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Barbosa Pereira PJ, Manso JA, Macedo-Ribeiro S. The structural plasticity of polyglutamine repeats. Curr Opin Struct Biol 2023; 80:102607. [PMID: 37178477 DOI: 10.1016/j.sbi.2023.102607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/15/2023]
Abstract
From yeast to humans, polyglutamine (polyQ) repeat tracts are found frequently in the proteome and are particularly prominent in the activation domains of transcription factors. PolyQ is a polymorphic motif that modulates functional protein-protein interactions and aberrant self-assembly. Expansion of the polyQ repeated sequences beyond critical physiological repeat length thresholds triggers self-assembly and is linked to severe pathological implications. This review provides an overview of the current knowledge on the structures of polyQ tracts in the soluble and aggregated states and discusses the influence of neighboring regions on polyQ secondary structure, aggregation, and fibril morphologies. The influence of the genetic context of the polyQ-encoding trinucleotides is briefly discussed as a challenge for future endeavors in this field.
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Affiliation(s)
- Pedro José Barbosa Pereira
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135, Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal.
| | - José A Manso
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135, Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal
| | - Sandra Macedo-Ribeiro
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135, Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal
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2
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Matsuura U, Tahara S, Kajimoto S, Nakabayashi T. Label-free autofluorescence lifetime reveals the structural dynamics of ataxin-3 inside droplets formed via liquid-liquid phase separation. Sci Rep 2023; 13:6389. [PMID: 37076520 PMCID: PMC10113985 DOI: 10.1038/s41598-023-33268-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
Liquid-liquid phase separation is a phenomenon that features the formation of liquid droplets containing concentrated solutes. The droplets of neurodegeneration-associated proteins are prone to generate aggregates and cause diseases. To uncover the aggregation process from the droplets, it is necessary to analyze the protein structure with keeping the droplet state in a label-free manner, but there was no suitable method. In this study, we observed the structural changes of ataxin-3, a protein associated with Machado-Joseph disease, inside the droplets, using autofluorescence lifetime microscopy. Each droplet showed autofluorescence due to tryptophan (Trp) residues, and its lifetime increased with time, reflecting structural changes toward aggregation. We used Trp mutants to reveal the structural changes around each Trp and showed that the structural change consists of several steps on different timescales. We demonstrated that the present method visualizes the protein dynamics inside a droplet in a label-free manner. Further investigations revealed that the aggregate structure formed in the droplets differs from that formed in dispersed solutions and that a polyglutamine repeat extension in ataxin-3 hardly modulates the aggregation dynamics in the droplets. These findings highlight that the droplet environment facilitates unique protein dynamics different from those in solutions.
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Affiliation(s)
- Uchu Matsuura
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Shinya Tahara
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan.
| | - Shinji Kajimoto
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
- JST PRESTO, Kawaguchi, Saitama, 332-0012, Japan
| | - Takakazu Nakabayashi
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan.
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3
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A Robust Assay to Monitor Ataxin-3 Amyloid Fibril Assembly. Cells 2022; 11:cells11121969. [PMID: 35741099 PMCID: PMC9222203 DOI: 10.3390/cells11121969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 02/05/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is caused by the expansion of a glutamine repeat in the protein ataxin-3, which is deposited as intracellular aggregates in affected brain regions. Despite the controversial role of ataxin-3 amyloid structures in SCA3 pathology, the identification of molecules with the capacity to prevent aberrant self-assembly and stabilize functional conformation(s) of ataxin-3 is a key to the development of therapeutic solutions. Amyloid-specific kinetic assays are routinely used to measure rates of protein self-assembly in vitro and are employed during screening for fibrillation inhibitors. The high tendency of ataxin-3 to assemble into oligomeric structures implies that minor changes in experimental conditions can modify ataxin-3 amyloid assembly kinetics. Here, we determine the self-association rates of ataxin-3 and present a detailed study of the aggregation of normal and pathogenic ataxin-3, highlighting the experimental conditions that should be considered when implementing and validating ataxin-3 amyloid progress curves in different settings and in the presence of ataxin-3 interactors. This assay provides a unique and robust platform to screen for modulators of the first steps of ataxin-3 aggregation—a starting point for further studies with cell and animal models of SCA3.
