1
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Lemarié FL, Sanders SS, Nguyen Y, Martin DDO, Hayden MR. Full-length huntingtin is palmitoylated at multiple sites and post-translationally myristoylated following caspase-cleavage. Front Physiol 2023; 14:1086112. [PMID: 36711022 PMCID: PMC9880554 DOI: 10.3389/fphys.2023.1086112] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Introduction: Huntington disease is an autosomal dominant neurodegenerative disorder which is caused by a CAG repeat expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. Huntingtin is subjected to multiple post-translational modifications which regulate its cellular functions and degradation. We have previously identified a palmitoylation site at cysteine 214 (C214), catalyzed by the enzymes ZDHHC17 and ZDHHC13. Reduced palmitoylation level of mutant huntingtin is linked to toxicity and loss of function. Moreover, we have described N-terminal myristoylation by the N-myristoyltransferases of a short fragment of huntingtin (HTT553-586) at glycine 553 (G553) following proteolysis at aspartate 552 (D552). Results: Here, we show that huntingtin is palmitoylated at numerous cysteines: C105, C433, C3134 and C3144. In addition, we confirm that full-length huntingtin is cleaved at D552 and post-translationally myristoylated at G553. Importantly, blocking caspase cleavage at the critical and pathogenic aspartate 586 (D586) significantly increases posttranslational myristoylation of huntingtin. In turn, myristoylation of huntingtin promotes the co-interaction between C-terminal and N-terminal huntingtin fragments, which is also protective. Discussion: This suggests that the protective effect of inhibiting caspase-cleavage at D586 may be mediated through post-translational myristoylation of huntingtin at G553.
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2
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Pepe G, Capocci L, Marracino F, Realini N, Lenzi P, Martinello K, Bovier TF, Bichell TJ, Scarselli P, Di Cicco C, Bowman AB, Digilio FA, Fucile S, Fornai F, Armirotti A, Parlato R, Di Pardo A, Maglione V. Treatment with THI, an inhibitor of sphingosine-1-phosphate lyase, modulates glycosphingolipid metabolism and results therapeutically effective in experimental models of Huntington's disease. Mol Ther 2023; 31:282-299. [PMID: 36116006 PMCID: PMC9840122 DOI: 10.1016/j.ymthe.2022.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/05/2022] [Accepted: 09/06/2022] [Indexed: 02/06/2023] Open
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder with no effective cure currently available. Over the past few years our research has shown that alterations in sphingolipid metabolism represent a critical determinant in HD pathogenesis. In particular, aberrant metabolism of sphingosine-1-phosphate (S1P) has been reported in multiple disease settings, including human postmortem brains from HD patients. In this study, we investigate the potential therapeutic effect of the inhibition of S1P degradative enzyme SGPL1, by the chronic administration of the 2-acetyl-5-tetrahydroxybutyl imidazole (THI) inhibitor. We show that THI mitigated motor dysfunctions in both mouse and fly models of HD. The compound evoked the activation of pro-survival pathways, normalized levels of brain-derived neurotrophic factor, preserved white matter integrity, and stimulated synaptic functions in HD mice. Metabolically, THI restored normal levels of hexosylceramides and stimulated the autophagic and lysosomal machinery, facilitating the reduction of nuclear inclusions of both wild-type and mutant huntingtin proteins.
