1
|
Gariballa N, Mohamed F, Badawi S, Ali BR. The double whammy of ER-retention and dominant-negative effects in numerous autosomal dominant diseases: significance in disease mechanisms and therapy. J Biomed Sci 2024; 31:64. [PMID: 38937821 PMCID: PMC11210014 DOI: 10.1186/s12929-024-01054-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 06/20/2024] [Indexed: 06/29/2024] Open
Abstract
The endoplasmic reticulum (ER) employs stringent quality control mechanisms to ensure the integrity of protein folding, allowing only properly folded, processed and assembled proteins to exit the ER and reach their functional destinations. Mutant proteins unable to attain their correct tertiary conformation or form complexes with their partners are retained in the ER and subsequently degraded through ER-associated protein degradation (ERAD) and associated mechanisms. ER retention contributes to a spectrum of monogenic diseases with diverse modes of inheritance and molecular mechanisms. In autosomal dominant diseases, when mutant proteins get retained in the ER, they can interact with their wild-type counterparts. This interaction may lead to the formation of mixed dimers or aberrant complexes, disrupting their normal trafficking and function in a dominant-negative manner. The combination of ER retention and dominant-negative effects has been frequently documented to cause a significant loss of functional proteins, thereby exacerbating disease severity. This review aims to examine existing literature and provide insights into the impact of dominant-negative effects exerted by mutant proteins retained in the ER in a range of autosomal dominant diseases including skeletal and connective tissue disorders, vascular disorders, neurological disorders, eye disorders and serpinopathies. Most crucially, we aim to emphasize the importance of this area of research, offering substantial potential for understanding the factors influencing phenotypic variability associated with genetic variants. Furthermore, we highlight current and prospective therapeutic approaches targeted at ameliorating the effects of mutations exhibiting dominant-negative effects. These approaches encompass experimental studies exploring treatments and their translation into clinical practice.
Collapse
Affiliation(s)
- Nesrin Gariballa
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Feda Mohamed
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
- ASPIRE Precision Medicine Research Institute Abu Dhabi, United Arab Emirates University, Abu Dhabi, United Arab Emirates
| | - Sally Badawi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Bassam R Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates.
- ASPIRE Precision Medicine Research Institute Abu Dhabi, United Arab Emirates University, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
2
|
Knorr S, Rauschenberger L, Muthuraman M, McFleder R, Ott T, Grundmann-Hauser K, Higuchi T, Volkmann J, Ip CW. Disturbed brain energy metabolism in a rodent model of DYT-TOR1A dystonia. Neurobiol Dis 2024; 194:106462. [PMID: 38442845 DOI: 10.1016/j.nbd.2024.106462] [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: 01/17/2024] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024] Open
Abstract
DYT-TOR1A (DYT1) dystonia, characterized by reduced penetrance and suspected environmental triggers, is explored using a "second hit" DYT-TOR1A rat model. We aim to investigate the biological mechanisms driving the conversion into a dystonic phenotype, focusing on the striatum's role in dystonia pathophysiology. Sciatic nerve crush injury was induced in ∆ETorA rats, lacking spontaneous motor abnormalities, and wild-type (wt) rats. Twelve weeks post-injury, unbiased RNA-sequencing was performed on the striatum to identify differentially expressed genes (DEGs) and pathways. Fenofibrate, a PPARα agonist, was introduced to assess its effects on gene expression. 18F-FDG autoradiography explored metabolic alterations in brain networks. Low transcriptomic variability existed between naïve wt and ∆ETorA rats (17 DEGs). Sciatic nerve injury significantly impacted ∆ETorA rats (1009 DEGs) compared to wt rats (216 DEGs). Pathway analyses revealed disruptions in energy metabolism, specifically in fatty acid β-oxidation and glucose metabolism. Fenofibrate induced gene expression changes in wt rats but failed in ∆ETorA rats. Fenofibrate increased dystonia-like movements in wt rats but reduced them in ∆ETorA rats. 18F-FDG autoradiography indicated modified glucose metabolism in motor and somatosensory cortices and striatum in both ∆ETorA and wt rats post-injury. Our findings highlight perturbed energy metabolism pathways in DYT-TOR1A dystonia, emphasizing compromised PPARα agonist efficacy in the striatum. Furthermore, we identify impaired glucose metabolism in the brain network, suggesting a potential shift in energy substrate utilization in dystonic DYT-TOR1A rats. These results contribute to understanding the pathophysiology and potential therapeutic targets for DYT-TOR1A dystonia.
Collapse
Affiliation(s)
- Susanne Knorr
- Department of Neurology, University Hospital Würzburg, 97080, Germany
| | | | | | - Rhonda McFleder
- Department of Neurology, University Hospital Würzburg, 97080, Germany
| | - Thomas Ott
- Institute for Medical Genetics and Applied Genomics, University of Tübingen, 72076, Germany; Core Facility Transgenic Animals, University Hospital of Tübingen, 72076, Germany; Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany
| | - Kathrin Grundmann-Hauser
- Institute for Medical Genetics and Applied Genomics, University of Tübingen, 72076, Germany; Centre for Rare Diseases, University of Tübingen, 72076, Germany
| | - Takahiro Higuchi
- Department of Nuclear Medicine, University Hospital Würzburg, 97080, Germany
| | - Jens Volkmann
- Department of Neurology, University Hospital Würzburg, 97080, Germany
| | - Chi Wang Ip
- Department of Neurology, University Hospital Würzburg, 97080, Germany.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Saeirad S, LeDoux MS. TOR2A Variants in Blepharospasm. Tremor Other Hyperkinet Mov (N Y) 2023; 13:44. [PMID: 38076033 PMCID: PMC10705022 DOI: 10.5334/tohm.825] [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: 10/11/2023] [Accepted: 11/12/2023] [Indexed: 12/18/2023] Open
Abstract
Background Genetic factors have been implicated in the pathogenesis of blepharospasm (BSP), a dystonia characterized by excessive blinking and involuntary eyelid closure. Previous research identified a co-segregating deleterious TOR2A variant (GRCh38/hg38, NC_000009.12: g.127733410G>A, NM_001085347.3:c.568C>T, p. Arg190Cys) in three subjects with BSP and three carriers within a multi-generation pedigree. Other TOR2A variants have been reported in patients with dystonia. Methods Sanger sequencing was used to screen a cohort of 307 subjects with isolated BSP or BSP-plus dystonia affecting additional anatomical segments (BSP+). We also utilized computational tools to uniformly assess the deleteriousness and potential pathogenicity of previously reported TOR2A variants. Results There were no highly deleterious TOR2A variants in the coding or contiguous splice site regions of TOR2A within our cohort of 307 subjects. Discussion Highly deleterious variants in TOR2A are rare in patients with BSP/BSP+ phenotypes. Highlights Over 300 patients with BSP were screened for variants in TOR2A, a TOR1A (DYT1) homologue. No highly deleterious variants were identified in our cohort. The role of TOR2A in BSP and other forms of dystonia remains indeterminant.
Collapse
Affiliation(s)
| | - Mark S LeDoux
- University of Memphis, Memphis, Tennessee, USA
- Veracity Neuroscience LLC, Memphis, Tennessee, USA
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Di Fonzo A, Albanese A, Jinnah HH. The apparent paradox of phenotypic diversity and shared mechanisms across dystonia syndromes. Curr Opin Neurol 2022; 35:502-509. [PMID: 35856917 PMCID: PMC9309988 DOI: 10.1097/wco.0000000000001076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW We describe here how such mechanisms shared by different genetic forms can give rise to motor performance dysfunctions with a clinical aspect of dystonia. RECENT FINDINGS The continuing discoveries of genetic causes for dystonia syndromes are transforming our view of these disorders. They share unexpectedly common underlying mechanisms, including dysregulation in neurotransmitter signaling, gene transcription, and quality control machinery. The field has further expanded to include forms recently associated with endolysosomal dysfunction. SUMMARY The discovery of biological pathways shared between different monogenic dystonias is an important conceptual advance in the understanding of the underlying mechanisms, with a significant impact on the pathophysiological understanding of clinical phenomenology. The functional relationship between dystonia genes could revolutionize current dystonia classification systems, classifying patients with different monogenic forms based on common pathways. The most promising effect of these advances is on future mechanism-based therapeutic approaches.