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4
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Raj K, Akundi RS. Mutant Ataxin-3-Containing Aggregates (MATAGGs) in Spinocerebellar Ataxia Type 3: Dynamics of the Disorder. Mol Neurobiol 2021; 58:3095-3118. [PMID: 33629274 DOI: 10.1007/s12035-021-02314-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: 10/11/2020] [Accepted: 01/25/2021] [Indexed: 11/25/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is the most common type of SCA worldwide caused by abnormal polyglutamine expansion in the coding region of the ataxin-3 gene. Ataxin-3 is a multi-faceted protein involved in various cellular processes such as deubiquitination, cytoskeletal organisation, and transcriptional regulation. The presence of an expanded poly(Q) stretch leads to altered processing and misfolding of the protein culminating in the production of insoluble protein aggregates in the cell. Various post-translational modifications affect ataxin-3 fibrillation and aggregation. This review provides an exhaustive assessment of the various pathogenic mechanisms undertaken by the mutant ataxin-3-containing aggregates (MATAGGs) for disease induction and neurodegeneration. This includes in-depth discussion on MATAGG dynamics including their formation, role in neuronal pathogenesis, and the debate over the toxic v/s protective nature of the MATAGGs in disease progression. Additionally, the currently available therapeutic strategies against SCA3 have been reviewed. The shift in the focus of such strategies, from targeting the steps that lead to or reduce aggregate formation to targeting the expression of mutant ataxin-3 itself via RNA-based therapeutics, has also been presented. We also discuss the intriguing promise that various growth and neurotrophic factors, especially the insulin pathway, hold in the modulation of SCA3 progression. These emerging areas show the newer directions through which SCA3 can be targeted including various preclinical and clinical trials. All these advances made in the last three decades since the discovery of the ataxin-3 gene have been critically reviewed here.
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Affiliation(s)
- Kritika Raj
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India
| | - Ravi Shankar Akundi
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India.
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5
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Ebo JS, Guthertz N, Radford SE, Brockwell DJ. Using protein engineering to understand and modulate aggregation. Curr Opin Struct Biol 2020; 60:157-166. [PMID: 32087409 PMCID: PMC7132541 DOI: 10.1016/j.sbi.2020.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 02/07/2023]
Abstract
Protein aggregation occurs through a variety of mechanisms, initiated by the unfolded, non-native, or even the native state itself. Understanding the molecular mechanisms of protein aggregation is challenging, given the array of competing interactions that control solubility, stability, cooperativity and aggregation propensity. An array of methods have been developed to interrogate protein aggregation, spanning computational algorithms able to identify aggregation-prone regions, to deep mutational scanning to define the entire mutational landscape of a protein's sequence. Here, we review recent advances in this exciting and emerging field, focussing on protein engineering approaches that, together with improved computational methods, hold promise to predict and control protein aggregation linked to human disease, as well as facilitating the manufacture of protein-based therapeutics.
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Affiliation(s)
- Jessica S Ebo
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK; School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Nicolas Guthertz
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK; School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK; School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Brockwell
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK; School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
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6
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Computational prediction and redesign of aberrant protein oligomerization. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 169:43-83. [DOI: 10.1016/bs.pmbts.2019.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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7
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Orlando G, Silva A, Macedo-Ribeiro S, Raimondi D, Vranken W. Accurate prediction of protein beta-aggregation with generalized statistical potentials. Bioinformatics 2019; 36:2076-2081. [DOI: 10.1093/bioinformatics/btz912] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 01/04/2023] Open
Abstract
Abstract
Motivation
Protein beta-aggregation is an important but poorly understood phenomena involved in diseases as well as in beneficial physiological processes. However, while this task has been investigated for over 50 years, very little is known about its mechanisms of action. Moreover, the identification of regions involved in aggregation is still an open problem and the state-of-the-art methods are often inadequate in real case applications.
