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Phenotype and management of neurologic intronic repeat disorders (NIRDs). Rev Neurol (Paris) 2023; 179:173-182. [PMID: 36371266 DOI: 10.1016/j.neurol.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 11/11/2022]
Abstract
During recent years an increasing number of neurologic disorders due to expanded tri-, tetra-, penta-, or hexa-nucleotide repeat motifs in introns of various genes have been described (neurologic intronic repeat disorders (NIRDs)). The repeat may be pathogenic in the heterozygous or homozygous form. Repeat lengths vary considerably and can be stable or unstable during transmission to the next generation. The most well-known NIRDs are Friedreich ataxia, spinocerebellar ataxia types-10, -31, and -36, CANVAS, C9Orf72 familial amyotrophic lateral sclerosis (fALS), and myotonic dystrophy-2 (MD2). Phenotypically, NIRDs manifest as mono-organ (e.g. spinocerebellar ataxia type 31) or multi-organ disease (e.g. Friedreich ataxia, myotonic dystrophy-2). A number of other more rare NIRDs have been recently detected. This review aims at summarising and discussing previous findings and recent advances concerning the etiology, pathophysiology, clinical presentation, and therapeutic management of the most common NIRDs.
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2
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Mechanistic and Therapeutic Insights into Ataxic Disorders with Pentanucleotide Expansions. Cells 2022; 11:cells11091567. [PMID: 35563872 PMCID: PMC9099484 DOI: 10.3390/cells11091567] [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: 04/14/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/01/2023] Open
Abstract
Pentanucleotide expansion diseases constitute a special class of neurodegeneration. The repeat expansions occur in non-coding regions, have likely arisen from Alu elements, and often result in autosomal dominant or recessive phenotypes with underlying cerebellar neuropathology. When transcribed (potentially bidirectionally), the expanded RNA forms complex secondary and tertiary structures that can give rise to RNA-mediated toxicity, including protein sequestration, pentapeptide synthesis, and mRNA dysregulation. Since several of these diseases have recently been discovered, our understanding of their pathological mechanisms is limited, and their therapeutic interventions underexplored. This review aims to highlight new in vitro and in vivo insights into these incurable diseases.
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3
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Monteuuis G, Wong JJL, Bailey CG, Schmitz U, Rasko JEJ. The changing paradigm of intron retention: regulation, ramifications and recipes. Nucleic Acids Res 2020; 47:11497-11513. [PMID: 31724706 PMCID: PMC7145568 DOI: 10.1093/nar/gkz1068] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/04/2019] [Accepted: 10/30/2019] [Indexed: 12/13/2022] Open
Abstract
Intron retention (IR) is a form of alternative splicing that has long been neglected in mammalian systems although it has been studied for decades in non-mammalian species such as plants, fungi, insects and viruses. It was generally assumed that mis-splicing, leading to the retention of introns, would have no physiological consequence other than reducing gene expression by nonsense-mediated decay. Relatively recent landmark discoveries have highlighted the pivotal role that IR serves in normal and disease-related human biology. Significant technical hurdles have been overcome, thereby enabling the robust detection and quantification of IR. Still, relatively little is known about the cis- and trans-acting modulators controlling this phenomenon. The fate of an intron to be, or not to be, retained in the mature transcript is the direct result of the influence exerted by numerous intrinsic and extrinsic factors at multiple levels of regulation. These factors have altered current biological paradigms and provided unexpected insights into the transcriptional landscape. In this review, we discuss the regulators of IR and methods to identify them. Our focus is primarily on mammals, however, we broaden the scope to non-mammalian organisms in which IR has been shown to be biologically relevant.
