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Henriques C, Lopes MM, Silva AC, Lobo DD, Badin RA, Hantraye P, Pereira de Almeida L, Nobre RJ. Viral-based animal models in polyglutamine disorders. Brain 2024; 147:1166-1189. [PMID: 38284949 DOI: 10.1093/brain/awae012] [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: 07/09/2023] [Revised: 11/26/2023] [Accepted: 12/30/2023] [Indexed: 01/30/2024] Open
Abstract
Polyglutamine disorders are a complex group of incurable neurodegenerative disorders caused by an abnormal expansion in the trinucleotide cytosine-adenine-guanine tract of the affected gene. To better understand these disorders, our dependence on animal models persists, primarily relying on transgenic models. In an effort to complement and deepen our knowledge, researchers have also developed animal models of polyglutamine disorders employing viral vectors. Viral vectors have been extensively used to deliver genes to the brain, not only for therapeutic purposes but also for the development of animal models, given their remarkable flexibility. In a time- and cost-effective manner, it is possible to use different transgenes, at varying doses, in diverse targeted tissues, at different ages, and in different species, to recreate polyglutamine pathology. This paper aims to showcase the utility of viral vectors in disease modelling, share essential considerations for developing animal models with viral vectors, and provide a comprehensive review of existing viral-based animal models for polyglutamine disorders.
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Affiliation(s)
- Carina Henriques
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Miguel M Lopes
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Ana C Silva
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Diana D Lobo
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Romina Aron Badin
- CEA, DRF, Institute of Biology François Jacob, Molecular Imaging Research Center (MIRCen), 92265 Fontenay-aux-Roses, France
- CNRS, CEA, Paris-Sud University, Université Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), 92265 Fontenay-aux-Roses, France
| | - Philippe Hantraye
- CEA, DRF, Institute of Biology François Jacob, Molecular Imaging Research Center (MIRCen), 92265 Fontenay-aux-Roses, France
- CNRS, CEA, Paris-Sud University, Université Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), 92265 Fontenay-aux-Roses, France
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Rui Jorge Nobre
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
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Pilotto F, Del Bondio A, Puccio H. Hereditary Ataxias: From Bench to Clinic, Where Do We Stand? Cells 2024; 13:319. [PMID: 38391932 PMCID: PMC10886822 DOI: 10.3390/cells13040319] [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: 12/01/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/24/2024] Open
Abstract
Cerebellar ataxias are a wide heterogeneous group of movement disorders. Within this broad umbrella of diseases, there are both genetics and sporadic forms. The clinical presentation of these conditions can exhibit a diverse range of symptoms across different age groups, spanning from pure cerebellar manifestations to sensory ataxia and multisystemic diseases. Over the last few decades, advancements in our understanding of genetics and molecular pathophysiology related to both dominant and recessive ataxias have propelled the field forward, paving the way for innovative therapeutic strategies aimed at preventing and arresting the progression of these diseases. Nevertheless, the rarity of certain forms of ataxia continues to pose challenges, leading to limited insights into the etiology of the disease and the identification of target pathways. Additionally, the lack of suitable models hampers efforts to comprehensively understand the molecular foundations of disease's pathophysiology and test novel therapeutic interventions. In the following review, we describe the epidemiology, symptomatology, and pathological progression of hereditary ataxia, including both the prevalent and less common forms of these diseases. Furthermore, we illustrate the diverse molecular pathways and therapeutic approaches currently undergoing investigation in both pre-clinical studies and clinical trials. Finally, we address the existing and anticipated challenges within this field, encompassing both basic research and clinical endeavors.