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Affiliation(s)
| | | | | | - Natalia Realini
- Analytical Chemistry Lab, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Paola Lenzi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy
| | | | - Tiziana Francesca Bovier
- Research Institute on Terrestrial Ecosystems (IRET), UOS Naples-CNR, Via Pietro Castellino 111, 80131 Naples, Italy; Department of Pediatrics Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Center for Host-Pathogen Interaction, Columbia University Vagelos College of Physicians and Surgeons, New York 10032, NY, USA
| | - Terry Jo Bichell
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA
| | | | | | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, USA
| | - Filomena A Digilio
- Research Institute on Terrestrial Ecosystems (IRET), UOS Naples-CNR, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Sergio Fucile
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Physiology and Pharmacology, Sapienza Rome University, Rome 00185, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy
| | - Andrea Armirotti
- Analytical Chemistry Lab, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Rosanna Parlato
- Division for Neurodegenerative Diseases, Department of Neurology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim Heidelberg University, Mannheim 68167, Germany
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3
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Chivet M, McCluskey M, Nicot AS, Brocard J, Beaufils M, Giovannini D, Giannesini B, Poreau B, Brocard J, Humbert S, Saudou F, Fauré J, Marty I. Huntingtin regulates calcium fluxes in skeletal muscle. J Gen Physiol 2022; 155:213700. [PMID: 36409218 PMCID: PMC9682417 DOI: 10.1085/jgp.202213103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/09/2022] [Accepted: 09/03/2022] [Indexed: 11/22/2022] Open
Abstract
The expression of the Huntingtin protein, well known for its involvement in the neurodegenerative Huntington's disease, has been confirmed in skeletal muscle. The impact of HTT deficiency was studied in human skeletal muscle cell lines and in a mouse model with inducible and muscle-specific HTT deletion. Characterization of calcium fluxes in the knock-out cell lines demonstrated a reduction in excitation-contraction (EC) coupling, related to an alteration in the coupling between the dihydropyridine receptor and the ryanodine receptor, and an increase in the amount of calcium stored within the sarcoplasmic reticulum, linked to the hyperactivity of store-operated calcium entry (SOCE). Immunoprecipitation experiments demonstrated an association of HTT with junctophilin 1 (JPH1) and stromal interaction molecule 1 (STIM1), both providing clues on the functional effects of HTT deletion on calcium fluxes. Characterization of muscle strength and muscle anatomy of the muscle-specific HTT-KO mice demonstrated that HTT deletion induced moderate muscle weakness and mild muscle atrophy associated with histological abnormalities, similar to the phenotype observed in tubular aggregate myopathy. Altogether, this study points toward the hypotheses of the involvement of HTT in EC coupling via its interaction with JPH1, and on SOCE via its interaction with JPH1 and/or STIM1.
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Affiliation(s)
- Mathilde Chivet
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Maximilian McCluskey
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Anne Sophie Nicot
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Julie Brocard
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Mathilde Beaufils
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Diane Giovannini
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Benoit Giannesini
- Centre National de la Recherche Scientifique, Centre de Résonance Magnétique Biologique et Médicale, Aix Marseille University, Marseille, France
| | - Brice Poreau
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Jacques Brocard
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Sandrine Humbert
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Frédéric Saudou
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Julien Fauré
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Isabelle Marty
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France,Correspondence to Isabelle Marty:
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4
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Ratovitski T, Jiang M, O'Meally RN, Rauniyar P, Chighladze E, Faragó A, Kamath SV, Jin J, Shevelkin AV, Cole RN, Ross CA. Interaction of huntingtin with PRMTs and its subsequent arginine methylation affects HTT solubility, phase transition behavior and neuronal toxicity. Hum Mol Genet 2022; 31:1651-1672. [PMID: 34888656 PMCID: PMC9122652 DOI: 10.1093/hmg/ddab351] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/16/2021] [Accepted: 12/02/2021] [Indexed: 11/12/2022] Open
Abstract
Huntington's disease (HD) is an incurable neurodegenerative disorder caused by a CAG expansion in the huntingtin gene (HTT). Post-translational modifications of huntingtin protein (HTT), such as phosphorylation, acetylation and ubiquitination, have been implicated in HD pathogenesis. Arginine methylation/dimethylation is an important modification with an emerging role in neurodegeneration; however, arginine methylation of HTT remains largely unexplored. Here we report nearly two dozen novel arginine methylation/dimethylation sites on the endogenous HTT from human and mouse brain and human cells suggested by mass spectrometry with data-dependent acquisition. Targeted quantitative mass spectrometry identified differential arginine methylation at specific sites in HD patient-derived striatal precursor cell lines compared to normal controls. We found that HTT can interact with several type I protein arginine methyltransferases (PRMTs) via its N-terminal domain. Using a combination of in vitro methylation and cell-based experiments, we identified PRMT4 (CARM1) and PRMT6 as major enzymes methylating HTT at specific arginines. Alterations of these methylation sites had a profound effect on biochemical properties of HTT rendering it less soluble in cells and affected its liquid-liquid phase separation and phase transition patterns in vitro. We found that expanded HTT 1-586 fragment can form liquid-like assemblies, which converted into solid-like assemblies when the R200/205 methylation sites were altered. Methyl-null alterations increased HTT toxicity to neuronal cells, while overexpression of PRMT 4 and 6 was beneficial for neuronal survival. Thus, arginine methylation pathways that involve specific HTT-modifying PRMT enzymes and modulate HTT biochemical and toxic properties could provide targets for HD-modifying therapies.