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Affiliation(s)
- Geoffray Monteuuis
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Justin J L Wong
- Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Epigenetics and RNA Biology Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Charles G Bailey
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia
| | - Ulf Schmitz
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Computational Biomedicine Laboratory Centenary Institute, The University of Sydney, Camperdown, Australia
| | - John E J Rasko
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Cell and Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, Australia
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4
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Swinnen B, Robberecht W, Van Den Bosch L. RNA toxicity in non-coding repeat expansion disorders. EMBO J 2020; 39:e101112. [PMID: 31721251 PMCID: PMC6939197 DOI: 10.15252/embj.2018101112] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 12/11/2022] Open
Abstract
Several neurodegenerative disorders like amyotrophic lateral sclerosis (ALS) and spinocerebellar ataxia (SCA) are caused by non-coding nucleotide repeat expansions. Different pathogenic mechanisms may underlie these non-coding repeat expansion disorders. While gain-of-function mechanisms, such as toxicity associated with expression of repeat RNA or toxicity associated with repeat-associated non-ATG (RAN) products, are most frequently connected with these disorders, loss-of-function mechanisms have also been implicated. We review the different pathways that have been linked to non-coding repeat expansion disorders such as C9ORF72-linked ALS/frontotemporal dementia (FTD), myotonic dystrophy, fragile X tremor/ataxia syndrome (FXTAS), SCA, and Huntington's disease-like 2. We discuss modes of RNA toxicity focusing on the identity and the interacting partners of the toxic RNA species. Using the C9ORF72 ALS/FTD paradigm, we further explore the efforts and different methods used to disentangle RNA vs. RAN toxicity. Overall, we conclude that there is ample evidence for a role of RNA toxicity in non-coding repeat expansion diseases.
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Affiliation(s)
- Bart Swinnen
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Wim Robberecht
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Ludo Van Den Bosch
- Department of NeurosciencesExperimental NeurologyLeuven Brain Institute (LBI)KU Leuven – University of LeuvenLeuvenBelgium
- Laboratory of NeurobiologyVIB, Center for Brain & Disease ResearchLeuvenBelgium
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5
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Hale MA, Johnson NE, Berglund JA. Repeat-associated RNA structure and aberrant splicing. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194405. [PMID: 31323433 DOI: 10.1016/j.bbagrm.2019.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022]
Abstract
Over 30 hereditary disorders attributed to the expansion of microsatellite repeats have been identified. Despite variant nucleotide content, number of consecutive repeats, and different locations in the genome, many of these diseases have pathogenic RNA gain-of-function mechanisms. The repeat-containing RNAs can form structures in vitro predicted to contribute to the disease through assembly of intracellular RNA aggregates termed foci. The expanded repeat RNAs within these foci sequester RNA binding proteins (RBPs) with important roles in the regulation of RNA metabolism, most notably alternative splicing (AS). These deleterious interactions lead to downstream alterations in transcriptome-wide AS directly linked with disease symptoms. This review summarizes existing knowledge about the association between the repeat RNA structures and RBPs as well as the resulting aberrant AS patterns, specifically in the context of myotonic dystrophy. The connection between toxic, structured RNAs and dysregulation of AS in other repeat expansion diseases is also discussed. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Melissa A Hale
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Nicholas E Johnson
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - J Andrew Berglund
- The RNA Institute, Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
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6
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Sun Z, Wang X, Zhang JZH, He Q. Sulfur-substitution-induced base flipping in the DNA duplex. Phys Chem Chem Phys 2019; 21:14923-14940. [PMID: 31233058 DOI: 10.1039/c9cp01989h] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Base flipping is widely observed in a number of important biological processes. The genetic codes deposited inside the DNA duplex become accessible to external agents upon base flipping. The sulfur substitution of guanine leads to thioguanine, which alters the thermodynamic stability of the GC base pairs and the GT mismatches. Experimental studies conclude that the sulfur substitution decreases the lifetime of the GC base pair. In this work, under three AMBER force fields for nucleotide systems, we firstly performed equilibrium and nonequilibrium free energy simulations to investigate the variation of the thermodynamic profiles in base flipping upon sulfur substitution. It is found that the bsc0 modification, the bsc1 modification and the OL15 modification of AMBER force fields are able to qualitatively describe the sulfur-substitution dependent behavior of the thermodynamics. However, only the two last-generation AMBER force fields are able to provide quantitatively correct predictions. The second computational study on the sulfur substitutions focused on the relative stability of the S6G-C base pair and the S6G-T mismatch. Two conflicting experimental observations were reported by the same authors. One suggested that the S6G-C base pair was more stable, while the other concludes that the S6G-T mismatch was more stable. We answered this question by constructing the free energy profiles along the base flipping pathway computationally.
