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Mehta K, Yentsch H, Lee J, Yook Y, Lee KY, Gao TT, Tsai NP, Zhang K. Phosphatidylinositol-3-phosphate mediates Arc capsid secretion through the multivesicular body pathway. Proc Natl Acad Sci U S A 2024; 121:e2322422121. [PMID: 39178227 PMCID: PMC11363301 DOI: 10.1073/pnas.2322422121] [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: 01/03/2024] [Accepted: 07/30/2024] [Indexed: 08/25/2024] Open
Abstract
Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1) is an immediate early gene that plays a vital role in learning and memory. Arc protein has structural and functional properties similar to viral Group-specific antigen (Gag) protein and mediates the intercellular RNA transfer through virus-like capsids. However, the regulators and secretion pathway through which Arc capsids maneuver cargos are unclear. Here, we identified that phosphatidylinositol-3-phosphate (PI3P) mediates Arc capsid assembly and secretion through the endosomal-multivesicular body (MVB) pathway. Indeed, reconstituted Arc protein preferably binds to PI3P. In HEK293T cells, Arc forms puncta that colocalize with FYVE, an endosomal PI3P marker, as well as Rab5 and CD63, early endosomal and MVB markers, respectively. Superresolution imaging resolves Arc accumulates within the intraluminal vesicles of MVB. CRISPR double knockout of RalA and RalB, crucial GTPases for MVB biogenesis and exocytosis, severely reduces the Arc-mediated RNA transfer efficiency. RalA/B double knockdown in cultured rat cortical neurons increases the percentage of mature dendritic spines. Intake of extracellular vesicles purified from Arc-expressing wild-type, but not RalA/B double knockdown, cells in mouse cortical neurons reduces their surface GlutA1 levels. These results suggest that unlike the HIV Gag, whose membrane targeting requires interaction with plasma-membrane-specific phosphatidyl inositol (4,5) bisphosphate (PI(4,5)P2), the assembly of Arc capsids is mediated by PI3P at endocytic membranes. Understanding Arc's secretion pathway helps gain insights into its role in intercellular cargo transfer and highlights the commonality and distinction of trafficking mechanisms between structurally resembled capsid proteins.
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Affiliation(s)
- Kritika Mehta
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL61801
- NSF Science and Technology Center for Quantitative Cell Biology (STC-QCB) Center, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Henry Yentsch
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Jungbin Lee
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Yeeun Yook
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Kwan Young Lee
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Tianyu Terry Gao
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL61801
| | - Kai Zhang
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL61801
- NSF Science and Technology Center for Quantitative Cell Biology (STC-QCB) Center, University of Illinois Urbana-Champaign, Urbana, IL61801
- Center for Biophysics and Quantitative Biology, College of Liberal Arts and Sciences, University of Illinois Urbana-Champaign, Urbana, IL61801
- Neuroscience Program, College of Liberal Arts and Sciences, University of Illinois Urbana-Champaign, Urbana, IL61801
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL61801
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, IL61801
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2
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Zhang Y, Yang Y, Ren L, Zhan M, Sun T, Zou Q, Zhang Y. Predicting intercellular communication based on metabolite-related ligand-receptor interactions with MRCLinkdb. BMC Biol 2024; 22:152. [PMID: 38978014 PMCID: PMC11232326 DOI: 10.1186/s12915-024-01950-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: 03/16/2024] [Accepted: 07/03/2024] [Indexed: 07/10/2024] Open
Abstract
BACKGROUND Metabolite-associated cell communications play critical roles in maintaining human biological function. However, most existing tools and resources focus only on ligand-receptor interaction pairs where both partners are proteinaceous, neglecting other non-protein molecules. To address this gap, we introduce the MRCLinkdb database and algorithm, which aggregates and organizes data related to non-protein L-R interactions in cell-cell communication, providing a valuable resource for predicting intercellular communication based on metabolite-related ligand-receptor interactions. RESULTS Here, we manually curated the metabolite-ligand-receptor (ML-R) interactions from the literature and known databases, ultimately collecting over 790 human and 670 mouse ML-R interactions. Additionally, we compiled information on over 1900 enzymes and 260 transporter entries associated with these metabolites. We developed Metabolite-Receptor based Cell Link Database (MRCLinkdb) to store these ML-R interactions data. Meanwhile, the platform also offers extensive information for presenting ML-R interactions, including fundamental metabolite information and the overall expression landscape of metabolite-associated gene sets (such as receptor, enzymes, and transporter proteins) based on single-cell transcriptomics sequencing (covering 35 human and 26 mouse tissues, 52 human and 44 mouse cell types) and bulk RNA-seq/microarray data (encompassing 62 human and 39 mouse tissues). Furthermore, MRCLinkdb introduces a web server dedicated to the analysis of intercellular communication based on ML-R interactions. MRCLinkdb is freely available at https://www.cellknowledge.com.cn/mrclinkdb/ . CONCLUSIONS In addition to supplementing ligand-receptor databases, MRCLinkdb may provide new perspectives for decoding the intercellular communication and advancing related prediction tools based on ML-R interactions.
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Affiliation(s)
- Yuncong Zhang
- Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Clinical Medical College of Jinan University), Jinan University, Zhuhai, Guangdong, China
| | - Yu Yang
- Innovative Institute of Chinese Medicine and Pharmacy, Academy for Interdiscipline, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Healthcare Technology, Chengdu Neusoft University, Chengdu, China
| | - Liping Ren
- School of Healthcare Technology, Chengdu Neusoft University, Chengdu, China
| | - Meixiao Zhan
- Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Clinical Medical College of Jinan University), Jinan University, Zhuhai, Guangdong, China
| | - Taoping Sun
- Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Clinical Medical College of Jinan University), Jinan University, Zhuhai, Guangdong, China.
| | - Quan Zou
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China.
| | - Yang Zhang
- Innovative Institute of Chinese Medicine and Pharmacy, Academy for Interdiscipline, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China.