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Affiliation(s)
- Federica Pilotto
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Andrea Del Bondio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Hélène Puccio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
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3
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Shorrock HK, Lennon CD, Aliyeva A, Davey EE, DeMeo CC, Pritchard CE, Planco L, Velez JM, Mascorro-Huamancaja A, Shin DS, Cleary JD, Berglund JA. Widespread alternative splicing dysregulation occurs presymptomatically in CAG expansion spinocerebellar ataxias. Brain 2024; 147:486-504. [PMID: 37776516 PMCID: PMC10834251 DOI: 10.1093/brain/awad329] [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: 05/31/2023] [Revised: 07/31/2023] [Accepted: 09/03/2023] [Indexed: 10/02/2023] Open
Abstract
The spinocerebellar ataxias (SCAs) are a group of dominantly inherited neurodegenerative diseases, several of which are caused by CAG expansion mutations (SCAs 1, 2, 3, 6, 7 and 12) and more broadly belong to the large family of over 40 microsatellite expansion diseases. While dysregulation of alternative splicing is a well defined driver of disease pathogenesis across several microsatellite diseases, the contribution of alternative splicing in CAG expansion SCAs is poorly understood. Furthermore, despite extensive studies on differential gene expression, there remains a gap in our understanding of presymptomatic transcriptomic drivers of disease. We sought to address these knowledge gaps through a comprehensive study of 29 publicly available RNA-sequencing datasets. We identified that dysregulation of alternative splicing is widespread across CAG expansion mouse models of SCAs 1, 3 and 7. These changes were detected presymptomatically, persisted throughout disease progression, were repeat length-dependent, and were present in brain regions implicated in SCA pathogenesis including the cerebellum, pons and medulla. Across disease progression, changes in alternative splicing occurred in genes that function in pathways and processes known to be impaired in SCAs, such as ion channels, synaptic signalling, transcriptional regulation and the cytoskeleton. We validated several key alternative splicing events with known functional consequences, including Trpc3 exon 9 and Kcnma1 exon 23b, in the Atxn1154Q/2Q mouse model. Finally, we demonstrated that alternative splicing dysregulation is responsive to therapeutic intervention in CAG expansion SCAs with Atxn1 targeting antisense oligonucleotide rescuing key splicing events. Taken together, these data demonstrate that widespread presymptomatic dysregulation of alternative splicing in CAG expansion SCAs may contribute to disease onset, early neuronal dysfunction and may represent novel biomarkers across this devastating group of neurodegenerative disorders.
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Affiliation(s)
| | - Claudia D Lennon
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
| | - Asmer Aliyeva
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
- Department of Biology, University at Albany—SUNY, Albany, NY 12222, USA
| | - Emily E Davey
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
| | - Cristina C DeMeo
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
| | | | - Lori Planco
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
| | - Jose M Velez
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
- Department of Biology, University at Albany—SUNY, Albany, NY 12222, USA
| | | | - Damian S Shin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - John D Cleary
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
| | - J Andrew Berglund
- The RNA Institute, University at Albany—SUNY, Albany, NY 12222, USA
- Department of Biology, University at Albany—SUNY, Albany, NY 12222, USA
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4
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Felício D, du Mérac TR, Amorim A, Martins S. Functional implications of paralog genes in polyglutamine spinocerebellar ataxias. Hum Genet 2023; 142:1651-1676. [PMID: 37845370 PMCID: PMC10676324 DOI: 10.1007/s00439-023-02607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023]
Abstract
Polyglutamine (polyQ) spinocerebellar ataxias (SCAs) comprise a group of autosomal dominant neurodegenerative disorders caused by (CAG/CAA)n expansions. The elongated stretches of adjacent glutamines alter the conformation of the native proteins inducing neurotoxicity, and subsequent motor and neurological symptoms. Although the etiology and neuropathology of most polyQ SCAs have been extensively studied, only a limited selection of therapies is available. Previous studies on SCA1 demonstrated that ATXN1L, a human duplicated gene of the disease-associated ATXN1, alleviated neuropathology in mice models. Other SCA-associated genes have paralogs (i.e., copies at different chromosomal locations derived from duplication of the parental gene), but their functional relevance and potential role in disease pathogenesis remain unexplored. Here, we review the protein homology, expression pattern, and molecular functions of paralogs in seven polyQ dominant ataxias-SCA1, SCA2, MJD/SCA3, SCA6, SCA7, SCA17, and DRPLA. Besides ATXN1L, we highlight ATXN2L, ATXN3L, CACNA1B, ATXN7L1, ATXN7L2, TBPL2, and RERE as promising functional candidates to play a role in the neuropathology of the respective SCA, along with the parental gene. Although most of these duplicates lack the (CAG/CAA)n region, if functionally redundant, they may compensate for a partial loss-of-function or dysfunction of the wild-type genes in SCAs. We aim to draw attention to the hypothesis that paralogs of disease-associated genes may underlie the complex neuropathology of dominant ataxias and potentiate new therapeutic strategies.