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Affiliation(s)
- Tamara Ratovitski
- To whom correspondence should be addressed at: or Christopher Ross, Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 600 North Wolfe Street, CMSC 9-123, 600 North Wolfe Street, Baltimore, MD 21287, USA. Fax: +1 4106140013; ,
| | | | | | | | - Ekaterine Chighladze
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Anikó Faragó
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Siddhi V Kamath
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jing Jin
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Alexey V Shevelkin
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Robert N Cole
- Mass Spectrometry and Proteomics Facility, Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Christopher A Ross
- To whom correspondence should be addressed at: or Christopher Ross, Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 600 North Wolfe Street, CMSC 9-123, 600 North Wolfe Street, Baltimore, MD 21287, USA. Fax: +1 4106140013; ,
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5
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Fischer DF, Dijkstra S, Lo K, Suijker J, Correia ACP, Naud P, Poirier M, Tessari MA, Boogaard I, Flynn G, Visser M, Lamers MBAC, McAllister G, Munoz-Sanjuan I, Macdonald D. Development of mAb-based polyglutamine-dependent and polyglutamine length-independent huntingtin quantification assays with cross-site validation. PLoS One 2022; 17:e0266812. [PMID: 35395060 PMCID: PMC8992994 DOI: 10.1371/journal.pone.0266812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/28/2022] [Indexed: 11/30/2022] Open
Abstract
Huntington's disease (HD) is caused by an expansion of the CAG trinucleotide repeat domain in the huntingtin gene that results in expression of a mutant huntingtin protein (mHTT) containing an expanded polyglutamine tract in the amino terminus. A number of therapeutic approaches that aim to reduce mHTT expression either locally in the CNS or systemically are in clinical development. We have previously described sensitive and selective assays that measure human HTT proteins either in a polyglutamine-independent (detecting both mutant expanded and non-expanded proteins) or in a polyglutamine length-dependent manner (detecting the disease-causing polyglutamine repeats) on the electrochemiluminescence Meso Scale Discovery detection platform. These original assays relied upon polyclonal antibodies. To ensure an accessible and sustainable resource for the HD field, we developed similar assays employing monoclonal antibodies. We demonstrate that these assays have equivalent sensitivity compared to our previous assays through the evaluation of cellular and animal model systems, as well as HD patient biosamples. We also demonstrate cross-site validation of these assays, allowing direct comparison of studies performed in geographically distinct laboratories.
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Affiliation(s)
- David F. Fischer
- Charles River, Chesterford Research Park, Saffron Walden, United Kingdom
| | | | | | | | | | - Patricia Naud
- Charles River, Shrewsbury, MA, United States of America
| | | | | | | | | | | | | | - George McAllister
- Charles River, Chesterford Research Park, Saffron Walden, United Kingdom
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
| | | | - Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
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6
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Gu X, Richman J, Langfelder P, Wang N, Zhang S, Bañez-Coronel M, Wang HB, Yang L, Ramanathan L, Deng L, Park CS, Choi CR, Cantle JP, Gao F, Gray M, Coppola G, Bates GP, Ranum LPW, Horvath S, Colwell CS, Yang XW. Uninterrupted CAG repeat drives striatum-selective transcriptionopathy and nuclear pathogenesis in human Huntingtin BAC mice. Neuron 2022; 110:1173-1192.e7. [PMID: 35114102 PMCID: PMC9462388 DOI: 10.1016/j.neuron.2022.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/30/2021] [Accepted: 01/06/2022] [Indexed: 02/08/2023]
Abstract
In Huntington's disease (HD), the uninterrupted CAG repeat length, but not the polyglutamine length, predicts disease onset. However, the underlying pathobiology remains unclear. Here, we developed bacterial artificial chromosome (BAC) transgenic mice expressing human mutant huntingtin (mHTT) with uninterrupted, and somatically unstable, CAG repeats that exhibit progressive disease-related phenotypes. Unlike prior mHTT transgenic models with stable, CAA-interrupted, polyglutamine-encoding repeats, BAC-CAG mice show robust striatum-selective nuclear inclusions and transcriptional dysregulation resembling those in murine huntingtin knockin models and HD patients. Importantly, the striatal transcriptionopathy in HD models is significantly correlated with their uninterrupted CAG repeat length but not polyglutamine length. Finally, among the pathogenic entities originating from mHTT genomic transgenes and only present or enriched in the uninterrupted CAG repeat model, somatic CAG repeat instability and nuclear mHTT aggregation are best correlated with early-onset striatum-selective molecular pathogenesis and locomotor and sleep deficits, while repeat RNA-associated pathologies and repeat-associated non-AUG (RAN) translation may play less selective or late pathogenic roles, respectively.