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3
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Tran NT, Le TBK. Control of a gene transfer agent cluster in Caulobacter crescentus by transcriptional activation and anti-termination. Nat Commun 2024; 15:4749. [PMID: 38834569 PMCID: PMC11150451 DOI: 10.1038/s41467-024-49114-2] [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: 11/19/2023] [Accepted: 05/23/2024] [Indexed: 06/06/2024] Open
Abstract
Gene Transfer Agents (GTAs) are phage-like particles that cannot self-multiply and be infectious. Caulobacter crescentus, a bacterium best known as a model organism to study bacterial cell biology and cell cycle regulation, has recently been demonstrated to produce bona fide GTA particles (CcGTA). Since C. crescentus ultimately die to release GTA particles, the production of GTA particles must be tightly regulated and integrated with the host physiology to prevent a collapse in cell population. Two direct activators of the CcGTA biosynthetic gene cluster, GafY and GafZ, have been identified, however, it is unknown how GafYZ controls transcription or how they coordinate gene expression of the CcGTA gene cluster with other accessory genes elsewhere on the genome for complete CcGTA production. Here, we show that the CcGTA gene cluster is transcriptionally co-activated by GafY, integration host factor (IHF), and by GafZ-mediated transcription anti-termination. We present evidence that GafZ is a transcription anti-terminator that likely forms an anti-termination complex with RNA polymerase, NusA, NusG, and NusE to bypass transcription terminators within the 14 kb CcGTA cluster. Overall, we reveal a two-tier regulation that coordinates the synthesis of GTA particles in C. crescentus.
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Affiliation(s)
- Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK.
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4
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Crane AB, Jetti SK, Littleton JT. A stochastic RNA editing process targets a limited number of sites in individual Drosophila glutamatergic motoneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594696. [PMID: 38798345 PMCID: PMC11118563 DOI: 10.1101/2024.05.17.594696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
RNA editing is a post-transcriptional source of protein diversity and occurs across the animal kingdom. Given the complete profile of mRNA targets and their editing rate in individual cells is unclear, we analyzed single cell RNA transcriptomes from Drosophila larval tonic and phasic glutamatergic motoneuron subtypes to determine the most highly edited targets and identify cell-type specific editing. From ∼15,000 genes encoded in the genome, 316 high confidence A-to-I canonical RNA edit sites were identified, with 102 causing missense amino acid changes in proteins regulating membrane excitability, synaptic transmission, and cellular function. Some sites showed 100% editing in single neurons as observed with mRNAs encoding mammalian AMPA receptors. However, most sites were edited at lower levels and generated variable expression of edited and unedited mRNAs within individual neurons. Together, these data provide insights into how the RNA editing landscape alters protein function to modulate the properties of two well-characterized neuronal populations in Drosophila .
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Xiao Z, Nian Z, Zhang M, Liu Z, Zhang P, Zhang Z. Single-cell and bulk RNA-sequencing reveal SPP1 and CXCL12 as cell-to-cell communication markers to predict prognosis in lung adenocarcinoma. ENVIRONMENTAL TOXICOLOGY 2024. [PMID: 38622884 DOI: 10.1002/tox.24297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/22/2024] [Accepted: 04/09/2024] [Indexed: 04/17/2024]
Abstract
Lung adenocarcinoma (LUAD) generally presents as an immunosuppressive microenvironment. The characteristics of cell-to-cell communication in the LUAD microenvironment has been unclear. In this study, the LUAD bulk RNA-seq data and single-cell RNA-seq data were retrieved from public dataset. Differential expression genes (DEGs) between LUAD tumor and adjacent non-tumor tissues were calculated by limma algorithm, and then detected by PPI, KEGG, and GO analysis. Cell-cell interactions were explored using the single-cell RNA-seq data. Finally, the first 15 CytoHubba genes were used to establish related pathways and these pathways were used to characterize the immune-related ligands and their receptors in LUAD. Our analyses showed that monocytes or macrophages interact with tissue stem cells and NK cells via SPP1 signaling pathway and tissue stem cells interact with T and B cells via CXCL signaling pathway in different states. Hub genes of SPP1 participated in SPP1 signaling pathway, which was negatively correlated with CD4+ T cell and CD8+ T cell. The expression of SPP1 in LUAD tumor tissues was negatively correlated with the prognosis. While CXCL12 participated in CXCL signaling pathway, which was positively correlated with CD4+ T cell and CD8+ T cell. The role of CXCL12 in LUAD tumor tissues exhibits an opposite effect to that of SPP1. This study reveals that tumor-associated monocytes or macrophages may affect tumor progression. Moreover, the SPP1 and CXCL12 may be the critic genes of cell-to-cell communication in LUAD, and targeting these pathways may provide a new molecular mechanism for the treatment of LUAD.
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Affiliation(s)
- Zengtuan Xiao
- Department of Lung Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Lung Cancer Center, Tianjin, China
- Department of Immunology, Biochemistry and Molecular Biology, Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease of the Ministry of Education, State Key Laboratory of Experimental Hematology, Tianjin Medical University, Tianjin, China
| | - Zhe Nian
- Department of Immunology, Biochemistry and Molecular Biology, Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease of the Ministry of Education, State Key Laboratory of Experimental Hematology, Tianjin Medical University, Tianjin, China
| | - Mengzhe Zhang
- Department of Lung Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Lung Cancer Center, Tianjin, China
| | - Zuo Liu
- Department of Lung Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Lung Cancer Center, Tianjin, China
| | - Pengpeng Zhang
- Department of Lung Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Lung Cancer Center, Tianjin, China
| | - Zhenfa Zhang
- Department of Lung Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Lung Cancer Center, Tianjin, China
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6
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Banks EJ, Le TBK. Co-opting bacterial viruses for DNA exchange: structure and regulation of gene transfer agents. Curr Opin Microbiol 2024; 78:102431. [PMID: 38309246 DOI: 10.1016/j.mib.2024.102431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 02/05/2024]
Abstract
Horizontal gene transfer occurs via a range of mechanisms, including transformation, conjugation and bacteriophage transduction. Gene transfer agents (GTAs) are an alternative, less-studied route for interbacterial DNA exchange. Encoded within bacterial or archaeal genomes, GTAs assemble into phage-like particles that selflessly package and transmit host DNA to recipient bacteria. Several unique features distinguish GTAs from canonical phages such as an inability to self-replicate, thus producing non-infectious particles. GTAs are also deeply integrated into the physiology of the host cell and are maintained under tight host-regulatory control. Recent advances in understanding the structure and regulation of GTAs have provided further insights into a DNA transfer mechanism that is proving increasingly widespread across the bacterial tree of life.
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Affiliation(s)
- Emma J Banks
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK.
| | - Tung B K Le
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK.
