1
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Bennett CL, Dastidar S, Arnold FJ, McKinstry SU, Stockford C, Freibaum BD, Sopher BL, Wu M, Seidner G, Joiner W, Taylor JP, West RJH, La Spada AR. Senataxin helicase, the causal gene defect in ALS4, is a significant modifier of C9orf72 ALS G4C2 and arginine-containing dipeptide repeat toxicity. Acta Neuropathol Commun 2023; 11:164. [PMID: 37845749 PMCID: PMC10580588 DOI: 10.1186/s40478-023-01665-z] [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: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023] Open
Abstract
Identifying genetic modifiers of familial amyotrophic lateral sclerosis (ALS) may reveal targets for therapeutic modulation with potential application to sporadic ALS. GGGGCC (G4C2) repeat expansions in the C9orf72 gene underlie the most common form of familial ALS, and generate toxic arginine-containing dipeptide repeats (DPRs), which interfere with membraneless organelles, such as the nucleolus. Here we considered senataxin (SETX), the genetic cause of ALS4, as a modifier of C9orf72 ALS, because SETX is a nuclear helicase that may regulate RNA-protein interactions involved in ALS dysfunction. After documenting that decreased SETX expression enhances arginine-containing DPR toxicity and C9orf72 repeat expansion toxicity in HEK293 cells and primary neurons, we generated SETX fly lines and evaluated the effect of SETX in flies expressing either (G4C2)58 repeats or glycine-arginine-50 [GR(50)] DPRs. We observed dramatic suppression of disease phenotypes in (G4C2)58 and GR(50) Drosophila models, and detected a striking relocalization of GR(50) out of the nucleolus in flies co-expressing SETX. Next-generation GR(1000) fly models, that show age-related motor deficits in climbing and movement assays, were similarly rescued with SETX co-expression. We noted that the physical interaction between SETX and arginine-containing DPRs is partially RNA-dependent. Finally, we directly assessed the nucleolus in cells expressing GR-DPRs, confirmed reduced mobility of proteins trafficking to the nucleolus upon GR-DPR expression, and found that SETX dosage modulated nucleolus liquidity in GR-DPR-expressing cells and motor neurons. These findings reveal a hitherto unknown connection between SETX function and cellular processes contributing to neuron demise in the most common form of familial ALS.
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Affiliation(s)
- Craig L Bennett
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Somasish Dastidar
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
- Center for Molecular Neurosciences, Kasturba Medical College, Manipal, 576104, India
| | - Frederick J Arnold
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
| | - Spencer U McKinstry
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Cameron Stockford
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
| | - Brian D Freibaum
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Bryce L Sopher
- Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, 98195, USA
| | - Meilin Wu
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Glen Seidner
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - William Joiner
- Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, 98195, USA
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA
| | - Ryan J H West
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK.
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Albert R La Spada
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA.
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Neurobiology and Behavior, University of California Irvine School of Biosciences, Irvine, CA, 92697, USA.
- UCI Center for Neurotherapeutics, University of California Irvine, Irvine, CA, 92697, USA.
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2
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Morón-Oset J, Fischer LK, Carcolé M, Giblin A, Zhang P, Isaacs AM, Grönke S, Partridge L. Toxicity of C9orf72-associated dipeptide repeat peptides is modified by commonly used protein tags. Life Sci Alliance 2023; 6:e202201739. [PMID: 37308278 PMCID: PMC10262077 DOI: 10.26508/lsa.202201739] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/14/2023] Open
Abstract
Hexanucleotide repeat expansions in the C9orf72 gene are the most prevalent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Transcripts of the expansions are translated into toxic dipeptide repeat (DPR) proteins. Most preclinical studies in cell and animal models have used protein-tagged polyDPR constructs to investigate DPR toxicity but the effects of tags on DPR toxicity have not been systematically explored. Here, we used Drosophila to assess the influence of protein tags on DPR toxicity. Tagging of 36 but not 100 arginine-rich DPRs with mCherry increased toxicity, whereas adding mCherry or GFP to GA100 completely abolished toxicity. FLAG tagging also reduced GA100 toxicity but less than the longer fluorescent tags. Expression of untagged but not GFP- or mCherry-tagged GA100 caused DNA damage and increased p62 levels. Fluorescent tags also affected GA100 stability and degradation. In summary, protein tags affect DPR toxicity in a tag- and DPR-dependent manner, and GA toxicity might be underestimated in studies using tagged GA proteins. Thus, including untagged DPRs as controls is important when assessing DPR toxicity in preclinical models.