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Affiliation(s)
- Xiaofeng Gu
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jeffrey Richman
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peter Langfelder
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Nan Wang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Shasha Zhang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Monica Bañez-Coronel
- Center for Neurogenetics, Department of Molecular Genetics and Microbiology, College of Medicine, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute of Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Huei-Bin Wang
- Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lucia Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lalini Ramanathan
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Linna Deng
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chang Sin Park
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher R Choi
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jeffrey P Cantle
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Fuying Gao
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Michelle Gray
- Department of Neurology and Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Giovanni Coppola
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gillian P Bates
- Huntington's Disease Centre, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Laura P W Ranum
- Center for Neurogenetics, Department of Molecular Genetics and Microbiology, College of Medicine, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute of Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Steve Horvath
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher S Colwell
- Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - X William Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA; Department Psychiatry and Biobehavioral Science, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
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7
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Huang B, Seefelder M, Buck E, Engler T, Lindenberg KS, Klein F, Landwehrmeyer GB, Kochanek S. HAP40 protein levels are huntingtin-dependent and decrease in Huntington disease. Neurobiol Dis 2021; 158:105476. [PMID: 34390835 DOI: 10.1016/j.nbd.2021.105476] [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: 02/08/2021] [Revised: 07/08/2021] [Accepted: 08/09/2021] [Indexed: 12/01/2022] Open
Abstract
The huntingtin-associated protein 40 (HAP40) is an abundant interactor of huntingtin (HTT). In complexes of these proteins, HAP40 tightly binds to HTT in a cleft formed by two larger domains rich in HEAT repeats, and a smaller bridge domain connecting the two. We show that HAP40 steady-state protein levels are directly dependent on HTT (both normal and mutant HTT) and that HAP40 is strongly stabilized by the interaction with HTT resulting in an at least 5-fold increase in HAP40's half-life when bound to HTT. Cellular HAP40 protein levels were reduced in primary fibroblasts and lymphoblasts of Huntington Disease (HD) patients and in brain tissue of a full-length HTT mouse model of HD, concomitant with decreased soluble HTT levels in these cell types. This data and our previous demonstration of coevolution between HTT and HAP40 and evolutionary conservation of their interaction suggest that HAP40 is an obligate interaction partner of HTT. Our observation of reduced HAP40 levels in HD invites further studies, whether HAP40 loss-of-function contributes to the pathophysiology of HD.
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Affiliation(s)
- Bin Huang
- Department of Gene Therapy, Ulm University, 89081 Ulm, Germany
| | | | - Eva Buck
- Department of Neurology, Ulm University, 89081 Ulm, Germany
| | - Tatjana Engler
- Department of Gene Therapy, Ulm University, 89081 Ulm, Germany
| | | | - Fabrice Klein
- Department of Neurology, Ulm University, 89081 Ulm, Germany
| | | | - Stefan Kochanek
- Department of Gene Therapy, Ulm University, 89081 Ulm, Germany.
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8
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Bartl S, Oueslati A, Southwell AL, Siddu A, Parth M, David LS, Maxan A, Salhat N, Burkert M, Mairhofer A, Friedrich T, Pankevych H, Balazs K, Staffler G, Hayden MR, Cicchetti F, Smrzka OW. Inhibiting cellular uptake of mutant huntingtin using a monoclonal antibody: Implications for the treatment of Huntington's disease. Neurobiol Dis 2020; 141:104943. [PMID: 32407769 DOI: 10.1016/j.nbd.2020.104943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/08/2020] [Accepted: 05/06/2020] [Indexed: 12/24/2022] Open
Abstract
Huntington's disease (HD) is caused by a highly polymorphic CAG trinucleotide expansion in the gene encoding for the huntingtin protein (HTT). The resulting mutant huntingtin protein (mutHTT) is ubiquitously expressed but also exhibits the ability to propagate from cell-to-cell to disseminate pathology; a property which may serve as a new therapeutic focus. Accordingly, we set out to develop a monoclonal antibody (mAB) targeting a particularly exposed region close to the aa586 caspase-6 cleavage site of the HTT protein. This monoclonal antibody, designated C6-17, effectively binds mutHTT and is able to deplete the protein from cell culture supernatants. Using cell-based assays, we demonstrate that extracellular secretion of mutHTT into cell culture media and its subsequent uptake in recipient HeLa cells can be almost entirely blocked by mAB C6-17. Immunohistochemical stainings of post-mortem HD brain tissue confirmed the specificity of mAB C6-17 to human mutHTT aggregates. These findings demonstrate that mAB C6-17 not only successfully engages with its target, mutHTT, but also inhibits cell uptake suggesting that this antibody could interfere with the pathological processes of mutHTT spreading in vivo.
