1
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Keeley O, Coyne AN. Nuclear and degradative functions of the ESCRT-III pathway: implications for neurodegenerative disease. Nucleus 2024; 15:2349085. [PMID: 38700207 PMCID: PMC11073439 DOI: 10.1080/19491034.2024.2349085] [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: 02/11/2024] [Accepted: 04/24/2024] [Indexed: 05/05/2024] Open
Abstract
The ESCRT machinery plays a pivotal role in membrane-remodeling events across multiple cellular processes including nuclear envelope repair and reformation, nuclear pore complex surveillance, endolysosomal trafficking, and neuronal pruning. Alterations in ESCRT-III functionality have been associated with neurodegenerative diseases including Frontotemporal Dementia (FTD), Amyotrophic Lateral Sclerosis (ALS), and Alzheimer's Disease (AD). In addition, mutations in specific ESCRT-III proteins have been identified in FTD/ALS. Thus, understanding how disruptions in the fundamental functions of this pathway and its individual protein components in the human central nervous system (CNS) may offer valuable insights into mechanisms underlying neurodegenerative disease pathogenesis and identification of potential therapeutic targets. In this review, we discuss ESCRT components, dynamics, and functions, with a focus on the ESCRT-III pathway. In addition, we explore the implications of altered ESCRT-III function for neurodegeneration with a primary emphasis on nuclear surveillance and endolysosomal trafficking within the CNS.
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Affiliation(s)
- Olivia Keeley
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alyssa N. Coyne
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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2
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Akter M, Cui H, Hosain MA, Liu J, Duan Y, Ding B. RANBP17 Overexpression Restores Nucleocytoplasmic Transport and Ameliorates Neurodevelopment in Induced DYT1 Dystonia Motor Neurons. J Neurosci 2024; 44:e1728232024. [PMID: 38438257 PMCID: PMC11007476 DOI: 10.1523/jneurosci.1728-23.2024] [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: 09/11/2023] [Revised: 02/18/2024] [Accepted: 02/20/2024] [Indexed: 03/06/2024] Open
Abstract
DYT1 dystonia is a debilitating neurological movement disorder, and it represents the most frequent and severe form of hereditary primary dystonia. There is currently no cure for this disease due to its unclear pathogenesis. In our previous study utilizing patient-specific motor neurons (MNs), we identified distinct cellular deficits associated with the disease, including a deformed nucleus, disrupted neurodevelopment, and compromised nucleocytoplasmic transport (NCT) functions. However, the precise molecular mechanisms underlying these cellular impairments have remained elusive. In this study, we revealed the genome-wide changes in gene expression in DYT1 MNs through transcriptomic analysis. We found that those dysregulated genes are intricately involved in neurodevelopment and various biological processes. Interestingly, we identified that the expression level of RANBP17, a RAN-binding protein crucial for NCT regulation, exhibited a significant reduction in DYT1 MNs. By manipulating RANBP17 expression, we further demonstrated that RANBP17 plays an important role in facilitating the nuclear transport of both protein and transcript cargos in induced human neurons. Excitingly, the overexpression of RANBP17 emerged as a substantial mitigating factor, effectively restoring impaired NCT activity and rescuing neurodevelopmental deficits observed in DYT1 MNs. These findings shed light on the intricate molecular underpinnings of impaired NCT in DYT1 neurons and provide novel insights into the pathophysiology of DYT1 dystonia, potentially leading to the development of innovative treatment strategies.
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Affiliation(s)
- Masuma Akter
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
| | - Haochen Cui
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
| | - Md Abir Hosain
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
| | - Jinmei Liu
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
| | - Yuntian Duan
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
| | - Baojin Ding
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, Louisiana 71130-3932
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3
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Reinhold C, Knorr S, McFleder RL, Rauschenberger L, Muthuraman M, Arampatzi P, Gräfenhan T, Schlosser A, Sendtner M, Volkmann J, Ip CW. Gene-environment interaction elicits dystonia-like features and impaired translational regulation in a DYT-TOR1A mouse model. Neurobiol Dis 2024; 193:106453. [PMID: 38402912 DOI: 10.1016/j.nbd.2024.106453] [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: 12/01/2023] [Revised: 02/17/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024] Open
Abstract
DYT-TOR1A dystonia is the most common monogenic dystonia characterized by involuntary muscle contractions and lack of therapeutic options. Despite some insights into its etiology, the disease's pathophysiology remains unclear. The reduced penetrance of about 30% suggests that extragenetic factors are needed to develop a dystonic phenotype. In order to systematically investigate this hypothesis, we induced a sciatic nerve crush injury in a genetically predisposed DYT-TOR1A mouse model (DYT1KI) to evoke a dystonic phenotype. Subsequently, we employed a multi-omic approach to uncover novel pathophysiological pathways that might be responsible for this condition. Using an unbiased deep-learning-based characterization of the dystonic phenotype showed that nerve-injured DYT1KI animals exhibited significantly more dystonia-like movements (DLM) compared to naive DYT1KI animals. This finding was noticeable as early as two weeks following the surgical procedure. Furthermore, nerve-injured DYT1KI mice displayed significantly more DLM than nerve-injured wildtype (wt) animals starting at 6 weeks post injury. In the cerebellum of nerve-injured wt mice, multi-omic analysis pointed towards regulation in translation related processes. These observations were not made in the cerebellum of nerve-injured DYT1KI mice; instead, they were localized to the cortex and striatum. Our findings indicate a failed translational compensatory mechanisms in the cerebellum of phenotypic DYT1KI mice that exhibit DLM, while translation dysregulations in the cortex and striatum likely promotes the dystonic phenotype.
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Affiliation(s)
- Colette Reinhold
- Department of Neurology, University Hospital of Würzburg, Germany
| | - Susanne Knorr
- Department of Neurology, University Hospital of Würzburg, Germany
| | | | | | | | | | - Tom Gräfenhan
- Core Unit Systems Medicine, Medical Faculty, University Würzburg, Germany
| | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital of Würzburg, Germany
| | - Jens Volkmann
- Department of Neurology, University Hospital of Würzburg, Germany
| | - Chi Wang Ip
- Department of Neurology, University Hospital of Würzburg, Germany.
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4
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Lauber C, Zhang X, Vaas J, Klingler F, Mutz P, Dubin A, Pietschmann T, Roth O, Neuman BW, Gorbalenya AE, Bartenschlager R, Seitz S. Deep mining of the Sequence Read Archive reveals major genetic innovations in coronaviruses and other nidoviruses of aquatic vertebrates. PLoS Pathog 2024; 20:e1012163. [PMID: 38648214 PMCID: PMC11065284 DOI: 10.1371/journal.ppat.1012163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 05/02/2024] [Accepted: 03/31/2024] [Indexed: 04/25/2024] Open
Abstract
Virus discovery by genomics and metagenomics empowered studies of viromes, facilitated characterization of pathogen epidemiology, and redefined our understanding of the natural genetic diversity of viruses with profound functional and structural implications. Here we employed a data-driven virus discovery approach that directly queries unprocessed sequencing data in a highly parallelized way and involves a targeted viral genome assembly strategy in a wide range of sequence similarity. By screening more than 269,000 datasets of numerous authors from the Sequence Read Archive and using two metrics that quantitatively assess assembly quality, we discovered 40 nidoviruses from six virus families whose members infect vertebrate hosts. They form 13 and 32 putative viral subfamilies and genera, respectively, and include 11 coronaviruses with bisegmented genomes from fishes and amphibians, a giant 36.1 kilobase coronavirus genome with a duplicated spike glycoprotein (S) gene, 11 tobaniviruses and 17 additional corona-, arteri-, cremega-, nanhypo- and nangoshaviruses. Genome segmentation emerged in a single evolutionary event in the monophyletic lineage encompassing the subfamily Pitovirinae. We recovered the bisegmented genome sequences of two coronaviruses from RNA samples of 69 infected fishes and validated the presence of poly(A) tails at both segments using 3'RACE PCR and subsequent Sanger sequencing. We report a genetic linkage between accessory and structural proteins whose phylogenetic relationships and evolutionary distances are incongruent with the phylogeny of replicase proteins. We rationalize these observations in a model of inter-family S recombination involving at least five ancestral corona- and tobaniviruses of aquatic hosts. In support of this model, we describe an individual fish co-infected with members from the families Coronaviridae and Tobaniviridae. Our results expand the scale of the known extraordinary evolutionary plasticity in nidoviral genome architecture and call for revisiting fundamentals of genome expression, virus particle biology, host range and ecology of vertebrate nidoviruses.
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Affiliation(s)
- Chris Lauber
- Institute for Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence 2155 RESIST, Hannover, Germany
| | - Xiaoyu Zhang
- Institute for Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Josef Vaas
- Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Medical Faculty Heidelberg, Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research, Heidelberg, Germany
| | - Franziska Klingler
- Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Medical Faculty Heidelberg, Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research, Heidelberg, Germany
| | - Pascal Mutz
- Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Arseny Dubin
- Marine Evolutionary Biology, Zoological Institute, Kiel University, Kiel, Germany
| | - Thomas Pietschmann
- Institute for Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence 2155 RESIST, Hannover, Germany
| | - Olivia Roth
- Marine Evolutionary Biology, Zoological Institute, Kiel University, Kiel, Germany
| | - Benjamin W. Neuman
- Department of Biology and Texas A&M Global Health Research Complex, Texas A&M University, College Station, Texas, United States
| | - Alexander E. Gorbalenya
- Leiden University Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
- Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Ralf Bartenschlager
- Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Medical Faculty Heidelberg, Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research, Heidelberg, Germany
| | - Stefan Seitz
- Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Medical Faculty Heidelberg, Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research, Heidelberg, Germany
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5
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Sule KC, Nakamura M, Parkhurst SM. Nuclear envelope budding: Getting large macromolecular complexes out of the nucleus. Bioessays 2024; 46:e2300182. [PMID: 38044581 PMCID: PMC10843589 DOI: 10.1002/bies.202300182] [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: 09/24/2023] [Revised: 11/19/2023] [Accepted: 11/21/2023] [Indexed: 12/05/2023]
Abstract
Transport of macromolecules from the nucleus to the cytoplasm is essential for nearly all cellular and developmental events, and when mis-regulated, is associated with diseases, tumor formation/growth, and cancer progression. Nuclear Envelope (NE)-budding is a newly appreciated nuclear export pathway for large macromolecular machineries, including those assembled to allow co-regulation of functionally related components, that bypasses canonical nuclear export through nuclear pores. In this pathway, large macromolecular complexes are enveloped by the inner nuclear membrane, transverse the perinuclear space, and then exit through the outer nuclear membrane to release its contents into the cytoplasm. NE-budding is a conserved process and shares many features with nuclear egress mechanisms used by herpesviruses. Despite its biological importance and clinical relevance, little is yet known about the regulatory and structural machineries that allow NE-budding to occur in any system. Here we summarize what is currently known or proposed for this intriguing nuclear export process.