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7
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Xu J, Erlendsson S, Singh M, Holling GA, Regier M, Ibiricu I, Einstein J, Hantak MP, Day GS, Piquet AL, Smith TL, Clardy SL, Whiteley AM, Feschotte C, Briggs JAG, Shepherd JD. PNMA2 forms immunogenic non-enveloped virus-like capsids associated with paraneoplastic neurological syndrome. Cell 2024; 187:831-845.e19. [PMID: 38301645 PMCID: PMC10922747 DOI: 10.1016/j.cell.2024.01.009] [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: 02/24/2023] [Revised: 09/20/2023] [Accepted: 01/05/2024] [Indexed: 02/03/2024]
Abstract
The paraneoplastic Ma antigen (PNMA) proteins are associated with cancer-induced paraneoplastic syndromes that present with an autoimmune response and neurological symptoms. Why PNMA proteins are associated with this severe autoimmune disease is unclear. PNMA genes are predominantly expressed in the central nervous system and are ectopically expressed in some tumors. We show that PNMA2, which has been co-opted from a Ty3 retrotransposon, encodes a protein that is released from cells as non-enveloped virus-like capsids. Recombinant PNMA2 capsids injected into mice induce autoantibodies that preferentially bind external "spike" PNMA2 capsid epitopes, whereas a capsid-assembly-defective PNMA2 protein is not immunogenic. PNMA2 autoantibodies in cerebrospinal fluid of patients with anti-Ma2 paraneoplastic disease show similar preferential binding to spike capsid epitopes. PNMA2 capsid-injected mice develop learning and memory deficits. These observations suggest that PNMA2 capsids act as an extracellular antigen, capable of generating an autoimmune response that results in neurological deficits.
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Affiliation(s)
- Junjie Xu
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Simon Erlendsson
- The Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK; Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Manvendra Singh
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - G Aaron Holling
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Matthew Regier
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Iosune Ibiricu
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jenifer Einstein
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Michael P Hantak
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Gregory S Day
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | - Amanda L Piquet
- Department of Neurology, University of Colorado, Aurora, CO, USA
| | - Tammy L Smith
- Department of Neurology, University of Utah and George E Wahlen VA Medical Center, Salt Lake City, UT, USA
| | - Stacey L Clardy
- Department of Neurology, University of Utah and George E Wahlen VA Medical Center, Salt Lake City, UT, USA
| | | | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - John A G Briggs
- The Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK; Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jason D Shepherd
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA.
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8
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Hermann DM, Peruzzotti-Jametti L, Giebel B, Pluchino S. Extracellular vesicles set the stage for brain plasticity and recovery by multimodal signalling. Brain 2024; 147:372-389. [PMID: 37768167 PMCID: PMC10834259 DOI: 10.1093/brain/awad332] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/07/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Extracellular vesicles (EVs) are extremely versatile naturally occurring membrane particles that convey complex signals between cells. EVs of different cellular sources are capable of inducing striking therapeutic responses in neurological disease models. Differently from pharmacological compounds that act by modulating defined signalling pathways, EV-based therapeutics possess multiple abilities via a variety of effectors, thus allowing the modulation of complex disease processes that may have very potent effects on brain tissue recovery. When applied in vivo in experimental models of neurological diseases, EV-based therapeutics have revealed remarkable effects on immune responses, cell metabolism and neuronal plasticity. This multimodal modulation of neuroimmune networks by EVs profoundly influences disease processes in a highly synergistic and context-dependent way. Ultimately, the EV-mediated restoration of cellular functions helps to set the stage for neurological recovery. With this review we first outline the current understanding of the mechanisms of action of EVs, describing how EVs released from various cellular sources identify their cellular targets and convey signals to recipient cells. Then, mechanisms of action applicable to key neurological conditions such as stroke, multiple sclerosis and neurodegenerative diseases are presented. Pathways that deserve attention in specific disease contexts are discussed. We subsequently showcase considerations about EV biodistribution and delineate genetic engineering strategies aiming at enhancing brain uptake and signalling. By sketching a broad view of EV-orchestrated brain plasticity and recovery, we finally define possible future clinical EV applications and propose necessary information to be provided ahead of clinical trials. Our goal is to provide a steppingstone that can be used to critically discuss EVs as next generation therapeutics for brain diseases.
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Affiliation(s)
- Dirk M Hermann
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, D-45122 Essen, Germany
| | - Luca Peruzzotti-Jametti
- Department of Clinical Neurosciences and National Institute for Health Research (NIHR) Biomedical Research Centre, University of Cambridge, Cambridge CB2 0AH, UK
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, UK
| | - Bernd Giebel
- Institute of Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, D-45147 Essen, Germany
| | - Stefano Pluchino
- Department of Clinical Neurosciences and National Institute for Health Research (NIHR) Biomedical Research Centre, University of Cambridge, Cambridge CB2 0AH, UK
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Mehta K, Yentsch H, Lee J, Gao TT, Zhang K. Phosphatidylinositol 3-phosphate mediates Arc capsids secretion through the multivesicular body pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.19.572392. [PMID: 38187623 PMCID: PMC10769229 DOI: 10.1101/2023.12.19.572392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1) is an immediate early gene that plays a vital role in learning and memory. The recent discovery that Arc mediates the inter-neuronal RNA transfer implies its role in regulating neuronal functions across long distances. Arc protein has structural and functional properties similar to viral Group-specific antigen (Gag). By assembling into high-order, virus-like capsids, Arc mediates the intercellular RNA transfer. However, the exact secretion pathway through which Arc capsids maneuver cargos is unclear. Here, we identified that Arc capsids assemble and secrete through the endosomal-multivesicular body (MVB) pathway. Arc's endosomal entry is likely mediated by phosphatidylinositol-3-phosphate (PI3P). Indeed, reconstituted Arc protein preferably binds to PI3P. In mammalian cells, Arc forms puncta that colocalizes with FYVE, an endosomal PI3P marker, and competitive binding to PI3P via prolonged FYVE expression reduces the average number of Arc puncta per cell. Overexpression of MTMR1, a PI3P phosphatase, significantly reduces Arc capsid secretion. Arc capsids secrete through the endosomal-MVB axis as extracellular vesicles. Live-cell imaging shows that fluorescently labeled Arc primarily colocalizes Rab5 and CD63, early endosomal and MVB markers, respectively. Superresolution imaging resolves Arc accumulates within the intraluminal vesicles of MVB. CRISPR double knockout of RalA and RalB, crucial GTPases for MVB biogenesis and exocytosis, severely reduces Arc-mediated RNA transfer efficiency. These results suggest that, unlike the Human Immunodeficiency Virus Gag, which assembles on and bud off from the plasma membrane, Arc capsids assemble at the endocytic membranes of the endosomal-MVB pathway mediated by PI3P. Understanding Arc's secretion pathway helps gain insights into its role in intercellular cargo transfer and highlights the commonality and distinction of trafficking mechanisms between structurally resembled capsid proteins.