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Affiliation(s)
| | | | - Mireia Carcolé
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
| | - Ashling Giblin
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Pingze Zhang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
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3
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Morón-Oset J, Fischer LKS, Jauré N, Zhang P, Jahn AJ, Supèr T, Pahl A, Isaacs AM, Grönke S, Partridge L. Repeat length of C9orf72-associated glycine-alanine polypeptides affects their toxicity. Acta Neuropathol Commun 2023; 11:140. [PMID: 37644512 PMCID: PMC10463776 DOI: 10.1186/s40478-023-01634-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/31/2023] Open
Abstract
G4C2 hexanucleotide repeat expansions in a non-coding region of the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). G4C2 insertion length is variable, and patients can carry up to several thousand repeats. Dipeptide repeat proteins (DPRs) translated from G4C2 transcripts are thought to be a main driver of toxicity. Experiments in model organisms with relatively short DPRs have shown that arginine-rich DPRs are most toxic, while polyGlycine-Alanine (GA) DPRs cause only mild toxicity. However, GA is the most abundant DPR in patient brains, and experimental work in animals has generally relied on the use of low numbers of repeats, with DPRs often tagged for in vivo tracking. Whether repeat length or tagging affect the toxicity of GA has not been systematically assessed. Therefore, we generated Drosophila fly lines expressing GA100, GA200 or GA400 specifically in adult neurons. Consistent with previous studies, expression of GA100 and GA200 caused only mild toxicity. In contrast, neuronal expression of GA400 drastically reduced climbing ability and survival of flies, indicating that long GA DPRs can be highly toxic in vivo. This toxicity could be abolished by tagging GA400. Proteomics analysis of fly brains showed a repeat-length-dependent modulation of the brain proteome, with GA400 causing earlier and stronger changes than shorter GA proteins. PolyGA expression up-regulated proteins involved in ER to Golgi trafficking, and down-regulated proteins involved in insulin signalling. Experimental down-regulation of Tango1, a highly conserved regulator of ER-to Golgi transport, partially rescued GA400 toxicity, suggesting that misregulation of this process contributes to polyGA toxicity. Experimentally increasing insulin signaling also rescued GA toxicity. In summary, our data show that long polyGA proteins can be highly toxic in vivo, and that they may therefore contribute to ALS/FTD pathogenesis in patients.
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Affiliation(s)
- Javier Morón-Oset
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | | | - Nathalie Jauré
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Pingze Zhang
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Annika Julia Jahn
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Tessa Supèr
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - André Pahl
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
| | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK.
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4
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Arnold FJ, Nguyen AD, Bedlack RS, Bennett CL, La Spada AR. Intercellular transmission of pathogenic proteins in ALS: Exploring the pathogenic wave. Neurobiol Dis 2023:106218. [PMID: 37394036 DOI: 10.1016/j.nbd.2023.106218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/16/2023] [Accepted: 06/28/2023] [Indexed: 07/04/2023] Open
Abstract
In patients with amyotrophic lateral sclerosis (ALS), disease symptoms and pathology typically spread in a predictable spatiotemporal pattern beginning at a focal site of onset and progressing along defined neuroanatomical tracts. Like other neurodegenerative diseases, ALS is characterized by the presence of protein aggregates in postmortem patient tissue. Cytoplasmic, ubiquitin-positive aggregates of TDP-43 are observed in approximately 97% of sporadic and familial ALS patients, while SOD1 inclusions are likely specific to cases of SOD1-ALS. Additionally, the most common subtype of familial ALS, caused by a hexanucleotide repeat expansion in the first intron of the C9orf72 gene (C9-ALS), is further characterized by the presence of aggregated dipeptide repeat proteins (DPRs). As we will describe, cell-to-cell propagation of these pathological proteins tightly correlates with the contiguous spread of disease. While TDP-43 and SOD1 are capable of seeding protein misfolding and aggregation in a prion-like manner, C9orf72 DPRs appear to induce (and transmit) a 'disease state' more generally. Multiple mechanisms of intercellular transport have been described for all of these proteins, including anterograde and retrograde axonal transport, extracellular vesicle secretion, and macropinocytosis. In addition to neuron-to-neuron transmission, transmission of pathological proteins occurs between neurons and glia. Given that the spread of ALS disease pathology corresponds with the spread of symptoms in patients, the various mechanisms by which ALS-associated protein aggregates propagate through the central nervous system should be closely examined.
