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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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Zhang W, Wang J, Shan C. The eEF1A protein in cancer: Clinical significance, oncogenic mechanisms, and targeted therapeutic strategies. Pharmacol Res 2024; 204:107195. [PMID: 38677532 DOI: 10.1016/j.phrs.2024.107195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/09/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Eukaryotic elongation factor 1A (eEF1A) is among the most abundant proteins in eukaryotic cells. Evolutionarily conserved across species, eEF1A is in charge of translation elongation for protein biosynthesis as well as a plethora of non-translational moonlighting functions for cellular homeostasis. In malignant cells, however, eEF1A becomes a pleiotropic driver of cancer progression via a broad diversity of pathways, which are not limited to hyperactive translational output. In the past decades, mounting studies have demonstrated the causal link between eEF1A and carcinogenesis, gaining deeper insights into its multifaceted mechanisms and corroborating its value as a prognostic marker in various cancers. On the other hand, an increasing number of natural and synthetic compounds were discovered as anticancer eEF1A-targeting inhibitors. Among them, plitidepsin was approved for the treatment of multiple myeloma whereas metarrestin was currently under clinical development. Despite significant achievements in these two interrelated fields, hitherto there lacks a systematic examination of the eEF1A protein in the context of cancer research. Therefore, the present work aims to delineate its clinical implications, molecular oncogenic mechanisms, and targeted therapeutic strategies as reflected in the ever expanding body of literature, so as to deepen mechanistic understanding of eEF1A-involved tumorigenesis and inspire the development of eEF1A-targeted chemotherapeutics and biologics.
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Affiliation(s)
- Weicheng Zhang
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China.
| | - Jiyan Wang
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China
| | - Changliang Shan
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China.
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3
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Moreno-Aguilera M, Neher AM, Mendoza MB, Dodel M, Mardakheh FK, Ortiz R, Gallego C. KIS counteracts PTBP2 and regulates alternative exon usage in neurons. eLife 2024; 13:e96048. [PMID: 38597390 PMCID: PMC11045219 DOI: 10.7554/elife.96048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024] Open
Abstract
Alternative RNA splicing is an essential and dynamic process in neuronal differentiation and synapse maturation, and dysregulation of this process has been associated with neurodegenerative diseases. Recent studies have revealed the importance of RNA-binding proteins in the regulation of neuronal splicing programs. However, the molecular mechanisms involved in the control of these splicing regulators are still unclear. Here, we show that KIS, a kinase upregulated in the developmental brain, imposes a genome-wide alteration in exon usage during neuronal differentiation in mice. KIS contains a protein-recognition domain common to spliceosomal components and phosphorylates PTBP2, counteracting the role of this splicing factor in exon exclusion. At the molecular level, phosphorylation of unstructured domains within PTBP2 causes its dissociation from two co-regulators, Matrin3 and hnRNPM, and hinders the RNA-binding capability of the complex. Furthermore, KIS and PTBP2 display strong and opposing functional interactions in synaptic spine emergence and maturation. Taken together, our data uncover a post-translational control of splicing regulators that link transcriptional and alternative exon usage programs in neuronal development.