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Affiliation(s)
| | - Abid Oueslati
- Université Laval/Centre de recherche du CHU, Québec, Canada
| | | | - Alberto Siddu
- Université Laval/Centre de recherche du CHU, Québec, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | - Oskar W Smrzka
- AFFiRiS AG, Vienna, Austria; Ablevia biotech GmbH, Vienna, Austria
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9
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Ultrasensitive quantitative measurement of huntingtin phosphorylation at residue S13. Biochem Biophys Res Commun 2020; 521:549-554. [DOI: 10.1016/j.bbrc.2019.09.097] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 09/22/2019] [Indexed: 11/21/2022]
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10
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Reindl W, Baldo B, Schulz J, Janack I, Lindner I, Kleinschmidt M, Sedaghat Y, Thiede C, Tillack K, Schmidt C, Cardaun I, Schwagarus T, Herrmann F, Hotze M, Osborne GF, Herrmann S, Weiss A, Zerbinatti C, Bates GP, Bard J, Munoz-Sanjuan I, Macdonald D. Meso scale discovery-based assays for the detection of aggregated huntingtin. PLoS One 2019; 14:e0213521. [PMID: 30913220 PMCID: PMC6435127 DOI: 10.1371/journal.pone.0213521] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/24/2019] [Indexed: 12/31/2022] Open
Abstract
Huntington's disease (HD) is a monogenic neurodegenerative disorder caused by an expansion of the CAG trinucleotide repeat domain in the huntingtin (HTT) gene, leading to an expanded poly-glutamine (polyQ) stretch in the HTT protein. This mutant HTT (mHTT) protein is highly prone to intracellular aggregation, causing significant damage and cellular loss in the striatal, cortical, and other regions of the brain. Therefore, modulation of mHTT levels in these brain regions in order to reduce intracellular mHTT and aggregate levels represents a direct approach in the development of HD therapeutics. To this end, assays that can be used to detect changes in HTT levels in biological samples are invaluable tools to assess target engagement and guide dose selection in clinical trials. The Meso Scale Discovery (MSD) ELISA-based assay platform is a robust and sensitive method previously employed for the quantification of HTT. However, the currently available MSD assays for HTT are primarily detecting the monomeric soluble form of the protein, but not aggregated species. In this study, we describe the development of novel MSD assays preferentially detecting mHTT in an aggregated form. Recombinant monomeric HTT(1-97)-Q46, which forms aggregates in a time-dependent manner, was used to characterize the ability of each established assay to distinguish between HTT monomers and HTT in a higher assembly state. Further validation of these assays was performed using brain lysates from R6/2, zQ175 knock-in, and BACHD mouse models, to replicate a previously well-characterized age-dependent increase in brain aggregate signals, as well as a significant reduction of aggregate levels in the striatum following mHTT knockdown with a CAG-directed allele-specific zinc-finger repressor protein (ZFP). Lastly, size exclusion chromatography was used to separate and characterize HTT species from brain tissue lysates to demonstrate specificity of the assays for the fractions containing aggregated HTT. In summary, we demonstrate that the newly developed assays preferentially detect aggregated HTT with improved performance in comparison to previous assay technologies. These assays complement the existing MSD platform assays specific for soluble HTT monomers, allowing for a more comprehensive analysis of disease-relevant HTT species in preclinical models of HD.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Georgina F. Osborne
- Dept. Neurodegenerative Disease, Huntington’s Disease Centre and Dementia Research Institute, Institute of Neurology, University College London, London, United Kingdom
| | | | | | | | - Gillian P. Bates
- Dept. Neurodegenerative Disease, Huntington’s Disease Centre and Dementia Research Institute, Institute of Neurology, University College London, London, United Kingdom
| | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
| | | | - Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
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Hensman Moss DJ, Robertson N, Farmer R, Scahill RI, Haider S, Tessari MA, Flynn G, Fischer DF, Wild EJ, Macdonald D, Tabrizi SJ. Quantification of huntingtin protein species in Huntington's disease patient leukocytes using optimised electrochemiluminescence immunoassays. PLoS One 2017; 12:e0189891. [PMID: 29272284 PMCID: PMC5741241 DOI: 10.1371/journal.pone.0189891] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/01/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal dominant neurodegenerative condition caused by an expanded CAG repeat in the gene encoding huntingtin (HTT). Optimizing peripheral quantification of huntingtin throughout the course of HD is valuable not only to illuminate the natural history and pathogenesis of disease, but also to detect peripheral effects of drugs in clinical trial. RATIONALE We previously demonstrated that mutant HTT (mHTT) was significantly elevated in purified HD patient leukocytes compared with controls and that these levels track disease progression. Our present study investigates whether the same result can be achieved with a simpler and more scalable collection technique that is more suitable for clinical trials. METHODS We collected whole blood at 133 patient visits in two sample sets and generated peripheral blood mononuclear cells (PBMCs). Levels of mHTT, as well as N-, and C-terminal and mid-region huntingtin were measured in the PBMCs using ELISA-based Meso Scale Discovery (MSD) electrochemiluminescence immunoassay platforms, and we evaluated the relationship between different HTT species, disease stage, and brain atrophy on magnetic resonance imaging. CONCLUSIONS The assays were sensitive and accurate. We confirm our previous findings that mHTT increases with advancing disease stage in patient PBMCs, this time using a simple collection protocol and scalable assay.
