1
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Diana D, Pirone L, Russo L, D'Abrosca G, Madheswaran M, Benfante R, Di Lascio S, Caldinelli L, Fornasari D, Acconcia C, Corvino A, Ventserova N, Pollegioni L, Isernia C, Di Gaetano S, Malgieri G, Pedone EM, Fattorusso R. Structural characterization of PHOX2B and its DNA interaction shed light on the molecular basis of the +7Ala variant pathogenicity in CCHS. Chem Sci 2024; 15:8858-8872. [PMID: 38873078 PMCID: PMC11168103 DOI: 10.1039/d3sc06427a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/12/2024] [Indexed: 06/15/2024] Open
Abstract
An expansion of poly-alanine up to +13 residues in the C-terminus of the transcription factor PHOX2B underlies the onset of congenital central hypoventilation syndrome (CCHS). Recent studies demonstrated that the alanine tract expansion influences PHOX2B folding and activity. Therefore, structural information on PHOX2B is an important target for obtaining clues to elucidate the insurgence of the alanine expansion-related syndrome and also for defining a viable therapy. Here we report by NMR spectroscopy the structural characterization of the homeodomain (HD) of PHOX2B and HD + C-terminus PHOX2B protein, free and in the presence of the target DNA. The obtained structural data are then exploited to obtain a structural model of the PHOX2B-DNA interaction. In addition, the variant +7Ala, responsible for one of the most frequent forms of the syndrome, was analysed, showing different conformational proprieties in solution and a strong propensity to aggregation. Our data suggest that the elongated poly-alanine tract would be related to disease onset through a loss-of-function mechanism. Overall, this study paves the way for the future rational design of therapeutic drugs, suggesting as a possible therapeutic route the use of specific anti-aggregating molecules capable of preventing variant aggregation and possibly restoring the DNA-binding activity of PHOX2B.
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Affiliation(s)
- Donatella Diana
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luciano Pirone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Gianluca D'Abrosca
- Department of Clinical and Experimental Medicine - University of Foggia Viale Luigi Pinto 71122 Foggia Italy
| | - Manoj Madheswaran
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
- CNR - Institute of Neuroscience Vedano Al Lambro (MB) Italy
- NeuroMi - Milan Center for Neuroscience, University of Milano Bicocca Milan Italy
| | - Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Laura Caldinelli
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Clementina Acconcia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Andrea Corvino
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Nataliia Ventserova
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Sonia Di Gaetano
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Emilia M Pedone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
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2
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Antón R, Treviño MÁ, Pantoja-Uceda D, Félix S, Babu M, Cabrita EJ, Zweckstetter M, Tinnefeld P, Vera AM, Oroz J. Alternative low-populated conformations prompt phase transitions in polyalanine repeat expansions. Nat Commun 2024; 15:1925. [PMID: 38431667 PMCID: PMC10908835 DOI: 10.1038/s41467-024-46236-5] [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: 06/16/2023] [Accepted: 02/19/2024] [Indexed: 03/05/2024] Open
Abstract
Abnormal trinucleotide repeat expansions alter protein conformation causing malfunction and contribute to a significant number of incurable human diseases. Scarce structural insights available on disease-related homorepeat expansions hinder the design of effective therapeutics. Here, we present the dynamic structure of human PHOX2B C-terminal fragment, which contains the longest polyalanine segment known in mammals. The major α-helical conformation of the polyalanine tract is solely extended by polyalanine expansions in PHOX2B, which are responsible for most congenital central hypoventilation syndrome cases. However, polyalanine expansions in PHOX2B additionally promote nascent homorepeat conformations that trigger length-dependent phase transitions into solid condensates that capture wild-type PHOX2B. Remarkably, HSP70 and HSP90 chaperones specifically seize PHOX2B alternative conformations preventing phase transitions. The precise observation of emerging polymorphs in expanded PHOX2B postulates unbalanced phase transitions as distinct pathophysiological mechanisms in homorepeat expansion diseases, paving the way towards the search of therapeutics modulating biomolecular condensates in central hypoventilation syndrome.
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Affiliation(s)
- Rosa Antón
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Miguel Á Treviño
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - David Pantoja-Uceda
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Sara Félix
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - María Babu
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
| | - Eurico J Cabrita
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
| | - Philip Tinnefeld
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Andrés M Vera
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Javier Oroz
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain.
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3
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Elena-Real CA, Mier P, Sibille N, Andrade-Navarro MA, Bernadó P. Structure-function relationships in protein homorepeats. Curr Opin Struct Biol 2023; 83:102726. [PMID: 37924569 DOI: 10.1016/j.sbi.2023.102726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 11/06/2023]
Abstract
Homorepeats (or polyX), protein segments containing repetitions of the same amino acid, are abundant in proteomes from all kingdoms of life and are involved in crucial biological functions as well as several neurodegenerative and developmental diseases. Mainly inserted in disordered segments of proteins, the structure/function relationships of homorepeats remain largely unexplored. In this review, we summarize present knowledge for the most abundant homorepeats, highlighting the role of the inherent structure and the conformational influence exerted by their flanking regions. Recent experimental and computational methods enable residue-specific investigations of these regions and promise novel structural and dynamic information for this elusive group of proteins. This information should increase our knowledge about the structural bases of phenomena such as liquid-liquid phase separation and trinucleotide repeat disorders.
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Affiliation(s)
- Carlos A Elena-Real
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS. 29 rue de Navacelles, 34090 Montpellier, France. https://twitter.com/carloselenareal
| | - Pablo Mier
- Institute of Organismic and Molecular Evolution, Faculty of Biology, Johannes Gutenberg University Mainz. Hans-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Nathalie Sibille
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS. 29 rue de Navacelles, 34090 Montpellier, France
| | - Miguel A Andrade-Navarro
- Institute of Organismic and Molecular Evolution, Faculty of Biology, Johannes Gutenberg University Mainz. Hans-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Pau Bernadó
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS. 29 rue de Navacelles, 34090 Montpellier, France.
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4
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Elena-Real CA, Urbanek A, Imbert L, Morató A, Fournet A, Allemand F, Sibille N, Boisbouvier J, Bernadó P. Site-Specific Introduction of Alanines for the Nuclear Magnetic Resonance Investigation of Low-Complexity Regions and Large Biomolecular Assemblies. ACS Chem Biol 2023; 18:2039-2049. [PMID: 37582223 DOI: 10.1021/acschembio.3c00288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Nuclear magnetic resonance (NMR) studies of large biomolecular machines and highly repetitive proteins remain challenging due to the difficulty of assigning frequencies to individual nuclei. Here, we present an efficient strategy to address this challenge by engineering a Pyrococcus horikoshii tRNA/alanyl-tRNA synthetase pair that enables the incorporation of up to three isotopically labeled alanine residues in a site-specific manner using in vitro protein expression. The general applicability of this approach for NMR assignment has been demonstrated by introducing isotopically labeled alanines into four distinct proteins: huntingtin exon-1, HMA8 ATPase, the 300 kDa molecular chaperone ClpP, and the alanine-rich Phox2B transcription factor. For large protein assemblies, our labeling approach enabled unambiguous assignments while avoiding potential artifacts induced by site-specific mutations. When applied to Phox2B, which contains two poly-alanine tracts of nine and twenty alanines, we observed that the helical stability is strongly dependent on the homorepeat length. The capacity to selectively introduce alanines with distinct labeling patterns is a powerful tool to probe structure and dynamics of challenging biomolecular systems.