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Affiliation(s)
- Daniela Felício
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313, Porto, Portugal
| | - Tanguy Rubat du Mérac
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Faculty of Science, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - António Amorim
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal
| | - Sandra Martins
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal.
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Du Z, Iyyanki T, Lessard S, Chao M, Asbrand C, Nassar D, Klinger K, de Rinaldis E, Khader S, Chatelain C. Genome-wide association study analysis of disease severity in Acne reveals novel biological insights. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.13.23298473. [PMID: 38014089 PMCID: PMC10680891 DOI: 10.1101/2023.11.13.23298473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Acne vulgaris is a common skin disease that affects >85% of teenage young adults among which >8% develop severe lesions that leaves permanent scars. Genetic heritability studies of acne in twin cohorts have estimated that the heritability for acne is 80%. Previous genome-wide association studies (GWAS) have identified 50 genetic loci associated with increased risk of developing acne when compared to healthy individuals. However only a few studies have investigated genetic association with disease severity. GWAS of disease progression may provide a more effective approach to unveil potential disease modifying therapeutic targets. Here, we performed a multi-ethnic GWAS analysis to capture disease severity in acne patients by using individuals with normal acne as a control. Our cohort consists of a total of 2,956 participants, including 290 severe acne cases and 930 normal acne controls from FinnGen, and 522 cases and 1,214 controls from BioVU. We also performed mendelian randomization (MR), colocalization analyses and transcriptome-wide association study (TWAS) to identify putative causal genes. Lastly, we performed gene-set enrichment analysis using MAGMA to implicate biological pathways that drive disease severity in Acne. We identified two new loci associated with acne severity at the genome-wide significance level, six novel associated genes by MR, colocalization and TWAS analyses, including genes CDC7, SLC7A1, ADAM23, TTLL10, CDK20 and DNAJA4 , and 5 novel pathways by MAGMA analyses. Our study suggests that the etiologies of acne susceptibility and severity have limited overlap, with only 26% of known acne risk loci presenting nominal association with acne severity and none of the novel severity associated genes reported as associated with acne risk in previous GWAS.
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Functional characterization of variants of unknown significance in a spinocerebellar ataxia patient using an unsupervised machine learning pipeline. Hum Genome Var 2022; 9:10. [PMID: 35422034 PMCID: PMC9010413 DOI: 10.1038/s41439-022-00188-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 02/08/2022] [Accepted: 02/23/2022] [Indexed: 01/15/2023] Open
Abstract
CAG-expanded ATXN7 has been previously defined in the pathogenesis of spinocerebellar ataxia type 7 (SCA7), a polyglutamine expansion autosomal dominant cerebellar ataxia. Pathology in SCA7 occurs as a result of a CAG triplet repeat expansion in excess of 37 in the first exon of ATXN7, which encodes ataxin-7. SCA7 presents clinically with spinocerebellar ataxia and cone-rod dystrophy. Here, we present a novel spinocerebellar ataxia variant occurring in a patient with mutations in both ATXN7 and TOP1MT, which encodes mitochondrial topoisomerase I (top1mt). Using machine-guided, unbiased microscopy image analysis, we demonstrate alterations in ataxin-7 subcellular localization, and through high-fidelity measurements of cellular respiration, bioenergetic defects in association with top1mt mutations. We identify ataxin-7 Q35P and top1mt R111W as deleterious mutations, potentially contributing to disease states. We recapitulate our mutations through Drosophila genetic models. Our work provides important insight into the cellular biology of ataxin-7 and top1mt and offers insight into the pathogenesis of spinocerebellar ataxia applicable to multiple subtypes of the illness. Moreover, our study demonstrates an effective pipeline for the characterization of previously unreported genetic variants at the level of cell biology.