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Affiliation(s)
| | - Alba M Neher
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Mónica B Mendoza
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Martin Dodel
- Barts Cancer Institute, Queen Mary University of LondonLondonUnited Kingdom
| | - Faraz K Mardakheh
- Barts Cancer Institute, Queen Mary University of LondonLondonUnited Kingdom
| | - Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
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4
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Schieweck R, Götz M. Pan-cellular organelles and suborganelles-from common functions to cellular diversity? Genes Dev 2024; 38:98-114. [PMID: 38485267 PMCID: PMC10982711 DOI: 10.1101/gad.351337.123] [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] [Indexed: 04/02/2024]
Abstract
Cell diversification is at the base of increasing multicellular organism complexity in phylogeny achieved during ontogeny. However, there are also functions common to all cells, such as cell division, cell migration, translation, endocytosis, exocytosis, etc. Here we revisit the organelles involved in such common functions, reviewing recent evidence of unexpected differences of proteins at these organelles. For instance, centrosomes or mitochondria differ significantly in their protein composition in different, sometimes closely related, cell types. This has relevance for development and disease. Particularly striking is the high amount and diversity of RNA-binding proteins at these and other organelles, which brings us to review the evidence for RNA at different organelles and suborganelles. We include a discussion about (sub)organelles involved in translation, such as the nucleolus and ribosomes, for which unexpected cell type-specific diversity has also been reported. We propose here that the heterogeneity of these organelles and compartments represents a novel mechanism for regulating cell diversity. One reason is that protein functions can be multiplied by their different contributions in distinct organelles, as also exemplified by proteins with moonlighting function. The specialized organelles still perform pan-cellular functions but in a cell type-specific mode, as discussed here for centrosomes, mitochondria, vesicles, and other organelles. These can serve as regulatory hubs for the storage and transport of specific and functionally important regulators. In this way, they can control cell differentiation, plasticity, and survival. We further include examples highlighting the relevance for disease and propose to examine organelles in many more cell types for their possible differences with functional relevance.
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Affiliation(s)
- Rico Schieweck
- Institute of Biophysics, National Research Council (CNR) Unit at Trento, 38123 Povo, Italy;
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Magdalena Götz
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany;
- Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, 82152 Planegg-Martinsried, Germany
- SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
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5
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Xie B, Zhang M, Li J, Cui J, Zhang P, Liu F, Wu Y, Deng W, Ma J, Li X, Pan B, Zhang B, Zhang H, Luo A, Xu Y, Li M, Pu Y. KAT8-catalyzed lactylation promotes eEF1A2-mediated protein synthesis and colorectal carcinogenesis. Proc Natl Acad Sci U S A 2024; 121:e2314128121. [PMID: 38359291 PMCID: PMC10895275 DOI: 10.1073/pnas.2314128121] [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: 08/23/2023] [Accepted: 12/18/2023] [Indexed: 02/17/2024] Open
Abstract
Aberrant lysine lactylation (Kla) is associated with various diseases which are caused by excessive glycolysis metabolism. However, the regulatory molecules and downstream protein targets of Kla remain largely unclear. Here, we observed a global Kla abundance profile in colorectal cancer (CRC) that negatively correlates with prognosis. Among lactylated proteins detected in CRC, lactylation of eEF1A2K408 resulted in boosted translation elongation and enhanced protein synthesis which contributed to tumorigenesis. By screening eEF1A2 interacting proteins, we identified that KAT8, a lysine acetyltransferase that acted as a pan-Kla writer, was responsible for installing Kla on many protein substrates involving in diverse biological processes. Deletion of KAT8 inhibited CRC tumor growth, especially in a high-lactic tumor microenvironment. Therefore, the KAT8-eEF1A2 Kla axis is utilized to meet increased translational requirements for oncogenic adaptation. As a lactyltransferase, KAT8 may represent a potential therapeutic target for CRC.