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Affiliation(s)
- Carlos A Elena-Real
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Annika Urbanek
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Lionel Imbert
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, avenue des martyrs, F-38044 Grenoble, France
| | - Anna Morató
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Aurélie Fournet
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Frédéric Allemand
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Nathalie Sibille
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
| | - Jérôme Boisbouvier
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, avenue des martyrs, F-38044 Grenoble, France
| | - Pau Bernadó
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS, 29 rue de Navacelles, 34090 Montpellier, France
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5
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Ho W, Huang H, Huang J. IFF: Identifying key residues in intrinsically disordered regions of proteins using machine learning. Protein Sci 2023; 32:e4739. [PMID: 37498545 PMCID: PMC10443345 DOI: 10.1002/pro.4739] [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: 04/02/2023] [Revised: 06/21/2023] [Accepted: 07/25/2023] [Indexed: 07/28/2023]
Abstract
Conserved residues in protein homolog sequence alignments are structurally or functionally important. For intrinsically disordered proteins or proteins with intrinsically disordered regions (IDRs), however, alignment often fails because they lack a steric structure to constrain evolution. Although sequences vary, the physicochemical features of IDRs may be preserved in maintaining function. Therefore, a method to retrieve common IDR features may help identify functionally important residues. We applied unsupervised contrastive learning to train a model with self-attention neuronal networks on human IDR orthologs. Parameters in the model were trained to match sequences in ortholog pairs but not in other IDRs. The trained model successfully identifies previously reported critical residues from experimental studies, especially those with an overall pattern (e.g., multiple aromatic residues or charged blocks) rather than short motifs. This predictive model can be used to identify potentially important residues in other proteins, improving our understanding of their functions. The trained model can be run directly from the Jupyter Notebook in the GitHub repository using Binder (mybinder.org). The only required input is the primary sequence. The training scripts are available on GitHub (https://github.com/allmwh/IFF). The training datasets have been deposited in an Open Science Framework repository (https://osf.io/jk29b).
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Affiliation(s)
- Wen‐Lin Ho
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Hsuan‐Cheng Huang
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Jie‐rong Huang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung UniversityTaipeiTaiwan
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung UniversityTaipeiTaiwan
- Department of Life Sciences and Institute of Genome SciencesNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
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6
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McIvor JAP, Larsen DS, Mercadante D. Simulating Polyproline II-Helix-Rich Peptides with the Latest Kirkwood-Buff Force Field: A Direct Comparison with AMBER and CHARMM. J Phys Chem B 2022; 126:7833-7846. [PMID: 36125334 DOI: 10.1021/acs.jpcb.2c03837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We simulated the dynamics of a set of peptides characterized by ensembles rich in PPII-helical content, to assess the ability of the most recent Kirkwood-Buff force field (KBFF20) to sample this conformational peculiarity. KBFF has been previously shown to capably reproduce experimental dimensions of disordered proteins, while being limited in confidently sampling structured proteins. Further development of the force field bridged this gap. It is however still unknown what are the main differences between KBFF and AMBER/CHARMM force fields. A direct comparison is now possible as both AMBER/CHARMM force fields have been used to sample peptides rich in PPII-helical content. We found that KBFF20 samples' PPII-helical content qualitatively matches both AMBER and CHARMM force fields, with the main difference being the KBFF ability to populate the αR region of the Ramachandran plot in the set of simulated peptides. Overall, KBFF20 is a well-balanced force field, able to sample the dynamics of both structured and unstructured proteins.
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Affiliation(s)
- Jordan A P McIvor
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Danaé S Larsen
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Davide Mercadante
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
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7
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Mier P, Elena-Real CA, Cortés J, Bernadó P, Andrade-Navarro MA. The sequence context in poly-alanine regions: structure, function and conservation. Bioinformatics 2022; 38:4851-4858. [PMID: 36106994 PMCID: PMC9620824 DOI: 10.1093/bioinformatics/btac610] [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: 01/05/2022] [Revised: 07/07/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Motivation Poly-alanine (polyA) regions are protein stretches mostly composed of alanines. Despite their abundance in eukaryotic proteomes and their association to nine inherited human diseases, the structural and functional roles exerted by polyA stretches remain poorly understood. In this work we study how the amino acid context in which polyA regions are settled in proteins influences their structure and function. Results We identified glycine and proline as the most abundant amino acids within polyA and in the flanking regions of polyA tracts, in human proteins as well as in 17 additional eukaryotic species. Our analyses indicate that the non-structuring nature of these two amino acids influences the α-helical conformations predicted for polyA, suggesting a relevant role in reducing the inherent aggregation propensity of long polyA. Then, we show how polyA position in protein N-termini relates with their function as transit peptides. PolyA placed just after the initial methionine is often predicted as part of mitochondrial transit peptides, whereas when placed in downstream positions, polyA are part of signal peptides. A few examples from known structures suggest that short polyA can emerge by alanine substitutions in α-helices; but evolution by insertion is observed for longer polyA. Our results showcase the importance of studying the sequence context of homorepeats as a mechanism to shape their structure–function relationships. Availability and implementation The datasets used and/or analyzed during the current study are available from the corresponding author onreasonable request. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Pablo Mier
- Faculty of Biology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz , 55128 Mainz, Germany
| | - Carlos A Elena-Real
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS , 34090 Montpellier, France
| | - Juan Cortés
- LAAS-CNRS, Université de Toulouse, CNRS , Toulouse, France
| | - Pau Bernadó
- Centre de Biologie Structurale (CBS), Université de Montpellier, INSERM, CNRS , 34090 Montpellier, France
| | - Miguel A Andrade-Navarro
- Faculty of Biology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz , 55128 Mainz, Germany
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8
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Markgren J, Rasheed F, Hedenqvist MS, Skepö M, Johansson E. Clustering and cross-linking of the wheat storage protein α-gliadin: A combined experimental and theoretical approach. Int J Biol Macromol 2022; 211:592-615. [PMID: 35577195 DOI: 10.1016/j.ijbiomac.2022.05.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/30/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023]
Abstract
Our aim was to understand mechanisms for clustering and cross-linking of gliadins, a wheat seed storage protein type, monomeric in native state, but incorporated in network while processed. The mechanisms were studied utilizing spectroscopy and high-performance liquid chromatography on a gliadin-rich fraction, in vitro produced α-gliadins, and synthetic gliadin peptides, and by coarse-grained modelling, Monte Carlo simulations and prediction algorithms. In solution, gliadins with α-helix structures (dip at 205 nm in CD) were primarily present as monomeric molecules and clusters of gliadins (peaks at 650- and 700-s on SE-HPLC). At drying, large polymers (Rg 90.3 nm by DLS) were formed and β-sheets increased (14% by FTIR). Trained algorithms predicted aggregation areas at amino acids 115-140, 150-179, and 250-268, and induction of liquid-liquid phase separation at P- and Poly-Q-sequences (Score = 1). Simulations showed that gliadins formed polymers by tail-to-tail or a hydrophobic core (Kratky plots and Ree = 35 and 60 for C- and N-terminal). Thus, the N-terminal formed clusters while the C-terminal formed aggregates by disulphide and lanthionine bonds, with favoured hydrophobic clustering of similar/exact peptide sections (synthetic peptide mixtures on SE-HPLC). Mechanisms of clustering and cross-linking of the gliadins presented here, contribute ability to tailor processing results, using these proteins.
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Affiliation(s)
- Joel Markgren
- Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box 190, SE-234 22 Lomma, Sweden.
| | - Faiza Rasheed
- Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box 190, SE-234 22 Lomma, Sweden; Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Mikael S Hedenqvist
- Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Marie Skepö
- Theoretical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
| | - Eva Johansson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box 190, SE-234 22 Lomma, Sweden.