Collapse
Affiliation(s)
- Alessio Di Fonzo
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Dino Ferrari Center, Neurology Unit, Milan, Italy
| | - Alberto Albanese
- Department of Neurology, IRCCS Humanitas Research Hospital, Rozzano, Milano, Italy
| | - Hyder H. Jinnah
- Departments of Neurology, Human Genetics, and Pediatrics, Emory University School of Medicine, Atlanta GA, 30322, USA
| |
Collapse
|
7
|
Caffall ZF, Wilkes BJ, Hernández-Martinez R, Rittiner JE, Fox JT, Wan KK, Shipman MK, Titus SA, Zhang YQ, Patnaik S, Hall MD, Boxer MB, Shen M, Li Z, Vaillancourt DE, Calakos N. The HIV protease inhibitor, ritonavir, corrects diverse brain phenotypes across development in mouse model of DYT-TOR1A dystonia. Sci Transl Med 2021; 13:13/607/eabd3904. [PMID: 34408078 DOI: 10.1126/scitranslmed.abd3904] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 12/14/2020] [Accepted: 06/03/2021] [Indexed: 12/22/2022]
Abstract
Dystonias are a group of chronic movement-disabling disorders for which highly effective oral medications or disease-modifying therapies are lacking. The most effective treatments require invasive procedures such as deep brain stimulation. In this study, we used a high-throughput assay based on a monogenic form of dystonia, DYT1 (DYT-TOR1A), to screen a library of compounds approved for use in humans, the NCATS Pharmaceutical Collection (NPC; 2816 compounds), and identify drugs able to correct mislocalization of the disease-causing protein variant, ∆E302/3 hTorsinA. The HIV protease inhibitor, ritonavir, was among 18 compounds found to normalize hTorsinA mislocalization. Using a DYT1 knock-in mouse model to test efficacy on brain pathologies, we found that ritonavir restored multiple brain abnormalities across development. Ritonavir acutely corrected striatal cholinergic interneuron physiology in the mature brain and yielded sustained correction of diffusion tensor magnetic resonance imaging signals when delivered during a discrete early developmental window. Mechanistically, we found that, across the family of HIV protease inhibitors, efficacy correlated with integrated stress response activation. These preclinical results identify ritonavir as a drug candidate for dystonia with disease-modifying potential.
Collapse
Affiliation(s)
- Zachary F Caffall
- Department of Neurology, Duke University Medical Center, Durham, NC 27715, USA
| | - Bradley J Wilkes
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA
| | | | - Joseph E Rittiner
- Department of Neurology, Duke University Medical Center, Durham, NC 27715, USA
| | - Jennifer T Fox
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Kanny K Wan
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Miranda K Shipman
- Department of Neurology, Duke University Medical Center, Durham, NC 27715, USA
| | - Steven A Titus
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Ya-Qin Zhang
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Samarjit Patnaik
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Matthew D Hall
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Matthew B Boxer
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Min Shen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Zhuyin Li
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.,Department of Neurology, Fixel Institute for Neurological Diseases, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
| | - Nicole Calakos
- Department of Neurology, Duke University Medical Center, Durham, NC 27715, USA. .,Department of Neurobiology, Duke University Medical Center, Durham, NC 27715, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC 27715, USA.,Duke Institute for Brain Sciences, Duke University, Durham, NC 27715, USA
| |
Collapse
|
8
|
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.
Collapse
|
9
|
Honer J, Niemeyer KM, Fercher C, Diez Tissera AL, Jaberolansar N, Jafrani YMA, Zhou C, Caramelo JJ, Shewan AM, Schulz BL, Brodsky JL, Zacchi LF. TorsinA folding and N-linked glycosylation are sensitive to redox homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119073. [PMID: 34062155 PMCID: PMC8889903 DOI: 10.1016/j.bbamcr.2021.119073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 05/18/2021] [Accepted: 05/26/2021] [Indexed: 01/03/2023]
Abstract
The Endoplasmic Reticulum (ER) is responsible for the folding and post-translational modification of secretory proteins, as well as for triaging misfolded proteins. During folding, there is a complex yet only partially understood interplay between disulfide bond formation, which is an enzyme catalyzed event in the oxidizing environment of the ER, along with other post-translational modifications (PTMs) and chaperone-supported protein folding. Here, we used the glycoprotein torsinA as a model substrate to explore the impact of ER redox homeostasis on PTMs and protein biogenesis. TorsinA is a AAA+ ATPase with unusual oligomeric properties and controversial functions. The deletion of a C-terminal glutamic acid residue (∆E) is associated with the development of Early-Onset Torsion Dystonia, a severe movement disorder. TorsinA differs from other AAA+ ATPases since it is an ER resident, and as a result of its entry into the ER torsinA contains two N-linked glycans and at least one disulfide bond. The role of these PTMs on torsinA biogenesis and function and the identity of the enzymes that catalyze them are poorly defined. Using a yeast torsinA expression system, we demonstrate that a specific protein disulfide isomerase, Pdi1, affects the folding and N-linked glycosylation of torsinA and torsinA∆E in a redox-dependent manner, suggesting that the acquisition of early torsinA folding intermediates is sensitive to perturbed interactions between Cys residues and the quality control machinery. We also highlight the role of specific Cys residues during torsinA biogenesis and demonstrate that torsinA∆E is more sensitive than torsinA when these Cys residues are mutated.
Collapse
Affiliation(s)
- Jonas Honer
- Department of Biological Sciences, A320 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, United States of America
| | - Katie M Niemeyer
- Department of Biological Sciences, A320 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, United States of America
| | - Christian Fercher
- Australian Research Council Training Centre for Biopharmaceutical Innovation, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Ana L Diez Tissera
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), 1405 Buenos Aires, Argentina
| | - Noushin Jaberolansar
- Australian Research Council Training Centre for Biopharmaceutical Innovation, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Yohaann M A Jafrani
- Australian Research Council Training Centre for Biopharmaceutical Innovation, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Chun Zhou
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Julio J Caramelo
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), 1405 Buenos Aires, Argentina
| | - Annette M Shewan
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Benjamin L Schulz
- Australian Research Council Training Centre for Biopharmaceutical Innovation, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Jeffrey L Brodsky
- Department of Biological Sciences, A320 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, United States of America
| | - Lucía F Zacchi
- Department of Biological Sciences, A320 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, United States of America; Australian Research Council Training Centre for Biopharmaceutical Innovation, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia; Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), 1405 Buenos Aires, Argentina; School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, 4072, Australia.
| |
Collapse
|
10
|
Downs AM, Fan X, Kadakia RF, Donsante Y, Jinnah HA, Hess EJ. Cell-intrinsic effects of TorsinA(ΔE) disrupt dopamine release in a mouse model of TOR1A dystonia. Neurobiol Dis 2021; 155:105369. [PMID: 33894367 DOI: 10.1016/j.nbd.2021.105369] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/29/2021] [Accepted: 04/19/2021] [Indexed: 11/19/2022] Open
Abstract
TOR1A-associated dystonia, otherwise known as DYT1 dystonia, is an inherited dystonia caused by a three base-pair deletion in the TOR1A gene (TOR1AΔE). Although the mechanisms underlying the dystonic movements are largely unknown, abnormalities in striatal dopamine and acetylcholine neurotransmission are consistently implicated whereby dopamine release is reduced while cholinergic tone is increased. Because striatal cholinergic neurotransmission mediates dopamine release, it is not known if the dopamine release deficit is mediated indirectly by abnormal acetylcholine neurotransmission or if Tor1a(ΔE) acts directly within dopaminergic neurons to attenuate release. To dissect the microcircuit that governs the deficit in dopamine release, we conditionally expressed Tor1a(ΔE) in either dopamine neurons or cholinergic interneurons in mice and assessed striatal dopamine release using ex vivo fast scan cyclic voltammetry or dopamine efflux using in vivo microdialysis. Conditional expression of Tor1a(ΔE) in cholinergic neurons did not affect striatal dopamine release. In contrast, conditional expression of Tor1a(ΔE) in dopamine neurons reduced dopamine release to 50% of normal, which is comparable to the deficit in Tor1a+/ΔE knockin mice that express the mutation ubiquitously. Despite the deficit in dopamine release, we found that the Tor1a(ΔE) mutation does not cause obvious nerve terminal dysfunction as other presynaptic mechanisms, including electrical excitability, vesicle recycling/refilling, Ca2+ signaling, D2 dopamine autoreceptor function and GABAB receptor function, are intact. Although the mechanistic link between Tor1a(ΔE) and dopamine release is unclear, these results clearly demonstrate that the defect in dopamine release is caused by the action of the Tor1a(ΔE) mutation within dopamine neurons.
Collapse
Affiliation(s)
- Anthony M Downs
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Xueliang Fan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Radhika F Kadakia
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Yuping Donsante
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - H A Jinnah
- Department of Neurology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA; Department of Human Genetics, Emory University School of Medicine, 101 Woodruff Circle, WMB 6300, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, 101 Woodruff Circle, WMB 6300, Atlanta, GA 30322, USA
| | - Ellen J Hess
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA; Department of Neurology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA.
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Effect of Gabapentin in a Neuropathic Pain Model in Mice Overexpressing Human Wild-Type or Human Mutated Torsin A. Life (Basel) 2021; 11:life11010041. [PMID: 33445430 PMCID: PMC7826569 DOI: 10.3390/life11010041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND DYT1 dystonia is the most common form of early-onset inherited dystonia, which is caused by mutation of torsin A (TA) belonging to the "ATPases associated with a variety of cellular activities" (AAA + ATPase). Dystonia is often accompanied by pain, and neuropathic pain can be associated to peripherally induced movement disorder and dystonia. However, no evidence exists on the effect of gabapentin in mice subjected to neuropathic pain model overexpressing human normal or mutated TA. METHODS Mice subjected to L5 spinal nerve ligation (SNL) develop mechanical allodynia and upregulation of the α2δ-1 L-type calcium channel subunit, forming a validated experimental model of neuropathic pain. Under these experimental conditions, TA is expressed in dorsal horn neurons and astrocytes and colocalizes with α2δ-1. Similar to this subunit, TA is overexpressed in dorsal horn 7 days after SNL. This model has been used to investigate (1) basal mechanical sensitivity; (2) neuropathic pain phases; and (3) the effect of gabapentin, an α2δ-1 ligand used against neuropathic pain, in non-transgenic (NT) C57BL/6 mice and in mice overexpressing human wild-type (hWT) or mutant (hMT) TA. RESULTS In comparison to non-transgenic mice, the threshold for mechanical sensitivity in hWT or hMT does not differ (Kruskal-Wallis test = 1.478; p = 0.4777, although, in the latter animals, neuropathic pain recovery phase is delayed. Interestingly, gabapentin (100 mg/Kg) reduces allodynia at its peak (occurring between post-operative day 7 and day 10) but not in the phase of recovery. CONCLUSIONS These data lend support to the investigation on the role of TA in the molecular machinery engaged during neuropathic pain.