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Affiliation(s)
- Zhaoxi Sun
- State Key Laboratory of Precision Spectroscopy, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China and Computational Biomedicine (IAS-5/INM-9), Forschungszentrum Jülich, Jülich 52425, Germany.
| | - Xiaohui Wang
- State Key Laboratory of Precision Spectroscopy, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China and Institute of Computational Science, Università della Svizzera italiana (USI), Via Giuseppe Buffi 13, CH-6900, Lugano, Ticino, Switzerland
| | - John Z H Zhang
- State Key Laboratory of Precision Spectroscopy, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China and Department of Chemistry, New York University, NY, NY 10003, USA
| | - Qiaole He
- Forschungszentrum Jülich GmbH, IBG-1: Biotechnology, Wilhelm-Johnen-Str. 1, 52425 Jülich, Germany. and State Key Laboratory of Bioreactor Engineering, R&D Center of Separation and Extraction Technology in Fermentation Industry, East China University of Science and Technology, Shanghai 200237, China
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7
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Sznajder ŁJ, Swanson MS. Short Tandem Repeat Expansions and RNA-Mediated Pathogenesis in Myotonic Dystrophy. Int J Mol Sci 2019; 20:ijms20133365. [PMID: 31323950 PMCID: PMC6651174 DOI: 10.3390/ijms20133365] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/27/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022] Open
Abstract
Short tandem repeat (STR) or microsatellite, expansions underlie more than 50 hereditary neurological, neuromuscular and other diseases, including myotonic dystrophy types 1 (DM1) and 2 (DM2). Current disease models for DM1 and DM2 propose a common pathomechanism, whereby the transcription of mutant DMPK (DM1) and CNBP (DM2) genes results in the synthesis of CUG and CCUG repeat expansion (CUGexp, CCUGexp) RNAs, respectively. These CUGexp and CCUGexp RNAs are toxic since they promote the assembly of ribonucleoprotein (RNP) complexes or RNA foci, leading to sequestration of Muscleblind-like (MBNL) proteins in the nucleus and global dysregulation of the processing, localization and stability of MBNL target RNAs. STR expansion RNAs also form phase-separated gel-like droplets both in vitro and in transiently transfected cells, implicating RNA-RNA multivalent interactions as drivers of RNA foci formation. Importantly, the nucleation and growth of these nuclear foci and transcript misprocessing are reversible processes and thus amenable to therapeutic intervention. In this review, we provide an overview of potential DM1 and DM2 pathomechanisms, followed by a discussion of MBNL functions in RNA processing and how multivalent interactions between expanded STR RNAs and RNA-binding proteins (RBPs) promote RNA foci assembly.
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Affiliation(s)
- Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA.
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
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8
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Wang X, Sun Z. Determination of Base-Flipping Free-Energy Landscapes from Nonequilibrium Stratification. J Chem Inf Model 2019; 59:2980-2994. [PMID: 31124677 DOI: 10.1021/acs.jcim.9b00263] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Correct calculation of the variation of free energy upon base flipping is crucial in understanding the dynamics of DNA systems. The free-energy landscape along the flipping pathway gives the thermodynamic stability and the flexibility of base-paired states. Although numerous free-energy simulations are performed in the base flipping cases, no theoretically rigorous nonequilibrium techniques are devised and employed to investigate the thermodynamics of base flipping. In the current work, we report a general nonequilibrium stratification scheme for the efficient calculation of the free-energy landscape of base flipping in DNA duplex. We carefully monitor the convergence behavior of the equilibrium sampling based free-energy simulation and the nonequilibrium stratification and determine the empirical length of time blocks required for converged sampling. Comparison between the performances of the equilibrium umbrella sampling and the nonequilibrium stratification is given. The results show that nonequilibrium free-energy simulation achieves similar accuracy and efficiency compared with the equilibrium enhanced sampling technique in the base flipping cases. We further test a convergence criterion we previously proposed and it comes out that the convergence determined by this criterion agrees with those given by the time-invariant behavior of PMF and the nonlinear dependence of standard deviation on the sample size.