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Affiliation(s)
- Bingteng Xie
- Key Laboratory of Molecular Medicine and Biological Diagnosis and Treatment (Ministry of Industry and Information Technology), School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Mengdi Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Jie Li
- State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
- National Clinical Research Center for Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
| | - Jianxin Cui
- Department of General Surgery & Institute of General Surgery, the First Medical Center of Chinese People's Liberation Army General Hospital, Beijing 100583, China
| | - Pengju Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Fangming Liu
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Yuxi Wu
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904
| | - Weiwei Deng
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Jihong Ma
- State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
- National Clinical Research Center for Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
| | - Xinyu Li
- State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
- National Clinical Research Center for Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
| | - Bingchen Pan
- Key Laboratory of Molecular Medicine and Biological Diagnosis and Treatment (Ministry of Industry and Information Technology), School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Baohui Zhang
- Department of Physiology, School of Life Science, China Medical University, Shenyang 110122, China
| | - Hongbing Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Aiqin Luo
- Key Laboratory of Molecular Medicine and Biological Diagnosis and Treatment (Ministry of Industry and Information Technology), School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Yinzhe Xu
- Faculty of Hepato-Biliary-Pancreatic Surgery, the First Medical Center of Chinese People's Liberation Army General Hospital, Beijing 100583, China
| | - Mo Li
- State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
- National Clinical Research Center for Obstetrics and Gynecology, Peking University Third Hospital, Beijing 10091, China
| | - Yang Pu
- State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
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6
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Hamey JJ, Nguyen A, Haddad M, Vázquez-Campos X, Pfeiffer PG, Wilkins MR. Methylation of elongation factor 1A by yeast Efm4 or human eEF1A-KMT2 involves a beta-hairpin recognition motif and crosstalks with phosphorylation. J Biol Chem 2024; 300:105639. [PMID: 38199565 PMCID: PMC10844748 DOI: 10.1016/j.jbc.2024.105639] [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: 07/24/2023] [Revised: 12/13/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Translation elongation factor 1A (eEF1A) is an essential and highly conserved protein required for protein synthesis in eukaryotes. In both Saccharomyces cerevisiae and human, five different methyltransferases methylate specific residues on eEF1A, making eEF1A the eukaryotic protein targeted by the highest number of dedicated methyltransferases after histone H3. eEF1A methyltransferases are highly selective enzymes, only targeting eEF1A and each targeting just one or two specific residues in eEF1A. However, the mechanism of this selectivity remains poorly understood. To reveal how S. cerevisiae elongation factor methyltransferase 4 (Efm4) specifically methylates eEF1A at K316, we have used AlphaFold-Multimer modeling in combination with crosslinking mass spectrometry (XL-MS) and enzyme mutagenesis. We find that a unique beta-hairpin motif, which extends out from the core methyltransferase fold, is important for the methylation of eEF1A K316 in vitro. An alanine mutation of a single residue on this beta-hairpin, F212, significantly reduces Efm4 activity in vitro and in yeast cells. We show that the equivalent residue in human eEF1A-KMT2 (METTL10), F220, is also important for its activity towards eEF1A in vitro. We further show that the eEF1A guanine nucleotide exchange factor, eEF1Bα, inhibits Efm4 methylation of eEF1A in vitro, likely due to competitive binding. Lastly, we find that phosphorylation of eEF1A at S314 negatively crosstalks with Efm4-mediated methylation of K316. Our findings demonstrate how protein methyltransferases can be highly selective towards a single residue on a single protein in the cell.
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Affiliation(s)
- Joshua J Hamey
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia.
| | - Amy Nguyen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia
| | - Mahdi Haddad
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia
| | - Xabier Vázquez-Campos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia
| | - Paige G Pfeiffer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, Australia
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7
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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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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: 3] [Impact Index Per Article: 3.0] [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: 5] [Impact Index Per Article: 5.0] [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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Zhang Y, Li SY, Zhu HJ, Lai JW, Sun SS, Lin Y, Li XL, Guo ZB, Lv Z, Meng H, Hu K, Xu M, Yu TT. Mechano-biomimetic hydrogel 3D cell cultivation as a strategy to improve mammalian cell protein expression. Mater Today Bio 2023; 21:100732. [PMID: 37521005 PMCID: PMC10371807 DOI: 10.1016/j.mtbio.2023.100732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/23/2023] [Accepted: 07/12/2023] [Indexed: 08/01/2023] Open
Abstract
Eukaryotic expression systems are frequently employed for the production of recombinant proteins as therapeutics as well as research tools. Among which mammalian cell protein expression approach is the most powerful one, which can express complex proteins or genetic engineered biological drugs, such as PD-1. However, the high expense, which partially derives from its low protein yielding efficiency, limited the further application of such approach in large scale production of target proteins. To address this issue, we proposed a novel technique to promote the protein production efficiency of mammal cells without using conventional genetic engineered approaches. By placing 293T cells in a hydrogel 3D cell culture platform and adjusting the stress relaxation of the matrix hydrogel, cells formed multicellular spheroids by self-organization. In particular, the multicellular spheroids have a significantly enhanced ability to transiently express multiple proteins (SHH-N, PD-1 and PDL-1). We also examined in detail the mechanism underlying this phenomenon, and found that the reorganization of cytoskeleton during spheroids formation enhances the translation process of protein by recruiting ribosomes. Overall, this finding provides a novel approach for subsequent improvement of large-scale mammalian protein expression cell systems.