Collapse
|
13
|
Fercher C, Zacchi LF. Resolving the TorsinA Oligomerization Conundrum: The Glycan Hypothesis. Front Mol Biosci 2020; 7:585643. [PMID: 33134321 PMCID: PMC7567157 DOI: 10.3389/fmolb.2020.585643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/14/2020] [Indexed: 11/13/2022] Open
Abstract
TorsinA is a AAA+ ATPase involved in the severe neurological disease Early Onset Torsion Dystonia. Despite the impressive progress in the field in the recent years, the structural organization and function of this intriguing molecule is still not clear. One outstanding difference between torsinA and other AAA+ ATPases is that torsinA is a glycoprotein. TorsinA N-linked glycans impact torsinA biogenesis and subcellular localization. Here, we propose that torsinA glycans also modulate torsinA oligomerization properties. We used structural modeling to test this idea, and show that N-linked glycans appear to restrict torsinA's ability to form closed homohexameric ring assemblies, and instead promote an open hexameric conformation that allows torsinA interaction with key cofactors required for ATP hydrolysis. This mechanism would make torsinA a prime example of Nature's sophisticated molecular glycoengineering.
Collapse
Affiliation(s)
- Christian Fercher
- Australian Research Council (ARC), Training Centre for Biopharmaceutical Innovation, The University of Queensland, St Lucia, QLD, Australia
| | - Lucía F Zacchi
- Australian Research Council (ARC), Training Centre for Biopharmaceutical Innovation, The University of Queensland, St Lucia, QLD, Australia
| |
Collapse
|
14
|
Giri S, Ghosh A, Roy S, Sankhla CS, Das SK, Ray K, Ray J. Association of TOR1A and GCH1 Polymorphisms with Isolated Dystonia in India. J Mol Neurosci 2020; 71:325-337. [PMID: 32662044 DOI: 10.1007/s12031-020-01653-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 06/30/2020] [Indexed: 11/29/2022]
Abstract
Isolated dystonia is a common movement disorder often caused by genetic mutations, although it is predominantly sporadic in nature. Common variants of dystonia-related genes were reported to be risk factors for idiopathic isolated dystonia. In this study, we aimed to analyse the roles of previously reported GTP cyclohydrolase (GCH1) and Torsin family 1 member A (TOR1A) polymorphisms in an Indian isolated dystonia case-control group. A total of 292 sporadic isolated dystonia patients and 316 control individuals were genotyped for single-nucleotide polymorphisms (SNPs) of GCH1 (rs3759664:G > A, rs12147422:A > G and rs10483639:C > G) and TOR1A (rs13300897:G > A, rs1801968:G > C, rs1182:G > T and rs3842225:G > Δ) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and confirmed by direct Sanger sequencing. The statistical significance of allelic, genotypic and haplotypic associations of all of the SNPs were evaluated using the two-tailed Fisher exact test. The minor allele (A) of rs3759664 is significantly associated with isolated limb dystonia as a risk factor (p = 0.005). The minor allele (C) of rs1801968 is strongly associated with isolated dystonia (p < 0.0001) and most of its subtypes. The major allele of rs3842225 (G) may act as a significant risk factor for Writer's cramp (p = 0.03). Four different haplogroups comprising of either rs1182 or rs3842225 or in combination with rs1801968 and rs13300897 were found to be significantly associated with isolated dystonia. No other allelic, genotypic or haplotypic association was found to be significant with isolated dystonia cohort or its endophenotype stratified groups. Our study suggests that TOR1A common variants have a significant role in isolated dystonia pathogenesis in the Indian population, whereas SNPs in the GCH1 gene may have a limited role.
Collapse
Affiliation(s)
- Subhajit Giri
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India
| | - Arunibha Ghosh
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India
| | - Shubhrajit Roy
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India
| | | | | | - Kunal Ray
- ATGC Diagnostics Private Limited, Kolkata, India
| | - Jharna Ray
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India.
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Yamanaka T, Nishiyama R, Shimogori T, Nukina N. Proteomics-Based Approach Identifies Altered ER Domain Properties by ALS-Linked VAPB Mutation. Sci Rep 2020; 10:7610. [PMID: 32376919 PMCID: PMC7203144 DOI: 10.1038/s41598-020-64517-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
An ER transmembrane protein, vesicle-associated membrane protein-associated protein B (VAPB), binds to several organelle-resident membrane proteins to mediate ER-organelle tethering. Mutation in amyotrophic lateral sclerosis (ALS) induces protein misfolding and aggregation, leading to ER disorganization. Gain or loss of function is suggested for VAPB mutation, however comprehensive study focusing on VAPB-ER domain has yet been performed. We here conducted proteomic characterization of the ER containing VAPB and its ALS-linked P56S mutant. For this purpose, we first optimized the proteomics of different ER domains immuno-isolated from cultured cells, and identified ER sheet- and tubule-specific proteomes. By using these as references, we found that VAPB-ER proteome had intermediate ER domain properties but its tubular property was specifically decreased by its mutation. Biochemical, immunofluorescence and proximity ligation assays suggested this was mediated by delocalization of VAPB from ER tubules. The VAPB-ER proteomics further suggested reduced incorporation of multiple proteins located in different organelles, which was confirmed by proximity ligation assay. Taken together, our proteomics-based approach indicates altered ER domain properties and impaired ER-organelle tethering by VAPB mutation.
Collapse
Affiliation(s)
- Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan.
| | - Risa Nishiyama
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan
| | - Tomomi Shimogori
- Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, Saitama, 351-0198, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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
|
19
|
Gill NK, Ly C, Kim PH, Saunders CA, Fong LG, Young SG, Luxton GWG, Rowat AC. DYT1 Dystonia Patient-Derived Fibroblasts Have Increased Deformability and Susceptibility to Damage by Mechanical Forces. Front Cell Dev Biol 2019; 7:103. [PMID: 31294022 PMCID: PMC6606767 DOI: 10.3389/fcell.2019.00103] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 05/27/2019] [Indexed: 12/24/2022] Open
Abstract
DYT1 dystonia is a neurological movement disorder that is caused by a loss-of-function mutation in the DYT1/TOR1A gene, which encodes torsinA, a conserved luminal ATPases-associated with various cellular activities (AAA+) protein. TorsinA is required for the assembly of functional linker of nucleoskeleton and cytoskeleton (LINC) complexes, and consequently the mechanical integration of the nucleus and the cytoskeleton. Despite the potential implications of altered mechanobiology in dystonia pathogenesis, the role of torsinA in regulating cellular mechanical phenotype, or mechanotype, in DYT1 dystonia remains unknown. Here, we define the deformability of mouse fibroblasts lacking functional torsinA as well as human fibroblasts isolated from DYT1 dystonia patients. We find that the deletion of torsinA or the expression of torsinA containing the DYT1 dystonia-causing ΔE302/303 (ΔE) mutation results in more deformable cells. We observe a similar increased deformability of mouse fibroblasts that lack lamina-associated polypeptide 1 (LAP1), which interacts with and stimulates the ATPase activity of torsinA in vitro, as well as with the absence of the LINC complex proteins, Sad1/UNC-84 1 (SUN1) and SUN2, lamin A/C, or lamin B1. Consistent with these findings, we also determine that DYT1 dystonia patient-derived fibroblasts are more compliant than fibroblasts isolated from unafflicted individuals. DYT1 dystonia patient-derived fibroblasts also exhibit increased nuclear strain and decreased viability following mechanical stretch. Taken together, our results establish the foundation for future mechanistic studies of the role of cellular mechanotype and LINC-dependent nuclear-cytoskeletal coupling in regulating cell survival following exposure to mechanical stresses.
Collapse
Affiliation(s)
- Navjot Kaur Gill
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Chau Ly
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States
| | - Paul H Kim
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cosmo A Saunders
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, United States
| | - Loren G Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, United States.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - G W Gant Luxton
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, United States.,Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Amy C Rowat
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Yu-Taeger L, Gaiser V, Lotzer L, Roenisch T, Fabry BT, Stricker-Shaver J, Casadei N, Walter M, Schaller M, Riess O, Nguyen HP, Ott T, Grundmann-Hauser K. Dynamic nuclear envelope phenotype in rats overexpressing mutated human torsinA protein. Biol Open 2018; 7:bio.032839. [PMID: 29739751 PMCID: PMC6078351 DOI: 10.1242/bio.032839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A three-base-pair deletion in the human TOR1A gene is causative for the most common form of primary dystonia: the early-onset dystonia type 1 (DYT1 dystonia). The pathophysiological consequences of this mutation are still unknown. To study the pathology of the mutant torsinA (TOR1A) protein, we have generated a transgenic rat line that overexpresses the human mutant protein under the control of the human TOR1A promoter. This new animal model was phenotyped with several approaches, including behavioral tests and neuropathological analyses. Motor phenotype, cellular and ultrastructural key features of torsinA pathology were found in this new transgenic rat line, supporting that it can be used as a model system for investigating the disease’s development. Analyses of mutant TOR1A protein expression in various brain regions also showed a dynamic expression pattern and a reversible nuclear envelope pathology. These findings suggest the differential vulnerabilities of distinct neuronal subpopulations. Furthermore, the reversibility of the nuclear envelope pathology might be a therapeutic target to treat the disease. Summary: A novel transgenic rat model displaying dystonia-like phenotypes and dynamic processes in NE pathology can become a useful tool for therapy development for dystonia and other related diseases.