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Affiliation(s)
- Kevin C. Sule
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Susan M. Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
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6
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Thomsen M, Lange LM, Zech M, Lohmann K. Genetics and Pathogenesis of Dystonia. ANNUAL REVIEW OF PATHOLOGY 2024; 19:99-131. [PMID: 37738511 DOI: 10.1146/annurev-pathmechdis-051122-110756] [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: 09/24/2023]
Abstract
Dystonia is a clinically and genetically highly heterogeneous neurological disorder characterized by abnormal movements and postures caused by involuntary sustained or intermittent muscle contractions. A number of groundbreaking genetic and molecular insights have recently been gained. While they enable genetic testing and counseling, their translation into new therapies is still limited. However, we are beginning to understand shared pathophysiological pathways and molecular mechanisms. It has become clear that dystonia results from a dysfunctional network involving the basal ganglia, cerebellum, thalamus, and cortex. On the molecular level, more than a handful of, often intertwined, pathways have been linked to pathogenic variants in dystonia genes, including gene transcription during neurodevelopment (e.g., KMT2B, THAP1), calcium homeostasis (e.g., ANO3, HPCA), striatal dopamine signaling (e.g., GNAL), endoplasmic reticulum stress response (e.g., EIF2AK2, PRKRA, TOR1A), autophagy (e.g., VPS16), and others. Thus, different forms of dystonia can be molecularly grouped, which may facilitate treatment development in the future.
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Affiliation(s)
- Mirja Thomsen
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
| | - Lara M Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
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7
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Keuenhof KS, Kohler V, Broeskamp F, Panagaki D, Speese SD, Büttner S, Höög JL. Nuclear envelope budding and its cellular functions. Nucleus 2023; 14:2178184. [PMID: 36814098 PMCID: PMC9980700 DOI: 10.1080/19491034.2023.2178184] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/03/2023] [Indexed: 02/24/2023] Open
Abstract
The nuclear pore complex (NPC) has long been assumed to be the sole route across the nuclear envelope, and under normal homeostatic conditions it is indeed the main mechanism of nucleo-cytoplasmic transport. However, it has also been known that e.g. herpesviruses cross the nuclear envelope utilizing a pathway entitled nuclear egress or envelopment/de-envelopment. Despite this, a thread of observations suggests that mechanisms similar to viral egress may be transiently used also in healthy cells. It has since been proposed that mechanisms like nuclear envelope budding (NEB) can facilitate the transport of RNA granules, aggregated proteins, inner nuclear membrane proteins, and mis-assembled NPCs. Herein, we will summarize the known roles of NEB as a physiological and intrinsic cellular feature and highlight the many unanswered questions surrounding these intriguing nuclear events.
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Affiliation(s)
| | - Verena Kohler
- Institute of Molecular Biosciences, University of Graz, Austria
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Filomena Broeskamp
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
| | - Dimitra Panagaki
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
| | - Sean D. Speese
- Knight Cancer Early Detection Advanced Research Center, Oregon Health and Science University, 2720 S Moody Ave, Portland, OR, 97201, USA
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Johanna L. Höög
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
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8
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Chen H, Lye MF, Gorgulla C, Ficarro SB, Cuny GD, Scott DA, Wu F, Rothlauf PW, Wang X, Fernandez R, Pesola JM, Draga S, Marto JA, Hogle JM, Arthanari H, Coen DM. A small molecule exerts selective antiviral activity by targeting the human cytomegalovirus nuclear egress complex. PLoS Pathog 2023; 19:e1011781. [PMID: 37976321 PMCID: PMC10691697 DOI: 10.1371/journal.ppat.1011781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 12/01/2023] [Accepted: 10/28/2023] [Indexed: 11/19/2023] Open
Abstract
Human cytomegalovirus (HCMV) is an important pathogen for which new antiviral drugs are needed. HCMV, like other herpesviruses, encodes a nuclear egress complex (NEC) composed of two subunits, UL50 and UL53, whose interaction is crucial for viral replication. To explore whether small molecules can exert selective antiviral activity by inhibiting NEC subunit interactions, we established a homogeneous time-resolved fluorescence (HTRF) assay of these interactions and used it to screen >200,000 compound-containing wells. Two compounds, designated GK1 and GK2, which selectively inhibited this interaction in the HTRF assay with GK1 also active in a co-immunoprecipitation assay, exhibited more potent anti-HCMV activity than cytotoxicity or activity against another herpesvirus. At doses that substantially reduced HCMV plaque formation, GK1 and GK2 had little or no effect on the expression of viral proteins and reduced the co-localization of UL53 with UL50 at the nuclear rim in a subset of cells. GK1 and GK2 contain an acrylamide moiety predicted to covalently interact with cysteines, and an analog without this potential lacked activity. Mass spectrometric analysis showed binding of GK2 to multiple cysteines on UL50 and UL53. Nevertheless, substitution of cysteine 214 of UL53 with serine (C214S) ablated detectable inhibitory activity of GK1 and GK2 in vitro, and the C214S substitution engineered into HCMV conferred resistance to GK1, the more potent of the two inhibitors. Thus, GK1 exerts selective antiviral activity by targeting the NEC. Docking studies suggest that the acrylamide tethers one end of GK1 or GK2 to C214 within a pocket of UL53, permitting the other end of the molecule to sterically hinder UL50 to prevent NEC formation. Our results prove the concept that targeting the NEC with small molecules can selectively block HCMV replication. Such compounds could serve as a foundation for development of anti-HCMV drugs and as chemical tools for studying HCMV.
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Affiliation(s)
- Han Chen
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ming F. Lye
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Christoph Gorgulla
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Structural Biology, St. Jude’s Children’s Research Hospital, Memphis Tennessee United States of America
| | - Scott B. Ficarro
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Center for Emergent Drug Targets, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gregory D. Cuny
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston College of Pharmacy, Houston, Texas, United States of America
| | - David A. Scott
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Medicinal Chemistry Core, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Fan Wu
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Paul W. Rothlauf
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xiaoou Wang
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rosio Fernandez
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jean M. Pesola
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sorin Draga
- Virtual Discovery, Inc. Chestnut Hill, Massachusetts United States of America
- Non-Governmental Research Organization Biologic, Bucharest Romania
| | - Jarrod A. Marto
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Center for Emergent Drug Targets, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - James M. Hogle
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Donald M. Coen
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
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9
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Kuiper EFE, Prophet SM, Schlieker C. Coordinating nucleoporin condensation and nuclear pore complex assembly. FEBS Lett 2023; 597:2534-2545. [PMID: 37620293 DOI: 10.1002/1873-3468.14725] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/24/2023] [Accepted: 08/10/2023] [Indexed: 08/26/2023]
Abstract
The nuclear pore complex (NPC) is among the most elaborate protein complexes in eukaryotes. While ribosomes and proteasomes are known to require dedicated assembly machinery, our understanding of NPC assembly is at a relatively early stage. Defects in NPC assembly or homeostasis are tied to movement disorders, including dystonia and amyotrophic lateral sclerosis (ALS), as well as aging, requiring a better understanding of these processes to enable therapeutic intervention. Here, we discuss recent progress in the understanding of NPC assembly and highlight how related defects in human disorders can shed light on NPC biogenesis. We propose that the condensation of phenylalanine-glycine repeat nucleoporins needs to be carefully controlled during NPC assembly to prevent aberrant condensation, aggregation, or amyloid formation.
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Affiliation(s)
- E F Elsiena Kuiper
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA
| | - Sarah M Prophet
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA
| | - Christian Schlieker
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
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10
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Fan Y, Si Z, Wang L, Zhang L. DYT- TOR1A dystonia: an update on pathogenesis and treatment. Front Neurosci 2023; 17:1216929. [PMID: 37638318 PMCID: PMC10448058 DOI: 10.3389/fnins.2023.1216929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
DYT-TOR1A dystonia is a neurological disorder characterized by involuntary muscle contractions and abnormal movements. It is a severe genetic form of dystonia caused by mutations in the TOR1A gene. TorsinA is a member of the AAA + family of adenosine triphosphatases (ATPases) involved in a variety of cellular functions, including protein folding, lipid metabolism, cytoskeletal organization, and nucleocytoskeletal coupling. Almost all patients with TOR1A-related dystonia harbor the same mutation, an in-frame GAG deletion (ΔGAG) in the last of its 5 exons. This recurrent variant results in the deletion of one of two tandem glutamic acid residues (i.e., E302/303) in a protein named torsinA [torsinA(△E)]. Although the mutation is hereditary, not all carriers will develop DYT-TOR1A dystonia, indicating the involvement of other factors in the disease process. The current understanding of the pathophysiology of DYT-TOR1A dystonia involves multiple factors, including abnormal protein folding, signaling between neurons and glial cells, and dysfunction of the protein quality control system. As there are currently no curative treatments for DYT-TOR1A dystonia, progress in research provides insight into its pathogenesis, leading to potential therapeutic and preventative strategies. This review summarizes the latest research advances in the pathogenesis, diagnosis, and treatment of DYT-TOR1A dystonia.
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Affiliation(s)
- Yuhang Fan
- Department of Neurology, the Second Hospital of Jilin University, Changchun, China
| | - Zhibo Si
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, China
| | - Linlin Wang
- Department of Ultrasound, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Lei Zhang
- Department of Neurology, the Second Hospital of Jilin University, Changchun, China
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11
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Davidson KA, Nakamura M, Verboon JM, Parkhurst SM. Centralspindlin proteins Pavarotti and Tumbleweed along with WASH regulate nuclear envelope budding. J Cell Biol 2023; 222:e202211074. [PMID: 37163553 PMCID: PMC10174194 DOI: 10.1083/jcb.202211074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/14/2023] [Accepted: 04/26/2023] [Indexed: 05/12/2023] Open
Abstract
Nuclear envelope (NE) budding is a nuclear pore-independent nuclear export pathway, analogous to the egress of herpesviruses, and required for protein quality control, synapse development, and mitochondrial integrity. The physical formation of NE buds is dependent on the Wiskott-Aldrich Syndrome protein, Wash, its regulatory complex (SHRC), and Arp2/3, and requires Wash's actin nucleation activity. However, the machinery governing cargo recruitment and organization within the NE bud remains unknown. Here, we identify Pavarotti (Pav) and Tumbleweed (Tum) as new molecular components of NE budding. Pav and Tum interact directly with Wash and define a second nuclear Wash-containing complex required for NE budding. Interestingly, we find that the actin-bundling activity of Pav is required, suggesting a structural role in the physical and/or organizational aspects of NE buds. Thus, Pav and Tum are providing exciting new entry points into the physical machineries of this alternative nuclear export pathway for large cargos during cell differentiation and development.