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9
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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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10
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Sheikhhassani V, Scalvini B, Ng J, Heling LWHJ, Ayache Y, Evers TMJ, Estébanez‐Perpiñá E, McEwan IJ, Mashaghi A. Topological dynamics of an intrinsically disordered N‐terminal domain of the human androgen receptor. Protein Sci 2022; 31:e4334. [PMID: 35634773 PMCID: PMC9134807 DOI: 10.1002/pro.4334] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 12/28/2022]
Abstract
Human androgen receptor contains a large N‐terminal domain (AR‐NTD) that is highly dynamic and this poses a major challenge for experimental and computational analysis to decipher its conformation. Misfolding of the AR‐NTD is implicated in prostate cancer and Kennedy's disease, yet our knowledge of its structure is limited to primary sequence information of the chain and a few functionally important secondary structure motifs. Here, we employed an innovative combination of molecular dynamics simulations and circuit topology (CT) analysis to identify the tertiary structure of AR‐NTD. We found that the AR‐NTD adopts highly dynamic loopy conformations with two identifiable regions with distinct topological make‐up and dynamics. This consists of a N‐terminal region (NR, residues 1–224) and a C‐terminal region (CR, residues 225–538), which carries a dense core. Topological mapping of the dynamics reveals a traceable time‐scale dependent topological evolution. NR adopts different positioning with respect to the CR and forms a cleft that can partly enclose the hormone‐bound ligand‐binding domain (LBD) of the androgen receptor. Furthermore, our data suggest a model in which dynamic NR and CR compete for binding to the DNA‐binding domain of the receptor, thereby regulating the accessibility of its DNA‐binding site. Our approach allowed for the identification of a previously unknown regulatory binding site within the CR core, revealing the structural mechanisms of action of AR inhibitor EPI‐001, and paving the way for other drug discovery applications.
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Affiliation(s)
- Vahid Sheikhhassani
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Barbara Scalvini
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Julian Ng
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Laurens W. H. J. Heling
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Yosri Ayache
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Tom M. J. Evers
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
| | - Eva Estébanez‐Perpiñá
- Department of Biochemistry and Molecular Biomedicine Institute of Biomedicine (IBUB) of the University of Barcelona (UB) Barcelona Spain
| | - Iain J. McEwan
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen Scotland UK
| | - Alireza Mashaghi
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science Leiden University Leiden The Netherlands
- Centre for Interdisciplinary Genome Research, Faculty of Science Leiden University Leiden The Netherlands
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11
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Chiu SH, Ho WL, Sun YC, Kuo JC, Huang JR. Phase separation driven by interchangeable properties in the intrinsically disordered regions of protein paralogs. Commun Biol 2022; 5:400. [PMID: 35487971 PMCID: PMC9054762 DOI: 10.1038/s42003-022-03354-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/10/2022] [Indexed: 11/09/2022] Open
Abstract
Paralogs, arising from gene duplications, increase the functional diversity of proteins. Protein functions in paralog families have been extensively studied, but little is known about the roles that intrinsically disordered regions (IDRs) play in their paralogs. Without a folded structure to restrain them, IDRs mutate more diversely along with evolution. However, how the diversity of IDRs in a paralog family affects their functions is unexplored. Using the RNA-binding protein Musashi family as an example, we applied multiple structural techniques and phylogenetic analysis to show how members in a paralog family have evolved their IDRs to different physicochemical properties but converge to the same function. In this example, the lower prion-like tendency of Musashi-1's IDRs, rather than Musashi-2's, is compensated by its higher α-helical propensity to assist their assembly. Our work suggests that, no matter how diverse they become, IDRs could evolve different traits to a converged function, such as liquid-liquid phase separation.
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Affiliation(s)
- Shih-Hui Chiu
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan
| | - Wen-Lin Ho
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan
| | - Yung-Chen Sun
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan
| | - Jean-Cheng Kuo
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan
| | - Jie-Rong Huang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan. .,Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan. .,Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, No. 155 Section 2, Li-nong Street, Taipei, Taiwan.
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12
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Owada R, Mitsui S, Nakamura K. Exogenous polyserine and polyleucine are toxic to recipient cells. Sci Rep 2022; 12:1685. [PMID: 35102230 PMCID: PMC8803884 DOI: 10.1038/s41598-022-05720-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/11/2022] [Indexed: 12/21/2022] Open
Abstract
Repeat-associated non-AUG (RAN) translation of mRNAs/transcripts responsible for polyglutamine (polyQ) diseases may generate peptides containing different mono amino acid tracts such as polyserine (polyS) and polyleucine (polyL). The propagation of aggregated polyQ from one cell to another is also an intriguing feature of polyQ proteins. However, whether the RAN translation-related polyS and polyL have the ability to propagate remains unclear, and if they do, whether the exogenous polyS and polyL exert toxicity on the recipient cells is also not known yet. In the present study, we found that aggregated polyS and polyL peptides spontaneously enter neuron-like cells and astrocytes in vitro. Aggregated polyS led to the degeneration of the differentiated neuron-like cultured cells. Likewise, the two types of aggregates taken up by astrocytes induced aberrant differentiation and cell death in vitro. Furthermore, injection of each of the two types of aggregates into the ventricles of adult mice resulted in their behavioral changes. The polyS-injected mice showed extensive vacuolar degeneration in the brain. Thus, the RAN translation-related proteins containing polyS and polyL have the potential to propagate and the proteins generated by all polyQ diseases might exert universal toxicity in the recipient cells.
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Affiliation(s)
- Ryuji Owada
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Shinichi Mitsui
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Kazuhiro Nakamura
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan.
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13
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Iizuka Y, Owada R, Kawasaki T, Hayashi F, Sonoyama M, Nakamura K. Toxicity of internalized polyalanine to cells depends on aggregation. Sci Rep 2021; 11:23441. [PMID: 34873226 PMCID: PMC8648788 DOI: 10.1038/s41598-021-02889-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/24/2021] [Indexed: 12/23/2022] Open
Abstract
In polyalanine (PA) diseases, the disease-causing transcription factors contain an expansion of alanine repeats. While aggregated proteins that are responsible for the pathogenesis of neurodegenerative disorders show cell-to-cell propagation and thereby exert toxic effects on the recipient cells, whether this is also the case with expanded PA has not been studied. It is also not known whether the internalized PA is toxic to recipient cells based on the degree of aggregation. In this study, we therefore prepared different degrees of aggregation of a peptide having 13 alanine repeats without flanking sequences of PA disease-causative proteins (13A). The aggregated 13A was spontaneously taken up by neuron-like cultured cells. Functionally, strong aggregates but not weak aggregates displayed a deficit in neuron-like differentiation in vitro. Moreover, the injection of strong but not weak 13A aggregates into the ventricle of mice during the neonatal stage led to enhanced spontaneous motor activity later in life. Thus, PA in the extracellular space has the potential to enter adjacent cells, and may exert toxicity depending on the degree of aggregation.
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Affiliation(s)
- Yutaro Iizuka
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Ryuji Owada
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Takayasu Kawasaki
- Accelerator Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
| | - Fumio Hayashi
- Center for Instrumental Analysis, Organization for Promotion of Research and University Industry Collaboration, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma, 376-8515, Japan
| | - Masashi Sonoyama
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515, Japan.,Gunma University Initiative for Advanced Research (GIAR), Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515, Japan.,Gunma University Center for Food Science and Wellness (GUCFW), Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515, Japan
| | - Kazuhiro Nakamura
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma, 371-8511, Japan.