Collapse
Affiliation(s)
- Libo Yu-Taeger
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Viktoria Gaiser
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Larissa Lotzer
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Tina Roenisch
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Core Facility Transgenic Animals, University Hospital Tuebingen, Otfried-Mueller-Str. 27, 72076 Tuebingen, Germany
| | - Benedikt Timo Fabry
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Janice Stricker-Shaver
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Nicolas Casadei
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Michael Walter
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Agilent Technologies, 5301 Stevens Creek Blvd, Santa Clara, CA 95051, USA
| | - Martin Schaller
- Department of Dermatology, University of Tuebingen, Liebermeisterstr. 25, 72076 Tuebingen, Germany
| | - Olaf Riess
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Huu Phuc Nguyen
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany .,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| | - Thomas Ott
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Core Facility Transgenic Animals, University Hospital Tuebingen, Otfried-Mueller-Str. 27, 72076 Tuebingen, Germany
| | - Kathrin Grundmann-Hauser
- Institute for Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany.,Centre for Rare Diseases, University of Tuebingen, Calwerstr. 7, 72076 Tuebingen, Germany
| |
Collapse
|
22
|
Abstract
The endoplasmic reticulum (ER) is a morphologically dynamic organelle containing different membrane subdomains with distinct cellular functions. Numerous observations have revealed that ER stress response induced by disturbed ER homeostasis is linked to various neurological/neurodegenerative disorders. In contrast, recent findings unveil that ER structural derangements are linked to the progression of several neurological diseases. The derangements involve two distinct, and likely opposing pathways. One is dysfunction of ER dynamics machinery, leading to disruption of ER network organization. Another one is facilitation of pre-existing machinery, leading to generation of markedly-ordered de novo membranous structure. Restoring the ER network can be the effective way toward the cure of ER-deranged neurological disorders.
Collapse
Affiliation(s)
- Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| |
Collapse
|
23
|
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.
Collapse
|
24
|
Human TorsinA can function in the yeast cytosol as a molecular chaperone. Biochem J 2017; 474:3439-3454. [PMID: 28871039 PMCID: PMC5628414 DOI: 10.1042/bcj20170395] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/25/2017] [Accepted: 09/01/2017] [Indexed: 11/17/2022]
Abstract
TorsinA (TorA) is an AAA+ (ATPases associated with diverse cellular activities) ATPase linked to dystonia type 1 (DYT1), a neurological disorder that leads to uncontrollable muscular movements. Although DYT1 is linked to a 3 bp deletion in the C-terminus of TorA, the biological function of TorA remains to be established. Here, we use the yeast Saccharomyces cerevisiae as a tractable in vivo model to explore TorA function. We demonstrate that TorA can protect yeast cells against different forms of environmental stress and show that in the absence of the molecular disaggregase Hsp104, TorA can refold heat-denatured luciferase in vivo in an ATP-dependent manner. However, this activity requires TorA to be translocated to the cytoplasm from the endoplasmic reticulum in order to access and process cytoplasmic protein aggregates. Furthermore, mutational or chemical inactivation of the ATPase activity of TorA blocks this activity. We also find that TorA can inhibit the propagation of certain conformational variants of [PSI+], the aggregated prion form of the endogenous Sup35 protein. Finally, we show that while cellular localisation remains unchanged in the dystonia-linked TorA mutant ΔE302-303, the ability of this mutant form of TorA to protect against cellular stress and to facilitate protein refolding is impaired, consistent with it being a loss-of-function mutation.
Collapse
|
25
|
Rittiner JE, Caffall ZF, Hernández-Martinez R, Sanderson SM, Pearson JL, Tsukayama KK, Liu AY, Xiao C, Tracy S, Shipman MK, Hickey P, Johnson J, Scott B, Stacy M, Saunders-Pullman R, Bressman S, Simonyan K, Sharma N, Ozelius LJ, Cirulli ET, Calakos N. Functional Genomic Analyses of Mendelian and Sporadic Disease Identify Impaired eIF2α Signaling as a Generalizable Mechanism for Dystonia. Neuron 2016; 92:1238-1251. [PMID: 27939583 DOI: 10.1016/j.neuron.2016.11.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/27/2016] [Accepted: 11/04/2016] [Indexed: 01/09/2023]
Abstract
Dystonia is a brain disorder causing involuntary, often painful movements. Apart from a role for dopamine deficiency in some forms, the cellular mechanisms underlying most dystonias are currently unknown. Here, we discover a role for deficient eIF2α signaling in DYT1 dystonia, a rare inherited generalized form, through a genome-wide RNAi screen. Subsequent experiments including patient-derived cells and a mouse model support both a pathogenic role and therapeutic potential for eIF2α pathway perturbations. We further find genetic and functional evidence supporting similar pathway impairment in patients with sporadic cervical dystonia, due to rare coding variation in the eIF2α effector ATF4. Considering also that another dystonia, DYT16, involves a gene upstream of the eIF2α pathway, these results mechanistically link multiple forms of dystonia and put forth a new overall cellular mechanism for dystonia pathogenesis, impairment of eIF2α signaling, a pathway known for its roles in cellular stress responses and synaptic plasticity.
Collapse
Affiliation(s)
| | | | | | | | - James L Pearson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Department of RNAi Screening Facility, Duke University, Durham, NC 27708, USA
| | | | - Anna Y Liu
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Changrui Xiao
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Samantha Tracy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | | | - Patrick Hickey
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Julia Johnson
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Burton Scott
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Mark Stacy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Rachel Saunders-Pullman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Susan Bressman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kristina Simonyan
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth T Cirulli
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Nicole Calakos
- Department of Neurology, Duke University, Durham, NC 27708, USA; Department of Neurobiology, Duke University, Durham, NC 27708, USA.
| |
Collapse
|
26
|
Cascalho A, Jacquemyn J, Goodchild RE. Membrane defects and genetic redundancy: Are we at a turning point for DYT1 dystonia? Mov Disord 2016; 32:371-381. [PMID: 27911022 DOI: 10.1002/mds.26880] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/24/2016] [Accepted: 10/29/2016] [Indexed: 12/11/2022] Open
Abstract
Heterozygosity for a 3-base pair deletion (ΔGAG) in TOR1A/torsinA is one of the most common causes of hereditary dystonia. In this review, we highlight current understanding of how this mutation causes disease from research spanning structural biochemistry, cell science, neurobiology, and several model organisms. We now know that homozygosity for ΔGAG has the same effects as Tor1aKO , implicating a partial loss of function mechanism in the ΔGAG/+ disease state. In addition, torsinA loss specifically affects neurons in mice, even though the gene is broadly expressed, apparently because of differential expression of homologous torsinB. Furthermore, certain neuronal subtypes are more severely affected by torsinA loss. Interestingly, these include striatal cholinergic interneurons that display abnormal responses to dopamine in several Tor1a animal models. There is also progress on understanding torsinA molecular cell biology. The structural basis of how ΔGAG inhibits torsinA ATPase activity is defined, although mutant torsinAΔGAG protein also displays some characteristics suggesting it contributes to dystonia by a gain-of-function mechanism. Furthermore, a consistent relationship is emerging between torsin dysfunction and membrane biology, including an evolutionarily conserved regulation of lipid metabolism. Considered together, these findings provide major advances toward understanding the molecular, cellular, and neurobiological pathologies of DYT1/TOR1A dystonia that can hopefully be exploited for new approaches to treat this disease. © 2016 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Ana Cascalho
- Vlaams Instituut voor Biotechnologie Centre for the Biology of Disease, Leuven, Belgium.,KU Leuven, Department of Human Genetics, Leuven, Belgium
| | - Julie Jacquemyn
- Vlaams Instituut voor Biotechnologie Centre for the Biology of Disease, Leuven, Belgium.,KU Leuven, Department of Human Genetics, Leuven, Belgium
| | - Rose E Goodchild
- Vlaams Instituut voor Biotechnologie Centre for the Biology of Disease, Leuven, Belgium.,KU Leuven, Department of Human Genetics, Leuven, Belgium
| |
Collapse
|
27
|
Pratt D, Mente K, Rahimpour S, Edwards NA, Tinaz S, Berman BD, Hallett M, Ray-Chaudhury A. Diminishing evidence for torsinA-positive neuronal inclusions in DYT1 dystonia. Acta Neuropathol Commun 2016; 4:85. [PMID: 27531128 PMCID: PMC4988029 DOI: 10.1186/s40478-016-0362-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 08/08/2016] [Indexed: 11/25/2022] Open
|
28
|
Abstract
Torsin ATPases (Torsins) belong to the widespread AAA+ (ATPases associated with a variety of cellular activities) family of ATPases, which share structural similarity but have diverse cellular functions. Torsins are outliers in this family because they lack many characteristics of typical AAA+ proteins, and they are the only members of the AAA+ family located in the endoplasmic reticulum and contiguous perinuclear space. While it is clear that Torsins have essential roles in many, if not all metazoans, their precise cellular functions remain elusive. Studying Torsins has significant medical relevance since mutations in Torsins or Torsin-associated proteins result in a variety of congenital human disorders, the most frequent of which is early-onset torsion (DYT1) dystonia, a severe movement disorder. A better understanding of the Torsin system is needed to define the molecular etiology of these diseases, potentially enabling corrective therapy. Here, we provide a comprehensive overview of the Torsin system in metazoans, discuss functional clues obtained from various model systems and organisms and provide a phylogenetic and structural analysis of Torsins and their regulatory cofactors in relation to disease-causative mutations. Moreover, we review recent data that have led to a dramatically improved understanding of these machines at a molecular level, providing a foundation for investigating the molecular defects underlying the associated movement disorders. Lastly, we discuss our ideas on how recent progress may be utilized to inform future studies aimed at determining the cellular role(s) of these atypical molecular machines and their implications for dystonia treatment options.