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Affiliation(s)
- Yi Zhang
- Department of Colorectal Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Si-yang Li
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Hang-ju Zhu
- Jiangsu Cancer Hospital, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, Jiangsu, China
| | - Jun-Wei Lai
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Shuo-shuo Sun
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 210009, Jiangsu, China
| | - Yue Lin
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 210009, Jiangsu, China
| | - Xing-ling Li
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Zhao-bin Guo
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Ziheng Lv
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 210009, Jiangsu, China
| | - Hongxu Meng
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, 314400, China
| | - Ke Hu
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 210009, Jiangsu, China
| | - Ming Xu
- Engineering Research Center of Health Emergency, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
- Jiangsu Province Engineering Research Center of Health Emergency, Nanjing, 210009, China
- Jiangsu Preventive Medicine Association, Nanjing, 210009, China
- School of Public Health, Nanjing Medical University, Nanjing, 211166, China
- Department of Pharmaceutics, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
| | - Ting-ting Yu
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, 211166, Jiangsu, China
- Jiangsu Preventive Medicine Association, Nanjing, 210009, China
- School of Public Health, Nanjing Medical University, Nanjing, 211166, China
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11
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Kim M, Serwa RA, Samluk L, Suppanz I, Kodroń A, Stępkowski TM, Elancheliyan P, Tsegaye B, Oeljeklaus S, Wasilewski M, Warscheid B, Chacinska A. Immunoproteasome-specific subunit PSMB9 induction is required to regulate cellular proteostasis upon mitochondrial dysfunction. Nat Commun 2023; 14:4092. [PMID: 37433777 DOI: 10.1038/s41467-023-39642-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 06/21/2023] [Indexed: 07/13/2023] Open
Abstract
Perturbed cellular protein homeostasis (proteostasis) and mitochondrial dysfunction play an important role in neurodegenerative diseases, however, the interplay between these two phenomena remains unclear. Mitochondrial dysfunction leads to a delay in mitochondrial protein import, causing accumulation of non-imported mitochondrial proteins in the cytosol and challenging proteostasis. Cells respond by increasing proteasome activity and molecular chaperones in yeast and C. elegans. Here, we demonstrate that in human cells mitochondrial dysfunction leads to the upregulation of a chaperone HSPB1 and, interestingly, an immunoproteasome-specific subunit PSMB9. Moreover, PSMB9 expression is dependent on the translation elongation factor EEF1A2. These mechanisms constitute a defense response to preserve cellular proteostasis under mitochondrial stress. Our findings define a mode of proteasomal activation through the change in proteasome composition driven by EEF1A2 and its spatial regulation, and are useful to formulate therapies to prevent neurodegenerative diseases.
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Affiliation(s)
- Minji Kim
- IMol Polish Academy of Sciences, Warsaw, Poland
| | - Remigiusz A Serwa
- IMol Polish Academy of Sciences, Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Lukasz Samluk
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Ida Suppanz
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Agata Kodroń
- IMol Polish Academy of Sciences, Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz M Stępkowski
- IMol Polish Academy of Sciences, Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | | | | | - Silke Oeljeklaus
- Department of Biochemistry, Theodor Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | | | - Bettina Warscheid
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Department of Biochemistry, Theodor Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Agnieszka Chacinska
- IMol Polish Academy of Sciences, Warsaw, Poland.
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland.