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14
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Masquelier E, Liang SP, Sepunaru L, Morse DE, Gordon MJ. Reversible electrochemical triggering and optical interrogation of polylysine α-helix formation. Bioelectrochemistry 2021; 144:108007. [PMID: 34871847 DOI: 10.1016/j.bioelechem.2021.108007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/30/2022]
Abstract
Reversible electrochemical triggering of the random coil to α-helix conformational transition of polylysine (Lys10, Lys20, Lys50) was accomplished at a Pt electrode at potentials < |1| V vs. Ag/AgCl. Direct electroreduction of the N-terminus vs ε-amino groups in Lys sidechains, as well as hydronium reduction and electrolysis, could be easily distinguished and deconvolved using differential pulse voltammetry. Electrochemistry was coupled with in situ UV absorbance and circular dichroism spectroscopies to dynamically follow the evolution of α-helix formation at different potentials. Isotope experiments in H2O vs. D2O unequivocally confirm that direct electroreduction of ε-NH3+/ND3+ groups in Lys sidechains, rather than electrochemically generated pH gradient-induced deprotonation, leads to subsequent α-helix formation. The site-selective electrochemistry and optical methodologies presented herein can be generalized and extended to interrogate other protonation-sensitive biomolecular systems, and potentially provide access to early intermediates and control over the dynamic structural evolution of peptides and proteins.
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Affiliation(s)
- Eloise Masquelier
- Materials Department, University of California, Santa Barbara, CA, United States
| | - Sheng-Ping Liang
- Dept. Of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States
| | - Lior Sepunaru
- Dept. Of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States
| | - Daniel E Morse
- Dept. Of Molecular, Cellular and Development Biology, University of California, Santa Barbara, CA, United States; Institue for Collaborative Biotechnologies, University of California, Santa Barbara, CA, United States
| | - Michael J Gordon
- Dept. Of Chemical Engineering, University of California, Santa Barbara, CA, United States; Institue for Collaborative Biotechnologies, University of California, Santa Barbara, CA, United States.
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15
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Scalia B, Venti V, Ciccia LM, Criscione R, Lo Bianco M, Sciuto L, Falsaperla R, Zanghì A, Praticò AD. Aristaless-Related Homeobox (ARX): Epilepsy Phenotypes beyond Lissencephaly and Brain Malformations. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractThe Aristaless-related homeobox (ARX) transcription factor is involved in the development of GABAergic and cholinergic neurons in the forebrain. ARX mutations have been associated with a wide spectrum of neurodevelopmental disorders in humans and are responsible for both malformation (in particular lissencephaly) and nonmalformation complex phenotypes. The epilepsy phenotypes related to ARX mutations are West syndrome and X-linked infantile spasms, X-linked myoclonic epilepsy with spasticity and intellectual development and Ohtahara and early infantile epileptic encephalopathy syndrome, which are related in most of the cases to intellectual disability and are often drug resistant. In this article, we shortly reviewed current knowledge of the function of ARX with a particular attention on its consequences in the development of epilepsy during early childhood.
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Affiliation(s)
- Bruna Scalia
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Valeria Venti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Lina M. Ciccia
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Roberta Criscione
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Laura Sciuto
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Neonatal Intensive Care unit and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Antonio Zanghì
- Department of Medical and Surgical Sciences and Advanced Technology “G.F. Ingrassia,” University of Catania, Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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16
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Jazurek-Ciesiolka M, Ciesiolka A, Komur AA, Urbanek-Trzeciak MO, Krzyzosiak WJ, Fiszer A. RAN Translation of the Expanded CAG Repeats in the SCA3 Disease Context. J Mol Biol 2020; 432:166699. [PMID: 33157084 DOI: 10.1016/j.jmb.2020.10.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 01/08/2023]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the ATXN3 gene encoding the ataxin-3 protein. Despite extensive research the exact pathogenic mechanisms of SCA3 are still not understood in depth. In the present study, to gain insight into the toxicity induced by the expanded CAG repeats in SCA3, we comprehensively investigated repeat-associated non-ATG (RAN) translation in various cellular models expressing translated or non-canonically translated ATXN3 sequences with an increasing number of CAG repeats. We demonstrate that two SCA3 RAN proteins, polyglutamine (polyQ) and polyalanine (polyA), are found only in the case of CAG repeats of pathogenic length. Despite having distinct cellular localization, RAN polyQ and RAN polyA proteins are very often coexpressed in the same cell, impairing nuclear integrity and inducing apoptosis. We provide for the first time mechanistic insights into SCA3 RAN translation indicating that ATXN3 sequences surrounding the repeat region have an impact on SCA3 RAN translation initiation and efficiency. We revealed that RAN translation of polyQ proteins starts at non-cognate codons upstream of the CAG repeats, whereas RAN polyA proteins are likely translated within repeats. Furthermore, integrated stress response activation enhances SCA3 RAN translation. Our findings suggest that the ATXN3 sequence context plays an important role in triggering SCA3 RAN translation and that SCA3 RAN proteins may cause cellular toxicity.
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Affiliation(s)
- Magdalena Jazurek-Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Adam Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Alicja A Komur
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Martyna O Urbanek-Trzeciak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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17
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Chavali S, Singh AK, Santhanam B, Babu MM. Amino acid homorepeats in proteins. Nat Rev Chem 2020; 4:420-434. [PMID: 37127972 DOI: 10.1038/s41570-020-0204-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2020] [Indexed: 12/16/2022]
Abstract
Amino acid homorepeats, or homorepeats, are polypeptide segments found in proteins that contain stretches of identical amino acid residues. Although abnormal homorepeat expansions are linked to pathologies such as neurodegenerative diseases, homorepeats are prevalent in eukaryotic proteomes, suggesting that they are important for normal physiology. In this Review, we discuss recent advances in our understanding of the biological functions of homorepeats, which range from facilitating subcellular protein localization to mediating interactions between proteins across diverse cellular pathways. We explore how the functional diversity of homorepeat-containing proteins could be linked to the ability of homorepeats to adopt different structural conformations, an ability influenced by repeat composition, repeat length and the nature of flanking sequences. We conclude by highlighting how an understanding of homorepeats will help us better characterize and develop therapeutics against the human diseases to which they contribute.
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Affiliation(s)
- Sreenivas Chavali
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK.
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, India.
| | - Anjali K Singh
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, India
| | - Balaji Santhanam
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
- Department of Structural Biology and Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK.
- Department of Structural Biology and Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, USA.
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18
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Musashi-1: An Example of How Polyalanine Tracts Contribute to Self-Association in the Intrinsically Disordered Regions of RNA-Binding Proteins. Int J Mol Sci 2020; 21:ijms21072289. [PMID: 32225071 PMCID: PMC7177541 DOI: 10.3390/ijms21072289] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 12/19/2022] Open
Abstract
RNA-binding proteins (RBPs) have intrinsically disordered regions (IDRs) whose biophysical properties have yet to be explored to the same extent as those of the folded RNA interacting domains. These IDRs are essential to the formation of biomolecular condensates, such as stress and RNA granules, but dysregulated assembly can be pathological. Because of their structural heterogeneity, IDRs are best studied by NMR spectroscopy. In this study, we used NMR spectroscopy to investigate the structural propensity and self-association of the IDR of the RBP Musashi-1. We identified two transient α-helical regions (residues ~208–218 and ~270–284 in the IDR, the latter with a polyalanine tract). Strong NMR line broadening in these regions and circular dichroism and micrography data suggest that the two α-helical elements and the hydrophobic residues in between may contribute to the formation of oligomers found in stress granules and implicated in Alzheimer’s disease. Bioinformatics analysis suggests that polyalanine stretches in the IDRs of RBPs may have evolved to promote RBP assembly.