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Affiliation(s)
- Xiaohui Wang
- State Key Laboratory of Precision Spectroscopy, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China.,Institute of Computational Science , Università della Svizzera Italiana (USI) , Via Giuseppe Buffi 13 , CH-6900 , Lugano , Ticino , Switzerland
| | - Zhaoxi Sun
- State Key Laboratory of Precision Spectroscopy, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai 200062 , China.,Computational Biomedicine (IAS-5/INM-9) , Forschungszentrum Jülich , Jülich 52425 , Germany
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9
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Intron retention induced by microsatellite expansions as a disease biomarker. Proc Natl Acad Sci U S A 2018; 115:4234-4239. [PMID: 29610297 DOI: 10.1073/pnas.1716617115] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Expansions of simple sequence repeats, or microsatellites, have been linked to ∼30 neurological-neuromuscular diseases. While these expansions occur in coding and noncoding regions, microsatellite sequence and repeat length diversity is more prominent in introns with eight different trinucleotide to hexanucleotide repeats, causing hereditary diseases such as myotonic dystrophy type 2 (DM2), Fuchs endothelial corneal dystrophy (FECD), and C9orf72 amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). Here, we test the hypothesis that these GC-rich intronic microsatellite expansions selectively trigger host intron retention (IR). Using DM2, FECD, and C9-ALS/FTD as examples, we demonstrate that retention is readily detectable in affected tissues and peripheral blood lymphocytes and conclude that IR screening constitutes a rapid and inexpensive biomarker for intronic repeat expansion disease.
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10
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Mlýnský V, Bussi G. Exploring RNA structure and dynamics through enhanced sampling simulations. Curr Opin Struct Biol 2018; 49:63-71. [PMID: 29414513 DOI: 10.1016/j.sbi.2018.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 12/20/2017] [Accepted: 01/02/2018] [Indexed: 01/23/2023]
Abstract
RNA function is intimately related to its structural dynamics. Molecular dynamics simulations are useful for exploring biomolecular flexibility but are severely limited by the accessible timescale. Enhanced sampling methods allow this timescale to be effectively extended in order to probe biologically relevant conformational changes and chemical reactions. Here, we review the role of enhanced sampling techniques in the study of RNA systems. We discuss the challenges and promises associated with the application of these methods to force-field validation, exploration of conformational landscapes and ion/ligand-RNA interactions, as well as catalytic pathways. Important technical aspects of these methods, such as the choice of the biased collective variables and the analysis of multi-replica simulations, are examined in detail. Finally, a perspective on the role of these methods in the characterization of RNA dynamics is provided.
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Affiliation(s)
- Vojtěch Mlýnský
- Scuola Internazionale Superiore di Studi Avanzati, SISSA, via Bonomea 265, 34136 Trieste, Italy
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, SISSA, via Bonomea 265, 34136 Trieste, Italy.
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11
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Rohilla KJ, Gagnon KT. RNA biology of disease-associated microsatellite repeat expansions. Acta Neuropathol Commun 2017; 5:63. [PMID: 28851463 PMCID: PMC5574247 DOI: 10.1186/s40478-017-0468-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/22/2017] [Indexed: 12/13/2022] Open
Abstract
Microsatellites, or simple tandem repeat sequences, occur naturally in the human genome and have important roles in genome evolution and function. However, the expansion of microsatellites is associated with over two dozen neurological diseases. A common denominator among the majority of these disorders is the expression of expanded tandem repeat-containing RNA, referred to as xtrRNA in this review, which can mediate molecular disease pathology in multiple ways. This review focuses on the potential impact that simple tandem repeat expansions can have on the biology and metabolism of RNA that contain them and underscores important gaps in understanding. Merging the molecular biology of repeat expansion disorders with the current understanding of RNA biology, including splicing, transcription, transport, turnover and translation, will help clarify mechanisms of disease and improve therapeutic development.