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Affiliation(s)
- Davina J. Hensman Moss
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Nicola Robertson
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Ruth Farmer
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rachael I. Scahill
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Salman Haider
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | | | | | | | - Edward J. Wild
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, California, United States of America
| | - Sarah J. Tabrizi
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
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12
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Phosphorylation of huntingtin at residue T3 is decreased in Huntington's disease and modulates mutant huntingtin protein conformation. Proc Natl Acad Sci U S A 2017; 114:E10809-E10818. [PMID: 29162692 PMCID: PMC5740681 DOI: 10.1073/pnas.1705372114] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Posttranslational modifications can have profound effects on the biological and biophysical properties of proteins associated with misfolding and aggregation. However, their detection and quantification in clinical samples and an understanding of the mechanisms underlying the pathological properties of misfolding- and aggregation-prone proteins remain a challenge for diagnostics and therapeutics development. We have applied an ultrasensitive immunoassay platform to develop and validate a quantitative assay for detecting a posttranslational modification (phosphorylation at residue T3) of a protein associated with polyglutamine repeat expansion, namely Huntingtin, and characterized its presence in a variety of preclinical and clinical samples. We find that T3 phosphorylation is greatly reduced in samples from Huntington's disease models and in Huntington's disease patients, and we provide evidence that bona-fide T3 phosphorylation alters Huntingtin exon 1 protein conformation and aggregation properties. These findings have significant implications for both mechanisms of disease pathogenesis and the development of therapeutics and diagnostics for Huntington's disease.
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13
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N-terminal Huntingtin Knock-In Mice: Implications of Removing the N-terminal Region of Huntingtin for Therapy. PLoS Genet 2016; 12:e1006083. [PMID: 27203582 PMCID: PMC4874551 DOI: 10.1371/journal.pgen.1006083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/04/2016] [Indexed: 02/07/2023] Open
Abstract
The Huntington’s disease (HD) protein, huntingtin (HTT), is a large protein consisting of 3144 amino acids and has conserved N-terminal sequences that are followed by a polyglutamine (polyQ) repeat. Loss of Htt is known to cause embryonic lethality in mice, whereas polyQ expansion leads to adult neuronal degeneration. Whether N-terminal HTT is essential for neuronal development or contributes only to late-onset neurodegeneration remains unknown. We established HTT knock-in mice (N160Q-KI) expressing the first 208 amino acids of HTT with 160Q, and they show age-dependent HTT aggregates in the brain and neurological phenotypes. Importantly, the N-terminal mutant HTT also preferentially accumulates in the striatum, the brain region most affected in HD, indicating the importance of N-terminal HTT in selective neuropathology. That said, homozygous N160Q-KI mice are also embryonic lethal, suggesting that N-terminal HTT alone is unable to support embryonic development. Using Htt knockout neurons, we found that loss of Htt selectively affects the survival of developing neuronal cells, but not astrocytes, in culture. This neuronal degeneration could be rescued by a truncated HTT lacking the first 237 amino acids, but not by N-terminal HTT (1–208 amino acids). Also, the rescue effect depends on the region in HTT known to be involved in intracellular trafficking. Thus, the N-terminal HTT region may not be essential for the survival of developing neurons, but when carrying a large polyQ repeat, can cause selective neuropathology. These findings imply a possible therapeutic benefit of removing the N-terminal region of HTT containing the polyQ repeat to treat the neurodegeneration in HD. The 17 amino acids in the N-terminal region of huntingtin (HTT) are conserved in a wide range of species and are followed by a polyglutamine repeat whose expansion causes selective neurodegeneration in Huntington’s disease (HD). Loss of Htt can affect developing neurons and early embryonic development in mice. Whether N-terminal HTT is important for the survival of developing neurons or contributes mainly to a gain of toxic function in HD remains unknown. In the current study, we generated N-terminal mutant HTT knock-in mice and found that N-terminal HTT with an expanded polyQ repeat is unable to support the early development of mice, but can cause age-dependent neurological phenotypes. Further, we show that a truncated HTT without the N-terminal region can rescue the Htt loss-mediated degeneration of developing neurons. Our studies suggest that removal of the N-terminal region of mutant HTT could be a strategy to abolish the neuronal toxicity of mutant HTT.