Collapse
Affiliation(s)
- April E Rose
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Rebecca S H Brown
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Christian Schlieker
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and.,b Department of Cell Biology , Yale School of Medicine , New Haven , CT , USA
| |
Collapse
|
29
|
Cerebellar synaptogenesis is compromised in mouse models of DYT1 dystonia. Exp Neurol 2015; 271:457-67. [DOI: 10.1016/j.expneurol.2015.07.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/01/2015] [Accepted: 07/07/2015] [Indexed: 12/16/2022]
|
30
|
Kim AY, Seo JB, Kim WT, Choi HJ, Kim SY, Morrow G, Tanguay RM, Steller H, Koh YH. The pathogenic human Torsin A in Drosophila activates the unfolded protein response and increases susceptibility to oxidative stress. BMC Genomics 2015; 16:338. [PMID: 25903460 PMCID: PMC4415242 DOI: 10.1186/s12864-015-1518-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 04/10/2015] [Indexed: 01/11/2023] Open
Abstract
Background Dystonia1 (DYT1) dystonia is caused by a glutamic acid deletion (ΔE) mutation in the gene encoding Torsin A in humans (HTorA). To investigate the unknown molecular and cellular mechanisms underlying DYT1 dystonia, we performed an unbiased proteomic analysis. Results We found that the amount of proteins and transcripts of an Endoplasmic reticulum (ER) resident chaperone Heat shock protein cognate 3 (HSC3) and a mitochondria chaperone Heat Shock Protein 22 (HSP22) were significantly increased in the HTorAΔE– expressing brains compared to the normal HTorA (HTorAWT) expressing brains. The physiological consequences included an increased susceptibility to oxidative and ER stress compared to normal HTorAWT flies. The alteration of transcripts of Inositol-requiring enzyme-1 (IRE1)-dependent spliced X box binding protein 1(Xbp1), several ER chaperones, a nucleotide exchange factor, Autophagy related protein 8b (ATG8b) and components of the ER associated degradation (ERAD) pathway and increased expression of the Xbp1-enhanced Green Fluorescence Protein (eGFP) in HTorAΔE brains strongly indicated the activation of the unfolded protein response (UPR). In addition, perturbed expression of the UPR sensors and inducers in the HTorAΔEDrosophila brains resulted in a significantly reduced life span of the flies. Furthermore, the types and quantities of proteins present in the anti-HSC3 positive microsomes in the HTorAΔE brains were different from those of the HTorAWT brains. Conclusion Taken together, these data show that HTorAΔE in Drosophila brains may activate the UPR and increase the expression of HSP22 to compensate for the toxic effects caused by HTorAΔE in the brains. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1518-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- A-Young Kim
- ILSONG Institute of Life Science, Hallym University, 1605-4 Gwanyangdong, Dongan-gu, Anyang, Gyeonggido, 431-060, Republic of Korea. .,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do, 200-702, Republic of Korea.
| | - Jong Bok Seo
- Korea Basic Science Institute, Sungbuk-gu, Seoul, 136-713, Republic of Korea.
| | - Won-Tae Kim
- National Academy of Agricultural Science, Rural Development Administration, Suwon, 441-707, Republic of Korea.
| | - Hee Jeong Choi
- ILSONG Institute of Life Science, Hallym University, 1605-4 Gwanyangdong, Dongan-gu, Anyang, Gyeonggido, 431-060, Republic of Korea. .,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do, 200-702, Republic of Korea.
| | - Soo-Young Kim
- Korea Basic Science Institute, Sungbuk-gu, Seoul, 136-713, Republic of Korea.
| | - Genevieve Morrow
- Department of Molecular Biology, Medical Biochemistry & Pathology, Université Laval, Québec, Qc, G1V 0A6, Canada.
| | - Robert M Tanguay
- Department of Molecular Biology, Medical Biochemistry & Pathology, Université Laval, Québec, Qc, G1V 0A6, Canada.
| | - Hermann Steller
- Howard Hughes Medical Institute, the Rockefeller University, New York, NY, 10065, USA.
| | - Young Ho Koh
- ILSONG Institute of Life Science, Hallym University, 1605-4 Gwanyangdong, Dongan-gu, Anyang, Gyeonggido, 431-060, Republic of Korea. .,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Gangwon-do, 200-702, Republic of Korea.
| |
Collapse
|
31
|
Wakabayashi-Ito N, Ajjuri RR, Henderson BW, Doherty OM, Breakefield XO, O'Donnell JM, Ito N. Mutant human torsinA, responsible for early-onset dystonia, dominantly suppresses GTPCH expression, dopamine levels and locomotion in Drosophila melanogaster. Biol Open 2015; 4:585-95. [PMID: 25887123 PMCID: PMC4434810 DOI: 10.1242/bio.201411080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Dystonia represents the third most common movement disorder in humans with over 20 genetic loci identified. TOR1A (DYT1), the gene responsible for the most common primary hereditary dystonia, encodes torsinA, an AAA ATPase family protein. Most cases of DYT1 dystonia are caused by a 3 bp (ΔGAG) deletion that results in the loss of a glutamic acid residue (ΔE302/303) in the carboxyl terminal region of torsinA. This torsinAΔE mutant protein has been speculated to act in a dominant-negative manner to decrease activity of wild type torsinA. Drosophila melanogaster has a single torsin-related gene, dtorsin. Null mutants of dtorsin exhibited locomotion defects in third instar larvae. Levels of dopamine and GTP cyclohydrolase (GTPCH) proteins were severely reduced in dtorsin-null brains. Further, the locomotion defect was rescued by the expression of human torsinA or feeding with dopamine. Here, we demonstrate that human torsinAΔE dominantly inhibited locomotion in larvae and adults when expressed in neurons using a pan-neuronal promoter Elav. Dopamine and tetrahydrobiopterin (BH4) levels were significantly reduced in larval brains and the expression level of GTPCH protein was severely impaired in adult and larval brains. When human torsinA and torsinAΔE were co-expressed in neurons in dtorsin-null larvae and adults, the locomotion rates and the expression levels of GTPCH protein were severely reduced. These results support the hypothesis that torsinAΔE inhibits wild type torsinA activity. Similarly, neuronal expression of a Drosophila DtorsinΔE equivalent mutation dominantly inhibited larval locomotion and GTPCH protein expression. These results indicate that both torsinAΔE and DtorsinΔE act in a dominant-negative manner. We also demonstrate that Dtorsin regulates GTPCH expression at the post-transcriptional level. This Drosophila model of DYT1 dystonia provides an important tool for studying the differences in the molecular function between the wild type and the mutant torsin proteins.
Collapse
Affiliation(s)
- Noriko Wakabayashi-Ito
- Department of Neurology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, MA 02129, USA
| | - Rami R Ajjuri
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Benjamin W Henderson
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Olugbenga M Doherty
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Xandra O Breakefield
- Department of Neurology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, MA 02129, USA
| | - Janis M O'Donnell
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Naoto Ito
- Department of Neurology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, MA 02129, USA
| |
Collapse
|
32
|
Yokoi F, Chen HX, Dang MT, Cheetham CC, Campbell SL, Roper SN, Sweatt JD, Li Y. Behavioral and electrophysiological characterization of Dyt1 heterozygous knockout mice. PLoS One 2015; 10:e0120916. [PMID: 25799505 PMCID: PMC4370625 DOI: 10.1371/journal.pone.0120916] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 01/28/2015] [Indexed: 12/19/2022] Open
Abstract
DYT1 dystonia is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most of the patients have a trinucleotide deletion (ΔGAG) corresponding to a glutamic acid in the C-terminal region (torsinA(ΔE)). Dyt1 ΔGAG heterozygous knock-in (KI) mice, which mimic ΔGAG mutation in the endogenous gene, exhibit motor deficits and deceased frequency of spontaneous excitatory post-synaptic currents (sEPSCs) and normal theta-burst-induced long-term potentiation (LTP) in the hippocampal CA1 region. Although Dyt1 KI mice show decreased hippocampal torsinA levels, it is not clear whether the decreased torsinA level itself affects the synaptic plasticity or torsinA(ΔE) does it. To analyze the effect of partial torsinA loss on motor behaviors and synaptic transmission, Dyt1 heterozygous knock-out (KO) mice were examined as a model of a frame-shift DYT1 mutation in patients. Consistent with Dyt1 KI mice, Dyt1 heterozygous KO mice showed motor deficits in the beam-walking test. Dyt1 heterozygous KO mice showed decreased hippocampal torsinA levels lower than those in Dyt1 KI mice. Reduced sEPSCs and normal miniature excitatory post-synaptic currents (mEPSCs) were also observed in the acute hippocampal brain slices from Dyt1 heterozygous KO mice, suggesting that the partial loss of torsinA function in Dyt1 KI mice causes action potential-dependent neurotransmitter release deficits. On the other hand, Dyt1 heterozygous KO mice showed enhanced hippocampal LTP, normal input-output relations and paired pulse ratios in the extracellular field recordings. The results suggest that maintaining an appropriate torsinA level is important to sustain normal motor performance, synaptic transmission and plasticity. Developing therapeutics to restore a normal torsinA level may help to prevent and treat the symptoms in DYT1 dystonia.