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10
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Sibarov DA, Tsytsarev V, Volnova A, Vaganova AN, Alves J, Rojas L, Sanabria P, Ignashchenkova A, Savage ED, Inyushin M. Arc protein, a remnant of ancient retrovirus, forms virus-like particles, which are abundantly generated by neurons during epileptic seizures, and affects epileptic susceptibility in rodent models. Front Neurol 2023; 14:1201104. [PMID: 37483450 PMCID: PMC10361770 DOI: 10.3389/fneur.2023.1201104] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/02/2023] [Indexed: 07/25/2023] Open
Abstract
A product of the immediate early gene Arc (Activity-regulated cytoskeleton-associated protein or Arc protein) of retroviral ancestry resides in the genome of all tetrapods for millions of years and is expressed endogenously in neurons. It is a well-known protein, very important for synaptic plasticity and memory consolidation. Activity-dependent Arc expression concentrated in glutamatergic synapses affects the long-time synaptic strength of those excitatory synapses. Because it modulates excitatory-inhibitory balance in a neuronal network, the Arc gene itself was found to be related to the pathogenesis of epilepsy. General Arc knockout rodent models develop a susceptibility to epileptic seizures. Because of activity dependence, synaptic Arc protein synthesis also is affected by seizures. Interestingly, it was found that Arc protein in synapses of active neurons self-assemble in capsids of retrovirus-like particles, which can transfer genetic information between neurons, at least across neuronal synaptic boutons. Released Arc particles can be accumulated in astrocytes after seizures. It is still not known how capsid assembling and transmission timescale is affected by seizures. This scientific field is relatively novel and is experiencing swift transformation as it grapples with difficult concepts in light of evolving experimental findings. We summarize the emergent literature on the subject and also discuss the specific rodent models for studying Arc effects in epilepsy. We summarized both to clarify the possible role of Arc-related pseudo-viral particles in epileptic disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Dmitry A. Sibarov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Anastasia N. Vaganova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Janaina Alves
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Legier Rojas
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Priscila Sanabria
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | | | | | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
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11
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Aria F, Pandey K, Alberini CM. Excessive Protein Accumulation and Impaired Autophagy in the Hippocampus of Angelman Syndrome Modeled in Mice. Biol Psychiatry 2023; 94:68-83. [PMID: 36764852 PMCID: PMC10276539 DOI: 10.1016/j.biopsych.2022.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 11/03/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Angelman syndrome (AS), a neurodevelopmental disorder caused by abnormalities of the 15q11.2-q13.1 chromosome region, is characterized by impairment of cognitive and motor functions, sleep problems, and seizures. How the genetic defects of AS produce these neurological symptoms is unclear. Mice modeling AS (AS mice) accumulate activity-regulated cytoskeleton-associated protein (ARC/ARG3.1), a neuronal immediate early gene (IEG) critical for synaptic plasticity. This accumulation suggests an altered protein metabolism. METHODS Focusing on the dorsal hippocampus (dHC), a brain region critical for memory formation and cognitive functions, we assessed levels and tissue distribution of IEGs, de novo protein synthesis, and markers of protein synthesis, endosomes, autophagy, and synaptic functions in AS mice at baseline and following learning. We also tested autophagic flux and memory retention following autophagy-promoting treatment. RESULTS AS dHC exhibited accumulation of IEGs ARC, FOS, and EGR1; autophagy proteins MLP3B, SQSTM1, and LAMP1; and reduction of the endosomal protein RAB5A. AS dHC also had increased levels of de novo protein synthesis, impaired autophagic flux with accumulation of autophagosome, and altered synaptic protein levels. Contextual fear conditioning significantly increased levels of IEGs and autophagy proteins, de novo protein synthesis, and autophagic flux in the dHC of normal mice, but not in AS mice. Enhancing autophagy in the dHC alleviated AS-related memory and autophagic flux impairments. CONCLUSIONS A major biological deficit of AS brain is a defective protein metabolism, particularly that dynamically regulated by learning, resulting in stalled autophagy and accumulation of neuronal proteins. Activating autophagy ameliorates AS cognitive impairments and dHC protein accumulation.
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Affiliation(s)
- Francesca Aria
- Center for Neural Science, New York University, New York, New York
| | - Kiran Pandey
- Center for Neural Science, New York University, New York, New York
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12
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Avallone M, Pardo J, Mergiya TF, Rájová J, Räsänen A, Davidsson M, Åkerblom M, Quintino L, Kumar D, Bramham CR, Björklund T. Visualizing Arc protein dynamics and localization in the mammalian brain using AAV-mediated in situ gene labeling. Front Mol Neurosci 2023; 16:1140785. [PMID: 37415832 PMCID: PMC10321715 DOI: 10.3389/fnmol.2023.1140785] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/11/2023] [Indexed: 07/08/2023] Open
Abstract
The activity-regulated cytoskeleton-associated (Arc) protein is essential for synaptic plasticity and memory formation. The Arc gene, which contains remnants of a structural GAG retrotransposon sequence, produces a protein that self-assembles into capsid-like structures harboring Arc mRNA. Arc capsids, released from neurons, have been proposed as a novel intercellular mechanism for mRNA transmission. Nevertheless, evidence for intercellular transport of Arc in the mammalian brain is still lacking. To enable the tracking of Arc molecules from individual neurons in vivo, we devised an adeno-associated virus (AAV) mediated approach to tag the N-terminal of the mouse Arc protein with a fluorescent reporter using CRISPR/Cas9 homologous independent targeted integration (HITI). We show that a sequence coding for mCherry can successfully be knocked in at the 5' end of the Arc open reading frame. While nine spCas9 gene editing sites surround the Arc start codon, the accuracy of the editing was highly sequence-dependent, with only a single target resulting in an in-frame reporter integration. When inducing long-term potentiation (LTP) in the hippocampus, we observed an increase of Arc protein highly correlated with an increase in fluorescent intensity and the number of mCherry-positive cells. By proximity ligation assay (PLA), we demonstrated that the mCherry-Arc fusion protein retains the Arc function by interacting with the transmembrane protein stargazin in postsynaptic spines. Finally, we recorded mCherry-Arc interaction with presynaptic protein Bassoon in mCherry-negative surrounding neurons at close proximity to mCherry-positive spines of edited neurons. This is the first study to provide support for inter-neuronal in vivo transfer of Arc in the mammalian brain.