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Affiliation(s)
- F J Arnold
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, USA; Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA
| | - A D Nguyen
- Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA
| | - R S Bedlack
- Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA
| | - C L Bennett
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, USA; Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA.
| | - A R La Spada
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, USA; Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA; Departments of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA; Department of Neurology, University of California, Irvine, Irvine, CA, USA; Department of Biological Chemistry, University of California, Irvine, Irvine, CA, USA; UCI Center for Neurotherapeutics, University of California, Irvine, Irvine, CA 92697, USA.
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5
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Marchi PM, Marrone L, Brasseur L, Coens A, Webster CP, Bousset L, Destro M, Smith EF, Walther CG, Alfred V, Marroccella R, Graves EJ, Robinson D, Shaw AC, Wan LM, Grierson AJ, Ebbens SJ, De Vos KJ, Hautbergue GM, Ferraiuolo L, Melki R, Azzouz M. C9ORF72-derived poly-GA DPRs undergo endocytic uptake in iAstrocytes and spread to motor neurons. Life Sci Alliance 2022; 5:5/9/e202101276. [PMID: 35568435 PMCID: PMC9108631 DOI: 10.26508/lsa.202101276] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 11/24/2022] Open
Abstract
Dipeptide repeat (DPR) proteins are aggregation-prone polypeptides encoded by the pathogenic GGGGCC repeat expansion in the C9ORF72 gene, the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. In this study, we focus on the role of poly-GA DPRs in disease spread. We demonstrate that recombinant poly-GA oligomers can directly convert into solid-like aggregates and form characteristic β-sheet fibrils in vitro. To dissect the process of cell-to-cell DPR transmission, we closely follow the fate of poly-GA DPRs in either their oligomeric or fibrillized form after administration in the cell culture medium. We observe that poly-GA DPRs are taken up via dynamin-dependent and -independent endocytosis, eventually converging at the lysosomal compartment and leading to axonal swellings in neurons. We then use a co-culture system to demonstrate astrocyte-to-motor neuron DPR propagation, showing that astrocytes may internalise and release aberrant peptides in disease pathogenesis. Overall, our results shed light on the mechanisms of poly-GA cellular uptake and propagation, suggesting lysosomal impairment as a possible feature underlying the cellular pathogenicity of these DPR species.
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Affiliation(s)
- Paolo M Marchi
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Lara Marrone
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Laurent Brasseur
- The French Alternative Energies and Atomic Energy Commission (CEA), Institut François Jacob (MIRcen) and The French National Centre for Scientific Research (CNRS), Laboratory of Neurodegenerative Diseases (UMR9199), Fontenay-aux-Roses, France
| | - Audrey Coens
- The French Alternative Energies and Atomic Energy Commission (CEA), Institut François Jacob (MIRcen) and The French National Centre for Scientific Research (CNRS), Laboratory of Neurodegenerative Diseases (UMR9199), Fontenay-aux-Roses, France
| | - Christopher P Webster
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Luc Bousset
- The French Alternative Energies and Atomic Energy Commission (CEA), Institut François Jacob (MIRcen) and The French National Centre for Scientific Research (CNRS), Laboratory of Neurodegenerative Diseases (UMR9199), Fontenay-aux-Roses, France
| | - Marco Destro
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Emma F Smith
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK.,Centre for Membrane Interactions and Dynamics, University of Sheffield, Western Bank, Sheffield, UK
| | - Christa G Walther
- The Wolfson Light Microscopy Facility, University of Sheffield, Sheffield, UK
| | - Victor Alfred
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Raffaele Marroccella
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Emily J Graves
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Darren Robinson
- The Wolfson Light Microscopy Facility, University of Sheffield, Sheffield, UK
| | - Allan C Shaw
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Lai Mei Wan
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Andrew J Grierson
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Stephen J Ebbens
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Kurt J De Vos
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK.,Centre for Membrane Interactions and Dynamics, University of Sheffield, Western Bank, Sheffield, UK