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19
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Pirone L, Caldinelli L, Di Lascio S, Di Girolamo R, Di Gaetano S, Fornasari D, Pollegioni L, Benfante R, Pedone E. Molecular insights into the role of the polyalanine region in mediating PHOX2B aggregation. FEBS J 2019; 286:2505-2521. [PMID: 30955232 DOI: 10.1111/febs.14841] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/27/2019] [Accepted: 04/04/2019] [Indexed: 11/26/2022]
Abstract
About 90% of congenital central hypoventilation syndrome (CCHS) patients show polyalanine triplet expansions in the coding region of transcription factor PHOX2B, which renders this protein an intriguing target to understand the insurgence of this syndrome and for the design of a novel therapeutical approach. Consistently with the role of PHOX2B as a transcriptional regulator, it is reasonable that a general transcriptional dysregulation caused by the polyalanine expansion might represent an important mechanism underlying CCHS pathogenesis. Therefore, this study focused on the biochemical characterization of different PHOX2B variants, such as a variant containing the correct C-terminal (20 alanines) stretch, one of the most frequent polyalanine expansions (+7 alanines), and a variant lacking the complete alanine stretch (0 alanines). Comparison of the different variants by a multidisciplinary approach based on different methodologies (including circular dichroism, spectrofluorimetry, light scattering, and Atomic Force Microscopy studies) highlighted the propensity to aggregate for the PHOX2B variant containing the polyalanine expansion (+7-alanines), especially in the presence of DNA, while the 0-alanines variant resembled the protein with the correct polyalanine length. Moreover, and unexpectedly, the formation of fibrils was revealed only for the pathological variant, suggesting a plausible role of such fibrils in the insurgence of CCHS.
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Affiliation(s)
- Luciano Pirone
- Institute of Biostructure and Bioimaging, CNR, Napoli, Italy
| | - Laura Caldinelli
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, Varese, Italy
| | - Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Italy
| | - Rocco Di Girolamo
- Department of Chemical Sciences, University of Naples Federico II, Italy
| | | | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli studi dell'Insubria, Varese, Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Italy
- CNR- Neuroscience Institute, Milan, Italy
| | - Emilia Pedone
- Institute of Biostructure and Bioimaging, CNR, Napoli, Italy
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20
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Dubos A, Meziane H, Iacono G, Curie A, Riet F, Martin C, Loaëc N, Birling MC, Selloum M, Normand E, Pavlovic G, Sorg T, Stunnenberg HG, Chelly J, Humeau Y, Friocourt G, Hérault Y. A new mouse model of ARX dup24 recapitulates the patients' behavioral and fine motor alterations. Hum Mol Genet 2019; 27:2138-2153. [PMID: 29659809 PMCID: PMC5985730 DOI: 10.1093/hmg/ddy122] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 03/26/2018] [Indexed: 01/27/2023] Open
Abstract
The aristaless-related homeobox (ARX) transcription factor is involved in the development of GABAergic and cholinergic neurons in the forebrain. ARX mutations have been associated with a wide spectrum of neurodevelopmental disorders in humans, among which the most frequent, a 24 bp duplication in the polyalanine tract 2 (c.428_451dup24), gives rise to intellectual disability, fine motor defects with or without epilepsy. To understand the functional consequences of this mutation, we generated a partially humanized mouse model carrying the c.428_451dup24 duplication (Arxdup24/0) that we characterized at the behavior, neurological and molecular level. Arxdup24/0 males presented with hyperactivity, enhanced stereotypies and altered contextual fear memory. In addition, Arxdup24/0 males had fine motor defects with alteration of reaching and grasping abilities. Transcriptome analysis of Arxdup24/0 forebrains at E15.5 showed a down-regulation of genes specific to interneurons and an up-regulation of genes normally not expressed in this cell type, suggesting abnormal interneuron development. Accordingly, interneuron migration was altered in the cortex and striatum between E15.5 and P0 with consequences in adults, illustrated by the defect in the inhibitory/excitatory balance in Arxdup24/0 basolateral amygdala. Altogether, we showed that the c.428_451dup24 mutation disrupts Arx function with a direct consequence on interneuron development, leading to hyperactivity and defects in precise motor movement control and associative memory. Interestingly, we highlighted striking similarities between the mouse phenotype and a cohort of 33 male patients with ARX c.428_451dup24, suggesting that this new mutant mouse line is a good model for understanding the pathophysiology and evaluation of treatment.
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Affiliation(s)
- Aline Dubos
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Hamid Meziane
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Giovanni Iacono
- Department of Molecular Biology, Radboud Institute for Molecular Life Sciences, Radboud University, 6500 HB Nijmegen, The Netherlands
| | - Aurore Curie
- Centre de Référence Déficiences Intellectuelles de Causes Rares, Hôpital Femmes Mères Enfants, Hospices Civils de Lyon, Institut des Sciences Cognitives, CNRS UMR5304, Université Claude Bernard Lyon1, 69675 Bron, France
| | - Fabrice Riet
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Christelle Martin
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, 33077 Bordeaux, France
| | - Nadège Loaëc
- Inserm UMR 1078, Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé, Etablissement Français du Sang (EFS) Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, 29200 Brest, France
| | | | - Mohammed Selloum
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Elisabeth Normand
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, 33077 Bordeaux, France.,Pole In Vivo, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, 33077 Bordeaux, France
| | - Guillaume Pavlovic
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Tania Sorg
- CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
| | - Henk G Stunnenberg
- Department of Molecular Biology, Radboud Institute for Molecular Life Sciences, Radboud University, 6500 HB Nijmegen, The Netherlands
| | - Jamel Chelly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,Service de Diagnostic Génétique, Hôpital Civil de Strasbourg, Hôpitaux Universitaires de Strasbourg, 67091 Strasbourg, France
| | - Yann Humeau
- Team Synapse in Cognition, Institut Interdisciplinaire de NeuroScience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, 33077 Bordeaux, France
| | - Gaëlle Friocourt
- Inserm UMR 1078, Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé, Etablissement Français du Sang (EFS) Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, 29200 Brest, France
| | - Yann Hérault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,CELPHEDIA, PHENOMIN, Institut Clinique de la Souris, 67404 Illkirch, France
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21
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Naito A, Kametani S, Aoki A, Asakura T. Structural Analyses of Alanine Trimer and Tetramer Crystals with Antiparallel and Parallel β-Sheet Structures Using Solid-State 1H Spin-Diffusion 2D Correlation NMR Spectroscopy. J Phys Chem B 2018; 122:9373-9381. [PMID: 30234305 DOI: 10.1021/acs.jpcb.8b07859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Poly-l-alanine (PLA) sequences are key elements of the crystalline domains of spider dragline and wild silkworm silks. In the present work, 1H spin-diffusion two-dimensional (2D) correlation NMR spectra were observed for selectively deuterated (Ala)3 and (Ala)4 crystals to develop the analytical method for the structure of PLA sequences. The build-up curves of the cross peaks for three kinds of 1H pairs in selectively deuterated (Ala)3 and (Ala)4 crystals were observed to obtain spin-diffusion rate constant k j, k from relaxation master equations P i, j(τm). The k j, k values subsequently lead to effective interproton distance r j, keff (obs) values for individual proton-proton pairs, which include intra- and intermolecular contributions. The r j, keff (obs) values were compared to r j, keff (calc) values obtained from the experimentally determined atomic coordinates of antiparallel (AP) β-sheet (Ala)3 and (Ala)4 and parallel (P) β-sheet of (Ala)3 and (Ala)4 crystals. The agreement between the r j, keff (obs) and r j, keff (calc) values was good for AP β-sheet (Ala)3 and (Ala)4 crystals but poor for P β-sheet (Ala)3 and (Ala)4 crystals. These deviations were obtained from the interproton distances of the interchain contributions due to different packing arrangements. The packing arrangements of the PLA region are important when considering the relevant structure and the mechanical properties of silks.