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Affiliation(s)
- Martino Avallone
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Joaquín Pardo
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
- Instituto de Investigaciones Bioquímicas de La Plata “Prof. Dr. Rodolfo R. Brenner” (INIBIOLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)—Universidad Nacional de La Plata (UNLP), La Plata, Argentina
| | - Tadiwos F. Mergiya
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
| | - Jana Rájová
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Atte Räsänen
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Marcus Davidsson
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Malin Åkerblom
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Luis Quintino
- CNS Gene Therapy, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | | | - Clive R. Bramham
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
| | - Tomas Björklund
- Molecular Neuromodulation, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
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13
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Mergiya TF, Gundersen JET, Kanhema T, Brighter G, Ishizuka Y, Bramham CR. Detection of Arc/Arg3.1 oligomers in rat brain: constitutive and synaptic activity-evoked dimer expression in vivo. Front Mol Neurosci 2023; 16:1142361. [PMID: 37363319 PMCID: PMC10289200 DOI: 10.3389/fnmol.2023.1142361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 05/12/2023] [Indexed: 06/28/2023] Open
Abstract
The immediate early gene product activity-regulated cytoskeleton-associated protein (Arc or Arg3.1) is a major regulator of long-term synaptic plasticity with critical roles in postnatal cortical development and memory formation. However, the molecular basis of Arc function is undefined. Arc is a hub protein with interaction partners in the postsynaptic neuronal compartment and nucleus. Previous in vitro biochemical and biophysical analysis of purified recombinant Arc showed formation of low-order oligomers and larger particles including retrovirus-like capsids. Here, we provide evidence for naturally occurring Arc oligomers in the mammalian brain. Using in situ protein crosslinking to trap weak Arc-Arc interactions, we identified in various preparations a prominent Arc immunoreactive band on SDS-PAGE of molecular mass corresponding to a dimer. While putative trimers, tetramers and heavier Arc species were detected, they were of lower abundance. Stimulus-evoked induction of Arc expression and dimer formation was first demonstrated in SH-SY5Y neuroblastoma cells treated with the muscarinic cholinergic agonist, carbachol, and in primary cortical neuronal cultures treated with brain-derived neurotrophic factor (BDNF). In the dentate gyrus (DG) of adult anesthetized rats, induction of long-term potentiation (LTP) by high-frequency stimulation (HFS) of medial perforant synapses or by brief intrahippocampal infusion of BDNF led to a massive increase in Arc dimer expression. Arc immunoprecipitation of crosslinked DG tissue showed enhanced dimer expression during 4 h of LTP maintenance. Mass spectrometric proteomic analysis of immunoprecipitated, gel-excised bands corroborated detection of Arc dimer. Furthermore, Arc dimer was constitutively expressed in naïve cortical, hippocampal and DG tissue, with the lowest levels in the DG. Taken together the results implicate Arc dimer as the predominant low-oligomeric form in mammalian brain, exhibiting regional differences in its constitutive expression and enhanced synaptic activity-evoked expression in LTP.
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Affiliation(s)
- Tadiwos F. Mergiya
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
| | - Jens Edvard Trygstad Gundersen
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
| | - Tambudzai Kanhema
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
| | - Grant Brighter
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Yuta Ishizuka
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Clive R. Bramham
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Mohn Research Center for the Brain, University of Bergen, Bergen, Norway
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14
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Cable J, Witwer KW, Coffey RJ, Milosavljevic A, von Lersner AK, Jimenez L, Pucci F, Barr MM, Dekker N, Barman B, Humphrys D, Williams J, de Palma M, Guo W, Bastos N, Hill AF, Levy E, Hantak MP, Crewe C, Aikawa E, Adamczyk AM, Zanotto TM, Ostrowski M, Arab T, Rabe DC, Sheikh A, da Silva DR, Jones JC, Okeoma C, Gaborski T, Zhang Q, Gololobova O. Exosomes, microvesicles, and other extracellular vesicles-a Keystone Symposia report. Ann N Y Acad Sci 2023; 1523:24-37. [PMID: 36961472 PMCID: PMC10715677 DOI: 10.1111/nyas.14974] [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: 03/20/2023]
Abstract
Extracellular vesicles (EVs) are small, lipid-bilayer-bound particles released by cells that can contain important bioactive molecules, including lipids, RNAs, and proteins. Once released in the extracellular environment, EVs can act as messengers locally as well as to distant tissues to coordinate tissue homeostasis and systemic responses. There is a growing interest in not only understanding the physiology of EVs as signaling particles but also leveraging them as minimally invasive diagnostic and prognostic biomarkers (e.g., they can be found in biofluids) and drug-delivery vehicles. On October 30-November 2, 2022, researchers in the EV field convened for the Keystone symposium "Exosomes, Microvesicles, and Other Extracellular Vesicles" to discuss developing standardized language and methodology, new data on the basic biology of EVs and potential clinical utility, as well as novel technologies to isolate and characterize EVs.
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Affiliation(s)
| | - Kenneth W Witwer
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Robert J Coffey
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Aleksandar Milosavljevic
- Department of Molecular and Human Genetics; Dan L Duncan Comprehensive Cancer Center; and Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, Texas, USA
| | | | - Lizandra Jimenez
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ferdinando Pucci
- Department of Otolaryngology-Head and Neck Surgery; Department of Cell, Developmental & Cancer Biology; Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Maureen M Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Niek Dekker
- Protein Sciences, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Bahnisikha Barman
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | | | - Justin Williams
- University of California, Berkeley, Berkeley, California, USA
| | - Michele de Palma
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL); Agora Cancer Research Center; and Swiss Cancer Center Léman (SCCL), Lausanne, Switzerland
| | - Wei Guo
- Department of Biology, School of Arts & Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nuno Bastos
- i3S Instituto de Investigação e Inovação em Saúde; IPATIMUP Institute of Molecular Pathology and Immunology; and ICBAS Instituto de Ciencias Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Andrew F Hill
- Research Centre for Extracellular Vesicles; Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Environment, La Trobe University and Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - Efrat Levy
- Center for Dementia Research, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Department of Psychiatry; Department of Biochemistry & Molecular Pharmacology; and NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, New York, USA
| | - Michael P Hantak
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, USA
| | - Clair Crewe
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Cell Biology, Washington University, St. Louis, Missouri, USA
| | - Elena Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine and Center for Excellence in Vascular Biology, Department of Medicine; Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Tamires M Zanotto
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Matias Ostrowski
- Facultad de Medicina, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Universidad de Buenos Aires (UBA) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Tanina Arab
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Daniel C Rabe
- Mass General Cancer Center, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Aadil Sheikh
- Department of Biology, College of Arts and Sciences, Baylor University, Waco, Texas, USA
| | | | - Jennifer C Jones
- Translational Nanobiology Section, Laboratory of Pathology and Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Chioma Okeoma
- Department of Pharmacology, Stony Brook University Renaissance School of Medicine, Stony Brook, New York, USA
- Department of Pathology, Microbiology, and Immunology, New York Medical College, Valhalla, New York, USA
| | - Thomas Gaborski
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, USA
| | - Qin Zhang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Olesia Gololobova
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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15
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Xu J, Erlendsson S, Singh M, Regier M, Ibiricu I, Day GS, Piquet AL, Clardy SL, Feschotte C, Briggs JAG, Shepherd JD. PNMA2 forms non-enveloped virus-like capsids that trigger paraneoplastic neurological syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.09.527862. [PMID: 36798413 PMCID: PMC9934673 DOI: 10.1101/2023.02.09.527862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The paraneoplastic Ma antigen (PNMA) genes are associated with cancer-induced paraneoplastic syndromes that present with neurological symptoms and autoantibody production. How PNMA proteins trigger a severe autoimmune disease is unclear. PNMA genes are predominately expressed in the central nervous system with little known functions but are ectopically expressed in some tumors. Here, we show that PNMA2 is derived from a Ty3 retrotransposon that encodes a protein which forms virus-like capsids released from cells as non-enveloped particles. Recombinant PNMA2 capsids injected into mice induce a robust autoimmune reaction with significant generation of autoantibodies that preferentially bind external "spike" PNMA2 capsid epitopes, while capsid-assembly-defective PNMA2 protein is not immunogenic. PNMA2 autoantibodies present in cerebrospinal fluid of patients with anti-Ma2 paraneoplastic neurologic disease show similar preferential binding to PNMA2 "spike" capsid epitopes. These observations suggest that PNMA2 capsids released from tumors trigger an autoimmune response that underlies Ma2 paraneoplastic neurological syndrome.