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12
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Morriss GR, Cooper TA. Protein sequestration as a normal function of long noncoding RNAs and a pathogenic mechanism of RNAs containing nucleotide repeat expansions. Hum Genet 2017; 136:1247-1263. [PMID: 28484853 DOI: 10.1007/s00439-017-1807-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/28/2017] [Indexed: 12/12/2022]
Abstract
An emerging class of long noncoding RNAs (lncRNAs) function as decoy molecules that bind and sequester proteins thereby inhibiting their normal functions. Titration of proteins by lncRNAs has wide-ranging effects affecting nearly all steps in gene expression. While decoy lncRNAs play a role in normal physiology, RNAs expressed from alleles containing nucleotide repeat expansions can be pathogenic due to protein sequestration resulting in disruption of normal functions. This review focuses on commonalities between decoy lncRNAs that regulate gene expression by competitive inhibition of protein function through sequestration and specific examples of nucleotide repeat expansion disorders mediated by toxic RNA that sequesters RNA-binding proteins and impedes their normal functions. Understanding how noncoding RNAs compete with various RNA and DNA molecules for binding of regulatory proteins will provide insight into how similar mechanisms contribute to disease pathogenesis.
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Affiliation(s)
- Ginny R Morriss
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Thomas A Cooper
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.
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13
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Ciesiolka A, Jazurek M, Drazkowska K, Krzyzosiak WJ. Structural Characteristics of Simple RNA Repeats Associated with Disease and their Deleterious Protein Interactions. Front Cell Neurosci 2017; 11:97. [PMID: 28442996 PMCID: PMC5387085 DOI: 10.3389/fncel.2017.00097] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/21/2017] [Indexed: 12/14/2022] Open
Abstract
Short Tandem Repeats (STRs) are frequent entities in many transcripts, however, in some cases, pathological events occur when a critical repeat length is reached. This phenomenon is observed in various neurological disorders, such as myotonic dystrophy type 1 (DM1), fragile X-associated tremor/ataxia syndrome, C9orf72-related amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS/FTD), and polyglutamine diseases, such as Huntington's disease (HD) and spinocerebellar ataxias (SCA). The pathological effects of these repeats are triggered by mutant RNA transcripts and/or encoded mutant proteins, which depend on the localization of the expanded repeats in non-coding or coding regions. A growing body of recent evidence revealed that the RNA structures formed by these mutant RNA repeat tracts exhibit toxic effects on cells. Therefore, in this review article, we present existing knowledge on the structural aspects of different RNA repeat tracts as revealed mainly using well-established biochemical and biophysical methods. Furthermore, in several cases, it was shown that these expanded RNA structures are potent traps for a variety of RNA-binding proteins and that the sequestration of these proteins from their normal intracellular environment causes alternative splicing aberration, inhibition of nuclear transport and export, or alteration of a microRNA biogenesis pathway. Therefore, in this review article, we also present the most studied examples of abnormal interactions that occur between mutant RNAs and their associated proteins.
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Affiliation(s)
- Adam Ciesiolka
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of SciencesPoznan, Poland
| | - Magdalena Jazurek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of SciencesPoznan, Poland
| | - Karolina Drazkowska
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of SciencesPoznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of SciencesPoznan, Poland
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14
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Zhang N, Ashizawa T. RNA toxicity and foci formation in microsatellite expansion diseases. Curr Opin Genet Dev 2017; 44:17-29. [PMID: 28208060 DOI: 10.1016/j.gde.2017.01.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/04/2017] [Accepted: 01/18/2017] [Indexed: 12/11/2022]
Abstract
More than 30 incurable neurological and neuromuscular diseases are caused by simple microsatellite expansions consisted of 3-6 nucleotides. These repeats can occur in non-coding regions and often result in a dominantly inherited disease phenotype that is characteristic of a toxic RNA gain-of-function. The expanded RNA adopts unusual secondary structures, sequesters various RNA binding proteins to form insoluble nuclear foci, and causes cellular defects at a multisystem level. Nuclear foci are dynamic in size, shape and colocalization of RNA binding proteins in different expansion diseases and tissue types. This review sets to provide new insights into the disease mechanisms of RNA toxicity and foci modulation, in light of recent advancement on bi-directional transcription, antisense RNA, repeat-associated non-ATG translation and beyond.