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Ronald Melki
- The French Alternative Energies and Atomic Energy Commission (CEA), Institut François Jacob (MIRcen) and The French National Centre for Scientific Research (CNRS), Laboratory of Neurodegenerative Diseases (UMR9199), Fontenay-aux-Roses, France
| | - Mimoun Azzouz
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK .,Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
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6
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Ramírez de Mingo D, Pantoja-Uceda D, Hervás R, Carrión-Vázquez M, Laurents DV. Conformational dynamics in the disordered region of human CPEB3 linked to memory consolidation. BMC Biol 2022; 20:129. [PMID: 35658951 PMCID: PMC9166367 DOI: 10.1186/s12915-022-01310-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 04/25/2022] [Indexed: 11/10/2022] Open
Abstract
Background Current understanding of the molecular basis of memory consolidation points to an important function of amyloid formation by neuronal-specific isoforms of the cytoplasmic polyadenylation element binding (CPEB) protein family. In particular, CPEB is thought to promote memory persistence through formation of self-sustaining prion-like amyloid assemblies at synapses, mediated by its intrinsically disordered region (IDR) and leading to permanent physical alterations at the basis of memory persistence. Although the molecular mechanisms by which amyloid formation takes place in CPEB have been described in invertebrates, the way amyloid formation occurs in the human homolog CPEB3 (hCPEB3) remains unclear. Here, we characterize by NMR spectroscopy the atomic level conformation and ps-ms dynamics of the 426-residue IDR of hCPEB3, which has been associated with episodic memory in humans. Results We show that the 426-residue N-terminal region of hCPEB3 is a dynamic, intrinsically disordered region (IDR) which lacks stable folded structures. The first 29 residues, M1QDDLLMDKSKTQPQPQQQQRQQQQPQP29, adopt a helical + disordered motif, and residues 86–93: P83QQPPPP93, and 166–175: P166PPPAPAPQP175 form polyproline II (PPII) helices. The (VG)5 repeat motif is completely disordered, and residues 200–250 adopt three partially populated α-helices. Residues 345–355, which comprise the nuclear localization signal (NLS), form a modestly populated α-helix which may mediate STAT5B binding. These findings allow us to suggest a model for nascent hCPEB3 structural transitions at single residue resolution, advancing that amyloid breaker residues, like proline, are a key difference between functional versus pathological amyloids. Conclusion Our NMR spectroscopic analysis of hCPEB3 provides insights into the first structural transitions involved in protein–protein and protein-mRNA interactions. The atomic level understanding of these structural transitions involved in hCPEB3 aggregation is a key first step toward understanding memory persistence in humans, as well as sequence features that differentiate beneficial amyloids from pathological ones. Areas Biophysics, Structural Biology, Biochemistry & Neurosciences. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01310-6.
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7
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Alpaugh M, Denis HL, Cicchetti F. Prion-like properties of the mutant huntingtin protein in living organisms: the evidence and the relevance. Mol Psychiatry 2022; 27:269-280. [PMID: 34711942 DOI: 10.1038/s41380-021-01350-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
If theories postulating that pathological proteins associated with neurodegenerative disorders behave similarly to prions were initially viewed with reluctance, it is now well-accepted that this occurs in several disease contexts. Notably, it has been reported that protein misfolding and subsequent prion-like properties can actively participate in neurodegenerative disorders. While this has been demonstrated in multiple cellular and animal model systems related to Alzheimer's and Parkinson's diseases, the prion-like properties of the mutant huntingtin protein (mHTT), associated with Huntington's disease (HD), have only recently been considered to play a role in this pathology, a concept our research group has contributed to extensively. In this review, we summarize the last few years of in vivo research in the field and speculate on the relationship between prion-like events and human HD. By interpreting observations primarily collected in in vivo models, our discussion will aim to discriminate which experimental factors contribute to the most efficient types of prion-like activities of mHTT and which routes of propagation may be more relevant to the human condition. A look back at nearly a decade of experimentation will inform future research and whether therapeutic strategies may emerge from this new knowledge.