Collapse
Affiliation(s)
- Fumiaki Yokoi
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Huan-Xin Chen
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Mai Tu Dang
- Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Chad C. Cheetham
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Susan L. Campbell
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steven N. Roper
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - J. David Sweatt
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Yuqing Li
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| |
Collapse
|
33
|
|
34
|
Hardy J, Rogaeva E. Motor neuron disease and frontotemporal dementia: sometimes related, sometimes not. Exp Neurol 2014; 262 Pt B:75-83. [DOI: 10.1016/j.expneurol.2013.11.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/27/2013] [Accepted: 11/07/2013] [Indexed: 12/12/2022]
|
35
|
Harata NC. Current Gaps in the Understanding of the Subcellular Distribution of Exogenous and Endogenous Protein TorsinA. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2014; 4:260. [PMID: 25279252 PMCID: PMC4175402 DOI: 10.7916/d8js9nr2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 08/25/2014] [Indexed: 12/01/2022]
Abstract
Background An in-frame deletion leading to the loss of a single glutamic acid residue in the protein torsinA (ΔE-torsinA) results in an inherited movement disorder, DYT1 dystonia. This autosomal dominant disease affects the function of the brain without causing neurodegeneration, by a mechanism that remains unknown. Methods We evaluated the literature regarding the subcellular localization of torsinA. Results Efforts to elucidate the pathophysiological basis of DYT1 dystonia have relied partly on examining the subcellular distribution of the wild-type and mutated proteins. A typical approach is to introduce the human torsinA gene (TOR1A) into host cells and overexpress the protein therein. In both neurons and non-neuronal cells, exogenous wild-type torsinA introduced in this manner has been found to localize mainly to the endoplasmic reticulum, whereas exogenous ΔE-torsinA is predominantly in the nuclear envelope or cytoplasmic inclusions. Although these outcomes are relatively consistent, findings for the localization of endogenous torsinA have been variable, leaving its physiological distribution a matter of debate. Discussion As patients’ cells do not overexpress torsinA proteins, it is important to understand why the reported distributions of the endogenous proteins are inconsistent. We propose that careful optimization of experimental methods will be critical in addressing the causes of the differences among the distributions of endogenous (non-overexpressed) vs. exogenously introduced (overexpressed) proteins.
Collapse
Affiliation(s)
- N Charles Harata
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| |
Collapse
|
36
|
Abstract
Isolated inherited dystonia-formerly referred to as primary dystonia-is characterized by abnormal motor functioning of a grossly normal appearing brain. The disease manifests as abnormal involuntary twisting movements. The absence of overt neuropathological lesions, while intriguing, has made it particularly difficult to unravel the pathogenesis of isolated inherited dystonia. The explosion of genetic techology enabling the identification of the causative gene mutations is transforming our understanding of dystonia pathogenesis, as the molecular, cellular and circuit level consequences of these mutations are identified in experimental systems. Here, I review the clinical genetics and cell biology of three forms of inherited dystonia for which the causative mutation is known: DYT1 (TOR1A), DYT6 (THAP1), DYT25 (GNAL).
Collapse
Affiliation(s)
- William Dauer
- Department of Neurology, Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109-220, USA,
| |
Collapse
|
37
|
Hettich J, Ryan SD, de Souza ON, Saraiva Macedo Timmers LF, Tsai S, Atai NA, da Hora CC, Zhang X, Kothary R, Snapp E, Ericsson M, Grundmann K, Breakefield XO, Nery FC. Biochemical and cellular analysis of human variants of the DYT1 dystonia protein, TorsinA/TOR1A. Hum Mutat 2014; 35:1101-13. [PMID: 24930953 DOI: 10.1002/humu.22602] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 06/04/2014] [Indexed: 12/24/2022]
Abstract
Early-onset dystonia is associated with the deletion of one of a pair of glutamic acid residues (c.904_906delGAG/c.907_909delGAG; p.Glu302del/Glu303del; ΔE 302/303) near the carboxyl-terminus of torsinA, a member of the AAA(+) protein family that localizes to the endoplasmic reticulum lumen and nuclear envelope. This deletion commonly underlies early-onset DYT1 dystonia. While the role of the disease-causing mutation, torsinAΔE, has been established through genetic association studies, it is much less clear whether other rare human variants of torsinA are pathogenic. Two missense variations have been described in single patients: R288Q (c.863G>A; p.Arg288Gln; R288Q) identified in a patient with onset of severe generalized dystonia and myoclonus since infancy and F205I (c.613T>A, p.Phe205Ile; F205I) in a psychiatric patient with late-onset focal dystonia. In this study, we have undertaken a series of analyses comparing the biochemical and cellular effects of these rare variants to torsinAΔE and wild-type (wt) torsinA to reveal whether there are common dysfunctional features. The results revealed that the variants, R288Q and F205I, are more similar in their properties to torsinAΔE protein than to torsinAwt. These findings provide functional evidence for the potential pathogenic nature of these rare sequence variants in the TOR1A gene, thus implicating these pathologies in the development of dystonia.
Collapse
Affiliation(s)
- Jasmin Hettich
- Molecular Neurogenetics Unit, Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, Massachusetts; Department of Medical Genetics and Applied Genomics, University of Tuebingen, Tübingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Vulinovic F, Lohmann K, Rakovic A, Capetian P, Alvarez-Fischer D, Schmidt A, Weißbach A, Erogullari A, Kaiser FJ, Wiegers K, Ferbert A, Rolfs A, Klein C, Seibler P. Unraveling cellular phenotypes of novel TorsinA/TOR1A mutations. Hum Mutat 2014; 35:1114-22. [PMID: 24931141 DOI: 10.1002/humu.22604] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/04/2014] [Indexed: 01/17/2023]
Abstract
A three-nucleotide (GAG) deletion (ΔE) in TorsinA (TOR1A) has been identified as the most common cause of dominantly inherited early-onset torsion dystonia (DYT1). TOR1A encodes a chaperone-like AAA+-protein localized in the endoplasmic reticulum. Currently, only three additional, likely mutations have been reported in single dystonia patients. Here, we report two new, putative TOR1A mutations (p.A14_P15del and p.E121K) that we examined functionally in comparison with wild-type (WT) protein and two known mutations (ΔE and p.R288Q). While inclusion formation is a characteristic feature for ΔE TOR1A, elevated levels of aggregates for other mutations were not observed when compared with WT TOR1A. WT and mutant TOR1A showed preferred degradation through the autophagy-lysosome pathway, which is most pronounced for p.A14_P15del, p.R288Q, and ΔE TOR1A. Notably, blocking of the autophagy pathway with bafilomycin resulted in a significant increase in inclusion formation in p.E121K TOR1A. In addition, all variants had an influence on protein stability. Although the p.A14_P15del mutation affects the proposed oligomerization domain of TOR1A, this mutation did not disturb the ability to dimerize. Our findings demonstrate functional changes for all four mutations on different levels. Thus, both diagnostic and research genetic screening of dystonia patients should not be limited to testing for the ∆E mutation.
Collapse
Affiliation(s)
- Franca Vulinovic
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Liang CC, Tanabe LM, Jou S, Chi F, Dauer WT. TorsinA hypofunction causes abnormal twisting movements and sensorimotor circuit neurodegeneration. J Clin Invest 2014; 124:3080-92. [PMID: 24937429 DOI: 10.1172/jci72830] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 04/10/2014] [Indexed: 12/20/2022] Open
Abstract
Lack of a preclinical model of primary dystonia that exhibits dystonic-like twisting movements has stymied identification of the cellular and molecular underpinnings of the disease. The classical familial form of primary dystonia is caused by the DYT1 (ΔE) mutation in TOR1A, which encodes torsinA, AAA⁺ ATPase resident in the lumen of the endoplasmic reticular/nuclear envelope. Here, we found that conditional deletion of Tor1a in the CNS (nestin-Cre Tor1a(flox/-)) or isolated CNS expression of DYT1 mutant torsinA (nestin-Cre Tor1a(flox/ΔE)) causes striking abnormal twisting movements. These animals developed perinuclear accumulation of ubiquitin and the E3 ubiquitin ligase HRD1 in discrete sensorimotor regions, followed by neurodegeneration that was substantially milder in nestin-Cre Tor1a(flox/ΔE) compared with nestin-Cre Tor1a(flox/-) animals. Similar to the neurodevelopmental onset of DYT1 dystonia in humans, the behavioral and histopathological abnormalities emerged and became fixed during CNS maturation in the murine models. Our results establish a genetic model of primary dystonia that is overtly symptomatic, and link torsinA hypofunction to neurodegeneration and abnormal twisting movements. These findings provide a cellular and molecular framework for how impaired torsinA function selectively disrupts neural circuits and raise the possibility that discrete foci of neurodegeneration may contribute to the pathogenesis of DYT1 dystonia.