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14
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Macdonald D, Tessari MA, Boogaard I, Smith M, Pulli K, Szynol A, Albertus F, Lamers MBAC, Dijkstra S, Kordt D, Reindl W, Herrmann F, McAllister G, Fischer DF, Munoz-Sanjuan I. Quantification assays for total and polyglutamine-expanded huntingtin proteins. PLoS One 2014; 9:e96854. [PMID: 24816435 PMCID: PMC4016121 DOI: 10.1371/journal.pone.0096854] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 04/12/2014] [Indexed: 11/18/2022] Open
Abstract
The expansion of a CAG trinucleotide repeat in the huntingtin gene, which produces huntingtin protein with an expanded polyglutamine tract, is the cause of Huntington's disease (HD). Recent studies have reported that RNAi suppression of polyglutamine-expanded huntingtin (mutant HTT) in HD animal models can ameliorate disease phenotypes. A key requirement for such preclinical studies, as well as eventual clinical trials, aimed to reduce mutant HTT exposure is a robust method to measure HTT protein levels in select tissues. We have developed several sensitive and selective assays that measure either total human HTT or polyglutamine-expanded human HTT proteins on the electrochemiluminescence Meso Scale Discovery detection platform with an increased dynamic range over other methods. In addition, we have developed an assay to detect endogenous mouse and rat HTT proteins in pre-clinical models of HD to monitor effects on the wild type protein of both allele selective and non-selective interventions. We demonstrate the application of these assays to measure HTT protein in several HD in vitro cellular and in vivo animal model systems as well as in HD patient biosamples. Furthermore, we used purified recombinant HTT proteins as standards to quantitate the absolute amount of HTT protein in such biosamples.
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Affiliation(s)
- Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, California, United States of America
- * E-mail:
| | | | | | - Melanie Smith
- BioFocus, a Charles River company, Saffron Walden, United Kingdom
| | | | | | | | | | - Sipke Dijkstra
- BioFocus, a Charles River company, Leiden, The Netherlands
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15
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Pardo R, Molina-Calavita M, Poizat G, Keryer G, Humbert S, Saudou F. pARIS-htt: an optimised expression platform to study huntingtin reveals functional domains required for vesicular trafficking. Mol Brain 2010; 3:17. [PMID: 20515468 PMCID: PMC2887845 DOI: 10.1186/1756-6606-3-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 06/01/2010] [Indexed: 01/02/2023] Open
Abstract
Background Huntingtin (htt) is a multi-domain protein of 350 kDa that is mutated in Huntington's disease (HD) but whose function is yet to be fully understood. This absence of information is due in part to the difficulty of manipulating large DNA fragments by using conventional molecular cloning techniques. Consequently, few studies have addressed the cellular function(s) of full-length htt and its dysfunction(s) associated with the disease. Results We describe a flexible synthetic vector encoding full-length htt called pARIS-htt (Adaptable, RNAi Insensitive &Synthetic). It includes synthetic cDNA coding for full-length human htt modified so that: 1) it is improved for codon usage, 2) it is insensitive to four different siRNAs allowing gene replacement studies, 3) it contains unique restriction sites (URSs) dispersed throughout the entire sequence without modifying the translated amino acid sequence, 4) it contains multiple cloning sites at the N and C-ter ends and 5) it is Gateway compatible. These modifications facilitate mutagenesis, tagging and cloning into diverse expression plasmids. Htt regulates dynein/dynactin-dependent trafficking of vesicles, such as brain-derived neurotrophic factor (BDNF)-containing vesicles, and of organelles, including reforming and maintenance of the Golgi near the cell centre. We used tests of these trafficking functions to validate various pARIS-htt constructs. We demonstrated, after silencing of endogenous htt, that full-length htt expressed from pARIS-htt rescues Golgi apparatus reformation following reversible microtubule disruption. A mutant form of htt that contains a 100Q expansion and a htt form devoid of either HAP1 or dynein