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Affiliation(s)
- Akira Naito
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
| | - Shunsuke Kametani
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
| | - Akihiro Aoki
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
| | - Tetsuo Asakura
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
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22
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Li HR, Chiang WC, Chou PC, Wang WJ, Huang JR. TAR DNA-binding protein 43 (TDP-43) liquid-liquid phase separation is mediated by just a few aromatic residues. J Biol Chem 2018; 293:6090-6098. [PMID: 29511089 DOI: 10.1074/jbc.ac117.001037] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 03/05/2018] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic cells contain distinct organelles, but not all of these compartments are enclosed by membranes. Some intrinsically disordered proteins mediate membraneless organelle formation through liquid-liquid phase separation (LLPS). LLPS facilitates many biological functions such as regulating RNA stability and ribonucleoprotein assembly, and disruption of LLPS pathways has been implicated in several diseases. Proteins exhibiting LLPS typically have low sequence complexity and specific repeat motifs. These motifs promote multivalent connections with other molecules and the formation of higher-order oligomers, and their removal usually prevents LLPS. The intrinsically disordered C-terminal domain of TAR DNA-binding protein 43 (TDP-43), a protein involved in motor neuron disease and dementia lacks a dominant LLPS motif, however, and how this domain forms condensates is unclear. Using extensive mutagenesis of TDP-43, we demonstrate here that three tryptophan residues and, to a lesser extent, four other aromatic residues are most important for TDP-43 to undergo LLPS. Our results also suggested that only a few residues may be required for TDP-43 LLPS because the α-helical segment (spanning ∼20 residues) in the middle part of the C-terminal domain tends to self-assemble, reducing the number of motifs required for forming a multivalent connection. Our results indicating that a self-associating α-helical element with a few key residues regulates condensate formation highlight a different type of LLPS involving intrinsically disordered regions. The C-terminal domain of TDP-43 contains ∼50 disease-related mutations, with no clear physicochemical link between them. We propose that they may disrupt LLPS indirectly by interfering with the key residues identified here.
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Affiliation(s)
- Hao-Ru Li
- From the Institute of Biochemistry and Molecular Biology and
| | - Wan-Chin Chiang
- From the Institute of Biochemistry and Molecular Biology and
| | - Po-Chun Chou
- From the Institute of Biochemistry and Molecular Biology and
| | - Won-Jing Wang
- From the Institute of Biochemistry and Molecular Biology and
| | - Jie-Rong Huang
- From the Institute of Biochemistry and Molecular Biology and .,the Institute of Biomedical Informatics, National Yang-Ming University, No. 155 Section 2, Li-nong Street, Taipei 11221, Taiwan
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23
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Naito A, Okushita K, Nishimura K, Boutis GS, Aoki A, Asakura T. Quantitative Analysis of Solid-State Homonuclear Correlation Spectra of Antiparallel β-Sheet Alanine Tetramers. J Phys Chem B 2018; 122:2715-2724. [PMID: 29420030 DOI: 10.1021/acs.jpcb.7b11126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Poly-l-alanine (PLA) sequences are a key element in the structure of the crystalline domains of spider dragline silks, wild silkworm silks, antifreeze proteins, and amyloids. To date, no atomic-level structures of antiparallel (AP)-PLA longer than Ala4 have been reported using the single-crystal X-ray diffraction analysis. In this work, dipolar-assisted rotational resonance solid-state NMR spectra were observed to determine the effective internuclear distances of 13C uniformly labeled alanine tetramer with antiparallel (AP) β-sheet structure whose atomic coordinates are determined from the X-ray crystallographic analysis. Initial build-up rates, R j, k, were obtained from the build-up curves of the cross peaks by considering the internuclear distances arising in the master equation. Subsequently, experimentally obtained effective internuclear distances, reffj, k(obs), were compared with the calculated reffj, k(calc) values obtained from the X-ray crystallographic data. Fairly good correlation between reffj, k(obs) and reffj, k(calc) was obtained in the range of 1.0-6.0 Å, with the standard deviation of 0.244 Å, without considering the zero-quantum line-shape functions. It was further noted that the internuclear distances of intermolecular contributions provide details relating to the molecular packing in solid-state samples. Thus, the present data agree well with AP-β-sheet packing but do not agree with P-β-sheet packing.
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Affiliation(s)
- Akira Naito
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
| | - Keiko Okushita
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan.,Institute for Molecular Science , 38 Nishigo-Naka , Myodaiji, Okazaki 444-8585 , Japan
| | - Katsuyuki Nishimura
- Institute for Molecular Science , 38 Nishigo-Naka , Myodaiji, Okazaki 444-8585 , Japan
| | - Gregory S Boutis
- Department of Physics , Brooklyn College of The City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Department of Physics , The Graduate Center of The City University of New York , 365 5th Avenue , New York , New York 10016 , United States
| | - Akihiro Aoki
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
| | - Tetsuo Asakura
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei , Tokyo 184-8588 , Japan
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24
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Abstract
The tragedy of epilepsy emerges from the combination of its high prevalence, impact upon sufferers and their families, and unpredictability. Childhood epilepsies are frequently severe, presenting in infancy with pharmaco-resistant seizures; are often accompanied by debilitating neuropsychiatric and systemic comorbidities; and carry a grave risk of mortality. Here, we review the most current basic science and translational research findings on several of the most catastrophic forms of pediatric epilepsy. We focus largely on genetic epilepsies and the research that is discovering the mechanisms linking disease genes to epilepsy syndromes. We also describe the strides made toward developing novel pharmacological and interventional treatment strategies to treat these disorders. The research reviewed provides hope for a complete understanding of, and eventual cure for, these childhood epilepsy syndromes.
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Affiliation(s)
- MacKenzie A Howard
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Texas, 78712;
| | - Scott C Baraban
- Epilepsy Research Laboratory in the Department of Neurological Surgery, Weill Institute for Neurosciences, University of California, San Francisco, California 94143;
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25
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Abstract
Accumulating evidence suggests that many classes of DNA repeats exhibit attributes that distinguish them from other genetic variants, including the fact that they are more liable to mutation; this enables them to mediate genetic plasticity. The expansion of tandem repeats, particularly of short tandem repeats, can cause a range of disorders (including Huntington disease, various ataxias, motor neuron disease, frontotemporal dementia, fragile X syndrome and other neurological disorders), and emerging data suggest that tandem repeat polymorphisms (TRPs) can also regulate gene expression in healthy individuals. TRPs in human genomes may also contribute to the missing heritability of polygenic disorders. A better understanding of tandem repeats and their associated repeatome, as well as their capacity for genetic plasticity via both germline and somatic mutations, is needed to transform our understanding of the role of TRPs in health and disease.
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Affiliation(s)
- Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
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26
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A biosensor-based framework to measure latent proteostasis capacity. Nat Commun 2018; 9:287. [PMID: 29348634 PMCID: PMC5773518 DOI: 10.1038/s41467-017-02562-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 12/11/2017] [Indexed: 12/11/2022] Open
Abstract
The pool of quality control proteins (QC) that maintains protein-folding homeostasis (proteostasis) is dynamic but can become depleted in human disease. A challenge has been in quantitatively defining the depth of the QC pool. With a new biosensor, flow cytometry-based methods and mathematical modeling we measure the QC capacity to act as holdases and suppress biosensor aggregation. The biosensor system comprises a series of barnase kernels with differing folding stability that engage primarily with HSP70 and HSP90 family proteins. Conditions of proteostasis stimulation and stress alter QC holdase activity and aggregation rates. The method reveals the HSP70 chaperone cycle to be rate limited by HSP70 holdase activity under normal conditions, but this is overcome by increasing levels of the BAG1 nucleotide exchange factor to HSPA1A or activation of the heat shock gene cluster by HSF1 overexpression. This scheme opens new paths for biosensors of disease and proteostasis systems. A pool of quality control proteins (QC) maintains the protein-folding homeostasis in the cell, but its quantitative analysis is challenging. Here the authors develop a FRET sensor based on the protein barnase, able to quantify QC holdase activity and its ability to suppress protein aggregation.