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7
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Goswami R, Bello AI, Bean J, Costanzo KM, Omer B, Cornelio-Parra D, Odah R, Ahluwalia A, Allan SK, Nguyen N, Shores T, Aziz NA, Mohan RD. The Molecular Basis of Spinocerebellar Ataxia Type 7. Front Neurosci 2022; 16:818757. [PMID: 35401096 PMCID: PMC8987156 DOI: 10.3389/fnins.2022.818757] [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: 11/19/2021] [Accepted: 02/07/2022] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia (SCA) type 7 (SCA7) is caused by a CAG trinucleotide repeat expansion in the ataxin 7 (ATXN7) gene, which results in polyglutamine expansion at the amino terminus of the ATXN7 protein. Although ATXN7 is expressed widely, the best characterized symptoms of SCA7 are remarkably tissue specific, including blindness and degeneration of the brain and spinal cord. While it is well established that ATXN7 functions as a subunit of the Spt Ada Gcn5 acetyltransferase (SAGA) chromatin modifying complex, the mechanisms underlying SCA7 remain elusive. Here, we review the symptoms of SCA7 and examine functions of ATXN7 that may provide further insights into its pathogenesis. We also examine phenotypes associated with polyglutamine expanded ATXN7 that are not considered symptoms of SCA7.
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Affiliation(s)
- Rituparna Goswami
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Abudu I. Bello
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Joe Bean
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Kara M. Costanzo
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Bwaar Omer
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Dayanne Cornelio-Parra
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Revan Odah
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Amit Ahluwalia
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Shefaa K. Allan
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Nghi Nguyen
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Taylor Shores
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - N. Ahmad Aziz
- Population Health Sciences, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ryan D. Mohan
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
- *Correspondence: Ryan D. Mohan,
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Ramos-Languren LE, Rodríguez-Labrada R, Magaña JJ, Canales-Ochoa N, González-Zaldivar Y, Velázquez-Pérez L, González-Piña R. Involvement of the Auditory Pathway in Spinocerebellar Ataxia Type 7. NEURODEGENER DIS 2021; 20:185-192. [PMID: 34247167 DOI: 10.1159/000517213] [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: 03/04/2021] [Accepted: 05/13/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a mutation in the ATXN7 gene. The involvement of the brainstem auditory pathway in pathogenesis of this disease has not been systematically assessed. AIM To determine involvement of the brainstem auditory pathway in SCA7 patients and its relationship to clinical features of the disease. METHODS In this case-control study, brainstem auditory-evoked potentials (BAEPs) were assessed in 12 SCA7 patients with clinical and molecular diagnosis, compared to 2 control groups of 16 SCA2 patients and 16 healthy controls. RESULTS SCA7 patients exhibited significant prolongation of I-wave and III-wave latencies, whereas SCA2 patients showed increased latencies for III and V waves and I-III interpeak interval. SCA7 patients with larger I-wave latencies exhibited larger CAG repeats, earlier onset age, and higher SARA scores, but in SCA2 cases, these were not observed. CONCLUSIONS BAEP tests revealed functional involvement of the auditory pathway in SCA7 (mainly at) peripheral portions, which gave new insights into the disease physiopathology different from SCA2 and may unravel distinct pathoanatomical effects of polyQ expansions in the central nervous system. SIGNIFICANCE These findings offer important insights into the distinctive disease mechanisms in SCA7 and SCA2, which could be useful for differential diagnosis and designing specific precision medicine approaches for both conditions.