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Affiliation(s)
- Nan Zhang
- Neurosciences Research Program, Houston Methodist Research Institute, Houston, TX 77030, United States; Division of Cell and Molecular Biology, South Kensington Campus, Imperial College London, London SW7 2AZ, UK
| | - Tetsuo Ashizawa
- Neurosciences Research Program, Houston Methodist Research Institute, Houston, TX 77030, United States.
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15
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Błaszczyk L, Rypniewski W, Kiliszek A. Structures of RNA repeats associated with neurological diseases. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28130835 DOI: 10.1002/wrna.1412] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 10/25/2016] [Accepted: 11/12/2016] [Indexed: 01/04/2023]
Abstract
All RNA molecules possess a 'propensity' to fold into complex secondary and tertiary structures. Although they are composed of only four types of nucleotides, they show an enormous structural richness which reflects their diverse functions in the cell. However, in some cases the folding of RNA can have deleterious consequences. Aberrantly expanded, repeated RNA sequences can exhibit gain-of-function abnormalities and become pathogenic, giving rise to many incurable neurological diseases. Most RNA repeats form long hairpin structures whose stem consists of noncanonical base pairs interspersed among Watson-Crick pairs. The expanded hairpins have an ability to sequester important proteins and form insoluble nuclear foci. The RNA pathology, common to many repeat disorders, has drawn attention to the structures of the RNA repeats. In this review, we summarize secondary structure probing and crystallographic studies of disease-related RNA repeat sequences. We discuss the unique structural features which can contribute to the pathogenic properties of the repeated runs. In addition, we present the newest reports concerning structural data linked to therapeutic approaches. WIREs RNA 2017, 8:e1412. doi: 10.1002/wrna.1412 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Leszek Błaszczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Wojciech Rypniewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Agnieszka Kiliszek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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16
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Park H, Tran T, Lee JH, Park H, Disney MD. Controlled dehydration improves the diffraction quality of two RNA crystals. BMC STRUCTURAL BIOLOGY 2016; 16:19. [PMID: 27809904 PMCID: PMC5093936 DOI: 10.1186/s12900-016-0069-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/18/2016] [Indexed: 01/07/2023]
Abstract
BACKGROUND Post-crystallization dehydration methods, applying either vapor diffusion or humidity control devices, have been widely used to improve the diffraction quality of protein crystals. Despite the fact that RNA crystals tend to diffract poorly, there is a dearth of reports on the application of dehydration methods to improve the diffraction quality of RNA crystals. RESULTS We use dehydration techniques with a Free Mounting System (FMS, a humidity control device) to recover the poor diffraction quality of RNA crystals. These approaches were applied to RNA constructs that model various RNA-mediated repeat expansion disorders. CONCLUSION The method we describe herein could serve as a general tool to improve diffraction quality of RNA crystals to facilitate structure determinations.
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Affiliation(s)
- HaJeung Park
- X-ray Core Facility, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Tuan Tran
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Jun Hyuck Lee
- Unit of Polar Genomics, Korea Polar Research Institute, Incheon, 21990 Republic of Korea ,Department of Polar Sciences, University of Science and Technology, Incheon, 21990 Republic of Korea
| | - Hyun Park
- Unit of Polar Genomics, Korea Polar Research Institute, Incheon, 21990 Republic of Korea ,Department of Polar Sciences, University of Science and Technology, Incheon, 21990 Republic of Korea
| | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458 USA
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Dodd DW, Tomchick DR, Corey DR, Gagnon KT. Pathogenic C9ORF72 Antisense Repeat RNA Forms a Double Helix with Tandem C:C Mismatches. Biochemistry 2016; 55:1283-6. [PMID: 26878348 DOI: 10.1021/acs.biochem.6b00136] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Expansion of a GGGGCC/CCCCGG repeat sequence in the first intron of the C9ORF72 gene is a leading cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). In this combined disorder, called c9FTD/ALS, the expansion is bidirectionally transcribed into sense and antisense repeat RNA associated with disease. To better understand the role of C9ORF72 repeat RNA in molecular disease pathology, we determined crystal structures of a [(CCCCGG)3(CCCC)] model antisense repeat RNA to 1.47 Å resolution. The RNA structure was an A-form-like double helix composed of repeating and regularly spaced tandem C:C mismatch pairs that perturbed helical geometry and surface charge. Solution studies revealed a preference for A-form-like helical conformations as the repeat number increased. Results provide a structural starting point for rationalizing the contribution of repeat RNA to c9FTD/ALS molecular disease mechanisms and for developing molecules to target C9ORF72 repeat RNA as potential therapeutics.