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Affiliation(s)
- Kerri A. Davidson
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | | | - Jeffrey M. Verboon
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Susan M. Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
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12
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Di Fonzo A, Jinnah HA, Zech M. Dystonia genes and their biological pathways. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:61-103. [PMID: 37482402 DOI: 10.1016/bs.irn.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
High-throughput sequencing has been instrumental in uncovering the spectrum of pathogenic genetic alterations that contribute to the etiology of dystonia. Despite the immense heterogeneity in monogenic causes, studies performed during the past few years have highlighted that many rare deleterious variants associated with dystonic presentations affect genes that have roles in certain conserved pathways in neural physiology. These various gene mutations that appear to converge towards the disruption of interconnected cellular networks were shown to produce a wide range of different dystonic disease phenotypes, including isolated and combined dystonias as well as numerous clinically complex, often neurodevelopmental disorder-related conditions that can manifest with dystonic features in the context of multisystem disturbances. In this chapter, we summarize the manifold dystonia-gene relationships based on their association with a discrete number of unifying pathophysiological mechanisms and molecular cascade abnormalities. The themes on which we focus comprise dopamine signaling, heavy metal accumulation and calcifications in the brain, nuclear envelope function and stress response, gene transcription control, energy homeostasis, lysosomal trafficking, calcium and ion channel-mediated signaling, synaptic transmission beyond dopamine pathways, extra- and intracellular structural organization, and protein synthesis and degradation. Enhancing knowledge about the concept of shared etiological pathways in the pathogenesis of dystonia will motivate clinicians and researchers to find more efficacious treatments that allow to reverse pathologies in patient-specific core molecular networks and connected multipathway loops.
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Affiliation(s)
- Alessio Di Fonzo
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - H A Jinnah
- Departments of Neurology, Human Genetics, and Pediatrics, Atlanta, GA, United States
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.
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13
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Kim S, Phan S, Shaw TR, Ellisman MH, Veatch SL, Barmada SJ, Pappas SS, Dauer WT. TorsinA is essential for the timing and localization of neuronal nuclear pore complex biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538491. [PMID: 37162852 PMCID: PMC10168336 DOI: 10.1101/2023.04.26.538491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Nuclear pore complexes (NPCs) regulate information transfer between the nucleus and cytoplasm. NPC defects are linked to several neurological diseases, but the processes governing NPC biogenesis and spatial organization are poorly understood. Here, we identify a temporal window of strongly upregulated NPC biogenesis during neuronal maturation. We demonstrate that the AAA+ protein torsinA, whose loss of function causes the neurodevelopmental movement disorder DYT-TOR1A (DYT1) dystonia, coordinates NPC spatial organization during this period without impacting total NPC density. Using a new mouse line in which endogenous Nup107 is Halo-Tagged, we find that torsinA is essential for correct localization of NPC formation. In the absence of torsinA, the inner nuclear membrane buds excessively at sites of mislocalized, nascent NPCs, and NPC assembly completion is delayed. Our work implies that NPC spatial organization and number are independently regulated and suggests that torsinA is critical for the normal localization and assembly kinetics of NPCs.
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Affiliation(s)
- Sumin Kim
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Sébastien Phan
- National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA
| | - Thomas R. Shaw
- Department of Biophysics, University of Michigan, Ann Arbor, MI
| | - Mark H. Ellisman
- National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA
| | - Sarah L. Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, MI
| | - Sami J. Barmada
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Samuel S. Pappas
- Peter O’Donnell Jr. Brain Institute, UT Southwestern, Dallas, TX
- Department of Neurology, UT Southwestern, Dallas, TX
| | - William T. Dauer
- Peter O’Donnell Jr. Brain Institute, UT Southwestern, Dallas, TX
- Department of Neurology, UT Southwestern, Dallas, TX
- Department of Neuroscience, UT Southwestern, Dallas, TX
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14
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Park JW, Lee EJ, Moon E, Kim HL, Kim IB, Hodzic D, Kim N, Kweon HS, Kim JW. Orthodenticle homeobox 2 is transported to lysosomes by nuclear budding vesicles. Nat Commun 2023; 14:1111. [PMID: 36849521 PMCID: PMC9971051 DOI: 10.1038/s41467-023-36697-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 02/08/2023] [Indexed: 03/01/2023] Open
Abstract
Transcription factors (TFs) are transported from the cytoplasm to the nucleus and disappear from the nucleus after they regulate gene expression. Here, we discover an unconventional nuclear export of the TF, orthodenticle homeobox 2 (OTX2), in nuclear budding vesicles, which transport OTX2 to the lysosome. We further find that torsin1a (Tor1a) is responsible for scission of the inner nuclear vesicle, which captures OTX2 using the LINC complex. Consistent with this, in cells expressing an ATPase-inactive Tor1aΔE mutant and the LINC (linker of nucleoskeleton and cytoskeleton) breaker KASH2, OTX2 accumulated and formed aggregates in the nucleus. Consequently, in the mice expressing Tor1aΔE and KASH2, OTX2 could not be secreted from the choroid plexus for transfer to the visual cortex, leading to failed development of parvalbumin neurons and reduced visual acuity. Together, our results suggest that unconventional nuclear egress and secretion of OTX2 are necessary not only to induce functional changes in recipient cells but also to prevent aggregation in donor cells.
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Affiliation(s)
- Jun Woo Park
- Department of Biological Sciences and Stem Cell Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Eun Jung Lee
- Department of Biological Sciences and Stem Cell Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Eunyoung Moon
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju, 28119, South Korea
| | - Hong-Lim Kim
- Integrative Research Support Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, South Korea
| | - In-Beom Kim
- Integrative Research Support Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, South Korea
| | - Didier Hodzic
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Namsuk Kim
- Department of Biological Sciences and Stem Cell Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.,Neurovascular Unit, Korea Brain Research Institute, Daegu, 41062, South Korea
| | - Hee-Seok Kweon
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju, 28119, South Korea
| | - Jin Woo Kim
- Department of Biological Sciences and Stem Cell Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
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15
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Atypical nuclear envelope condensates linked to neurological disorders reveal nucleoporin-directed chaperone activities. Nat Cell Biol 2022; 24:1630-1641. [PMID: 36302970 PMCID: PMC10041656 DOI: 10.1038/s41556-022-01001-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 08/26/2022] [Indexed: 01/18/2023]
Abstract
DYT1 dystonia is a debilitating neurological movement disorder arising from mutation in the AAA+ ATPase TorsinA. The hallmark of Torsin dysfunction is nuclear envelope blebbing resulting from defects in nuclear pore complex biogenesis. Whether blebs actively contribute to disease manifestation is unknown. We report that FG-nucleoporins in the bleb lumen form aberrant condensates and contribute to DYT1 dystonia by provoking two proteotoxic insults. Short-lived ubiquitylated proteins that are normally rapidly degraded partition into the bleb lumen and become stabilized. In addition, blebs selectively sequester a specific HSP40-HSP70 chaperone network that is modulated by the bleb component MLF2. MLF2 suppresses the ectopic accumulation of FG-nucleoporins and modulates the selective properties and size of condensates in vitro. Our study identifies dual mechanisms of proteotoxicity in the context of condensate formation and establishes FG-nucleoporin-directed activities for a nuclear chaperone network.
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16
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Mannino PJ, Lusk CP. Quality control mechanisms that protect nuclear envelope identity and function. J Biophys Biochem Cytol 2022; 221:213424. [PMID: 36036741 PMCID: PMC9442147 DOI: 10.1083/jcb.202205123] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/22/2022] Open
Abstract
The nuclear envelope (NE) is a specialization of the endoplasmic reticulum with distinct biochemistry that defines inner and outer membranes connected at a pore membrane that houses nuclear pore complexes (NPCs). Quality control mechanisms that maintain the physical integrity and biochemical identity of these membranes are critical to ensure that the NE acts as a selective barrier that also contributes to genome stability and metabolism. As the proteome of the NE is highly integrated, it is challenging to turn over by conventional ubiquitin-proteasome and autophagy mechanisms. Further, removal of entire sections of the NE requires elaborate membrane remodeling that is poorly understood. Nonetheless, recent work has made inroads into discovering specializations of cellular degradative machineries tailored to meeting the unique challenges imposed by the NE. In addition, cells have evolved mechanisms to surveil and repair the NE barrier to protect against the deleterious effects of a breach in NE integrity, in the form of either a ruptured NE or a dysfunctional NPC. Here, we synthesize the most recent work exploring NE quality control mechanisms across eukaryotes.
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17
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Kamikawa Y, Saito A, Imaizumi K. Impact of Nuclear Envelope Stress on Physiological and Pathological Processes in Central Nervous System. Neurochem Res 2022; 47:2478-2487. [PMID: 35486254 DOI: 10.1007/s11064-022-03608-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/07/2022] [Accepted: 04/12/2022] [Indexed: 01/10/2023]
Abstract
The nuclear envelope (NE) separates genomic DNA from the cytoplasm and provides the molecular platforms for nucleocytoplasmic transport, higher-order chromatin organization, and physical links between the nucleus and cytoskeleton. Recent studies have shown that the NE is often damaged by various stresses termed "NE stress", leading to critical cellular dysfunction. Accumulating evidence has revealed the crucial roles of NE stress in the pathology of a broad spectrum of diseases. In the central nervous system (CNS), NE dysfunction impairs neural development and is associated with several neurological disorders, such as Alzheimer's disease and autosomal dominant leukodystrophy. In this review, the structure and functions of the NE are summarized, and the concepts of NE stress and NE stress responses are introduced. Additionally, the significant roles of the NE in the development of CNS and the mechanistic connections between NE stress and neurological disorders are described.
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Affiliation(s)
- Yasunao Kamikawa
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
| | - Atsushi Saito
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
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18
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DYT-TOR1A subcellular proteomics reveals selective vulnerability of the nuclear proteome to cell stress. Neurobiol Dis 2021; 158:105464. [PMID: 34358617 DOI: 10.1016/j.nbd.2021.105464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 07/07/2021] [Accepted: 08/02/2021] [Indexed: 11/23/2022] Open
Abstract
TorsinA is a AAA+ ATPase that shuttles between the ER lumen and outer nuclear envelope in an ATP-dependent manner and is functionally implicated in nucleocytoplasmic transport. We hypothesized that the DYT-TOR1A dystonia disease-causing variant, ΔE TorsinA, may therefore disrupt the normal subcellular distribution of proteins between the nuclear and cytosolic compartments. To test this hypothesis, we performed proteomic analysis on nuclear and cytosolic subcellular fractions from DYT-TOR1A and wildtype mouse embryonic fibroblasts (MEFs). We further examined the compartmental proteomes following exposure to thapsigargin (Tg), an endoplasmic reticulum (ER) stressor, because DYT-TOR1A dystonia models have previously shown abnormalities in cellular stress responses. Across both subcellular compartments, proteomes of DYT-TOR1A cells showed basal state disruptions consistent with an activated stress response, and in response to thapsigargin, a blunted stress response. However, the DYT-TOR1A nuclear proteome under Tg cell stress showed the most pronounced and disproportionate degree of protein disruptions - 3-fold greater than all other conditions. The affected proteins extended beyond those typically associated with stress responses, including enrichments for processes critical for neuronal synaptic function. These findings highlight the advantage of subcellular proteomics to reveal events that localize to discrete subcellular compartments and refine thinking about the mechanisms and significance of cell stress in DYT-TOR1A pathogenesis.
