent mRNAs specifically activate eIF4A1, enabling assembly of the helicase-competent multimeric eIF4A1 complex, and positioning these complexes proximal to stable localised RNA structure allowing ribosomal subunit scanning.
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Affiliation(s)
- Tobias Schmidt
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Adrianna Dabrowska
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
- Department of Urology, University of California, San Francisco, CA 94158, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph A Waldron
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Kelly Hodge
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Grigorios Koulouras
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Mads Gabrielsen
- MVLS Structural Biology and Biophysical Characterisation Facility, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - June Munro
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - David C Tack
- Spectrum Health Office of Research and Education, Spectrum Health System, 15 Michigan Street NE, Grand Rapids, MI 49503, USA
| | - Gemma Harris
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0FA, UK
| | - Ewan McGhee
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - David Scott
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0FA, UK
- ISIS Spallation Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, DidcotOX11 0QX, UK
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington LE12 5RD, UK
| | - Leo M Carlin
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
| | - Danny Huang
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
| | - John Le Quesne
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
| | - Ania Wilczynska
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
| | - Martin Bushell
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1QH, UK
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Paul MS, Duncan AR, Genetti CA, Pan H, Jackson A, Grant PE, Shi J, Pinelli M, Brunetti-Pierri N, Garza-Flores A, Shahani D, Saneto RP, Zampino G, Leoni C, Agolini E, Novelli A, Blümlein U, Haack TB, Heinritz W, Matzker E, Alhaddad B, Abou Jamra R, Bartolomaeus T, AlHamdan S, Carapito R, Isidor B, Bahram S, Ritter A, Izumi K, Shakked BP, Barel O, Ben Zeev B, Begtrup A, Carere DA, Mullegama SV, Palculict TB, Calame DG, Schwan K, Aycinena ARP, Traberg R, Douzgou S, Pirt H, Ismayilova N, Banka S, Chao HT, Agrawal PB. Rare EIF4A2 variants are associated with a neurodevelopmental disorder characterized by intellectual disability, hypotonia, and epilepsy. Am J Hum Genet 2023; 110:120-145. [PMID: 36528028 PMCID: PMC9892767 DOI: 10.1016/j.ajhg.2022.11.011] [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: 04/15/2022] [Accepted: 11/15/2022] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic initiation factor-4A2 (EIF4A2) is an ATP-dependent RNA helicase and a member of the DEAD-box protein family that recognizes the 5' cap structure of mRNAs, allows mRNA to bind to the ribosome, and plays an important role in microRNA-regulated gene repression. Here, we report on 15 individuals from 14 families presenting with global developmental delay, intellectual disability, hypotonia, epilepsy, and structural brain anomalies, all of whom have extremely rare de novo mono-allelic or inherited bi-allelic variants in EIF4A2. Neurodegeneration was predominantly reported in individuals with bi-allelic variants. Molecular modeling predicts these variants would perturb structural interactions in key protein domains. To determine the pathogenicity of the EIF4A2 variants in vivo, we examined the mono-allelic variants in Drosophila melanogaster (fruit fly) and identified variant-specific behavioral and developmental defects. The fruit fly homolog of EIF4A2 is eIF4A, a negative regulator of decapentaplegic (dpp) signaling that regulates embryo patterning, eye and wing morphogenesis, and stem cell identity determination. Our loss-of-function (LOF) rescue assay demonstrated a pupal lethality phenotype induced by loss of eIF4A, which was fully rescued with human EIF4A2 wild-type (WT) cDNA expression. In comparison, the EIF4A2 variant cDNAs failed or incompletely rescued the lethality. Overall, our findings reveal that EIF4A2 variants cause a genetic neurodevelopmental syndrome with both LOF and gain of function as underlying mechanisms.