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Affiliation(s)
- Melanie Alpaugh
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Hélèna L Denis
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada. .,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada.
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8
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Guo S, Nguyen L, Ranum LPW. RAN proteins in neurodegenerative disease: Repeating themes and unifying therapeutic strategies. Curr Opin Neurobiol 2021; 72:160-170. [PMID: 34953315 DOI: 10.1016/j.conb.2021.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/29/2022]
Abstract
Microsatellite-expansion mutations cause >50 neurological diseases but there are no effective treatments. Mechanistic studies have historically focused on protein loss-of-function and protein or RNA gain-of-function effects. It is now clear that many expansion mutations are bidirectionally transcribed producing two toxic expansion RNAs, which can produce up to six mutant proteins by repeat associated non-AUG (RAN) translation. Multiple types of RAN proteins have been shown to be toxic in cell and animal models, to lead to common types of neuropathological changes, and to dysregulate key pathways. How RAN proteins are produced without the canonical AUG or close-cognate AUG-like initiation codons is not yet completely understood but RNA structure, flanking sequences and stress pathways have been shown to be important. Here, we summarize recent progress in understanding the role of RAN proteins, mechanistic insights into their production, and the identification of novel therapeutic strategies that may be applicable across these neurodegenerative disorders.
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Affiliation(s)
- Shu Guo
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA
| | - Lien Nguyen
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA.
| | - Laura P W Ranum
- Center for NeuroGenetics, College of Medicine, University of Florida, USA; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, USA; Genetics Institute, University of Florida, USA; McKnight Brain Institute, University of Florida, USA; Norman Fixel Institute for Neurological Diseases, University of Florida, USA.
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9
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Sharpe JL, Harper NS, Garner DR, West RJH. Modeling C9orf72-Related Frontotemporal Dementia and Amyotrophic Lateral Sclerosis in Drosophila. Front Cell Neurosci 2021; 15:770937. [PMID: 34744635 PMCID: PMC8566814 DOI: 10.3389/fncel.2021.770937] [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: 09/05/2021] [Accepted: 09/27/2021] [Indexed: 12/28/2022] Open
Abstract
An intronic hexanucleotide (GGGGCC) expansion in the C9orf72 gene is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). In the decade following its discovery, much progress has been made in enhancing our understanding of how it precipitates disease. Both loss of function caused by reduced C9orf72 transcript levels, and gain of function mechanisms, triggered by the production of repetitive sense and antisense RNA and dipeptide repeat proteins, are thought to contribute to the toxicity. Drosophila models, with their unrivaled genetic tractability and short lifespan, have played a key role in developing our understanding of C9orf72-related FTD/ALS. There is no C9orf72 homolog in fly, and although this precludes investigations into loss of function toxicity, it is useful for elucidating mechanisms underpinning gain of function toxicity. To date there are a range of Drosophila C9orf72 models, encompassing different aspects of gain of function toxicity. In addition to pure repeat transgenes, which produce both repeat RNA and dipeptide repeat proteins (DPRs), RNA only models and DPR models have been generated to unpick the individual contributions of RNA and each dipeptide repeat protein to C9orf72 toxicity. In this review, we discuss how Drosophila models have shaped our understanding of C9orf72 gain of function toxicity, and address opportunities to utilize these models for further research.
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Affiliation(s)
- Joanne L Sharpe
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Nikki S Harper
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Duncan R Garner
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, United Kingdom.,Neuroscience Institute, The University of Sheffield, Sheffield, United Kingdom
| | - Ryan J H West
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, United Kingdom.,Neuroscience Institute, The University of Sheffield, Sheffield, United Kingdom
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10
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Liguori F, Amadio S, Volonté C. Fly for ALS: Drosophila modeling on the route to amyotrophic lateral sclerosis modifiers. Cell Mol Life Sci 2021; 78:6143-6160. [PMID: 34322715 PMCID: PMC11072332 DOI: 10.1007/s00018-021-03905-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rare, devastating disease, causing movement impairment, respiratory failure and ultimate death. A plethora of genetic, cellular and molecular mechanisms are involved in ALS signature, although the initiating causes and progressive pathological events are far from being understood. Drosophila research has produced seminal discoveries for more than a century and has been successfully used in the past 25 years to untangle the process of ALS pathogenesis, and recognize potential markers and novel strategies for therapeutic solutions. This review will provide an updated view of several ALS modifiers validated in C9ORF72, SOD1, FUS, TDP-43 and Ataxin-2 Drosophila models. We will discuss basic and preclinical findings, illustrating recent developments and novel breakthroughs, also depicting unsettled challenges and limitations in the Drosophila-ALS field. We intend to stimulate a renewed debate on Drosophila as a screening route to identify more successful disease modifiers and neuroprotective agents.