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19
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Jacquemyn J, Foroozandeh J, Vints K, Swerts J, Verstreken P, Gounko NV, Gallego SF, Goodchild R. Torsin and NEP1R1-CTDNEP1 phosphatase affect interphase nuclear pore complex insertion by lipid-dependent and lipid-independent mechanisms. EMBO J 2021; 40:e106914. [PMID: 34313336 PMCID: PMC8408595 DOI: 10.15252/embj.2020106914] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 05/30/2021] [Accepted: 06/28/2021] [Indexed: 12/25/2022] Open
Abstract
The interphase nuclear envelope (NE) is extensively remodeled during nuclear pore complex (NPC) insertion. How this remodeling occurs and why it requires Torsin ATPases, which also regulate lipid metabolism, remains poorly understood. Here, we show that Drosophila Torsin (dTorsin) affects lipid metabolism via the NEP1R1‐CTDNEP1 phosphatase and the Lipin phosphatidic acid (PA) phosphatase. This includes that Torsins remove NEP1R1‐CTDNEP1 from the NE in fly and mouse cells, leading to subsequent Lipin exclusion from the nucleus. NEP1R1‐CTDNEP1 downregulation also restores nuclear pore membrane fusion in post‐mitotic dTorsinKO fat body cells. However, dTorsin‐associated nuclear pore defects do not correlate with lipidomic abnormalities and are not resolved by silencing of Lipin. Further testing confirmed that membrane fusion continues in cells with hyperactivated Lipin. It also led to the surprising finding that excessive PA metabolism inhibits recruitment of the inner ring complex Nup35 subunit, resulting in elongated channel‐like structures in place of mature nuclear pores. We conclude that the NEP1R1‐CTDNEP1 phosphatase affects interphase NPC biogenesis by lipid‐dependent and lipid‐independent mechanisms, explaining some of the pleiotropic effects of Torsins.
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Affiliation(s)
- Julie Jacquemyn
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Joyce Foroozandeh
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Katlijn Vints
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Brain & Disease Research, Electron Microscopy Platform & VIB-Bioimaging Core, Leuven, Belgium
| | - Jef Swerts
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Natalia V Gounko
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Brain & Disease Research, Electron Microscopy Platform & VIB-Bioimaging Core, Leuven, Belgium
| | - Sandra F Gallego
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Rose Goodchild
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
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20
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Panagaki D, Croft JT, Keuenhof K, Larsson Berglund L, Andersson S, Kohler V, Büttner S, Tamás MJ, Nyström T, Neutze R, Höög JL. Nuclear envelope budding is a response to cellular stress. Proc Natl Acad Sci U S A 2021; 118:e2020997118. [PMID: 34290138 PMCID: PMC8325156 DOI: 10.1073/pnas.2020997118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nuclear envelope budding (NEB) is a recently discovered alternative pathway for nucleocytoplasmic communication distinct from the movement of material through the nuclear pore complex. Through quantitative electron microscopy and tomography, we demonstrate how NEB is evolutionarily conserved from early protists to human cells. In the yeast Saccharomyces cerevisiae, NEB events occur with higher frequency during heat shock, upon exposure to arsenite or hydrogen peroxide, and when the proteasome is inhibited. Yeast cells treated with azetidine-2-carboxylic acid, a proline analog that induces protein misfolding, display the most dramatic increase in NEB, suggesting a causal link to protein quality control. This link was further supported by both localization of ubiquitin and Hsp104 to protein aggregates and NEB events, and the evolution of these structures during heat shock. We hypothesize that NEB is part of normal cellular physiology in a vast range of species and that in S. cerevisiae NEB comprises a stress response aiding the transport of protein aggregates across the nuclear envelope.
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Affiliation(s)
- Dimitra Panagaki
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Jacob T Croft
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Katharina Keuenhof
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Lisa Larsson Berglund
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Stefanie Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Verena Kohler
- Department of Molecular Bioscienses, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Bioscienses, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Markus J Tamás
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Thomas Nyström
- Department of Microbiology and Immunology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Richard Neutze
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Johanna L Höög
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden;
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21
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Host and Viral Factors Involved in Nuclear Egress of Herpes Simplex Virus 1. Viruses 2021; 13:v13050754. [PMID: 33923040 PMCID: PMC8146395 DOI: 10.3390/v13050754] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) replicates its genome and packages it into capsids within the nucleus. HSV-1 has evolved a complex mechanism of nuclear egress whereby nascent capsids bud on the inner nuclear membrane to form perinuclear virions that subsequently fuse with the outer nuclear membrane, releasing capsids into the cytosol. The viral-encoded nuclear egress complex (NEC) plays a crucial role in this vesicle-mediated nucleocytoplasmic transport. Nevertheless, similar system mediates the movement of other cellular macromolecular complexes in normal cells. Therefore, HSV-1 may utilize viral proteins to hijack the cellular machinery in order to facilitate capsid transport. However, little is known about the molecular mechanisms underlying this phenomenon. This review summarizes our current understanding of the cellular and viral factors involved in the nuclear egress of HSV-1 capsids.
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22
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Lee CP, Chen MR. Conquering the Nuclear Envelope Barriers by EBV Lytic Replication. Viruses 2021; 13:702. [PMID: 33919628 PMCID: PMC8073350 DOI: 10.3390/v13040702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/14/2021] [Accepted: 04/14/2021] [Indexed: 12/14/2022] Open
Abstract
The nuclear envelope (NE) of eukaryotic cells has a highly structural architecture, comprising double lipid-bilayer membranes, nuclear pore complexes, and an underlying nuclear lamina network. The NE structure is held in place through the membrane-bound LINC (linker of nucleoskeleton and cytoskeleton) complex, spanning the inner and outer nuclear membranes. The NE functions as a barrier between the nucleus and cytoplasm and as a transverse scaffold for various cellular processes. Epstein-Barr virus (EBV) is a human pathogen that infects most of the world's population and is associated with several well-known malignancies. Within the nucleus, the replicated viral DNA is packaged into capsids, which subsequently egress from the nucleus into the cytoplasm for tegumentation and final envelopment. There is increasing evidence that viral lytic gene expression or replication contributes to the pathogenesis of EBV. Various EBV lytic proteins regulate and modulate the nuclear envelope structure in different ways, especially the viral BGLF4 kinase and the nuclear egress complex BFRF1/BFRF2. From the aspects of nuclear membrane structure, viral components, and fundamental nucleocytoplasmic transport controls, this review summarizes our findings and recently updated information on NE structure modification and NE-related cellular processes mediated by EBV.
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Affiliation(s)
- Chung-Pei Lee
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei 112303, Taiwan;
| | - Mei-Ru Chen
- Graduate Institute and Department of Microbiology, College of Medicine, National Taiwan University, Taipei 100233, Taiwan
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23
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Ding B, Sepehrimanesh M. Nucleocytoplasmic Transport: Regulatory Mechanisms and the Implications in Neurodegeneration. Int J Mol Sci 2021; 22:4165. [PMID: 33920577 PMCID: PMC8072611 DOI: 10.3390/ijms22084165] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
Nucleocytoplasmic transport (NCT) across the nuclear envelope is precisely regulated in eukaryotic cells, and it plays critical roles in maintenance of cellular homeostasis. Accumulating evidence has demonstrated that dysregulations of NCT are implicated in aging and age-related neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer's disease (AD), and Huntington disease (HD). This is an emerging research field. The molecular mechanisms underlying impaired NCT and the pathogenesis leading to neurodegeneration are not clear. In this review, we comprehensively described the components of NCT machinery, including nuclear envelope (NE), nuclear pore complex (NPC), importins and exportins, RanGTPase and its regulators, and the regulatory mechanisms of nuclear transport of both protein and transcript cargos. Additionally, we discussed the possible molecular mechanisms of impaired NCT underlying aging and neurodegenerative diseases, such as ALS/FTD, HD, and AD.
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Affiliation(s)
- Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, 410 East Saint Mary Boulevard, Lafayette, LA 70503, USA;
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24
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Ding B, Tang Y, Ma S, Akter M, Liu ML, Zang T, Zhang CL. Disease Modeling with Human Neurons Reveals LMNB1 Dysregulation Underlying DYT1 Dystonia. J Neurosci 2021; 41:2024-2038. [PMID: 33468570 PMCID: PMC7939088 DOI: 10.1523/jneurosci.2507-20.2020] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 02/08/2023] Open
Abstract
DYT1 dystonia is a hereditary neurologic movement disorder characterized by uncontrollable muscle contractions. It is caused by a heterozygous mutation in Torsin A (TOR1A), a gene encoding a membrane-embedded ATPase. While animal models provide insights into disease mechanisms, significant species-dependent differences exist since animals with the identical heterozygous mutation fail to show pathology. Here, we model DYT1 by using human patient-specific cholinergic motor neurons (MNs) that are generated through either direct conversion of patients' skin fibroblasts or differentiation of induced pluripotent stem cells (iPSCs). These human MNs with the heterozygous TOR1A mutation show reduced neurite length and branches, markedly thickened nuclear lamina, disrupted nuclear morphology, and impaired nucleocytoplasmic transport (NCT) of mRNAs and proteins, whereas they lack the perinuclear "blebs" that are often observed in animal models. Furthermore, we uncover that the nuclear lamina protein LMNB1 is upregulated in DYT1 cells and exhibits abnormal subcellular distribution in a cholinergic MNs-specific manner. Such dysregulation of LMNB1 can be recapitulated by either ectopic expression of the mutant TOR1A gene or shRNA-mediated downregulation of endogenous TOR1A in healthy control MNs. Interestingly, downregulation of LMNB1 can largely ameliorate all the cellular defects in DYT1 MNs. These results reveal the value of disease modeling with human patient-specific neurons and indicate that dysregulation of LMNB1, a crucial component of the nuclear lamina, may constitute a major molecular mechanism underlying DYT1 pathology.SIGNIFICANCE STATEMENT Inaccessibility to patient neurons greatly impedes our understanding of the pathologic mechanisms for dystonia. In this study, we employ reprogrammed human patient-specific motor neurons (MNs) to model DYT1, the most severe hereditary form of dystonia. Our results reveal disease-dependent deficits in nuclear morphology and nucleocytoplasmic transport (NCT). Most importantly, we further identify LMNB1 dysregulation as a major contributor to these deficits, uncovering a new pathologic mechanism for DYT1 dystonia.