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Affiliation(s)
- Junjie Xu
- Department of Neurobiology, Spencer Fox Eccles School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Simon Erlendsson
- The Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Manvendra Singh
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Matthew Regier
- Department of Neurobiology, Spencer Fox Eccles School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Iosune Ibiricu
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Gregory S. Day
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | - Amanda L. Piquet
- Department of Neurology, University of Colorado, Aurora, CO, USA
| | - Stacey L. Clardy
- Department of Neurology, Spencer Fox Eccles School of Medicine, University of Utah, and George E Wahlen VA Medical Center, Salt Lake City, UT, USA
| | - Cedric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - John A. G. Briggs
- The Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jason D. Shepherd
- Department of Neurobiology, Spencer Fox Eccles School of Medicine, University of Utah, Salt Lake City, UT, USA
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16
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Villarreal L, Witzany G. Self-empowerment of life through RNA networks, cells and viruses. F1000Res 2023; 12:138. [PMID: 36785664 PMCID: PMC9918806 DOI: 10.12688/f1000research.130300.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 01/05/2024] Open
Abstract
Our understanding of the key players in evolution and of the development of all organisms in all domains of life has been aided by current knowledge about RNA stem-loop groups, their proposed interaction motifs in an early RNA world and their regulative roles in all steps and substeps of nearly all cellular processes, such as replication, transcription, translation, repair, immunity and epigenetic marking. Cooperative evolution was enabled by promiscuous interactions between single-stranded regions in the loops of naturally forming stem-loop structures in RNAs. It was also shown that cooperative RNA stem-loops outcompete selfish ones and provide foundational self-constructive groups (ribosome, editosome, spliceosome, etc.). Self-empowerment from abiotic matter to biological behavior does not just occur at the beginning of biological evolution; it is also essential for all levels of socially interacting RNAs, cells and viruses.
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Affiliation(s)
- Luis Villarreal
- Center for Virus Research, University of California, Irvine, California, USA
| | - Guenther Witzany
- Telos - Philosophische Praxis, Buermoos, Salzburg, 5111, Austria
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17
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Abstract
Our understanding of the key players in evolution and of the development of all organisms in all domains of life has been aided by current knowledge about RNA stem-loop groups, their proposed interaction motifs in an early RNA world and their regulative roles in all steps and substeps of nearly all cellular processes, such as replication, transcription, translation, repair, immunity and epigenetic marking. Cooperative evolution was enabled by promiscuous interactions between single-stranded regions in the loops of naturally forming stem-loop structures in RNAs. It was also shown that cooperative RNA stem-loops outcompete selfish ones and provide foundational self-constructive groups (ribosome, editosome, spliceosome, etc.). Self-empowerment from abiotic matter to biological behavior does not just occur at the beginning of biological evolution; it is also essential for all levels of socially interacting RNAs, cells and viruses.
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Affiliation(s)
- Luis Villarreal
- Center for Virus Research, University of California, Irvine, California, USA
| | - Guenther Witzany
- Telos - Philosophische Praxis, Buermoos, Salzburg, 5111, Austria
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18
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The molecular memory code and synaptic plasticity: A synthesis. Biosystems 2023; 224:104825. [PMID: 36610586 DOI: 10.1016/j.biosystems.2022.104825] [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: 10/14/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023]
Abstract
The most widely accepted view of memory in the brain holds that synapses are the storage sites of memory, and that memories are formed through associative modification of synapses. This view has been challenged on conceptual and empirical grounds. As an alternative, it has been proposed that molecules within the cell body are the storage sites of memory, and that memories are formed through biochemical operations on these molecules. This paper proposes a synthesis of these two views, grounded in a computational model of memory. Synapses are conceived as storage sites for the parameters of an approximate posterior probability distribution over latent causes. Intracellular molecules are conceived as storage sites for the parameters of a generative model. The model stipulates how these two components work together as part of an integrated algorithm for learning and inference.
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19
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Heisserer C, Selosse MA, Drezen JM. [Plants and animals biological functions obtained from viruses]. Med Sci (Paris) 2022; 38:1016-1027. [PMID: 36692281 DOI: 10.1051/medsci/2022171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Viruses can provide new biological functions to plants and animals. Some viruses persisting at low levels in plants might confer resistance to stress and parasites. In animals, more numerous examples of genes originating from viruses and used by different organisms have been described. For examples these genes might contribute to protect from new infections, or to ensure communication between neurons or to enable placenta development. In parasitic wasps, a complex viral machinery has been conserved as an endogenous virus dispersed in the wasp genome, which produces virions. These virions infect the parasitized host resulting in the production of virulence factors that inhibit defense mechanisms against the parasite. Different organisms have used the same viral functions repeatedly during animal evolution.