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Affiliation(s)
- Laura E Ramos-Languren
- Psychobiology and Neurosciences Department, Psychology's Faculty, UNAM, Mexico City, Mexico
| | - Roberto Rodríguez-Labrada
- Center for Research and Rehabilitation of Hereditary Ataxias, Holguin, Cuba.,Cuban Centre for Neurosciences, Havana, Cuba
| | - Jonathan J Magaña
- Genetics Department, Genomic Medicine Laboratory, National Rehabilitation Institute LGII, Mexico City, Mexico
| | | | | | - Luis Velázquez-Pérez
- Center for Research and Rehabilitation of Hereditary Ataxias, Holguin, Cuba.,Cuban Academy of Sciences, Havana, Cuba
| | - Rigoberto González-Piña
- National Geriatrics Institute, Aging Biology Laboratory, Mexico City, Mexico.,America's University, Puebla 223 Col, Mexico City, Mexico
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9
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Zou X, Yao F, Li F, Wu S, Li H, Sun Z, Zhu T, Wei X, Li D, Sui R. Clinical characterization and the improved molecular diagnosis of autosomal dominant cone-rod dystrophy in patients with SCA7. Mol Vis 2021; 27:221-232. [PMID: 34012225 PMCID: PMC8116265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 05/05/2021] [Indexed: 10/31/2022] Open
Abstract
Purpose To evaluate the retinal phenotype and genetic features of Chinese patients with spinocerebellar ataxia type 7 (SCA7). Methods Detailed ophthalmic examinations, including electroretinograms, fundus photography, fundus autofluorescence and optical coherence tomography, were performed to analyse the retinal lesions of patients with SCA7. A molecular genetic analysis was completed to confirm the number of CAG repeats in ATXN7 gene on the patients and their family members. Results Eight patients from three families with SCA7 were included in this study. Trinucleotide repeat was expanded from 43 to 113 in the affected patients. The affected patients were characterized by different degrees of cone-rod dystrophy, which is positively related to the number of CAG repeats and age. All patients complained of progressive bilateral visual loss, and most cases reported visual disturbance earlier than gait movement or dysarthria. A coarse granular appearance of the macular region on scanning laser ophthalmoscopy, hypofluorescence in the macula on autofluorescence, retinal atrophy on optic coherence tomography, depression of multifocal electroretinograms and prominent abnormalities in cone-mediated responses on electrograms are the general features of SCA7-related retinopathy. Hyperreflective dots in the outer retinal layers and choroidal vessel layers are a common sign in optic coherence tomography in the advanced stage. Conclusions SCA7 shows a cone-rod dystrophy phenotype. The multimodal imaging of the retina is beneficial to detect the early lesions of cone-rod dystrophy related to SCA7.
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Affiliation(s)
- Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Fengxia Yao
- Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Fengrong Li
- Department of Ophthalmology, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Donghui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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10
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Cornelio-Parra DV, Goswami R, Costanzo K, Morales-Sosa P, Mohan RD. Function and regulation of the Spt-Ada-Gcn5-Acetyltransferase (SAGA) deubiquitinase module. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194630. [PMID: 32911111 DOI: 10.1016/j.bbagrm.2020.194630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 12/27/2022]
Abstract
The Spt-Ada-Gcn5 Acetyltransferase (SAGA) chromatin modifying complex is a critical regulator of gene expression and is highly conserved across species. Subunits of SAGA arrange into discrete modules with lysine aceyltransferase and deubiquitinase activities housed separately. Mutation of the SAGA deubiquitinase module can lead to substantial biological misfunction and diseases such as cancer, neurodegeneration, and blindness. Here, we review the structure and functions of the SAGA deubiquitinase module and regulatory mechanisms acting to control these.