interaction domains are both unable to rescue loss of endogenous htt. These mutants have also an impaired capacity to promote BDNF vesicular trafficking in neuronal cells. Conclusion We report the validation of a synthetic gene encoding full-length htt protein that will facilitate analyses of its structure/function. This may help provide relevant information about the cellular dysfunctions operating during the disease. As proof of principle, we show that either polyQ expansion or deletion of key interacting domains within full-length htt protein impairs its function in transport indicating that HD mutation induces defects on intrinsic properties of the protein and further demonstrating the importance of studying htt in its full-length context.
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16
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Dehay B, Weber C, Trottier Y, Bertolotti A. Mapping of the epitope of monoclonal antibody 2B4 to the proline-rich region of human Huntingtin, a region critical for aggregation and toxicity. Biotechnol J 2007; 2:559-64. [PMID: 17373643 DOI: 10.1002/biot.200600249] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Huntington's disease is a neurodegenerative disease caused by a polyglutamine (polyQ) expansion in Huntingtin, which provokes aggregation of a proteolytic amino-terminal fragment of the affected protein encompassing the polyQ expansion. Accumulation of mutant Huntingtin somehow triggers cellular dysfunction and leads to a progressive degeneration of striatal neurons. Despite considerable efforts, the function of Huntingtin as well as the precise molecular mechanisms by which the expanded polyQ elicits cellular dysfunction remain unclear. In addition, no treatment is available to prevent, cure, or even slow down the progression of this devastating disorder. Antibodies are valuable tools to understand protein function and disease mechanisms. Here, we have identified the epitope recognized by the mAb 2B4, a broadly used antibody generated against the amino-terminal region of Huntingtin, which detects both aggregated and soluble Huntingtin. The 2B4 antibody specifically recognizes amino acids 50-64 of human Huntingtin but not the murine homologous region. Furthermore, the 2B4 epitope resides within the proline-rich region of Huntingtin, which is critical for polyQ aggregation and toxicity. These properties suggest that the 2B4 antibody might be useful in antibody-based therapeutic strategies.
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Affiliation(s)
- Benjamin Dehay
- Laboratoire de Génétique Moléculaire, CNRS UMR8541, Ecole Normale Supérieure, Paris, France
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Cong SY, Pepers BA, Roos RAC, van Ommen GJB, Dorsman JC. Small N-terminal mutant huntingtin fragments, but not wild type, are mainly present in monomeric form: Implications for pathogenesis. Exp Neurol 2005; 199:257-64. [PMID: 16380118 DOI: 10.1016/j.expneurol.2005.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 11/14/2005] [Accepted: 11/15/2005] [Indexed: 11/29/2022]
Abstract
N-terminal fragments of huntingtin containing an expanded polyglutamine stretch play an important role in the molecular pathogenesis of Huntington's disease. Their ultimate accumulation in insoluble protein aggregates constitutes an important pathological hallmark of Huntington's disease. We report on systematic biochemical comparison studies of soluble wild type and mutant N-terminal huntingtin fragments. The results show that soluble wild type exon 1 fragments are predominantly present in higher molecular weight complexes with a molecular size of approximately 300 kDa, while their mutant counterparts are mainly present in their monomeric form. In contrast, longer N-terminal fragments corresponding to peptides produced by caspase cleavage do not display these differential properties. These findings suggest that especially an increased amount of monomeric form of small N-terminal mutant huntingtin fragments may facilitate aberrant interactions both with itself via the polyglutamine stretch and with other proteins and thereby contribute to molecular pathogenesis.
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Affiliation(s)
- Shu-Yan Cong
- CBG-Center of Human and Clinical Genetics, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands
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