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Affiliation(s)
- David W Dodd
- Department of Pharmacology, ‡Department of Biophysics, and §Department of Biochemistry, University of Texas Southwestern Medical Center , Dallas, Texas 75390, United States.,Department of Biochemistry and Molecular Biology, School of Medicine, and ⊥Department of Chemistry and Biochemistry, Southern Illinois University , Carbondale, Illinois 62901, United States
| | - Diana R Tomchick
- Department of Pharmacology, ‡Department of Biophysics, and §Department of Biochemistry, University of Texas Southwestern Medical Center , Dallas, Texas 75390, United States.,Department of Biochemistry and Molecular Biology, School of Medicine, and ⊥Department of Chemistry and Biochemistry, Southern Illinois University , Carbondale, Illinois 62901, United States
| | - David R Corey
- Department of Pharmacology, ‡Department of Biophysics, and §Department of Biochemistry, University of Texas Southwestern Medical Center , Dallas, Texas 75390, United States.,Department of Biochemistry and Molecular Biology, School of Medicine, and ⊥Department of Chemistry and Biochemistry, Southern Illinois University , Carbondale, Illinois 62901, United States
| | - Keith T Gagnon
- Department of Pharmacology, ‡Department of Biophysics, and §Department of Biochemistry, University of Texas Southwestern Medical Center , Dallas, Texas 75390, United States.,Department of Biochemistry and Molecular Biology, School of Medicine, and ⊥Department of Chemistry and Biochemistry, Southern Illinois University , Carbondale, Illinois 62901, United States
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18
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Nakano M, Tateishi-Karimata H, Tanaka S, Tama F, Miyashita O, Nakano SI, Sugimoto N. Thermodynamic properties of water molecules in the presence of cosolute depend on DNA structure: a study using grid inhomogeneous solvation theory. Nucleic Acids Res 2015; 43:10114-25. [PMID: 26538600 PMCID: PMC4666364 DOI: 10.1093/nar/gkv1133] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/14/2015] [Indexed: 01/11/2023] Open
Abstract
In conditions that mimic those of the living cell, where various biomolecules and other components are present, DNA strands can adopt many structures in addition to the canonical B-form duplex. Previous studies in the presence of cosolutes that induce molecular crowding showed that thermal stabilities of DNA structures are associated with the properties of the water molecules around the DNAs. To understand how cosolutes, such as ethylene glycol, affect the thermal stability of DNA structures, we investigated the thermodynamic properties of water molecules around a hairpin duplex and a G-quadruplex using grid inhomogeneous solvation theory (GIST) with or without cosolutes. Our analysis indicated that (i) cosolutes increased the free energy of water molecules around DNA by disrupting water–water interactions, (ii) ethylene glycol more effectively disrupted water–water interactions around Watson–Crick base pairs than those around G-quartets or non-paired bases, (iii) due to the negative electrostatic potential there was a thicker hydration shell around G-quartets than around Watson–Crick-paired bases. Our findings suggest that the thermal stability of the hydration shell around DNAs is one factor that affects the thermal stabilities of DNA structures under the crowding conditions.
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Affiliation(s)
- Miki Nakano
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan Advanced Institute for Computational Sciences, RIKEN, 7-1-26, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Hisae Tateishi-Karimata
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Shigenori Tanaka
- Department of Computational Science, Graduate School of System Informatics, Kobe University, 1-1, Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Florence Tama
- Advanced Institute for Computational Sciences, RIKEN, 7-1-26, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Osamu Miyashita
- Advanced Institute for Computational Sciences, RIKEN, 7-1-26, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Shu-Ichi Nakano
- Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
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