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Nuño-Cabanes C, Rodríguez-Navarro S. The promiscuity of the SAGA complex subunits: Multifunctional or moonlighting proteins? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194607. [PMID: 32712338 DOI: 10.1016/j.bbagrm.2020.194607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022]
Abstract
Gene expression, the decoding of DNA information into accessible instructions for protein synthesis, is a complex process in which multiple steps, including transcription, mRNA processing and mRNA export, are regulated by different factors. One of the first steps in this process involves chemical and structural changes in chromatin to allow transcription. For such changes to occur, histone tail and DNA epigenetic modifications foster the binding of transcription factors to promoter regions. The SAGA coactivator complex plays a crucial role in this process by mediating histone acetylation through Gcn5, and histone deubiquitination through Ubp8 enzymes. However, most SAGA subunits interact physically with other proteins beyond the SAGA complex. These interactions could represent SAGA-independent functions or a mechanism to widen SAGA multifunctionality. Among the different mechanisms to perform more than one function, protein moonlighting defines unrelated molecular activities for the same polypeptide sequence. Unlike pleiotropy, where a single gene can affect different phenotypes, moonlighting necessarily involves separate functions of a protein at the molecular level. In this review we describe in detail some of the alternative physical interactions of several SAGA subunits. In some cases, the alternative role constitutes a clear moonlighting function, whereas in most of them the lack of molecular evidence means that we can only define these interactions as promiscuous that require further work to verify if these are moonlighting functions.
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Affiliation(s)
- Carme Nuño-Cabanes
- Gene Expression and RNA Metabolism Laboratory, Instituto de Biomedicina de Valencia (CSIC), Jaume Roig, 11, E-46010 Valencia, Spain
| | - Susana Rodríguez-Navarro
- Gene Expression and RNA Metabolism Laboratory, Instituto de Biomedicina de Valencia (CSIC), Jaume Roig, 11, E-46010 Valencia, Spain.
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12
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Niewiadomska-Cimicka A, Trottier Y. Molecular Targets and Therapeutic Strategies in Spinocerebellar Ataxia Type 7. Neurotherapeutics 2019; 16:1074-1096. [PMID: 31432449 PMCID: PMC6985300 DOI: 10.1007/s13311-019-00778-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a rare autosomal dominant neurodegenerative disorder characterized by progressive neuronal loss in the cerebellum, brainstem, and retina, leading to cerebellar ataxia and blindness as major symptoms. SCA7 is due to the expansion of a CAG triplet repeat that is translated into a polyglutamine tract in ATXN7. Larger SCA7 expansions are associated with earlier onset of symptoms and more severe and rapid disease progression. Here, we summarize the pathological and genetic aspects of SCA7, compile the current knowledge about ATXN7 functions, and then focus on recent advances in understanding the pathogenesis and in developing biomarkers and therapeutic strategies. ATXN7 is a bona fide subunit of the multiprotein SAGA complex, a transcriptional coactivator harboring chromatin remodeling activities, and plays a role in the differentiation of photoreceptors and Purkinje neurons, two highly vulnerable neuronal cell types in SCA7. Polyglutamine expansion in ATXN7 causes its misfolding and intranuclear accumulation, leading to changes in interactions with native partners and/or partners sequestration in insoluble nuclear inclusions. Studies of cellular and animal models of SCA7 have been crucial to unveil pathomechanistic aspects of the disease, including gene deregulation, mitochondrial and metabolic dysfunctions, cell and non-cell autonomous protein toxicity, loss of neuronal identity, and cell death mechanisms. However, a better understanding of the principal molecular mechanisms by which mutant ATXN7 elicits neurotoxicity, and how interconnected pathogenic cascades lead to neurodegeneration is needed for the development of effective therapies. At present, therapeutic strategies using nucleic acid-based molecules to silence mutant ATXN7 gene expression are under development for SCA7.
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Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France
| | - Yvon Trottier
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France.