Collapse
|
40
|
Zacchi LF, Wu HC, Bell SL, Millen L, Paton AW, Paton JC, Thomas PJ, Zolkiewski M, Brodsky JL. The BiP molecular chaperone plays multiple roles during the biogenesis of torsinA, an AAA+ ATPase associated with the neurological disease early-onset torsion dystonia. J Biol Chem 2014; 289:12727-47. [PMID: 24627482 PMCID: PMC4007462 DOI: 10.1074/jbc.m113.529123] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 03/09/2014] [Indexed: 01/02/2023] Open
Abstract
Early-onset torsion dystonia (EOTD) is a neurological disorder characterized by involuntary and sustained muscle contractions that can lead to paralysis and abnormal posture. EOTD is associated with the deletion of a glutamate (ΔE) in torsinA, an endoplasmic reticulum (ER) resident AAA(+) ATPase. To date, the effect of ΔE on torsinA and the reason that this mutation results in EOTD are unclear. Moreover, there are no specific therapeutic options to treat EOTD. To define the underlying biochemical defects associated with torsinAΔE and to uncover factors that might be targeted to offset defects associated with torsinAΔE, we developed a yeast torsinA expression system and tested the roles of ER chaperones in mediating the folding and stability of torsinA and torsinAΔE. We discovered that the ER lumenal Hsp70, BiP, an associated Hsp40, Scj1, and a nucleotide exchange factor, Lhs1, stabilize torsinA and torsinAΔE. BiP also maintained torsinA and torsinAΔE solubility. Mutations predicted to compromise specific torsinA functional motifs showed a synthetic interaction with the ΔE mutation and destabilized torsinAΔE, suggesting that the ΔE mutation predisposes torsinA to defects in the presence of secondary insults. In this case, BiP was required for torsinAΔE degradation, consistent with data that specific chaperones exhibit either pro-degradative or pro-folding activities. Finally, using two independent approaches, we established that BiP stabilizes torsinA and torsinAΔE in mammalian cells. Together, these data define BiP as the first identified torsinA chaperone, and treatments that modulate BiP might improve symptoms associated with EOTD.
Collapse
Affiliation(s)
- Lucía F. Zacchi
- From the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Hui-Chuan Wu
- the Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506
| | - Samantha L. Bell
- From the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Linda Millen
- the Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, and
| | - Adrienne W. Paton
- the Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - James C. Paton
- the Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Philip J. Thomas
- the Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, and
| | - Michal Zolkiewski
- the Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506
| | - Jeffrey L. Brodsky
- From the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| |
Collapse
|
41
|
Rose AE, Zhao C, Turner EM, Steyer AM, Schlieker C. Arresting a Torsin ATPase reshapes the endoplasmic reticulum. J Biol Chem 2013; 289:552-64. [PMID: 24275647 DOI: 10.1074/jbc.m113.515791] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Torsins are membrane-tethered AAA+ ATPases residing in the nuclear envelope (NE) and endoplasmic reticulum (ER). Here, we show that the induction of a conditional, dominant-negative TorsinB variant provokes a profound reorganization of the endomembrane system into foci containing double membrane structures that are derived from the ER. These double-membrane sinusoidal structures are formed by compressing the ER lumen to a constant width of 15 nm, and are highly enriched in the ATPase activator LULL1. Further, we define an important role for a highly conserved aromatic motif at the C terminus of Torsins. Mutations in this motif perturb LULL1 binding, reduce ATPase activity, and profoundly limit the induction of sinusoidal structures.
Collapse
Affiliation(s)
- April E Rose
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | | | | | | | | |
Collapse
|
42
|
Koh JY, Iwabuchi S, Harata NC. Dystonia-associated protein torsinA is not detectable at the nerve terminals of central neurons. Neuroscience 2013; 253:316-29. [PMID: 24025868 DOI: 10.1016/j.neuroscience.2013.08.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/28/2013] [Accepted: 08/28/2013] [Indexed: 01/23/2023]
Abstract
Presynaptic functions of the mammalian central neurons are regulated by a network of protein interactions. Synaptic vesicle recycling in and neurotransmitter release from the presynaptic nerve terminals are altered when a glutamate-deleting mutation is present in the torsinA protein (ΔE-torsinA). This mutation is linked with a hereditary form of the movement disorder dystonia known as DYT1 dystonia. Although torsinA expression is prevalent throughout the central nervous system, its subcellular localization - in particular with respect to presynaptic nerve terminals - remains unclear. This information would be useful in narrowing down possible models for how wild-type torsinA affects presynaptic function, as well as the nature of the presynaptic dysfunction that arises in the context of ΔE-torsinA mutation. Here we report on an analysis of the presynaptic localization of torsinA in cultured neurons obtained from a knock-in mouse model of DYT1 dystonia. Primary cultures of neurons were established from heterozygous and homozygous ΔE-torsinA knock-in mice, as well as from their wild-type littermates. Neurons were obtained from the striatum, cerebral cortex and hippocampus of these mice, and were subjected to immunocytochemistry. This analysis revealed the expression of both proteins in the somata and dendrites. However, neither the nerve terminals nor axonal shafts were immunoreactive. These results were confirmed by fluorogram-based quantitation. Our findings indicate that neither the wild-type nor the ΔE-torsinA mutant protein is present at substantial levels in the presynaptic structures of cultured neurons. Thus, the effects of torsinA, in wild-type and mutant forms, appear to influence presynaptic function indirectly, without residing in presynaptic structures.
Collapse
Affiliation(s)
- J-Y Koh
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | | | | |
Collapse
|
43
|
Puglisi F, Vanni V, Ponterio G, Tassone A, Sciamanna G, Bonsi P, Pisani A, Mandolesi G. Torsin A Localization in the Mouse Cerebellar Synaptic Circuitry. PLoS One 2013; 8:e68063. [PMID: 23840813 PMCID: PMC3686744 DOI: 10.1371/journal.pone.0068063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/24/2013] [Indexed: 11/19/2022] Open
Abstract
Torsin A (TA) is a ubiquitous protein belonging to the superfamily of proteins called "ATPases associated with a variety of cellular activities" (AAA(+) ATPase). To date, a great deal of attention has been focused on neuronal TA since its mutant form causes early-onset (DYT1) torsion dystonia, an inherited movement disorder characterized by sustained muscle contractions and abnormal postures. Interestingly, it has been proposed that TA, by interacting with the cytoskeletal network, may contribute to the control of neurite outgrowth and/or by acting as a chaperone at synapses could affect synaptic vesicle turnover and neurotransmitter release. Accordingly, both its peculiar developmental expression in striatum and cerebellum and evidence from DYT1 knock-in mice suggest that TA may influence dendritic arborization and synaptogenesis in the brain. Therefore, to better understand TA function a detailed description of its localization at synaptic level is required. Here, we characterized by means of rigorous quantitative confocal analysis TA distribution in the mouse cerebellum at postnatal day 14 (P14), when both cerebellar synaptogenesis and TA expression peak. We observed that the protein is broadly distributed both in cerebellar cortex and in the deep cerebellar nuclei (DCN). Of note, Purkinje cells (PC) express high levels of TA also in the spines and axonal terminals. In addition, abundant expression of the protein was found in the main GABA-ergic and glutamatergic inputs of the cerebellar cortex. Finally, TA was observed also in glial cells, a cellular population little explored so far. These results extend our knowledge on TA synaptic localization providing a clue to its potential role in synaptic development.
Collapse
Affiliation(s)
- Francesca Puglisi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Valentina Vanni
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Giulia Ponterio
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Annalisa Tassone
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Giuseppe Sciamanna
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Paola Bonsi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Antonio Pisani
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
- * E-mail:
| | - Georgia Mandolesi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| |
Collapse
|
44
|
Abstract
TorsinA is a membrane-associated AAA+ (ATPases associated with a variety of cellular activities) ATPase implicated in primary dystonia, an autosomal-dominant movement disorder. We reconstituted TorsinA and its cofactors in vitro and show that TorsinA does not display ATPase activity in isolation; ATP hydrolysis is induced upon association with LAP1 and LULL1, type II transmembrane proteins residing in the nuclear envelope and endoplasmic reticulum. This interaction requires TorsinA to be in the ATP-bound state, and can be attributed to the luminal domains of LAP1 and LULL1. This ATPase activator function controls the activities of other members of the Torsin family in distinct fashion, leading to an acceleration of the hydrolysis step by up to two orders of magnitude. The dystonia-causing mutant of TorsinA is defective in this activation mechanism, suggesting a loss-of-function mechanism for this congenital disorder.