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27
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Oliva C, Sánchez-Murcia PA, Rico E, Bravo A, Menéndez M, Gago F, Jiménez-Ruiz A. Structure-based domain assignment in Leishmania infantum EndoG: characterization of a pH-dependent regulatory switch and a C-terminal extension that largely dictates DNA substrate preferences. Nucleic Acids Res 2017; 45:9030-9045. [PMID: 28911117 PMCID: PMC5587815 DOI: 10.1093/nar/gkx629] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/11/2017] [Indexed: 11/28/2022] Open
Abstract
Mitochondrial endonuclease G from Leishmania infantum (LiEndoG) participates in the degradation of double-stranded DNA (dsDNA) during parasite cell death and is catalytically inactive at a pH of 8.0 or above. The presence, in the primary sequence, of an acidic amino acid-rich insertion exclusive to trypanosomatids and its spatial position in a homology-built model of LiEndoG led us to postulate that this peptide stretch might act as a pH sensor for self-inhibition. We found that a LiEndoG variant lacking residues 145–180 is indeed far more active than its wild-type counterpart at pH values >7.0. In addition, we discovered that (i) LiEndoG exists as a homodimer, (ii) replacement of Ser211 in the active-site SRGH motif with the canonical aspartate from the DRGH motif of other nucleases leads to a catalytically deficient enzyme, (iii) the activity of the S211D variant can be restored upon the concomitant replacement of Ala247 with Arg and (iv) a C-terminal extension is responsible for the observed preferential cleavage of single-stranded DNA (ssDNA) and ssDNA–dsDNA junctions. Taken together, our results support the view that LiEndoG is a multidomain molecular machine whose nuclease activity can be subtly modulated or even abrogated through architectural changes brought about by environmental conditions and interaction with other binding partners.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Catalytic Domain
- Cloning, Molecular
- DNA Cleavage
- DNA, Protozoan/chemistry
- DNA, Protozoan/genetics
- DNA, Protozoan/metabolism
- DNA, Single-Stranded/chemistry
- DNA, Single-Stranded/genetics
- DNA, Single-Stranded/metabolism
- Endodeoxyribonucleases/chemistry
- Endodeoxyribonucleases/genetics
- Endodeoxyribonucleases/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Hydrogen-Ion Concentration
- Kinetics
- Leishmania infantum/chemistry
- Leishmania infantum/enzymology
- Models, Molecular
- Nucleic Acid Conformation
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Protein Multimerization
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Alignment
- Sequence Deletion
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
- Substrate Specificity
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Affiliation(s)
- Cristina Oliva
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Pedro A. Sánchez-Murcia
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Eva Rico
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Ana Bravo
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Margarita Menéndez
- Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas (CSIC), E-28006 Madrid, Spain
| | - Federico Gago
- Departamento de Ciencias Biomédicas y “Unidad Asociada IQM-CSIC”, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 918 855 109; Fax: +34 918 854 585; . Correspondence may also be addressed to Federico Gago. Tel: +34 918 854 514; Fax: +34 918 854 591;
| | - Antonio Jiménez-Ruiz
- Departamento de Biología de Sistemas, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
- To whom correspondence should be addressed. Tel: +34 918 855 109; Fax: +34 918 854 585; . Correspondence may also be addressed to Federico Gago. Tel: +34 918 854 514; Fax: +34 918 854 591;
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28
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Naito A, Tasei Y, Nishimura A, Asakura T. Packing Arrangements and Intersheet Interaction of Alanine Oligopeptides As Revealed by Relaxation Parameters Obtained from High-Resolution 13C Solid-State NMR. J Phys Chem B 2017; 121:8946-8955. [DOI: 10.1021/acs.jpcb.7b07068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Akira Naito
- Department of Biotechnology, Tokyo University of Agriculture and Technology Koganei, Tokyo 184-8588 Japan
| | - Yugo Tasei
- Department of Biotechnology, Tokyo University of Agriculture and Technology Koganei, Tokyo 184-8588 Japan
| | - Akio Nishimura
- Department of Biotechnology, Tokyo University of Agriculture and Technology Koganei, Tokyo 184-8588 Japan
| | - Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology Koganei, Tokyo 184-8588 Japan
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29
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Moily NS, Ormsby AR, Stojilovic A, Ramdzan YM, Diesch J, Hannan RD, Zajac MS, Hannan AJ, Oshlack A, Hatters DM. Transcriptional profiles for distinct aggregation states of mutant Huntingtin exon 1 protein unmask new Huntington's disease pathways. Mol Cell Neurosci 2017; 83:103-112. [DOI: 10.1016/j.mcn.2017.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/23/2017] [Accepted: 07/21/2017] [Indexed: 11/16/2022] Open
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30
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Ying Y, Wang XJ, Vuong CK, Lin CH, Damianov A, Black DL. Splicing Activation by Rbfox Requires Self-Aggregation through Its Tyrosine-Rich Domain. Cell 2017; 170:312-323.e10. [PMID: 28708999 DOI: 10.1016/j.cell.2017.06.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/31/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
Abstract
Proteins of the Rbfox family act with a complex of proteins called the Large Assembly of Splicing Regulators (LASR). We find that Rbfox interacts with LASR via its C-terminal domain (CTD), and this domain is essential for its splicing activity. In addition to LASR recruitment, a low-complexity (LC) sequence within the CTD contains repeated tyrosines that mediate higher-order assembly of Rbfox/LASR and are required for splicing activation by Rbfox. This sequence spontaneously aggregates in solution to form fibrous structures and hydrogels, suggesting an assembly similar to the insoluble cellular inclusions formed by FUS and other proteins in neurologic disease. Unlike the pathological aggregates, we find that assembly of the Rbfox CTD plays an essential role in its normal splicing function. Rather than simple recruitment of individual regulators to a target exon, alternative splicing choices also depend on the higher-order assembly of these regulators within the nucleus.
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Affiliation(s)
- Yi Ying
- Molecular Biology Interdepartmental Doctoral Program, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Xiao-Jun Wang
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Celine K Vuong
- Molecular Biology Interdepartmental Doctoral Program, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chia-Ho Lin
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Andrey Damianov
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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31
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ARX polyalanine expansion mutations lead to migration impediment in the rostral cortex coupled with a developmental deficit of calbindin-positive cortical GABAergic interneurons. Neuroscience 2017. [PMID: 28627419 DOI: 10.1016/j.neuroscience.2017.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Aristaless-related homeobox gene (ARX) is indispensable for interneuron development. Patients with ARX polyalanine expansion mutations of the first two tracts (namely PA1 and PA2) suffer from intellectual disability of varying severity, with seizures a frequent comorbidity. The impact of PA1 and PA2 mutations on the brain development is unknown, hindering the search for therapeutic interventions. Here, we characterized the disturbances to cortical interneuron development in mice modeling the two most common ARX polyalanine expansion mutations in human. We found a consistent ∼40-50% reduction of calbindin-positive interneurons, but not Stt+ or Cr+ interneurons, within the cortex of newborn hemizygous mice (p=0.024) for both mutant strains compared to wildtype (p=0.011). We demonstrate that this was a consequence of calbindin precursor cells being arrested or delayed at the ventral subpallium en route of tangential migration. Ex-vivo assay validated this migration deficit in PA1 cells (p=0.0002) suggesting that the defect is contributed by intrinsic loss of Arx function within migrating cells. Both humans and mice with PA1 mutations present with severe clinical features, including intellectual disability and infantile spasms. Our data further demonstrated the pathogenic mechanism was robustly shared between PA1 and PA2 mutations, as previously reported including Arx protein reduction and overlapping transcriptome profiles within the developing mouse brains. Data from our study demonstrated that cortical calbindin interneuron development and migration is negatively affected by ARX polyalanine expansion mutations. Understanding the cellular pathogenesis contributing to disease manifestation is necessary to screen efficacy of potential therapeutic interventions.