Results
In this article we present AgMata, an unsupervised tool for the identification of such regions from amino acidic sequence based on a generalized definition of statistical potentials that includes biophysical information. The tool outperforms the state-of-the-art methods on two different benchmarks. As case-study, we applied our tool to human ataxin-3, a protein involved in Machado–Joseph disease. Interestingly, AgMata identifies aggregation-prone residues that share the very same structural environment. Additionally, it successfully predicts the outcome of in vitro mutagenesis experiments, identifying point mutations that lead to an alteration of the aggregation propensity of the wild-type ataxin-3.
Availability and implementation
A python implementation of the tool is available at https://bitbucket.org/bio2byte/agmata.
Supplementary information
Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Gabriele Orlando
- Interuniversity Institute of Bioinformatics in Brussels, ULB/VUB, Triomflaan, Brussels 1050, Belgium
- Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium
| | - Alexandra Silva
- IBMC-Instituto de Biologia Molecular e Celular
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal
| | - Sandra Macedo-Ribeiro
- IBMC-Instituto de Biologia Molecular e Celular
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal
| | | | - Wim Vranken
- Interuniversity Institute of Bioinformatics in Brussels, ULB/VUB, Triomflaan, Brussels 1050, Belgium
- Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium
- Centre for Structural Biology, VIB, Brussels 1050, Belgium
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8
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Amigoni L, Airoldi C, Natalello A, Romeo M, Diomede L, Tortora P, Regonesi ME. Methacycline displays a strong efficacy in reducing toxicity in a SCA3 Caenorhabditis elegans model. Biochim Biophys Acta Gen Subj 2019; 1863:279-290. [DOI: 10.1016/j.bbagen.2018.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 10/10/2018] [Accepted: 10/12/2018] [Indexed: 11/28/2022]
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9
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Giorgetti S, Greco C, Tortora P, Aprile FA. Targeting Amyloid Aggregation: An Overview of Strategies and Mechanisms. Int J Mol Sci 2018; 19:E2677. [PMID: 30205618 PMCID: PMC6164555 DOI: 10.3390/ijms19092677] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/02/2018] [Accepted: 09/05/2018] [Indexed: 12/26/2022] Open
Abstract
Amyloids result from the aggregation of a set of diverse proteins, due to either specific mutations or promoting intra- or extra-cellular conditions. Structurally, they are rich in intermolecular β-sheets and are the causative agents of several diseases, both neurodegenerative and systemic. It is believed that the most toxic species are small aggregates, referred to as oligomers, rather than the final fibrillar assemblies. Their mechanisms of toxicity are mostly mediated by aberrant interactions with the cell membranes, with resulting derangement of membrane-related functions. Much effort is being exerted in the search for natural antiamyloid agents, and/or in the development of synthetic molecules. Actually, it is well documented that the prevention of amyloid aggregation results in several cytoprotective effects. Here, we portray the state of the art in the field. Several natural compounds are effective antiamyloid agents, notably tetracyclines and polyphenols. They are generally non-specific, as documented by their partially overlapping mechanisms and the capability to interfere with the aggregation of several unrelated proteins. Among rationally designed molecules, we mention the prominent examples of β-breakers peptides, whole antibodies and fragments thereof, and the special case of drugs with contrasting transthyretin aggregation. In this framework, we stress the pivotal role of the computational approaches. When combined with biophysical methods, in several cases they have helped clarify in detail the protein/drug modes of interaction, which makes it plausible that more effective drugs will be developed in the future.
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Affiliation(s)
- Sofia Giorgetti
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Via Taramelli 3b, 27100 Pavia, Italy.
| | - Claudio Greco
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milano, Italy.
| | - Paolo Tortora
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy.