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Affiliation(s)
- Maimuna S Paul
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Anna R Duncan
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Division of Neonatology and Newborn Medicine, Massachusetts General Hospital for Children, Boston, MA, USA
| | - Casie A Genetti
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Hongling Pan
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Adam Jackson
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9WL, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | - Patricia E Grant
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Department of Radiology, Boston Children's Hospital, Boston, MA, USA
| | - Jiahai Shi
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Michele Pinelli
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Translational Medicine, University of Naples "Federico II", Naples, Italy
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Translational Medicine, University of Naples "Federico II", Naples, Italy
| | | | - Dave Shahani
- Department of Neurology and Epileptology, Cook Children's Hospital, Fort Worth, TX 76104, USA
| | - Russell P Saneto
- Neuroscience Institute, Center for Integrative Brain Research, Departments of Pediatric Neurology and Neurology Seattle Children's Hospital, University of Washington, Seattle, WA, USA
| | - Giuseppe Zampino
- Center for Rare Diseases and Birth Defects, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli, Rome, Italy; Catholic University of the Sacred Heart, Faculty of Medicine and Surgery, Rome, Italy
| | - Chiara Leoni
- Center for Rare Diseases and Birth Defects, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli, Rome, Italy
| | - Emanuele Agolini
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Ulrike Blümlein
- Department of Pediatrics, Carl-Thiem-Klinikum Cottbus, Cottbus, Germany
| | - Tobias B Haack
- Institute of Human Genetics, Technical University of Munich, 81675 Munich, Germany; Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
| | | | - Eva Matzker
- Department of Pediatrics, Carl-Thiem-Klinikum Cottbus, Cottbus, Germany
| | - Bader Alhaddad
- Institute of Human Genetics, Technical University of Munich, 81675 Munich, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Tobias Bartolomaeus
- Institute of Human Genetics, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | | | - Raphael Carapito
- Laboratoire 'ImmunoRhumatologie Moléculaire, Plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), ITI TRANSPLANTEX NG, Université de Strasbourg, 67085 Strasbourg, France; Service d'Immunologie Biologique, Plateau Technique de Biologie, Pôle de Biologie, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 1 Place de l'Hôpital, 67091, Strasbourg, France
| | - Bertrand Isidor
- Service de Génétique Médicale, Hôpital Hôtel-Dieu, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Seiamak Bahram
- Laboratoire 'ImmunoRhumatologie Moléculaire, Plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), ITI TRANSPLANTEX NG, Université de Strasbourg, 67085 Strasbourg, France; Service d'Immunologie Biologique, Plateau Technique de Biologie, Pôle de Biologie, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, 1 Place de l'Hôpital, 67091, Strasbourg, France
| | - Alyssa Ritter
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kosuke Izumi
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ben Pode Shakked
- Pediatric Neurology Department, The Edmond and Lilly Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Ortal Barel
- Pediatric Neurology Department, The Edmond and Lilly Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel
| | - Bruria Ben Zeev
- Pediatric Neurology Department, The Edmond and Lilly Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Amber Begtrup
- Clinical Genomics Program, GeneDx, Gaithersburg, MD 20877, USA
| | | | | | | | - Daniel G Calame
- Section of Pediatric Neurology and Developmental Neurosciences, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | - Rasa Traberg
- Department of Genetics and Molecular Medicine, Hospital of Lithuanian University of Health Sciences Kauno klinikos, Kaunas, Lithuania
| | - Sofia Douzgou
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9WL, UK; Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Harrison Pirt
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9WL, UK
| | - Naila Ismayilova
- Department of Paediatric Neurology, Chelsea and Westminster NHS Foundation Trust, London, UK
| | - Siddharth Banka
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9WL, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | - Hsiao-Tuan Chao
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX, USA.
| | - Pankaj B Agrawal
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
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Zhang X, Li F, Tang Y, Ren Q, Xiao B, Wan Y, Jiang S. miR-21a in exosomes from Lewis lung carcinoma cells accelerates tumor growth through targeting PDCD4 to enhance expansion of myeloid-derived suppressor cells. Oncogene 2020; 39:6354-6369. [DOI: 10.1038/s41388-020-01406-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 07/08/2020] [Accepted: 07/23/2020] [Indexed: 02/06/2023]
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Wilczynska A, Gillen SL, Schmidt T, Meijer HA, Jukes-Jones R, Langlais C, Kopra K, Lu WT, Godfrey JD, Hawley BR, Hodge K, Zanivan S, Cain K, Le Quesne J, Bushell M. eIF4A2 drives repression of translation at initiation by Ccr4-Not through purine-rich motifs in the 5'UTR. Genome Biol 2019; 20:262. [PMID: 31791371 PMCID: PMC6886185 DOI: 10.1186/s13059-019-1857-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 10/10/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Regulation of the mRNA life cycle is central to gene expression control and determination of cell fate. miRNAs represent a critical mRNA regulatory mechanism, but despite decades of research, their mode of action is still not fully understood. RESULTS Here, we show that eIF4A2 is a major effector of the repressive miRNA pathway functioning via the Ccr4-Not complex. We demonstrate that while DDX6 interacts with Ccr4-Not, its effects in the mechanism are not as pronounced. Through its interaction with the Ccr4-Not complex, eIF4A2 represses mRNAs at translation initiation. We show evidence that native eIF4A2 has similar RNA selectivity to chemically inhibited eIF4A1. eIF4A2 exerts its repressive effect by binding purine-rich motifs which are enriched in the 5'UTR of target mRNAs directly upstream of the AUG start codon. CONCLUSIONS Our data support a model whereby purine motifs towards the 3' end of the 5'UTR are associated with increased ribosome occupancy and possible uORF activation upon eIF4A2 binding.