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Affiliation(s)
- Baojin Ding
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana 70503
| | - Yu Tang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- National Clinical Research Center for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan Province 410008, China
| | - Shuaipeng Ma
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Masuma Akter
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana 70503
| | - Meng-Lu Liu
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Tong Zang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Chun-Li Zhang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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25
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Cascalho A, Foroozandeh J, Hennebel L, Swerts J, Klein C, Rous S, Dominguez Gonzalez B, Pisani A, Meringolo M, Gallego SF, Verstreken P, Seibler P, Goodchild RE. Excess Lipin enzyme activity contributes to TOR1A recessive disease and DYT-TOR1A dystonia. Brain 2021; 143:1746-1765. [PMID: 32516804 DOI: 10.1093/brain/awaa139] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/11/2020] [Accepted: 03/09/2020] [Indexed: 11/14/2022] Open
Abstract
TOR1A/TorsinA mutations cause two incurable diseases: a recessive congenital syndrome that can be lethal, and a dominantly-inherited childhood-onset dystonia (DYT-TOR1A). TorsinA has been linked to phosphatidic acid lipid metabolism in Drosophila melanogaster. Here we evaluate the role of phosphatidic acid phosphatase (PAP) enzymes in TOR1A diseases using induced pluripotent stem cell-derived neurons from patients, and mouse models of recessive Tor1a disease. We find that Lipin PAP enzyme activity is abnormally elevated in human DYT-TOR1A dystonia patient cells and in the brains of four different Tor1a mouse models. Its severity also correlated with the dosage of Tor1a/TOR1A mutation. We assessed the role of excess Lipin activity in the neurological dysfunction of Tor1a disease mouse models by interbreeding these with Lpin1 knock-out mice. Genetic reduction of Lpin1 improved the survival of recessive Tor1a disease-model mice, alongside suppressing neurodegeneration, motor dysfunction, and nuclear membrane pathology. These data establish that TOR1A disease mutations cause abnormal phosphatidic acid metabolism, and suggest that approaches that suppress Lipin PAP enzyme activity could be therapeutically useful for TOR1A diseases.
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Affiliation(s)
- Ana Cascalho
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium
| | - Joyce Foroozandeh
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium
| | - Lise Hennebel
- Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium
| | - Jef Swerts
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium.,Leuven Brain Institute, 3000 Leuven, Belgium
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Stef Rous
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium
| | - Beatriz Dominguez Gonzalez
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium
| | - Antonio Pisani
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia and Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia and Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Sandra F Gallego
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium.,Leuven Brain Institute, 3000 Leuven, Belgium
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Rose E Goodchild
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, 3000 Leuven, Belgium.,Leuven Brain Institute, 3000 Leuven, Belgium
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26
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Luithle N, de Bos JU, Hovius R, Maslennikova D, Lewis RT, Ungricht R, Fierz B, Kutay U. Torsin ATPases influence chromatin interaction of the Torsin regulator LAP1. eLife 2020; 9:63614. [PMID: 33320087 PMCID: PMC7773337 DOI: 10.7554/elife.63614] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/15/2020] [Indexed: 12/28/2022] Open
Abstract
The inner nuclear membrane is functionalized by diverse transmembrane proteins that associate with nuclear lamins and/or chromatin. When cells enter mitosis, membrane-chromatin contacts must be broken to allow for proper chromosome segregation; yet how this occurs remains ill-understood. Unexpectedly, we observed that an imbalance in the levels of the lamina-associated polypeptide 1 (LAP1), an activator of ER-resident Torsin AAA+-ATPases, causes a failure in membrane removal from mitotic chromatin, accompanied by chromosome segregation errors and changes in post-mitotic nuclear morphology. These defects are dependent on a hitherto unknown chromatin-binding region of LAP1 that we have delineated. LAP1-induced NE abnormalities are efficiently suppressed by expression of wild-type but not ATPase-deficient Torsins. Furthermore, a dominant-negative Torsin induces chromosome segregation defects in a LAP1-dependent manner. These results indicate that association of LAP1 with chromatin in the nucleus can be modulated by Torsins in the perinuclear space, shedding new light on the LAP1-Torsin interplay.
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Affiliation(s)
- Naemi Luithle
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Jelmi Uit de Bos
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Ruud Hovius
- Institute of Chemical Sciences and Engineering - ISIC, EPFL, Lausanne, Switzerland
| | - Daria Maslennikova
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Renard Tm Lewis
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Rosemarie Ungricht
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Beat Fierz
- Institute of Chemical Sciences and Engineering - ISIC, EPFL, Lausanne, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
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27
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Markert SM, Skoruppa M, Yu B, Mulcahy B, Zhen M, Gao S, Sendtner M, Stigloher C. Overexpression of an ALS-associated FUS mutation in C. elegans disrupts NMJ morphology and leads to defective neuromuscular transmission. Biol Open 2020; 9:bio055129. [PMID: 33148607 PMCID: PMC7746668 DOI: 10.1242/bio.055129] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/27/2020] [Indexed: 12/26/2022] Open
Abstract
The amyotrophic lateral sclerosis (ALS) neurodegenerative disorder has been associated with multiple genetic lesions, including mutations in the gene for fused in sarcoma (FUS), a nuclear-localized RNA/DNA-binding protein. Neuronal expression of the pathological form of FUS proteins in Caenorhabditis elegans results in mislocalization and aggregation of FUS in the cytoplasm, and leads to impairment of motility. However, the mechanisms by which the mutant FUS disrupts neuronal health and function remain unclear. Here we investigated the impact of ALS-associated FUS on motor neuron health using correlative light and electron microscopy, electron tomography, and electrophysiology. We show that ectopic expression of wild-type or ALS-associated human FUS impairs synaptic vesicle docking at neuromuscular junctions. ALS-associated FUS led to the emergence of a population of large, electron-dense, and filament-filled endosomes. Electrophysiological recording revealed reduced transmission from motor neurons to muscles. Together, these results suggest a pathological effect of ALS-causing FUS at synaptic structure and function organization.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Sebastian M Markert
- University of Würzburg, Biocenter, Imaging Core Facility, Am Hubland, Würzburg 97074, Germany
| | - Michael Skoruppa
- University Hospital Würzburg, Institute of Clinical Neurobiology, Versbacherstraße 5, 97080 Würzburg, Germany
| | - Bin Yu
- Huazhong University of Science and Technology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Wuhan 430074, China
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada
- University of Toronto, Department of Molecular Genetics, Physiology and Institute of Medical Science, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Shangbang Gao
- Huazhong University of Science and Technology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Wuhan 430074, China
| | - Michael Sendtner
- University Hospital Würzburg, Institute of Clinical Neurobiology, Versbacherstraße 5, 97080 Würzburg, Germany
| | - Christian Stigloher
- University of Würzburg, Biocenter, Imaging Core Facility, Am Hubland, Würzburg 97074, Germany
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28
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ESCRT-III controls nuclear envelope deformation induced by progerin. Sci Rep 2020; 10:18877. [PMID: 33139753 PMCID: PMC7606583 DOI: 10.1038/s41598-020-75852-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/21/2020] [Indexed: 01/29/2023] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder, caused by mutation in the gene encoding lamin A/C, which produces a truncated protein called progerin. In cells from HGPS patients, progerin accumulates at the nuclear membrane (NM), where it causes NM deformations. In this study, we investigated whether progerin-induced NM deformation involved ESCRT-III, a protein complex that remodels nuclear and cytoplasmic membranes. The ESCRT-III protein CHMP4B was recruited to sites of aberrant NM proliferation in human cells ectopically expressing progerin and in patient-derived HGPS fibroblasts. Derepression of NM deformation in these cells was observed following depletion of CHMP4B or an ESCRT-III adaptor, ALIX. Treatment with rapamycin (which induce autophagic clearance of progerin and reverse progerin-induced cellular phenotypes) down-regulated progerin-induced NM deformation, whereas treatment with bafilomycin A1 (an inhibitor of autophagy and lysosome-based degradation) or CHMP4B depletion antagonized the effects of rapamycin. These results indicate that the ALIX-mediated ESCRT-III pathway plays a suppressive role in progerin-induced NM deformation and suggest that autophagy down-regulates progerin-induced NM deformation in a manner dependent on ESCRT-III machinery.
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29
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Abstract
During viral replication, herpesviruses utilize a unique strategy, termed nuclear egress, to translocate capsids from the nucleus into the cytoplasm. This initial budding step transfers a newly formed capsid from within the nucleus, too large to fit through nuclear pores, through the inner nuclear membrane to the perinuclear space. The perinuclear enveloped virion must then fuse with the outer nuclear membrane to be released into the cytoplasm for further maturation, undergoing budding once again at the trans-Golgi network or early endosomes, and ultimately exit the cell non-lytically to spread infection. This first budding process is mediated by two conserved viral proteins, UL31 and UL34, that form a heterodimer called the nuclear egress complex (NEC). This review focuses on what we know about how the NEC mediates capsid transport to the perinuclear space, including steps prior to and after this budding event. Additionally, we discuss the involvement of other viral proteins in this process and how NEC-mediated budding may be regulated during infection.
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Affiliation(s)
- Elizabeth B Draganova
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Michael K Thorsen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Ekaterina E Heldwein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
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30
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Verboon JM, Nakamura M, Davidson KA, Decker JR, Nandakumar V, Parkhurst SM. Drosophila Wash and the Wash regulatory complex function in nuclear envelope budding. J Cell Sci 2020; 133:jcs243576. [PMID: 32503943 PMCID: PMC7358131 DOI: 10.1242/jcs.243576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Nuclear envelope (NE) budding is a recently described phenomenon wherein large macromolecular complexes are packaged inside the nucleus and extruded through the nuclear membranes. Although a general outline of the cellular events occurring during NE budding is now in place, little is yet known about the molecular machinery and mechanisms underlying the physical aspects of NE bud formation. Using a multidisciplinary approach, we identify Wash, its regulatory complex (SHRC), capping protein and Arp2/3 as new molecular components involved in the physical aspects of NE bud formation in a Drosophila model system. Interestingly, Wash affects NE budding in two ways: indirectly through general nuclear lamina disruption via an SHRC-independent interaction with Lamin B leading to inefficient NE bud formation, and directly by blocking NE bud formation along with its SHRC, capping protein and Arp2/3. In addition to NE budding emerging as an important cellular process, it shares many similarities with herpesvirus nuclear egress mechanisms, suggesting new avenues for exploration in both normal and disease biology.