- Milan Center for Neuroscience (Neuro-MI), 20126 Milano, Italy.
| | - Francesco Antonio Aprile
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
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10
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Visentin C, Navarro S, Grasso G, Regonesi ME, Deriu MA, Tortora P, Ventura S. Protein Environment: A Crucial Triggering Factor in Josephin Domain Aggregation: The Role of 2,2,2-Trifluoroethanol. Int J Mol Sci 2018; 19:ijms19082151. [PMID: 30042316 PMCID: PMC6121581 DOI: 10.3390/ijms19082151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022] Open
Abstract
The protein ataxin-3 contains a polyglutamine stretch that triggers amyloid aggregation when it is expanded beyond a critical threshold. This results in the onset of the spinocerebellar ataxia type 3. The protein consists of the globular N-terminal Josephin domain and a disordered C-terminal tail where the polyglutamine stretch is located. Expanded ataxin-3 aggregates via a two-stage mechanism: first, Josephin domain self-association, then polyQ fibrillation. This highlights the intrinsic amyloidogenic potential of Josephin domain. Therefore, much effort has been put into investigating its aggregation mechanism(s). A key issue regards the conformational requirements for triggering amyloid aggregation, as it is believed that, generally, misfolding should precede aggregation. Here, we have assayed the effect of 2,2,2-trifluoroethanol, a co-solvent capable of stabilizing secondary structures, especially α-helices. By combining biophysical methods and molecular dynamics, we demonstrated that both secondary and tertiary JD structures are virtually unchanged in the presence of up to 5% 2,2,2-trifluoroethanol. Despite the preservation of JD structure, 1% of 2,2,2-trifluoroethanol suffices to exacerbate the intrinsic aggregation propensity of this domain, by slightly decreasing its conformational stability. These results indicate that in the case of JD, conformational fluctuations might suffice to promote a transition towards an aggregated state without the need for extensive unfolding, and highlights the important role played by the environment on the aggregation of this globular domain.
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Affiliation(s)
- Cristina Visentin
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Susanna Navarro
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Gianvito Grasso
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Maria Elena Regonesi
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Marco Agostino Deriu
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Paolo Tortora
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
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11
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Knight PD, Karamanos TK, Radford SE, Ashcroft AE. Identification of a novel site of interaction between ataxin-3 and the amyloid aggregation inhibitor polyglutamine binding peptide 1. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2018; 24:129-140. [PMID: 29334808 PMCID: PMC6134688 DOI: 10.1177/1469066717729298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/10/2017] [Indexed: 05/09/2023]
Abstract
Amyloid diseases represent a growing social and economic burden in the developed world. Understanding the assembly pathway and the inhibition of amyloid formation is key to developing therapies to treat these diseases. The neurodegenerative condition Machado-Joseph disease is characterised by the self-aggregation of the protein ataxin-3. Ataxin-3 consists of a globular N-terminal Josephin domain, which can aggregate into curvilinear protofibrils, and an unstructured, dynamically disordered C-terminal domain containing three ubiquitin interacting motifs separated by a polyglutamine stretch. Upon expansion of the polyglutamine region above 50 residues, ataxin-3 undergoes a second stage of aggregation in which long, straight amyloid fibrils form. A peptide inhibitor of polyglutamine aggregation, known as polyQ binding peptide 1, has been shown previously to prevent the maturation of ataxin-3 fibrils. However, the mechanism of this inhibition remains unclear. Using nanoelectrospray ionisation-mass spectrometry, we demonstrate that polyQ binding peptide 1 binds to monomeric ataxin-3. By investigating the ability of polyQ binding peptide 1 to bind to truncated ataxin-3 constructs lacking one or more domains, we localise the site of this interaction to a 39-residue sequence immediately C-terminal to the Josephin domain. The results suggest a new mechanism for the inhibition of polyglutamine aggregation by polyQ binding peptide 1 in which binding to a region outside of the polyglutamine tract can prevent fibril formation, highlighting the importance of polyglutamine flanking regions in controlling aggregation and disease.