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32
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Radwan M, Wood RJ, Sui X, Hatters DM. When proteostasis goes bad: Protein aggregation in the cell. IUBMB Life 2017; 69:49-54. [PMID: 28066979 DOI: 10.1002/iub.1597] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/09/2016] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a hallmark of the major neurodegenerative diseases including Alzheimer's, Parkinson's, Huntington's and motor neuron and is a symptom of a breakdown in the management of proteome foldedness. Indeed, it is remarkable that under normal conditions cells can keep their proteome in a highly crowded and confined space without uncontrollable aggregation. Proteins pose a particular challenge relative to other classes of biomolecules because upon synthesis they must typically follow a complex folding pathway to reach their functional conformation (native state). Non-native conformations, including the unfolded nascent chain, are highly prone to aberrant interactions, leading to aggregation. Here we review recent advances in knowledge of proteostasis, approaches to monitor proteostasis and the impact that protein aggregation has on biology. We also include discussion of the outstanding challenges. © 2017 IUBMB Life, 69(2):49-54, 2017.
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Affiliation(s)
- Mona Radwan
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Melbourne, Victoria, Australia
| | - Rebecca J Wood
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Melbourne, Victoria, Australia
| | - Xiaojing Sui
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Melbourne, Victoria, Australia
| | - Danny M Hatters
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Melbourne, Victoria, Australia
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33
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Kametani S, Tasei Y, Nishimura A, Asakura T. Distinct solvent- and temperature-dependent packing arrangements of anti-parallel β-sheet polyalanines studied with solid-state 13C NMR and MD simulation. Phys Chem Chem Phys 2017; 19:20829-20838. [DOI: 10.1039/c7cp03693k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Change from rectangular arrangement to staggered arrangement of (Ala)6 by heat treatment.
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Affiliation(s)
- Shunsuke Kametani
- Department of Biotechnology
- Tokyo University of Agriculture and Technology
- Koganei
- Japan
- Mitsui Chemical Analysis & Consulting Service, Inc
| | - Yugo Tasei
- Department of Biotechnology
- Tokyo University of Agriculture and Technology
- Koganei
- Japan
| | - Akio Nishimura
- Department of Biotechnology
- Tokyo University of Agriculture and Technology
- Koganei
- Japan
| | - Tetsuo Asakura
- Department of Biotechnology
- Tokyo University of Agriculture and Technology
- Koganei
- Japan
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34
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Chen MZ, Mok SA, Ormsby AR, Muchowski PJ, Hatters DM. N-Terminal Fragments of Huntingtin Longer than Residue 170 form Visible Aggregates Independently to Polyglutamine Expansion. J Huntingtons Dis 2017; 6:79-91. [PMID: 28339398 DOI: 10.3233/jhd-160207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND A hallmark of Huntington's disease is the progressive aggregation of full length and N-terminal fragments of polyglutamine (polyQ)-expanded Huntingtin (Htt) into intracellular inclusions. The production of N-terminal fragments appears important for enabling pathology and aggregation; and hence the direct expression of a variety of N-terminal fragments are commonly used to model HD in animal and cellular models. OBJECTIVE It remains unclear how the length of the N-terminal fragments relates to polyQ - mediated aggregation. We investigated the fundamental intracellular aggregation process of eight different-length N-terminal fragments of Htt in both short (25Q) and long polyQ (97Q). METHODS N-terminal fragments were fused to fluorescent proteins and transiently expressed in mammalian cell culture models. These included the classic exon 1 fragment (90 amino acids) and longer forms of 105, 117, 171, 513, 536, 552, and 586 amino acids based on wild-type Htt (of 23Q) sequence length nomenclature. RESULTS N-terminal fragments of less than 171 amino acids only formed inclusions in polyQ-expanded form. By contrast the longer fragments formed inclusions irrespective of Q-length, with Q-length playing a negligible role in extent of aggregation. The inclusions could be classified into 3 distinct morphological categories. One type (Type A) was universally associated with polyQ expansions whereas the other two types (Types B and C) formed independently of polyQ length expansion. CONCLUSIONS PolyQ-expansion was only required for fragments of less than 171 amino acids to aggregate. Longer fragments aggregated predominately through a non-polyQ mechanism, involving at least one, and probably more distinct clustering mechanisms.
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Affiliation(s)
- Moore Z Chen
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - Sue-Ann Mok
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Angelique R Ormsby
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | | | - Danny M Hatters
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
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35
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Multiple discrete soluble aggregates influence polyglutamine toxicity in a Huntington's disease model system. Sci Rep 2016; 6:34916. [PMID: 27721444 PMCID: PMC5056504 DOI: 10.1038/srep34916] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/21/2016] [Indexed: 12/16/2022] Open
Abstract
Huntington’s disease (HD) results from expansions of polyglutamine stretches (polyQ) in the huntingtin protein (Htt) that promote protein aggregation, neurodegeneration, and death. Since the diversity and sizes of the soluble Htt-polyQ aggregates that have been linked to cytotoxicity are unknown, we investigated soluble Htt-polyQ aggregates using analytical ultracentrifugation. Soon after induction in a yeast HD model system, non-toxic Htt-25Q and cytotoxic Htt-103Q both formed soluble aggregates 29S to 200S in size. Because current models indicate that Htt-25Q does not form soluble aggregates, reevaluation of previous studies may be necessary. Only Htt-103Q aggregation behavior changed, however, with time. At 6 hr mid-sized aggregates (33S to 84S) and large aggregates (greater than 100S) became present while at 24 hr primarily only mid-sized aggregates (20S to 80S) existed. Multiple factors that decreased cytotoxicity of Htt-103Q (changing the length of or sequences adjacent to the polyQ, altering ploidy or chaperone dosage, or deleting anti-aging factors) altered the Htt-103Q aggregation pattern in which the suite of mid-sized aggregates at 6 hr were most correlative with cytotoxicity. Hence, the amelioration of HD and other neurodegenerative diseases may require increased attention to and discrimination of the dynamic alterations in soluble aggregation processes.
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Atkins JF, Loughran G, Bhatt PR, Firth AE, Baranov PV. Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use. Nucleic Acids Res 2016; 44:7007-78. [PMID: 27436286 PMCID: PMC5009743 DOI: 10.1093/nar/gkw530] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression.
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Affiliation(s)
- John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland School of Microbiology, University College Cork, Cork, Ireland Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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Protein aggregation and ER stress. Brain Res 2016; 1648:658-666. [PMID: 27037184 DOI: 10.1016/j.brainres.2016.03.044] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/26/2016] [Accepted: 03/28/2016] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a common feature of the protein misfolding or conformational diseases, among them most of the neurodegenerative diseases. These disorders are a major scourge, with scarce if any effective therapies at present. Recent research has identified ER stress as a major mechanism implicated in cytotoxicity in these diseases. Whether amyloid-β or tau in Alzheimer's, α-synuclein in Parkinson's, huntingtin in Huntington's disease or other aggregation-prone proteins in many other neurodegenerative diseases, there is a shared pathway of oligomerization and aggregation into amyloid fibrils. There is increasing evidence in recent years that the toxic species, and those that evoke ER stress, are the intermediate oligomeric forms and not the final amyloid aggregates. This review focuses on recent findings on the mechanisms and importance of the development of ER stress upon protein aggregation, especially in neurodegenerative diseases, and possible therapeutic approaches that are being examined. This article is part of a Special Issue entitled SI:ER stress.
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Murphy RM. Q&A: repeat-containing proteins. Nat Struct Mol Biol 2015; 22:943-5. [DOI: 10.1038/nsmb.3135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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