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Affiliation(s)
- Ania Wilczynska
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
| | - Sarah L Gillen
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Tobias Schmidt
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Hedda A Meijer
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
- Present Address: Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | | | | | - Kari Kopra
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
- Present Address: Department of Chemistry, University of Turku, Vatselankatu 2, FI-20500, Turku, Finland
| | - Wei-Ting Lu
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Jack D Godfrey
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | | | - Kelly Hodge
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Kelvin Cain
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - John Le Quesne
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Martin Bushell
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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PRMT1 Deficiency in Mouse Juvenile Heart Induces Dilated Cardiomyopathy and Reveals Cryptic Alternative Splicing Products. iScience 2018; 8:200-213. [PMID: 30321814 PMCID: PMC6197527 DOI: 10.1016/j.isci.2018.09.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 12/11/2022] Open
Abstract
Protein arginine methyltransferase 1 (PRMT1) catalyzes the asymmetric dimethylation of arginine residues in proteins and methylation of various RNA-binding proteins and is associated with alternative splicing in vitro. Although PRMT1 has essential in vivo roles in embryonic development, CNS development, and skeletal muscle regeneration, the functional importance of PRMT1 in the heart remains to be elucidated. Here, we report that juvenile cardiomyocyte-specific PRMT1-deficient mice develop severe dilated cardiomyopathy and exhibit aberrant cardiac alternative splicing. Furthermore, we identified previously undefined cardiac alternative splicing isoforms of four genes (Asb2, Fbxo40, Nrap, and Eif4a2) in PRMT1-cKO mice and revealed that eIF4A2 protein isoforms translated from alternatively spliced mRNA were differentially ubiquitinated and degraded by the ubiquitin-proteasome system. These findings highlight the essential roles of PRMT1 in cardiac homeostasis and alternative splicing regulation. PRMT1 deficiency in cardiomyocytes causes dilated cardiomyopathy in juvenile mice PRMT1-deficient heart shows abnormal alternative splicing patterns Previously undefined cardiac splicing events are revealed by transcriptome analysis eIF4A2 isoforms are differentially ubiquitinated and degraded
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Translational dysregulation in cancer: eIF4A isoforms and sequence determinants of eIF4A dependence. Biochem Soc Trans 2016; 43:1227-33. [PMID: 26614665 DOI: 10.1042/bst20150163] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The malignant phenotype is largely the consequence of dysregulated gene expression. Transformed cells depend upon not just a global increase in protein synthesis but an altered translational landscape in which pro-oncogenic mRNAs are translationally up-regulated. Such mRNAs have been shown to possess longer and more structured 5'-UTRs requiring high levels of eukaryotic initiation factor 4A (eIF4A) helicase activity for efficient translation. As such there is a developing focus on targeting eIF4A as a cancer therapy. In order for such treatments to be successful, we must develop a detailed understanding of the mechanisms which make specific mRNAs more dependent on eIF4A activity than others. It is also crucial to fully characterize the potentially distinct roles of eIF4A1 and eIF4A2, which until recently were thought to be functionally interchangeable. This review will highlight the recent advances made in this field that address these issues.
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Chu J, Cargnello M, Topisirovic I, Pelletier J. Translation Initiation Factors: Reprogramming Protein Synthesis in Cancer. Trends Cell Biol 2016; 26:918-933. [PMID: 27426745 DOI: 10.1016/j.tcb.2016.06.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/03/2016] [Accepted: 06/13/2016] [Indexed: 12/11/2022]
Abstract
Control of mRNA translation plays a crucial role in the regulation of gene expression and is critical for cellular homeostasis. Dysregulation of translation initiation factors has been documented in several pathologies including cancer. Aberrant function of translation initiation factors leads to translation reprogramming that promotes proliferation, survival, angiogenesis, and metastasis. In such context, understanding how altered levels (and presumably activity) of initiation factors can contribute to tumor initiation and/or maintenance is of major interest for the development of novel therapeutic strategies. In this review we provide an overview of translation initiation mechanisms and focus on recent findings describing the role of individual initiation factors and their aberrant activity in cancer.