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12
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Visentin C, Pellistri F, Natalello A, Vertemara J, Bonanomi M, Gatta E, Penco A, Relini A, De Gioia L, Airoldi C, Regonesi ME, Tortora P. Epigallocatechin-3-gallate and related phenol compounds redirect the amyloidogenic aggregation pathway of ataxin-3 towards non-toxic aggregates and prevent toxicity in neural cells and Caenorhabditis elegans animal model. Hum Mol Genet 2018. [PMID: 28633380 DOI: 10.1093/hmg/ddx211] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The protein ataxin-3 (ATX3) triggers an amyloid-related neurodegenerative disease when its polyglutamine stretch is expanded beyond a critical threshold. We formerly demonstrated that the polyphenol epigallocatechin-3-gallate (EGCG) could redirect amyloid aggregation of a full-length, expanded ATX3 (ATX3-Q55) towards non-toxic, soluble, SDS-resistant aggregates. Here, we have characterized other related phenol compounds, although smaller in size, i.e. (-)-epigallocatechin gallate (EGC), and gallic acid (GA). We analysed the aggregation pattern of ATX3-Q55 and of the N-terminal globular Josephin domain (JD) by assessing the time course of the soluble protein, as well its structural features by FTIR and AFM, in the presence and the absence of the mentioned compounds. All of them redirected the aggregation pattern towards soluble, SDS-resistant aggregates. They also prevented the appearance of ordered side-chain hydrogen bonding in ATX3-Q55, which is the hallmark of polyQ-related amyloids. Molecular docking analyses on the JD highlighted three interacting regions, including the central, aggregation-prone one. All three compounds bound to each of them, although with different patterns. This might account for their capability to prevent amyloidogenesis. Saturation transfer difference NMR experiments also confirmed EGCG and EGC binding to monomeric JD. ATX3-Q55 pre-incubation with any of the three compounds prevented its calcium-influx-mediated cytotoxicity towards neural cells. Finally, all the phenols significantly reduced toxicity in a transgenic Caenorhabditis elegans strain expressing an expanded ATX3. Overall, our results show that the three polyphenols act in a substantially similar manner. GA, however, might be more suitable for antiamyloid treatments due to its simpler structure and higher chemical stability.
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Affiliation(s)
- Cristina Visentin
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | | | - Antonino Natalello
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy.,Milan Center of Neuroscience (NeuroMI), 20126 Milan, Italy
| | - Jacopo Vertemara
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Marcella Bonanomi
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Elena Gatta
- Department of Physics, University of Genoa, 16146 Genoa, Italy
| | - Amanda Penco
- Department of Physics, University of Genoa, 16146 Genoa, Italy.,Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Annalisa Relini
- Department of Physics, University of Genoa, 16146 Genoa, Italy.,National Institute of Biostructures and Biosystems (INBB), 00136 Rome, Italy
| | - Luca De Gioia
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Cristina Airoldi
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy.,Milan Center of Neuroscience (NeuroMI), 20126 Milan, Italy
| | - Maria E Regonesi
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy.,Milan Center of Neuroscience (NeuroMI), 20126 Milan, Italy
| | - Paolo Tortora
- Department of Biotechnologies and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy.,Milan Center of Neuroscience (NeuroMI), 20126 Milan, Italy
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13
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Polyglutamine-Independent Features in Ataxin-3 Aggregation and Pathogenesis of Machado-Joseph Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:275-288. [PMID: 29427109 DOI: 10.1007/978-3-319-71779-1_14] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The expansion of a trinucleotide (CAG) repeat, translated into a polyglutamine expanded sequence in the protein encoded by the MJD gene, was identified over 20 years ago as the causative mutation in a severe neurodegenerative disorder originally diagnosed in individuals of Portuguese ancestry. This incapacitating disease, called Machado-Joseph disease or spinocebellar ataxia type 3, is integrated into a larger group of neurodegenerative disorders-the polyglutamine expansion disorders-caused by extension of a CAG repeat in the coding sequence of otherwise unrelated genes. These diseases are generally linked with the appearance of intracellular inclusions , which despite having a controversial role in disease appearance and development represent a characteristic common fingerprint in all polyglutamine-related disorders. Although polyglutamine expansion is an obvious trigger for neuronal dysfunction, the role of the different domains of these complex proteins in the function and aggregation properties of the carrier proteins is being uncovered in recent studies. In this review the current knowledge about the structural and functional features of full-length ataxin-3 protein will be discussed. The intrinsic conformational dynamics and interplay between the globular and intrinsically disordered regions of ataxin-3 will be highlighted, and a perspective picture of the role of known ataxin-3 post-translational modifications on regulating ataxin-3 aggregation and function will be drawn.