Collapse
|
45
|
Jinnah H, Richter A, Mink JW, Caldwell GA, Caldwell KA, Gonzalez-Alegre P, Cookson MR, Breakefield XO, Delong MR, Hess EJ. Animal models for drug discovery in dystonia. Expert Opin Drug Discov 2013; 3:83-97. [PMID: 23480141 DOI: 10.1517/17460441.3.1.83] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Dystonia is a neurological disorder characterized by involuntary twisting movements and unnatural postures. There are many different forms of dystonia, which affect over three million people worldwide. Effective treatments are available only for a minority of patients, so new treatments are sorely needed. Several animal species have been used to develop models for different forms of dystonia, each with differing strengths and weaknesses. This review outlines the strategies that have been used to exploit these models for drug discovery. Some have been used to dissect the pathogenesis of dystonia for the identification of molecular targets for intervention. Others have been used for the empirical identification of candidate drugs. Therefore, the animal models provide promising new tools for developing better treatments for dystonia.
Collapse
Affiliation(s)
- Ha Jinnah
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA +1 410 614 6551 ; +1 410 505 6737
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Grundmann K, Hübener J, Häbig K, Reischmann B, Poths S, Hauser TK, Magg J, Riess O, Bonin M, Nguyen HP. Gene expression changes in a transgenic mouse model overexpressing human wildtype and mutant torsinA. Proteomics Clin Appl 2012; 2:720-36. [PMID: 21136869 DOI: 10.1002/prca.200780053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Primary torsion dystonia is an autosomal-dominantly inherited, neurodevelopmental movement disorder caused by a GAG deletion (ΔGAG) in the DYT1 gene, encoding torsinA. This mutation is responsible for approximately 70% of cases of early-onset primary torsion dystonia. The function of wildtype torsinA is still unknown, and it is unsolved how the deletion in the DYT1 gene contributes to the development of the disease. To better understand the molecular processes involved in torsinA pathology, we used genome-wide oligonucleotide microarrays to characterize gene expression patterns in the striatum of mouse models overexpressing the human wildtype and mutant torsinA. By this approach we were able to detect gene expression changes that seem to be specific for torsinA pathology. We found an impact of torsinA, independent from genotype, on vesicle trafficking, exocytosis, and neurotransmitter release in our mouse model. In addition, we were able to identify several new pathways and processes involved in the development of the nervous system that are affected by wildtype and mutant torsinA. Furthermore, we have striking evidence from our gene expression data that glutamate receptor mediated synaptic plasticity in the striatum is the affected underlying cellular process for impaired motor learning in human ΔGAG torsinA transgenic mice.
Collapse
|
47
|
The zebrafish homologue of the human DYT1 dystonia gene is widely expressed in CNS neurons but non-essential for early motor system development. PLoS One 2012; 7:e45175. [PMID: 23028827 PMCID: PMC3460957 DOI: 10.1371/journal.pone.0045175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/17/2012] [Indexed: 11/19/2022] Open
Abstract
DYT1 dystonia is caused by mutation of the TOR1A gene, resulting in the loss of a single glutamic acid residue near the carboxyl terminal of TorsinA. The neuronal functions perturbed by TorsinA[ΔE] are a major unresolved issue in understanding the pathophysiology of dystonia, presenting a critical roadblock to developing effective treatments. We identified and characterized the zebrafish homologue of TOR1A, as a first step towards elucidating the functions of TorsinA in neurons, in vivo, using the genetically-manipulable zebrafish model. The zebrafish genome was found to contain a single alternatively-spliced tor1 gene, derived from a common ancestral locus shared with the dual TOR1A and TOR1B paralogues found in tertrapods. tor1 was expressed ubiquitously during early embryonic development and in multiple adult tissues, including the CNS. The 2.1 kb tor1 mRNA encodes Torsin1, which is 59% identical and 78% homologous to human TorsinA. Torsin1 was expressed as major 45 kDa and minor 47 kDa glycoproteins, within the cytoplasm of neurons and neuropil throughout the CNS. Similar to previous findings relating to human TorsinA, mutations of the ATP hydrolysis domain of Torsin1 resulted in relocalization of the protein in cultured cells from the endoplasmic reticulum to the nuclear envelope. Zebrafish embryos lacking tor1 during early development did not show impaired viability, overt morphological abnormalities, alterations in motor behavior, or developmental defects in the dopaminergic system. Torsin1 is thus non-essential for early development of the motor system, suggesting that important CNS functions may occur later in development, consistent with the critical time window in late childhood when dystonia symptoms usually emerge in DYT1 patients. The similarities between Torsin1 and human TorsinA in domain organization, expression pattern, and cellular localization suggest that the zebrafish will provide a useful model to understand the neuronal functions of Torsins in vivo.
Collapse
|
48
|
Gordon KL, Glenn KA, Bode N, Wen HM, Paulson HL, Gonzalez-Alegre P. The ubiquitin ligase F-box/G-domain protein 1 promotes the degradation of the disease-linked protein torsinA through the ubiquitin-proteasome pathway and macroautophagy. Neuroscience 2012; 224:160-71. [PMID: 22917612 DOI: 10.1016/j.neuroscience.2012.08.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/31/2012] [Accepted: 08/14/2012] [Indexed: 01/24/2023]
Abstract
DYT1 dystonia is a dominantly inherited, disabling neurological disorder with low penetrance that is caused by the deletion of a glutamic acid (ΔE) in the protein torsinA. We previously showed that torsinA(wt) is degraded through macroautophagy while torsinA(ΔE) is targeted to the ubiquitin-proteasome pathway (UPP). The different catabolism of torsinA(wt) and (ΔE) potentially modulates torsinA(wt):torsinA(ΔE) stoichiometry. Therefore, gaining a mechanistic understanding on how the protein quality control machinery clears torsinA(ΔE) in neurons may uncover important regulatory steps in disease pathogenesis. Here, we asked whether F-box/G-domain protein 1 (FBG1), a ubiquitin ligase known to degrade neuronal glycoproteins, is implicated in the degradation of torsinA(ΔE) by the UPP. In a first set of studies completed in cultured cells, we show that FBG1 interacts with and influences the steady-state levels of torsinA(wt) and (ΔE). Interestingly, FBG1 achieves this effect promoting the degradation of torsinA not only through the UPP, but also by macroautophagy. To determine the potential clinical significance of these findings, we asked if eliminating expression of Fbg1 triggers a motor phenotype in torsinA(ΔE) knock in (KI) mice, a model of non-manifesting DYT1 mutation carriers. We detected differences in spontaneous locomotion between aged torsinA(ΔE) KI-Fbg1 knock out and control mice. Furthermore, neuronal levels of torsinA were unaltered in Fbg1 null mice, indicating that redundant systems likely compensate in vivo for the absence of this ubiquitin ligase. In summary, our studies support a non-essential role for FBG1 on the degradation of torsinA and uncover a novel link of FBG1 to the autophagy pathway.
Collapse
Affiliation(s)
- K L Gordon
- Graduate Program of Neuroscience, University of Iowa, Iowa City, IA 52242, USA.
| | | | | | | | | | | |
Collapse
|
49
|
Untethering the nuclear envelope and cytoskeleton: biologically distinct dystonias arising from a common cellular dysfunction. Int J Cell Biol 2012; 2012:634214. [PMID: 22611399 PMCID: PMC3352338 DOI: 10.1155/2012/634214] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/12/2011] [Accepted: 01/08/2012] [Indexed: 12/31/2022] Open
Abstract
Most cases of early onset DYT1 dystonia in humans are caused by a GAG deletion in the TOR1A gene leading to loss of a glutamic acid (ΔE) in the torsinA protein, which underlies a movement disorder associated with neuronal dysfunction without apparent neurodegeneration. Mutation/deletion of the gene (Dst) encoding dystonin in mice results in a dystonic movement disorder termed dystonia musculorum, which resembles aspects of dystonia in humans. While torsinA and dystonin proteins do not share modular domain architecture, they participate in a similar function by modulating a structural link between the nuclear envelope and the cytoskeleton in neuronal cells. We suggest that through a shared interaction with the nuclear envelope protein nesprin-3α, torsinA and the neuronal dystonin-a2 isoform comprise a bridge complex between the outer nuclear membrane and the cytoskeleton, which is critical for some aspects of neuronal development and function. Elucidation of the overlapping roles of torsinA and dystonin-a2 in nuclear/endoplasmic reticulum dynamics should provide insights into the cellular mechanisms underlying the dystonic phenotype.
Collapse
|
50
|
Abstract
The cytoskeleton is connected to the nuclear interior by LINC (linker of nucleoskeleton and cytoskeleton) complexes located in the nuclear envelope. These complexes consist of SUN proteins and nesprins present in the inner and outer nuclear membrane respectively. Whereas SUN proteins can bind the nuclear lamina, members of the nesprin protein family connect the nucleus to different components of the cytoskeleton. Nesprin-1 and -2 can establish a direct link with actin filaments, whereas nesprin-4 associates indirectly with microtubules through its interaction with kinesin-1. Nesprin-3 is the only family member known that can link the nuclear envelope to intermediate filaments. This indirect interaction is mediated by the binding of nesprin-3 to the cytoskeletal linker protein plectin. Furthermore, nesprin-3 can connect the nucleus to microtubules by its interactions with BPAG1 (bullous pemphigoid antigen 1) and MACF (microtubule-actin cross-linking factor). In contrast with the active roles that nesprin-1, -2 and -4 have in actin- and microtubule-dependent nuclear positioning, the role of nesprin-3 is likely to be more passive. We suggest that it helps to stabilize the anchorage of the nucleus within the cytoplasm and maintain the structural integrity and shape of the nucleus.
Collapse
|