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Affiliation(s)
- Francesco Liguori
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy
| | - Susanna Amadio
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy
| | - Cinzia Volonté
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy.
- Institute for Systems Analysis and Computer Science "A. Ruberti", National Research Council (IASI-CNR), Via dei Taurini 19, 00185, Rome, Italy.
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11
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Layalle S, They L, Ourghani S, Raoul C, Soustelle L. Amyotrophic Lateral Sclerosis Genes in Drosophila melanogaster. Int J Mol Sci 2021; 22:ijms22020904. [PMID: 33477509 PMCID: PMC7831090 DOI: 10.3390/ijms22020904] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating adult-onset neurodegenerative disease characterized by the progressive degeneration of upper and lower motoneurons. Most ALS cases are sporadic but approximately 10% of ALS cases are due to inherited mutations in identified genes. ALS-causing mutations were identified in over 30 genes with superoxide dismutase-1 (SOD1), chromosome 9 open reading frame 72 (C9orf72), fused in sarcoma (FUS), and TAR DNA-binding protein (TARDBP, encoding TDP-43) being the most frequent. In the last few decades, Drosophila melanogaster emerged as a versatile model for studying neurodegenerative diseases, including ALS. In this review, we describe the different Drosophila ALS models that have been successfully used to decipher the cellular and molecular pathways associated with SOD1, C9orf72, FUS, and TDP-43. The study of the known fruit fly orthologs of these ALS-related genes yielded significant insights into cellular mechanisms and physiological functions. Moreover, genetic screening in tissue-specific gain-of-function mutants that mimic ALS-associated phenotypes identified disease-modifying genes. Here, we propose a comprehensive review on the Drosophila research focused on four ALS-linked genes that has revealed novel pathogenic mechanisms and identified potential therapeutic targets for future therapy.
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Affiliation(s)
- Sophie Layalle
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Laetitia They
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Sarah Ourghani
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Cédric Raoul
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
- Laboratory of Neurobiology, Kazan Federal University, 420008 Kazan, Russia
- Correspondence: (C.R.); (L.S.)
| | - Laurent Soustelle
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
- Correspondence: (C.R.); (L.S.)
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12
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Riemslagh FW, van der Toorn EC, Verhagen RFM, Maas A, Bosman LWJ, Hukema RK, Willemsen R. Inducible expression of human C9ORF72 36x G 4C 2 hexanucleotide repeats is sufficient to cause RAN translation and rapid muscular atrophy in mice. Dis Model Mech 2021; 14:dmm.044842. [PMID: 33431483 PMCID: PMC7903916 DOI: 10.1242/dmm.044842] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 12/17/2020] [Indexed: 12/29/2022] Open
Abstract
The hexanucleotide G4C2 repeat expansion in the first intron of the C9ORF72 gene explains the majority of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) cases. Numerous studies have indicated the toxicity of dipeptide repeats (DPRs) which are produced via repeat-associated non-AUG (RAN) translation from the repeat expansion and accumulate in the brain of C9FTD/ALS patients. Mouse models expressing the human C9ORF72 repeat and/or DPRs show variable pathological, functional, and behavioral characteristics of FTD and ALS. Here, we report a new Tet-on inducible mouse model that expresses 36x pure G4C2 repeats with 100bp upstream and downstream human flanking regions. Brain specific expression causes the formation of sporadic sense DPRs aggregates upon 6 months dox induction but no apparent neurodegeneration. Expression in the rest of the body evokes abundant sense DPRs in multiple organs, leading to weight loss, neuromuscular junction disruption, myopathy, and a locomotor phenotype within the time frame of four weeks. We did not observe any RNA foci or pTDP-43 pathology. Accumulation of DPRs and the myopathy phenotype could be prevented when 36x G4C2 repeat expression was stopped after 1 week. After 2 weeks of expression, the phenotype could not be reversed, even though DPR levels were reduced. In conclusion, expression of 36x pure G4C2 repeats including 100bp human flanking regions is sufficient for RAN translation of sense DPRs and evokes a functional locomotor phenotype. Our inducible mouse model suggests early diagnosis and treatment are important for C9FTD/ALS patients.