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14
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Toyoshima Y, Takahashi H. Spinocerebellar Ataxia Type 17 (SCA17). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:219-231. [PMID: 29427105 DOI: 10.1007/978-3-319-71779-1_10] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
In 1999, a polyglutamine expansion was identified in the transcription factor TATA-binding protein (TBP) in a patient with ataxia with negative family history. Subsequently, CAG/CAA repeat expansions in the TBP gene were identified in families with spinocerebellar ataxia (SCA), establishing this repeat expansion as the underlying mutation in SCA type 17 (SCA17). There are several characteristic differences between SCA17 and other polyglutamine diseases. First, SCA17 shows a complex and variable clinical phenotype, in some cases overlapping that of Huntington's disease. Second, compared to the other SCA subtypes caused by expanded trinucleotide repeats, anticipation in SCA17 kindreds is rare because of the characteristic structure of the TBP gene. And thirdly, SCA17 patients often have diagnostic problems that may arise from non-penetrance. Because the gap between normal and abnormal repeat numbers is very narrow, it is difficult to determine a cutoff value for pathologic CAG repeat number in SCA17. Herein, we review the clinical, genetic and pathologic features of SCA17.
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Affiliation(s)
- Yasuko Toyoshima
- Department of Pathology, Brain Research Institute, University of Niigata, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan.
| | - Hitoshi Takahashi
- Department of Pathology, Brain Research Institute, University of Niigata, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
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Fernández MR, Batlle C, Gil-García M, Ventura S. Amyloid cores in prion domains: Key regulators for prion conformational conversion. Prion 2017; 11:31-39. [PMID: 28281928 DOI: 10.1080/19336896.2017.1282020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Despite the significant efforts devoted to decipher the particular protein features that encode for a prion or prion-like behavior, they are still poorly understood. The well-characterized yeast prions constitute an ideal model system to address this question, because, in these proteins, the prion activity can be univocally assigned to a specific region of their sequence, known as the prion forming domain (PFD). These PFDs are intrinsically disordered, relatively long and, in many cases, of low complexity, being enriched in glutamine/asparagine residues. Computational analyses have identified a significant number of proteins having similar domains in the human proteome. The compositional bias of these regions plays an important role in the transition of the prions to the amyloid state. However, it is difficult to explain how composition alone can account for the formation of specific contacts that position correctly PFDs and provide the enthalpic force to compensate for the large entropic cost of immobilizing these domains in the initial assemblies. We have hypothesized that short, sequence-specific, amyloid cores embedded in PFDs can perform these functions and, accordingly, act as preferential nucleation centers in both spontaneous and seeded aggregation. We have shown that the implementation of this concept in a prediction algorithm allows to score the prion propensities of putative PFDs with high accuracy. Recently, we have provided experimental evidence for the existence of such amyloid cores in the PFDs of Sup35, Ure2, Swi1, and Mot3 yeast prions. The fibrils formed by these short stretches may recognize and promote the aggregation of the complete proteins inside cells, being thus a promising tool for targeted protein inactivation.