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Affiliation(s)
- Camille Heisserer
- Institut de recherche sur la biologie de l'insecte, UMR 7261 CNRS-Université de Tours, Parc de Grandmont 37200 Tours, France
| | - Marc-André Selosse
- Institut de systématique, évolution, biodiversité, UMR 7205 MNHN-CNRS-SU-EPHE-UA, 12 rue Buffon 75005 Paris, France
| | - Jean-Michel Drezen
- Institut de recherche sur la biologie de l'insecte, UMR 7261 CNRS-Université de Tours, Parc de Grandmont 37200 Tours, France
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20
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Eriksen MS, Bramham CR. Molecular physiology of Arc/Arg3.1: The oligomeric state hypothesis of synaptic plasticity. Acta Physiol (Oxf) 2022; 236:e13886. [PMID: 36073248 PMCID: PMC9787330 DOI: 10.1111/apha.13886] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/15/2022] [Accepted: 09/05/2022] [Indexed: 01/29/2023]
Abstract
The immediate early gene, Arc, is a pivotal regulator of synaptic plasticity, memory, and cognitive flexibility. But what is Arc protein? How does it work? Inside the neuron, Arc is a protein interaction hub and dynamic regulator of intra-cellular signaling in synaptic plasticity. In remarkable contrast, Arc can also self-assemble into retrovirus-like capsids that are released in extracellular vesicles and capable of intercellular transfer of RNA. Elucidation of the molecular basis of Arc hub and capsid functions, and the relationship between them, is vital for progress. Here, we discuss recent findings on Arc structure-function and regulation of oligomerization that are giving insight into the molecular physiology of Arc. The unique features of mammalian Arc are emphasized, while drawing comparisons with Drosophila Arc and retroviral Gag. The Arc N-terminal domain, found only in mammals, is proposed to play a key role in regulating Arc hub signaling, oligomerization, and formation of capsids. Bringing together several lines of evidence, we hypothesize that Arc function in synaptic plasticity-long-term potentiation (LTP) and long-term depression (LTD)-are dictated by different oligomeric forms of Arc. Specifically, monomer/dimer function in LTP, tetramer function in basic LTD, and 32-unit oligomer function in enhanced LTD. The role of mammalian Arc capsids is unclear but likely depends on the cross-section of captured neuronal activity-induced RNAs. As the functional states of Arc are revealed, it may be possible to selectively manipulate specific forms of Arc-dependent plasticity and intercellular communication involved in brain function and dysfunction.
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Affiliation(s)
| | - Clive R. Bramham
- Department of BiomedicineUniversity of BergenBergenNorway,Mohn Research Center for the BrainUniversity of BergenBergenNorway
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21
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Abstract
Transposable elements are known by many names, including 'transposons', 'interspersed repeats', 'selfish genetic elements', 'jumping genes', and 'parasitic DNA', but here we will refer to them simply as transposable elements. Many biologists will have heard of transposable elements and their ability to transpose (change position) within the genome. But fewer may be aware of their varied influences on host biology, including contributions to the evolution of diverse host traits such as internal gestation, memory, colouration, and adaptive immunity. Transposable elements are a near ubiquitous feature of eukaryotic genomes, and they often comprise a substantial proportion of total genomic content. Consequently, transposable element genes are considered among the most abundant coding sequences in nature. Recent advances in genome sequencing have ushered in a golden age for transposable-element research, providing opportunities to greatly improve our understanding of the effects of transposable elements on host evolution and disease. However, our ability to detect and analyse transposable elements still faces significant challenges, impairing efforts to decipher their evolution, characterise their diversity, and elucidate their myriad host influences. Below, we summarise key aspects of transposable element biology in eukaryotes and discuss major outstanding research questions.
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Affiliation(s)
- Alexander Hayward
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Cornwall TR10 9FE, UK.
| | - Clément Gilbert
- Université Paris-Saclay, CNRS, IRD, UMR Evolution, Génomes, Comportement et Ecologie, Gif-sur-Yvette 91198, France.
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22
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Koonin EV, Dolja VV, Krupovic M, Kuhn JH. Viruses Defined by the Position of the Virosphere within the Replicator Space. Microbiol Mol Biol Rev 2021; 85:e0019320. [PMID: 34468181 PMCID: PMC8483706 DOI: 10.1128/mmbr.00193-20] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Originally, viruses were defined as miniscule infectious agents that passed through filters that retain even the smallest cells. Subsequently, viruses were considered obligate intracellular parasites whose reproduction depends on their cellular hosts for energy supply and molecular building blocks. However, these features are insufficient to unambiguously define viruses as they are broadly understood today. We outline possible approaches to define viruses and explore the boundaries of the virosphere within the virtual space of replicators and the relationships between viruses and other types of replicators. Regardless of how, exactly, viruses are defined, viruses clearly have evolved on many occasions from nonviral replicators, such as plasmids, by recruiting host proteins to become virion components. Conversely, other types of replicators have repeatedly evolved from viruses. Thus, the virosphere is a dynamic entity with extensive evolutionary traffic across its boundaries. We argue that the virosphere proper, here termed orthovirosphere, consists of a distinct variety of replicators that encode structural proteins encasing the replicators' genomes, thereby providing protection and facilitating transmission among hosts. Numerous and diverse replicators, such as virus-derived but capsidless RNA and DNA elements, or defective viruses occupy the zone surrounding the orthovirosphere in the virtual replicator space. We define this zone as the perivirosphere. Although intense debates on the nature of certain replicators that adorn the internal and external boundaries of the virosphere will likely continue, we present an operational definition of virus that recently has been accepted by the International Committee on Taxonomy of Viruses.
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Affiliation(s)
- Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Valerian V. Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
| | - Mart Krupovic
- Archaeal Virology Unit, Institut Pasteur, Paris, France
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
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23
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Neuron-specific chromosomal megadomain organization is adaptive to recent retrotransposon expansions. Nat Commun 2021; 12:7243. [PMID: 34903713 PMCID: PMC8669064 DOI: 10.1038/s41467-021-26862-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 10/27/2021] [Indexed: 01/16/2023] Open
Abstract
Regulatory mechanisms associated with repeat-rich sequences and chromosomal conformations in mature neurons remain unexplored. Here, we map cell-type specific chromatin domain organization in adult mouse cerebral cortex and report strong enrichment of Endogenous Retrovirus 2 (ERV2) repeat sequences in the neuron-specific heterochromatic B2NeuN+ megabase-scaling subcompartment. Single molecule long-read sequencing and comparative Hi-C chromosomal contact mapping in wild-derived SPRET/EiJ (Mus spretus) and laboratory inbred C57BL/6J (Mus musculus) reveal neuronal reconfigurations tracking recent ERV2 expansions in the murine germline, with significantly higher B2NeuN+ contact frequencies at sites with ongoing insertions in Mus musculus. Neuronal ablation of the retrotransposon silencer Kmt1e/Setdb1 triggers B2NeuN+ disintegration and rewiring with open chromatin domains enriched for cellular stress response genes, along with severe neuroinflammation and proviral assembly with infiltration of dendrites . We conclude that neuronal megabase-scale chromosomal architectures include an evolutionarily adaptive heterochromatic organization which, upon perturbation, results in transcriptional dysregulation and unleashes ERV2 proviruses with strong neuronal tropism.