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Affiliation(s)
- Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Marie Cargnello
- Lady Davis Institute, SMBD JGH, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada; Lady Davis Institute, SMBD JGH, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada.
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada; Gerald Bronfman Department of Oncology, McGill University, Quebec, Canada; The Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada.
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Huber R, Panterodt T, Welz B, Christmann M, Friesenhagen J, Westphal A, Pietsch D, Brand K. C/EBPβ-LAP*/LAP Expression Is Mediated by RSK/eIF4B-Dependent Signalling and Boosted by Increased Protein Stability in Models of Monocytic Differentiation. PLoS One 2015; 10:e0144338. [PMID: 26646662 PMCID: PMC4672875 DOI: 10.1371/journal.pone.0144338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/17/2015] [Indexed: 11/30/2022] Open
Abstract
The transcription factor C/EBPβ plays a key role in monocytic differentiation and inflammation. Its small isoform LIP is associated with proliferation at early premonocytic developmental stages and regulated via mTOR-dependent signalling. During later stages of (pre)monocytic differentiation there is a considerable increase in the large C/EBPβ isoforms LAP*/LAP which inhibit proliferation thus supporting terminal differentiation. Here, we showed in different models of monocytic differentiation that this dramatic increase in the LAP*/LAP protein and LAP/LIP ratio was accompanied by an only modest/retarded mRNA increase suggesting an important role for (post)translational mechanisms. We found that LAP*/LAP formation was induced via MEK/RSK-dependent cascades, whereas mTOR/S6K1 were not involved. Remarkably, LAP*/LAP expression was dependent on phosphorylated eIF4B, an acceleratory protein of RNA helicase eIF4A. PKR inhibition reduced the expression of eIF4B and C/EBPβ in an eIF2α-independent manner. Furthermore, under our conditions a marked stabilisation of LAP*/LAP protein occurred, accompanied by reduced chymotrypsin-like proteasome/calpain activities and increased calpastatin levels. Our study elucidates new signalling pathways inducing LAP*/LAP expression and indicates new alternative PKR functions in monocytes. The switch from mTOR- to RSK-mediated signalling to orchestrate eIF4B-dependent LAP*/LAP translation, accompanied by increased protein stability but only small mRNA changes, may be a prototypical example for the regulation of protein expression during selected processes of differentiation/proliferation.
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Affiliation(s)
- René Huber
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Thomas Panterodt
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Bastian Welz
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Martin Christmann
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Judith Friesenhagen
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Andreas Westphal
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Daniel Pietsch
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Korbinian Brand
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
- * E-mail:
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Galicia-Vázquez G, Chu J, Pelletier J. eIF4AII is dispensable for miRNA-mediated gene silencing. RNA (NEW YORK, N.Y.) 2015; 21:1826-33. [PMID: 26286746 PMCID: PMC4574758 DOI: 10.1261/rna.052225.115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 07/21/2015] [Indexed: 05/03/2023]
Abstract
MicroRNAs (miRNAs) are short noncoding RNAs that regulate gene expression through partial complementary base-pairing to the 3' untranslated region (UTR) of target mRNAs. Inhibition of translation initiation has been identified as an early event of miRNA-mediated gene repression, but the underlying mechanistic details of this process are not well understood. Recently, eukaryotic initiation factor (eIF) 4AII was identified as a critical modulator of miRNA activity with depletion of this factor alleviating miRNA-mediated gene repression. Using the CRISPR/Cas9-editing system, we generated a novel cell line in which expression of eIF4AII was eliminated. The absence of eIF4AII does not affect cell viability, proliferation, or global mRNA translation. Importantly, we show that eIF4AII is dispensable for miRNA-mediated gene silencing.
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Affiliation(s)
| | - Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Québec H3G 1Y6, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Québec H3G 1Y6, Canada The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec H3G 1Y6, Canada Department of Oncology, McGill University, Montreal, Québec H3G 1Y6, Canada
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