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Affiliation(s)
- Jeffrey M Verboon
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Kerri A Davidson
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jacob R Decker
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Vivek Nandakumar
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Susan M Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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31
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Bahmanyar S, Schlieker C. Lipid and protein dynamics that shape nuclear envelope identity. Mol Biol Cell 2020; 31:1315-1323. [PMID: 32530796 PMCID: PMC7353140 DOI: 10.1091/mbc.e18-10-0636] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/13/2020] [Accepted: 04/17/2020] [Indexed: 12/17/2022] Open
Abstract
The nuclear envelope (NE) is continuous with the endoplasmic reticulum (ER), yet the NE carries out many functions distinct from those of bulk ER. This functional specialization depends on a unique protein composition that defines NE identity and must be both established and actively maintained. The NE undergoes extensive remodeling in interphase and mitosis, so mechanisms that seal NE holes and protect its unique composition are critical for maintaining its functions. New evidence shows that closure of NE holes relies on regulated de novo lipid synthesis, providing a link between lipid metabolism and generating and maintaining NE identity. Here, we review regulation of the lipid bilayers of the NE and suggest ways to generate lipid asymmetry across the NE despite its direct continuity with the ER. We also discuss the elusive mechanism of membrane fusion during nuclear pore complex (NPC) biogenesis. We propose a model in which NPC biogenesis is carefully controlled to ensure that a permeability barrier has been established before membrane fusion, thereby avoiding a major threat to compartmentalization.
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Affiliation(s)
- Shirin Bahmanyar
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520
| | - Christian Schlieker
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
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32
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Rampello AJ, Laudermilch E, Vishnoi N, Prophet SM, Shao L, Zhao C, Lusk CP, Schlieker C. Torsin ATPase deficiency leads to defects in nuclear pore biogenesis and sequestration of MLF2. J Cell Biol 2020; 219:151708. [PMID: 32342107 PMCID: PMC7265317 DOI: 10.1083/jcb.201910185] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/11/2020] [Accepted: 03/25/2020] [Indexed: 12/13/2022] Open
Abstract
Nuclear envelope herniations (blebs) containing FG-nucleoporins and ubiquitin are the phenotypic hallmark of Torsin ATPase manipulation. Both the dynamics of blebbing and the connection to nuclear pore biogenesis remain poorly understood. We employ a proteomics-based approach to identify myeloid leukemia factor 2 (MLF2) as a luminal component of the bleb. Using an MLF2-based live-cell imaging platform, we demonstrate that nuclear envelope blebbing occurs rapidly and synchronously immediately after nuclear envelope reformation during mitosis. Bleb formation is independent of ubiquitin conjugation within the bleb, but strictly dependent on POM121, a transmembrane nucleoporin essential for interphase nuclear pore biogenesis. Nup358, a late marker for interphase nuclear pore complex (NPC) biogenesis, is underrepresented relative to FG-nucleoporins in nuclear envelopes of Torsin-deficient cells. The kinetics of bleb formation, its dependence on POM121, and a reduction of mature NPCs in Torsin-deficient cells lead us to conclude that the hallmark phenotype of Torsin manipulation represents aberrant NPC intermediates.
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Affiliation(s)
- Anthony J Rampello
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - Ethan Laudermilch
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - Nidhi Vishnoi
- Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Sarah M Prophet
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - Lin Shao
- Department of Neuroscience, Yale School of Medicine, New Haven, CT
| | - Chenguang Zhao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - C Patrick Lusk
- Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Christian Schlieker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT.,Department of Cell Biology, Yale School of Medicine, New Haven, CT
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33
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Mutant Allele-Specific CRISPR Disruption in DYT1 Dystonia Fibroblasts Restores Cell Function. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 21:1-12. [PMID: 32502938 PMCID: PMC7270506 DOI: 10.1016/j.omtn.2020.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/15/2020] [Accepted: 05/12/2020] [Indexed: 12/16/2022]
Abstract
Most individuals affected with DYT1 dystonia have a heterozygous 3-bp deletion in the TOR1A gene (c.907_909delGAG). The mutation appears to act through a dominant-negative mechanism compromising normal torsinA function, and it is proposed that reducing mutant torsinA may normalize torsinA activity. In this study, we used an engineered Cas9 variant from Streptococcus pyogenes (SpCas9-VRQR) to target the mutation in the TOR1A gene in order to disrupt mutant torsinA in DYT1 patient fibroblasts. Selective targeting of the DYT1 allele was highly efficient with most common non-homologous end joining (NHEJ) edits, leading to a predicted premature stop codon with loss of the torsinA C terminus (delta 302–332 aa). Structural analysis predicted a functionally inactive status of this truncated torsinA due to the loss of residues associated with ATPase activity and binding to LULL1. Immunoblotting showed a reduction of the torsinA protein level in Cas9-edited DYT1 fibroblasts, and a functional assay using HSV infection indicated a phenotypic recovery toward that observed in control fibroblasts. These findings suggest that the selective disruption of the mutant TOR1A allele using CRISPR-Cas9 inactivates mutant torsinA, allowing the remaining wild-type torsinA to exert normal function.
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34
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Xu L, Yang Z, Li W, Luo Z, Zhang C, Huang X, Ma S, Long Y, Chu Y, Qian Y, Wang X, Sun H. Cellular analysis of a novel mutation p. Ser287Tyr in TOR1A in late-onset isolated dystonia. Neurobiol Dis 2020; 140:104851. [PMID: 32243914 DOI: 10.1016/j.nbd.2020.104851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/06/2020] [Accepted: 03/29/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Variations in TOR1A were thought to be associated with early-onset isolated dystonia. The variant S287Y (NM_000113.2: c.860C > A, p. Ser287Tyr, rs766483672) was found in our late-onset isolated dystonia patient. This missense variant is adjacent to R288Q (c.863G > A, p. Arg288Gln), which was reported to be associated with isolated dystonia. The potentially pathogenic role of S287Y is not conclusively known. METHODS Cytological and molecular biological analyses were performed in vitro to determine whether this variant damages the structure and function of the cell. RESULTS Compared with the SH-SY5Y cells overexpressing wild-type TOR1A, the cells overexpressing the protein with S287Y have an enlarged peri-nuclear space. The same changes in nuclear morphology were also found in the cells overexpressing the pathogenic variants ΔE (NM_000113.2:c.904_906delGAG, p. Glu302del), F205I (NM_000113.2:c.613 T > A, p. Phe205Ile), and R288Q (NM_000113.2:c.863G > A, p. Arg288Gln). Mutated proteins with S287Y presented a higher tendency to form dimers under reducing conditions. The same tendencies were observed in other mutated proteins but not in wild-type torsinA. CONCLUSIONS TorsinA with S287Y damages the structure of the cell nucleus and may be a novel pathogenic mutation that causes isolated dystonia.
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Affiliation(s)
- Longjiang Xu
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Zhaoqing Yang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Wenwu Li
- The Department of Neurology, The People's Hospital of ChuXiong Yi Autonomous Prefecture, Chuxiong, China
| | - Zhiling Luo
- The Department of Ultrasound, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Changjun Zhang
- Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Shiyan, China
| | - Xiaoqin Huang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Shaohui Ma
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Yuzhou Long
- The Second People's Hospital of Yunnan Province, Kunming, China
| | - Yan Chu
- The Second People's Hospital of Yunnan Province, Kunming, China
| | - Yuan Qian
- Yunnan Key Laboratory of Laboratory Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiuyun Wang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Hao Sun
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China.
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35
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Ding B, Akter M, Zhang CL. Differential Influence of Sample Sex and Neuronal Maturation on mRNA and Protein Transport in Induced Human Neurons. Front Mol Neurosci 2020; 13:46. [PMID: 32317929 PMCID: PMC7146707 DOI: 10.3389/fnmol.2020.00046] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/06/2020] [Indexed: 12/11/2022] Open
Abstract
Nucleocytoplasmic transport (NCT) across thenuclear envelope (NE) is tightly regulated in eukaryotic cells and iscritical for maintaining cellular homeostasis. Its dysregulationleads to aging and neurodegeneration. Because they maintainaging-associated hallmarks, directly reprogrammed neurons from human fibroblasts are invaluable in understanding NCT. However, it is not clear whether NCT activity is influenced by neuronal maturation and sample sex [a key biological variable emphasized by the National Institutes of Health (NIH) policy]. We examined here NCT activity at the single-cell level by measuring mRNA subcellular distribution and protein transport in directly induced motor neurons (diMNs) from adult human fibroblasts. The results show that mRNA subcellular distribution but not protein transport is affected by neuronal maturation stages, whereas both transport processes are not influenced by the sample sex. This study also provides quantitative methods and optimized conditions for measuring NCTs of mRNAs or protein cargoes, establishing a robust way for future functional examinations of NCT activity in directly induced neurons from diseased human patients.
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Affiliation(s)
- Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, United States
| | - Masuma Akter
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, United States
| | - Chun-Li Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
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36
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The Role of Torsin AAA+ Proteins in Preserving Nuclear Envelope Integrity and Safeguarding Against Disease. Biomolecules 2020; 10:biom10030468. [PMID: 32204310 PMCID: PMC7175109 DOI: 10.3390/biom10030468] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 12/17/2022] Open
Abstract
Torsin ATPases are members of the AAA+ (ATPases associated with various cellular activities) superfamily of proteins, which participate in essential cellular processes. While AAA+ proteins are ubiquitously expressed and demonstrate distinct subcellular localizations, Torsins are the only AAA+ to reside within the nuclear envelope (NE) and endoplasmic reticulum (ER) network. Moreover, due to the absence of integral catalytic features, Torsins require the NE- and ER-specific regulatory cofactors, lamina-associated polypeptide 1 (LAP1) and luminal domain like LAP1 (LULL1), to efficiently trigger their atypical mode of ATP hydrolysis. Despite their implication in an ever-growing list of diverse processes, the specific contributions of Torsin/cofactor assemblies in maintaining normal cellular physiology remain largely enigmatic. Resolving gaps in the functional and mechanistic principles of Torsins and their cofactors are of considerable medical importance, as aberrant Torsin behavior is the principal cause of the movement disorder DYT1 early-onset dystonia. In this review, we examine recent findings regarding the phenotypic consequences of compromised Torsin and cofactor activities. In particular, we focus on the molecular features underlying NE defects and the contributions of Torsins to nuclear pore complex biogenesis, as well as the growing implications of Torsins in cellular lipid metabolism. Additionally, we discuss how understanding Torsins may facilitate the study of essential but poorly understood processes at the NE and ER, and aid in the development of therapeutic strategies for dystonia.