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Affiliation(s)
- María Rosario Fernández
- a Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular , Universitat Autonoma de Barcelona , Bellaterra (Barcelona) , Spain
| | - Cristina Batlle
- a Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular , Universitat Autonoma de Barcelona , Bellaterra (Barcelona) , Spain
| | - Marcos Gil-García
- a Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular , Universitat Autonoma de Barcelona , Bellaterra (Barcelona) , Spain
| | - Salvador Ventura
- a Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular , Universitat Autonoma de Barcelona , Bellaterra (Barcelona) , Spain
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16
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Polyglutamine expansion diseases: More than simple repeats. J Struct Biol 2017; 201:139-154. [PMID: 28928079 DOI: 10.1016/j.jsb.2017.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/24/2017] [Accepted: 09/15/2017] [Indexed: 12/27/2022]
Abstract
Polyglutamine (polyQ) repeat-containing proteins are widespread in the human proteome but only nine of them are associated with highly incapacitating neurodegenerative disorders. The genetic expansion of the polyQ tract in disease-related proteins triggers a series of events resulting in neurodegeneration. The polyQ tract plays the leading role in the aggregation mechanism, but other elements modulate the aggregation propensity in the context of the full-length proteins, as implied by variations in the length of the polyQ tract required to trigger the onset of a given polyQ disease. Intrinsic features such as the presence of aggregation-prone regions (APRs) outside the polyQ segments and polyQ-flanking sequences, which synergistically participate in the aggregation process, are emerging for several disease-related proteins. The inherent polymorphic structure of polyQ stretches places the polyQ proteins in a central position in protein-protein interaction networks, where interacting partners may additionally shield APRs or reshape the aggregation course. Expansion of the polyQ tract perturbs the cellular homeostasis and contributes to neuronal failure by modulating protein-protein interactions and enhancing toxic oligomerization. Post-translational modifications further regulate self-assembly either by directly altering the intrinsic aggregation propensity of polyQ proteins, by modulating their interaction with different macromolecules or by modifying their withdrawal by the cell quality control machinery. Here we review the recent data on the multifaceted aggregation pathways of disease-related polyQ proteins, focusing on ataxin-3, the protein mutated in Machado-Joseph disease. Further mechanistic understanding of this network of events is crucial for the development of effective therapies for polyQ diseases.
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17
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Kuiper EFE, de Mattos EP, Jardim LB, Kampinga HH, Bergink S. Chaperones in Polyglutamine Aggregation: Beyond the Q-Stretch. Front Neurosci 2017; 11:145. [PMID: 28386214 PMCID: PMC5362620 DOI: 10.3389/fnins.2017.00145] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/08/2017] [Indexed: 01/12/2023] Open
Abstract
Expanded polyglutamine (polyQ) stretches in at least nine unrelated proteins lead to inherited neuronal dysfunction and degeneration. The expansion size in all diseases correlates with age at onset (AO) of disease and with polyQ protein aggregation, indicating that the expanded polyQ stretch is the main driving force for the disease onset. Interestingly, there is marked interpatient variability in expansion thresholds for a given disease. Between different polyQ diseases the repeat length vs. AO also indicates the existence of modulatory effects on aggregation of the upstream and downstream amino acid sequences flanking the Q expansion. This can be either due to intrinsic modulation of aggregation by the flanking regions, or due to differential interaction with other proteins, such as the components of the cellular protein quality control network. Indeed, several lines of evidence suggest that molecular chaperones have impact on the handling of different polyQ proteins. Here, we review factors differentially influencing polyQ aggregation: the Q-stretch itself, modulatory flanking sequences, interaction partners, cleavage of polyQ-containing proteins, and post-translational modifications, with a special focus on the role of molecular chaperones. By discussing typical examples of how these factors influence aggregation, we provide more insight on the variability of AO between different diseases as well as within the same polyQ disorder, on the molecular level.