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Affiliation(s)
- F W Riemslagh
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - E C van der Toorn
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - R F M Verhagen
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - A Maas
- Department of Cell Biology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - L W J Bosman
- Department of Neuroscience, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - R K Hukema
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - R Willemsen
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
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13
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Tittelmeier J, Nachman E, Nussbaum-Krammer C. Molecular Chaperones: A Double-Edged Sword in Neurodegenerative Diseases. Front Aging Neurosci 2020; 12:581374. [PMID: 33132902 PMCID: PMC7572858 DOI: 10.3389/fnagi.2020.581374] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022] Open
Abstract
Aberrant accumulation of misfolded proteins into amyloid deposits is a hallmark in many age-related neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS). Pathological inclusions and the associated toxicity appear to spread through the nervous system in a characteristic pattern during the disease. This has been attributed to a prion-like behavior of amyloid-type aggregates, which involves self-replication of the pathological conformation, intercellular transfer, and the subsequent seeding of native forms of the same protein in the neighboring cell. Molecular chaperones play a major role in maintaining cellular proteostasis by assisting the (re)-folding of cellular proteins to ensure their function or by promoting the degradation of terminally misfolded proteins to prevent damage. With increasing age, however, the capacity of this proteostasis network tends to decrease, which enables the manifestation of neurodegenerative diseases. Recently, there has been a plethora of studies investigating how and when chaperones interact with disease-related proteins, which have advanced our understanding of the role of chaperones in protein misfolding diseases. This review article focuses on the steps of prion-like propagation from initial misfolding and self-templated replication to intercellular spreading and discusses the influence that chaperones have on these various steps, highlighting both the positive and adverse consequences chaperone action can have. Understanding how chaperones alleviate and aggravate disease progression is vital for the development of therapeutic strategies to combat these debilitating diseases.
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Affiliation(s)
- Jessica Tittelmeier
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Eliana Nachman
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carmen Nussbaum-Krammer
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
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14
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West RJH, Sharpe JL, Voelzmann A, Munro AL, Hahn I, Baines RA, Pickering-Brown S. Co-expression of C9orf72 related dipeptide-repeats over 1000 repeat units reveals age- and combination-specific phenotypic profiles in Drosophila. Acta Neuropathol Commun 2020; 8:158. [PMID: 32894207 PMCID: PMC7487709 DOI: 10.1186/s40478-020-01028-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 02/08/2023] Open
Abstract
A large intronic hexanucleotide repeat expansion (GGGGCC) within the C9orf72 (C9orf72-SMCR8 Complex Subunit) locus is the most prevalent genetic cause of both Frontotemporal Dementia (FTD) and Motor Neuron Disease (MND). In patients this expansion is typically hundreds to thousands of repeat units in length. Repeat associated non-AUG translation of the expansion leads to the formation of toxic, pathological Dipeptide-Repeat Proteins (DPRs). To date there remains a lack of in vivo models expressing C9orf72 related DPRs with a repeat length of more than a few hundred repeats. As such our understanding of how physiologically relevant repeat length DPRs effect the nervous system in an ageing in vivo system remains limited. In this study we generated Drosophila models expressing DPRs over 1000 repeat units in length, a known pathological length in humans. Using these models, we demonstrate each DPR exhibits a unique, age-dependent, phenotypic and pathological profile. Furthermore, we show co-expression of specific DPR combinations leads to distinct, age-dependent, phenotypes not observed through expression of single DPRs. We propose these models represent a unique, in vivo, tool for dissecting the molecular mechanisms implicated in disease pathology, opening up new avenues in the study of both MND and FTD.
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Affiliation(s)
- Ryan J. H. West
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN UK
| | - Joanne L. Sharpe
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - André Voelzmann
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Anna L. Munro
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Ines Hahn
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Richard A. Baines
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Stuart Pickering-Brown
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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