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37
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Hölper JE, Klupp BG, Luxton GWG, Franzke K, Mettenleiter TC. Function of Torsin AAA+ ATPases in Pseudorabies Virus Nuclear Egress. Cells 2020; 9:cells9030738. [PMID: 32192107 PMCID: PMC7140721 DOI: 10.3390/cells9030738] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/14/2020] [Accepted: 03/15/2020] [Indexed: 02/07/2023] Open
Abstract
Newly assembled herpesvirus nucleocapsids traverse the intact nuclear envelope by a vesicle-mediated nucleo-cytoplasmic transport for final virion maturation in the cytoplasm. For this, they bud at the inner nuclear membrane resulting in primary enveloped particles in the perinuclear space (PNS) followed by fusion of the primary envelope with the outer nuclear membrane (ONM). While the conserved viral nuclear egress complex orchestrates the first steps, effectors of fusion of the primary virion envelope with the ONM are still mostly enigmatic but might include cellular proteins like SUN2 or ESCRT-III components. Here, we analyzed the influence of the only known AAA+ ATPases located in the endoplasmic reticulum and the PNS, the Torsins (Tor), on nuclear egress of the alphaherpesvirus pseudorabies virus. For this overexpression of wild type and mutant proteins as well as CRISPR/Cas9 genome editing was applied. Neither single overexpression nor gene knockout (KO) of TorA or TorB had a significant impact. However, TorA/B double KO cells showed decreased viral titers at early time points of infection and an accumulation of primary virions in the PNS pointing to a delay in capsid release during nuclear egress.
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Affiliation(s)
- Julia E. Hölper
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany; (J.E.H.); (B.G.K.)
| | - Barbara G. Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany; (J.E.H.); (B.G.K.)
| | - G. W. Gant Luxton
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Kati Franzke
- Institute of Infectology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany;
| | - Thomas C. Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany; (J.E.H.); (B.G.K.)
- Correspondence: ; Tel.: +49-38351-71250; Fax: +49-38351-71151
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Unraveling Molecular Mechanisms of THAP1 Missense Mutations in DYT6 Dystonia. J Mol Neurosci 2020; 70:999-1008. [PMID: 32112337 PMCID: PMC7334247 DOI: 10.1007/s12031-020-01490-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Mutations in THAP1 (THAP domain-containing apoptosis-associated protein 1) are responsible for DYT6 dystonia. Until now, more than eighty different mutations in THAP1 gene have been found in patients with primary dystonia, and two third of them are missense mutations. The potential pathogeneses of these missense mutations in human are largely elusive. In the present study, we generated stable transfected human neuronal cell lines expressing wild-type or mutated THAP1 proteins found in DYT6 patients. Transcriptional profiling using microarrays revealed a set of 28 common genes dysregulated in two mutated THAP1 (S21T and F81L) overexpression cell lines suggesting a common mechanism of these mutations. ChIP-seq showed that THAP1 can bind to the promoter of one of these genes, superoxide dismutase 2 (SOD2). Overexpression of THAP1 in SK-N-AS cells resulted in increased SOD2 protein expression, whereas fibroblasts from THAP1 patients have less SOD2 expression, which indicates that SOD2 is a direct target gene of THAP1. In addition, we show that some THAP1 mutations (C54Y and F81L) decrease the protein stability which might also be responsible for altered transcription regulation due to dosage insufficiency. Taking together, the current study showed different potential pathogenic mechanisms of THAP1 mutations which lead to the same consequence of DYT6 dystonia.
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Abstract
Cellular membranes can form two principally different involutions, which either exclude or contain cytosol. The 'classical' budding reactions, such as those occurring during endocytosis or formation of exocytic vesicles, involve proteins that assemble on the cytosol-excluding face of the bud neck. Inverse membrane involution occurs in a wide range of cellular processes, supporting cytokinesis, endosome maturation, autophagy, membrane repair and many other processes. Such inverse membrane remodelling is mediated by a heteromultimeric protein machinery known as endosomal sorting complex required for transport (ESCRT). ESCRT proteins assemble on the cytosolic (or nucleoplasmic) face of the neck of the forming involution and cooperate with the ATPase VPS4 to drive membrane scission or sealing. Here, we review similarities and differences of various ESCRT-dependent processes, with special emphasis on mechanisms of ESCRT recruitment.
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40
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The AAA + ATPase TorsinA polymerizes into hollow helical tubes with 8.5 subunits per turn. Nat Commun 2019; 10:3262. [PMID: 31332180 PMCID: PMC6646356 DOI: 10.1038/s41467-019-11194-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/24/2019] [Indexed: 01/25/2023] Open
Abstract
TorsinA is an ER-resident AAA + ATPase, whose deletion of glutamate E303 results in the genetic neuromuscular disease primary dystonia. TorsinA is an unusual AAA + ATPase that needs an external activator. Also, it likely does not thread a peptide substrate through a narrow central channel, in contrast to its closest structural homologs. Here, we examined the oligomerization of TorsinA to get closer to a molecular understanding of its still enigmatic function. We observe TorsinA to form helical filaments, which we analyzed by cryo-electron microscopy using helical reconstruction. The 4.4 Å structure reveals long hollow tubes with a helical periodicity of 8.5 subunits per turn, and an inner channel of ~ 4 nm diameter. We further show that the protein is able to induce tubulation of membranes in vitro, an observation that may reflect an entirely new characteristic of AAA + ATPases. We discuss the implications of these observations for TorsinA function.
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41
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Gonzalez-Alegre P. Advances in molecular and cell biology of dystonia: Focus on torsinA. Neurobiol Dis 2019; 127:233-241. [DOI: 10.1016/j.nbd.2019.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/20/2019] [Accepted: 03/09/2019] [Indexed: 12/15/2022] Open
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Thaller DJ, Allegretti M, Borah S, Ronchi P, Beck M, Lusk CP. An ESCRT-LEM protein surveillance system is poised to directly monitor the nuclear envelope and nuclear transport system. eLife 2019; 8:e45284. [PMID: 30942170 PMCID: PMC6461442 DOI: 10.7554/elife.45284] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/02/2019] [Indexed: 12/22/2022] Open
Abstract
The integrity of the nuclear membranes coupled to the selective barrier of nuclear pore complexes (NPCs) are essential for the segregation of nucleoplasm and cytoplasm. Mechanical membrane disruption or perturbation to NPC assembly triggers an ESCRT-dependent surveillance system that seals nuclear pores: how these pores are sensed and sealed is ill defined. Using a budding yeast model, we show that the ESCRT Chm7 and the integral inner nuclear membrane (INM) protein Heh1 are spatially segregated by nuclear transport, with Chm7 being actively exported by Xpo1/Crm1. Thus, the exposure of the INM triggers surveillance with Heh1 locally activating Chm7. Sites of Chm7 hyperactivation show fenestrated sheets at the INM and potential membrane delivery at sites of nuclear envelope herniation. Our data suggest that perturbation to the nuclear envelope barrier would lead to local nuclear membrane remodeling to promote membrane sealing. Our findings have implications for disease mechanisms linked to NPC assembly and nuclear envelope integrity.
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Affiliation(s)
- David J Thaller
- Department of Cell BiologyYale School of MedicineNew HavenUnited States
| | - Matteo Allegretti
- Structural and Computational Biology UnitEuropean Molecular Biology LaboratoryMeyerhofstrasseGermany
| | - Sapan Borah
- Department of Cell BiologyYale School of MedicineNew HavenUnited States
| | - Paolo Ronchi
- Electron Microscopy Core FacilityEuropean Molecular Biology LaboratoryMeyerhofstrasseGermany
| | - Martin Beck
- Structural and Computational Biology UnitEuropean Molecular Biology LaboratoryMeyerhofstrasseGermany
| | - C Patrick Lusk
- Department of Cell BiologyYale School of MedicineNew HavenUnited States
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43
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Chalfant M, Barber KW, Borah S, Thaller D, Lusk CP. Expression of TorsinA in a heterologous yeast system reveals interactions with lumenal domains of LINC and nuclear pore complex components. Mol Biol Cell 2019; 30:530-541. [PMID: 30625036 PMCID: PMC6589686 DOI: 10.1091/mbc.e18-09-0585] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
DYT1 dystonia is caused by an in-frame deletion of a glutamic acid codon in the gene encoding the AAA+ ATPase TorsinA (TorA). TorA localizes within the lumen of the nuclear envelope/endoplasmic reticulum and binds to a membrane-spanning cofactor, lamina associated polypeptide 1 (LAP1) or lumenal domain like LAP1 (LULL1), to form an ATPase; the substrate(s) of TorA remains ill-defined. Here we use budding yeast, which lack Torsins, to interrogate TorA function. We show that TorA accumulates at nuclear envelope-embedded spindle pole bodies (SPBs) in a way that requires its oligomerization and the SUN (Sad1 and UNc-84)-domain protein, Mps3. We further show that TorA physically interacts with human SUN1/2 within this system, supporting the physiological relevance of these interactions. Consistent with the idea that TorA acts on a SPB substrate, its binding to SPBs is modulated by the ATPase-stimulating activity of LAP1. TorA and TorA-ΔE reduce the fitness of cells expressing mps3 alleles, whereas TorA alone inhibits growth of cells lacking Pom152, a component of the nuclear pore complex. This genetic specificity is mirrored biochemically as TorA, but not TorA-ΔE, binds Pom152. Thus, TorA–nucleoporin interactions might be abrogated by TorA-ΔE, suggesting new experimental avenues to interrogate the molecular basis behind nuclear envelope herniations seen in mammalian cells lacking TorA function.
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Affiliation(s)
| | - Karl W. Barber
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT 06520
- Systems Biology Institute, Yale University, West Haven, CT 06477
| | - Sapan Borah
- Department of Cell Biology, Yale University, New Haven, CT 06520
| | - David Thaller
- Department of Cell Biology, Yale University, New Haven, CT 06520
| | - C. Patrick Lusk
- Department of Cell Biology, Yale University, New Haven, CT 06520
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44
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Serrano JB, Martins F, Pereira CD, van Pelt AMM, da Cruz E Silva OAB, Rebelo S. TorsinA Is Functionally Associated with Spermatogenesis. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:221-228. [PMID: 30246678 DOI: 10.1017/s1431927618015179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
TorsinA is a member of the AAA+ superfamily of adenosine triphosphatases. These AAA+ proteins have numerous biological functions, including vesicle fusion, cytoskeleton dynamics, intracellular trafficking, protein folding, and degradation as well as organelle biogenesis. Of particular interest is torsinA, which is mainly located in the endoplasmic reticulum (ER) and nuclear envelope (NE). Interestingly, mutations in the TOR1A gene (the gene encoding torsinA) are associated with DYT1 dystonia and with the preferential localization of mutated torsinA at the NE, where it is associated with lamina-associated polypeptide 1. A bioinformatics study of the torsinA interactome revealed reproductive processes to be highly relevant, as proteins in this class were found to interact with the former. Interestingly, the torsin protein family had never been previously described to be associated with the mammalian spermatogenic process. Histological staining of torsinA in human testis tissue revealed a granular cytoplasmic localization in mid- and late spermatocytes. We further sought to understand this newly discovered expression of torsinA in the meiotic phase of human spermatogenesis by studying its specific subcellular distribution. TorsinA is not present in the ER as commonly described. The proposal that torsinA might relocate to the pro-acrosomal vesicles in the Golgi apparatus is discussed.