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Affiliation(s)
- E F E Kuiper
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Eduardo P de Mattos
- Department of Cell Biology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil
| | - Laura B Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil; Departamento de Medicina Interna, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Steven Bergink
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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18
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Lucato CM, Lupton CJ, Halls ML, Ellisdon AM. Amyloidogenicity at a Distance: How Distal Protein Regions Modulate Aggregation in Disease. J Mol Biol 2017; 429:1289-1304. [PMID: 28342736 DOI: 10.1016/j.jmb.2017.03.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/12/2017] [Accepted: 03/14/2017] [Indexed: 12/14/2022]
Abstract
The misfolding of proteins to form amyloid is a key pathological feature of several progressive, and currently incurable, diseases. A mechanistic understanding of the pathway from soluble, native protein to insoluble amyloid is crucial for therapeutic design, and recent efforts have helped to elucidate the key molecular events that trigger protein misfolding. Generally, either global or local structural perturbations occur early in amyloidogenesis to expose aggregation-prone regions of the protein that can then self-associate to form toxic oligomers. Surprisingly, these initiating structural changes are often caused or influenced by protein regions distal to the classically amyloidogenic sequences. Understanding the importance of these distal regions in the pathogenic process has highlighted many remaining knowledge gaps regarding the precise molecular events that occur in classic aggregation pathways. In this review, we discuss how these distal regions can influence aggregation in disease and the recent technical and conceptual advances that have allowed this insight.
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Affiliation(s)
- Christina M Lucato
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Christopher J Lupton
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew M Ellisdon
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia.
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19
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Grasso G, Tuszynski JA, Morbiducci U, Licandro G, Danani A, Deriu MA. Thermodynamic and kinetic stability of the Josephin Domain closed arrangement: evidences from replica exchange molecular dynamics. Biol Direct 2017; 12:2. [PMID: 28103906 PMCID: PMC5244572 DOI: 10.1186/s13062-016-0173-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/21/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Molecular phenomena driving pathological aggregation in neurodegenerative diseases are not completely understood yet. Peculiar is the case of Spinocerebellar Ataxia 3 (SCA3) where the conformational properties of the AT-3 N-terminal region, also called Josephin Domain (JD), play a key role in the first step of aggregation, having the JD an amyloidogenic propensity itself. For this reason, unraveling the intimate relationship between JD structural features and aggregation tendency may lead to a step forward in understanding the pathology and rationally design a cure. In this connection, computational modeling has demonstrated to be helpful in exploring the protein molecular dynamics and mechanism of action. RESULTS Conformational dynamics of the JD is here finely investigated by replica exchange molecular dynamics simulations able to sample the microsecond time scale and to provide both a thermodynamic and kinetic description of the protein conformational changes. Accessible structural conformations of the JD have been identified in: open, intermediate and closed like arrangement. Data indicated the closed JD arrangement as the most likely protein arrangement. The protein transition from closed toward intermediate/open states was characterized by a rate constant higher than 700 ns. This result also explains the inability of classical molecular dynamics to explore transitions from closed to open JD configuration on a time scale of hundreds of nanoseconds. CONCLUSION This work provides the first kinetic estimation of the JD transition pathway from open-like to closed-like arrangement and vice-versa, indicating the closed-like arrangement as the most likely configuration for a JD in water environment. More widely, the importance of our results is also underscored considering that the ability to provide a kinetic description of the protein conformational changes is a scientific challenge for both experimental and theoretical approaches to date. REVIEWERS This article was reviewed by Oliviero Carugo, Bojan Zagrovic.
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Affiliation(s)
- Gianvito Grasso
- Istituto Dalle Molle di studi sull’Intelligenza Artificiale (IDSIA), Scuola universitaria professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), Centro Galleria 2, Manno, CH-6928 Switzerland
| | - Jack A. Tuszynski
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10128 Torino, Italy
| | | | - Ginevra Licandro
- Istituto Dalle Molle di studi sull’Intelligenza Artificiale (IDSIA), Scuola universitaria professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), Centro Galleria 2, Manno, CH-6928 Switzerland
| | - Andrea Danani
- Istituto Dalle Molle di studi sull’Intelligenza Artificiale (IDSIA), Scuola universitaria professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), Centro Galleria 2, Manno, CH-6928 Switzerland
| | - Marco A. Deriu
- Istituto Dalle Molle di studi sull’Intelligenza Artificiale (IDSIA), Scuola universitaria professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), Centro Galleria 2, Manno, CH-6928 Switzerland
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