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24
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Senft AD, Macfarlan TS. Transposable elements shape the evolution of mammalian development. Nat Rev Genet 2021; 22:691-711. [PMID: 34354263 DOI: 10.1038/s41576-021-00385-1] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 02/06/2023]
Abstract
Transposable elements (TEs) promote genetic innovation but also threaten genome stability. Despite multiple layers of host defence, TEs actively shape mammalian-specific developmental processes, particularly during pre-implantation and extra-embryonic development and at the maternal-fetal interface. Here, we review how TEs influence mammalian genomes both directly by providing the raw material for genetic change and indirectly via co-evolving TE-binding Krüppel-associated box zinc finger proteins (KRAB-ZFPs). Throughout mammalian evolution, individual activities of ancient TEs were co-opted to enable invasive placentation that characterizes live-born mammals. By contrast, the widespread activity of evolutionarily young TEs may reflect an ongoing co-evolution that continues to impact mammalian development.
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Affiliation(s)
- Anna D Senft
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA.
| | - Todd S Macfarlan
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA.
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mRNA Trafficking in the Nervous System: A Key Mechanism of the Involvement of Activity-Regulated Cytoskeleton-Associated Protein (Arc) in Synaptic Plasticity. Neural Plast 2021; 2021:3468795. [PMID: 34603440 PMCID: PMC8486535 DOI: 10.1155/2021/3468795] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/15/2021] [Accepted: 09/07/2021] [Indexed: 12/18/2022] Open
Abstract
Synaptic activity mediates information storage and memory consolidation in the brain and requires a fast de novo synthesis of mRNAs in the nucleus and proteins in synapses. Intracellular localization of a protein can be achieved by mRNA trafficking and localized translation. Activity-regulated cytoskeleton-associated protein (Arc) is a master regulator of synaptic plasticity and plays an important role in controlling large signaling networks implicated in learning, memory consolidation, and behavior. Transcription of the Arc gene may be induced by a short behavioral event, resulting in synaptic activation. Arc mRNA is exported into the cytoplasm and can be trafficked into the dendrite of an activated synapse where it is docked and translated. The structure of Arc is similar to the viral GAG (group-specific antigen) protein, and phylogenic analysis suggests that Arc may originate from the family of Ty3/Gypsy retrotransposons. Therefore, Arc might evolve through “domestication” of retroviruses. Arc can form a capsid-like structure that encapsulates a retrovirus-like sentence in the 3′-UTR (untranslated region) of Arc mRNA. Such complex can be loaded into extracellular vesicles and transported to other neurons or muscle cells carrying not only genetic information but also regulatory signals within neuronal networks. Therefore, Arc mRNA inter- and intramolecular trafficking is essential for the modulation of synaptic activity required for memory consolidation and cognitive functions. Recent studies with single-molecule imaging in live neurons confirmed and extended the role of Arc mRNA trafficking in synaptic plasticity.
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Perez JD, Fusco CM, Schuman EM. A Functional Dissection of the mRNA and Locally Synthesized Protein Population in Neuronal Dendrites and Axons. Annu Rev Genet 2021; 55:183-207. [PMID: 34460296 DOI: 10.1146/annurev-genet-030321-054851] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurons are characterized by a complex morphology that enables the generation of subcellular compartments with unique biochemical and biophysical properties, such as dendrites, axons, and synapses. To sustain these different compartments and carry a wide array of elaborate operations, neurons express a diverse repertoire of gene products. Extensive regulation at both the messenger RNA (mRNA) and protein levels allows for the differentiation of subcellular compartments as well as numerous forms of plasticity in response to variable stimuli. Among the multiple mechanisms that control cellular functions, mRNA translation is manipulated by neurons to regulate where and when a protein emerges. Interestingly, transcriptomic and translatomic profiles of both dendrites and axons have revealed that the mRNA population only partially predicts the local protein population and that this relation significantly varies between different gene groups. Here, we describe the space that local translation occupies within the large molecular and regulatory complexity of neurons, in contrast to other modes of regulation. We then discuss the specialized organization of mRNAs within different neuronal compartments, as revealed by profiles of the local transcriptome. Finally, we discuss the features and functional implications of both locally correlated-and anticorrelated-mRNA-protein relations both under baseline conditions and during synaptic plasticity. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Julio D Perez
- Max Planck Institute for Brain Research, 60438 Frankfurt, Germany;
| | - Claudia M Fusco
- Max Planck Institute for Brain Research, 60438 Frankfurt, Germany;
| | - Erin M Schuman
- Max Planck Institute for Brain Research, 60438 Frankfurt, Germany;
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Ferrari R, Grandi N, Tramontano E, Dieci G. Retrotransposons as Drivers of Mammalian Brain Evolution. Life (Basel) 2021; 11:life11050376. [PMID: 33922141 PMCID: PMC8143547 DOI: 10.3390/life11050376] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/11/2022] Open
Abstract
Retrotransposons, a large and diverse class of transposable elements that are still active in humans, represent a remarkable force of genomic innovation underlying mammalian evolution. Among the features distinguishing mammals from all other vertebrates, the presence of a neocortex with a peculiar neuronal organization, composition and connectivity is perhaps the one that, by affecting the cognitive abilities of mammals, contributed mostly to their evolutionary success. Among mammals, hominids and especially humans display an extraordinarily expanded cortical volume, an enrichment of the repertoire of neural cell types and more elaborate patterns of neuronal connectivity. Retrotransposon-derived sequences have recently been implicated in multiple layers of gene regulation in the brain, from transcriptional and post-transcriptional control to both local and large-scale three-dimensional chromatin organization. Accordingly, an increasing variety of neurodevelopmental and neurodegenerative conditions are being recognized to be associated with retrotransposon dysregulation. We review here a large body of recent studies lending support to the idea that retrotransposon-dependent evolutionary novelties were crucial for the emergence of mammalian, primate and human peculiarities of brain morphology and function.
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Affiliation(s)
- Roberto Ferrari
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy;
| | - Nicole Grandi
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy; (N.G.); (E.T.)
| | - Enzo Tramontano
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato, Italy; (N.G.); (E.T.)
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, 09042 Monserrato, Italy
| | - Giorgio Dieci
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy;
- Correspondence:
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