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12
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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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13
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Romaus-Sanjurjo D, Saikia JM, Kim HJ, Tsai KM, Le GQ, Zheng B. Overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins to promote corticospinal axon repair after injury. Cell Death Discov 2022; 8:390. [PMID: 36123349 PMCID: PMC9485247 DOI: 10.1038/s41420-022-01186-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Although protein synthesis is hypothesized to have a pivotal role in axonal repair after central nervous system (CNS) injury, the role of core components of the protein synthesis machinery has not been examined. Notably, some elongation factors possess non-canonical functions that may further impact axonal repair. Here, we examined whether overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins enhances the collateral sprouting of corticospinal tract (CST) neurons after unilateral pyramidotomy, along with the underlying molecular mechanisms. We found that overexpressing eEF1A proteins in CST neurons increased the levels of pS6, an indicator for mTOR activity, but not pSTAT3 and pAKT levels, in neuronal somas. Strikingly, overexpressing eEF1A2 alone, but neither eEF1A1 alone nor both factors simultaneously, increased protein synthesis and actin rearrangement in CST neurons. While eEF1A1 overexpression only slightly enhanced CST sprouting after pyramidotomy, eEF1A2 overexpression substantially enhanced this sprouting. Surprisingly, co-overexpression of both eEF1A1 and eEF1A2 led to a sprouting phenotype similar to wild-type controls, suggesting an antagonistic effect of overexpressing both proteins. These data provide the first evidence that overexpressing a core component of the translation machinery, eEF1A2, enhances CST sprouting, likely by a combination of increased protein synthesis, mTOR signaling and actin cytoskeleton rearrangement.
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Affiliation(s)
- Daniel Romaus-Sanjurjo
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratories (LINCs), Health Research Institute of Santiago de Compostela (IDIS), 15706, Santiago de Compostela, Spain
| | - Junmi M Saikia
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, 92093, USA
| | - Hugo J Kim
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kristen M Tsai
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Geneva Q Le
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA.
- VA San Diego Research Service, San Diego, CA, 92161, USA.
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14
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eEF1A2 knockdown impairs neuronal proliferation and inhibits neurite outgrowth of differentiating neurons. Neuroreport 2022; 33:336-344. [PMID: 35594436 DOI: 10.1097/wnr.0000000000001791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The translation elongation factor-1, alpha-2 (eEF1A2) plays an important role in protein synthesis. Mutations in this gene have been described in individuals with neurodevelopmental disorders. Here, we silenced the expression of eEFA2 in human SH-SY5Y neuroblastoma cells and observed its roles in neuronal proliferation and differentiation upon induction with retinoic acid. METHODS eEF1A2 were silenced using siRNA transfection. Cell proliferation was qualitatively evaluated by Ki-67 immunocytochemistry. Neuronal differentiation was induced with retinoic acid for 3, 5, 7 and 10 days. Neurite length was measured. The expression of microtubule-associated protein 2 (MAP2) was analyzed by western blotting. Tyrosine hydroxylase expression was visualized by immunofluorescence. Cytotoxicity to a neurotoxin, 1-methyl-4-phenylpyridinium (MPP+), was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and western blotting of cleaved caspase-3. RESULTS eEF1A2 knockdown suppressed the proliferative activity of undifferentiated SH-SY5Y cells as shown by decreased Ki-67 immunostaining. Upon retinoic acid-induction, differentiated neurons with eEF1A2 knockdown exhibited shorter neurite length than untransfected cells, which was associated with the reduction of tyrosine hydroxylase and suppression of MAP2 at 10 days of differentiation. eEF1A2 knockdown decreased the survival of neurons, which was clearly observed in undifferentiated and short-term differentiated cells. Upon treatment with MPP+, cells with eEF1A2 knockdown showed a further reduction in cell survival and an increase of cleaved caspase-3 protein. CONCLUSIONS Our results suggest that eEF1A2 may be required for neuronal proliferation and differentiation of SH-SY5Y cells. Increased cell death susceptibility against MPP+ in eEF1A2-knockdown neurons may imply the neuroprotective role of eEF1A2.
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