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Affiliation(s)
- Joana B Serrano
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Filipa Martins
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Cátia D Pereira
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Ans M M van Pelt
- 2Center for Reproductive Medicine, Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Odete A B da Cruz E Silva
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Sandra Rebelo
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
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45
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Pappas SS, Liang CC, Kim S, Rivera CO, Dauer WT. TorsinA dysfunction causes persistent neuronal nuclear pore defects. Hum Mol Genet 2019; 27:407-420. [PMID: 29186574 DOI: 10.1093/hmg/ddx405] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/15/2017] [Indexed: 01/09/2023] Open
Abstract
A critical challenge to deciphering the pathophysiology of neurodevelopmental disease is identifying which of the myriad abnormalities that emerge during CNS maturation persist to contribute to long-term brain dysfunction. Childhood-onset dystonia caused by a loss-of-function mutation in the AAA+ protein torsinA exemplifies this challenge. Neurons lacking torsinA develop transient nuclear envelope (NE) malformations during CNS maturation, but no NE defects are described in mature torsinA null neurons. We find that during postnatal CNS maturation torsinA null neurons develop mislocalized and dysfunctional nuclear pore complexes (NPC) that lack NUP358, normally added late in NPC biogenesis. SUN1, a torsinA-related molecule implicated in interphase NPC biogenesis, also exhibits localization abnormalities. Whereas SUN1 and associated nuclear membrane abnormalities resolve in juvenile mice, NPC defects persist into adulthood. These findings support a role for torsinA function in NPC biogenesis during neuronal maturation and implicate altered NPC function in dystonia pathophysiology.
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Affiliation(s)
| | | | - Sumin Kim
- Cellular and Molecular Biology Program
| | | | - William T Dauer
- Department of Neurology.,Cellular and Molecular Biology Program.,Department of Cell and Developmental Biology.,VA Ann Arbor Health System, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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46
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Arii J, Watanabe M, Maeda F, Tokai-Nishizumi N, Chihara T, Miura M, Maruzuru Y, Koyanagi N, Kato A, Kawaguchi Y. ESCRT-III mediates budding across the inner nuclear membrane and regulates its integrity. Nat Commun 2018; 9:3379. [PMID: 30139939 PMCID: PMC6107581 DOI: 10.1038/s41467-018-05889-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/28/2018] [Indexed: 11/30/2022] Open
Abstract
Vesicle-mediated nucleocytoplasmic transport is a nuclear pore-independent mechanism for the nuclear export of macromolecular complexes, but the molecular basis for this transport remains largely unknown. Here we show that endosomal sorting complex required for transport-III (ESCRT-III) is recruited to the inner nuclear membrane (INM) during the nuclear export of herpes simplex virus 1 (HSV-1). Scission during HSV-1 budding through the INM is prevented by depletion of ESCRT-III proteins. Interestingly, in uninfected human cells, the depletion of ESCRT-III proteins induces aberrant INM proliferation. Our results show that HSV-1 expropriates the ESCRT-III machinery in infected cells for scission of the INM to produce vesicles containing progeny virus nucleocapsids. In uninfected cells, ESCRT-III regulates INM integrity by downregulating excess INM. The endosomal sorting complex required for transport-III (ESCRT-III) has been implicated in the packaging of HIV and HSV-1 viruses in the cytoplasm. Here the authors show that ESCRT-III proteins are required for the transport of HSV-1 nucleocapsids from nucleoplasm to cytosol through the nuclear envelope and confirm that the same mechanism is also used for the nucleocytoplasmic transport of RNP in Drosophila cells.
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Affiliation(s)
- Jun Arii
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Mizuki Watanabe
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Fumio Maeda
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Noriko Tokai-Nishizumi
- Microscope Core Laboratory, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Takahiro Chihara
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.,Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8526, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yuhei Maruzuru
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Naoto Koyanagi
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Akihisa Kato
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Yasushi Kawaguchi
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan. .,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.
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47
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Fantastic nuclear envelope herniations and where to find them. Biochem Soc Trans 2018; 46:877-889. [PMID: 30026368 DOI: 10.1042/bst20170442] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 12/19/2022]
Abstract
Morphological abnormalities of the bounding membranes of the nucleus have long been associated with human diseases from cancer to premature aging to neurodegeneration. Studies over the past few decades support that there are both cell intrinsic and extrinsic factors (e.g. mechanical force) that can lead to nuclear envelope 'herniations', a broad catch-all term that reveals little about the underlying molecular mechanisms that contribute to these morphological defects. While there are many genetic perturbations that could ultimately change nuclear shape, here, we focus on a subset of nuclear envelope herniations that likely arise as a consequence of disrupting physiological nuclear membrane remodeling pathways required to maintain nuclear envelope homeostasis. For example, stalling of the interphase nuclear pore complex (NPC) biogenesis pathway and/or triggering of NPC quality control mechanisms can lead to herniations in budding yeast, which are remarkably similar to those observed in human disease models of early-onset dystonia. By also examining the provenance of nuclear envelope herniations associated with emerging nuclear autophagy and nuclear egress pathways, we will provide a framework to help understand the molecular pathways that contribute to nuclear deformation.
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Jurek M, Obersztyn E, Milewski M. The mutation responsible for torsion dystonia type 1 shows the ability to stimulate intracellular aggregation of mutant huntingtin. DEVELOPMENTAL PERIOD MEDICINE 2018; 22. [PMID: 29641419 PMCID: PMC8522924 DOI: 10.34763/devperiodmed.20182201.3338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Introduction: Torsion dystonia type 1 is the most common form of early-onset primary dystonia. Previous reports have suggested that torsin 1A, a protein mutated in this disease, might function as a chaperone that prevents the toxic aggregation of misfolded polypeptides. The aim of the study: The aim of this study was to verify the chaperone function of torsin 1A by investigating its ability to prevent the aggregation of huntingtin model peptides. PATIENTS AND METHODS Materials and methods: N-terminal mutant huntingtin fragments of different length were co-expressed in neuronal HT-22 and non-neuronal HeLa cells with either the wild-type or mutant (ΔE302/303) torsin 1A protein. The transfected cells were immunostained and analyzed for the presence of huntingtin aggregates using fluorescence microscopy. RESULTS Results: The immunofluorescence analysis of huntingtin subcellular distribution within the transfected cells showed no significant difference between the huntingtin aggregation levels in cells co-expressing the wild-type torsin 1A and in control cells co-transfected with an empty vector. Instead, it was the increased level of huntingtin aggregation in the presence of the torsion dystonia-causing ΔE302/303 mutant that reached statistical significance in both neuronal and non-neuronal cells. CONCLUSION Conclusions: Either torsin 1A does not function as a chaperone protein or huntingtin is not an efficient substrate for such a hypothetical chaperone activity. However, the ability of mutant torsin 1A to stimulate the accumulation of aggregation-prone polypeptides might constitute an important source of ΔE302/303 pathogenicity and thus a potential target for future therapy.
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Affiliation(s)
- Marta Jurek
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Ewa Obersztyn
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Michał Milewski
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland,Michał Milewski Cell Biology Laboratory, Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland phone: (+48 22) 32-77-299 fax: (+48 22) 32-77-200
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49
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Liu GT, Kung HN, Chen CK, Huang C, Wang YL, Yu CP, Lee CP. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy. FASEB J 2018; 32:3968-3983. [PMID: 29481305 DOI: 10.1096/fj.201701253r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although a vesicular nucleocytoplasmic transport system is believed to exist in eukaryotic cells, the features of this pathway are mostly unknown. Here, we report that the BFRF1 protein of the Epstein-Barr virus improves vesicular transport of nuclear envelope (NE) to facilitate the translocation and clearance of nuclear components. BFRF1 expression induces vesicles that selectively transport nuclear components to the cytoplasm. With the use of aggregation-prone proteins as tools, we found that aggregated nuclear proteins are dispersed when these BFRF1-induced vesicles are formed. BFRF1-containing vesicles engulf the NE-associated aggregates, exit through from the NE, and putatively fuse with autophagic vacuoles. Chemical treatment and genetic ablation of autophagy-related factors indicate that autophagosome formation and autophagy-linked FYVE protein-mediated autophagic proteolysis are involved in this selective clearance of nuclear proteins. Remarkably, vesicular transport, elicited by BFRF1, also attenuated nuclear aggregates accumulated in neuroblastoma cells. Accordingly, induction of NE-derived vesicles by BFRF1 facilitates nuclear protein translocation and clearance, suggesting that autophagy-coupled transport of nucleus-derived vesicles can be elicited for nuclear component catabolism in mammalian cells.-Liu, G.-T., Kung, H.-N., Chen, C.-K., Huang, C., Wang, Y.-L., Yu, C.-P., Lee, C.-P. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.
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Affiliation(s)
- Guan-Ting Liu
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Hsiu-Ni Kung
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan; and
| | - Chung-Kuan Chen
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Cheng Huang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yung-Li Wang
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Cheng-Pu Yu
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Chung-Pei Lee
- School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
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Mutant torsinA in the heterozygous DYT1 state compromises HSV propagation in infected neurons and fibroblasts. Sci Rep 2018; 8:2324. [PMID: 29396398 PMCID: PMC5797141 DOI: 10.1038/s41598-018-19865-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/09/2018] [Indexed: 12/18/2022] Open
Abstract
Most cases of early onset torsion dystonia (DYT1) are caused by a 3-base pair deletion in one allele of the TOR1A gene causing loss of a glutamate in torsinA, a luminal protein in the nuclear envelope. This dominantly inherited neurologic disease has reduced penetrance and no other medical manifestations. It has been challenging to understand the neuronal abnormalities as cells and mouse models which are heterozygous (Het) for the mutant allele are quite similar to wild-type (WT) controls. Here we found that patient fibroblasts and mouse neurons Het for this mutation showed significant differences from WT cells in several parameters revealed by infection with herpes simplex virus type 1 (HSV) which replicates in the nucleus and egresses out through the nuclear envelope. Using a red fluorescent protein capsid to monitor HSV infection, patient fibroblasts showed decreased viral plaque formation as compared to controls. Mouse Het neurons had a decrease in cytoplasmic, but not nuclear HSV fluorescence, and reduced numbers of capsids entering axons as compared to infected WT neurons. These findings point to altered dynamics of the nuclear envelope in cells with the patient genotype, which can provide assays to screen for therapeutic agents that can normalize these cells.
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