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13
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Szpisjak L, Zadori D, Klivenyi P, Vecsei L. Clinical Characteristics and Possible Drug Targets in Autosomal Dominant Spinocerebellar Ataxias. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2019; 18:279-293. [DOI: 10.2174/1871527318666190311155846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/10/2018] [Accepted: 01/31/2019] [Indexed: 12/28/2022]
Abstract
Background & Objective:
The autosomal dominant spinocerebellar ataxias (SCAs) belong
to a large and expanding group of neurodegenerative disorders. SCAs comprise more than 40 subtypes
characterized by progressive ataxia as a common feature. The most prevalent diseases among SCAs
are caused by CAG repeat expansions in the coding-region of the causative gene resulting in polyglutamine
(polyQ) tract formation in the encoded protein. Unfortunately, there is no approved therapy to
treat cerebellar motor dysfunction in SCA patients. In recent years, several studies have been conducted
to recognize the clinical and pathophysiological aspects of the polyQ SCAs more accurately.
This scientific progress has provided new opportunities to develop promising gene therapies, including
RNA interference and antisense oligonucleotides.
Conclusion:
The aim of the current work is to give a brief summary of the clinical features of SCAs
and to review the cardinal points of pathomechanisms of the most common polyQ SCAs. In addition,
we review the last few year’s promising gene suppression therapies of the most frequent polyQ SCAs
in animal models, on the basis of which human trials may be initiated in the near future.
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Affiliation(s)
- Laszlo Szpisjak
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Denes Zadori
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Peter Klivenyi
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Laszlo Vecsei
- Department of Neurology, University of Szeged, Szeged, Hungary
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Buijsen RAM, Toonen LJA, Gardiner SL, van Roon-Mom WMC. Genetics, Mechanisms, and Therapeutic Progress in Polyglutamine Spinocerebellar Ataxias. Neurotherapeutics 2019; 16:263-286. [PMID: 30607747 PMCID: PMC6554265 DOI: 10.1007/s13311-018-00696-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative disorders characterized by degeneration of the cerebellum and its connections. All ADCAs have progressive ataxia as their main clinical feature, frequently accompanied by dysarthria and oculomotor deficits. The most common spinocerebellar ataxias (SCAs) are 6 polyglutamine (polyQ) SCAs. These diseases are all caused by a CAG repeat expansion in the coding region of a gene. Currently, no curative treatment is available for any of the polyQ SCAs, but increasing knowledge on the genetics and the pathological mechanisms of these polyQ SCAs has provided promising therapeutic targets to potentially slow disease progression. Potential treatments can be divided into pharmacological and gene therapies that target the toxic downstream effects, gene therapies that target the polyQ SCA genes, and stem cell replacement therapies. Here, we will provide a review on the genetics, mechanisms, and therapeutic progress in polyglutamine spinocerebellar ataxias.
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Affiliation(s)
- Ronald A M Buijsen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - Lodewijk J A Toonen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Sarah L Gardiner
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
- Department of Neurology, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
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15
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Nabirochkina EN, Kurshakova MM, Georgieva SG, Kopytova DV. The role of SAGA in the transcription and export of mRNA. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj19.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
SAGA/TFTC, which is a histone acetyltransferase complex, plays an important role in the regulation of transcription. We have identified that the metazoan TFTC/STAGA complexes had histone H2A and H2B deubiquitinase activity that is carried out by a DUBm (deubiquitination module). We studied the DUBm of SAGA in Drosophila melanogaster and identified Drosophila homologs of yeast DUBm components. Two subunits of DUBm (Sus1/ENY2 and Sgf11) were shown to have functions separate from DUBm function. Thus, Sus1/ENY2 was shown to be present in several different complexes. Sgf11 was found to be associated with the cap-binding complex (CBC) and recruited onto growing messenger ribonucleic acid (mRNA). Also, we have shown that Sgf11 interacted with the TREX-2/AMEX mRNA export complex and was essential for mRNA export from the nucleus. Immunostaining of the polytene chromosomes of Drosophila larvae revealed that Sgf11 is present at the sites of localization of snRNA genes. It was also found in immunostaining experiments that dPbp45, the subunit of the PBP complex, the key player in the snRNA transcription process, is associated not only with the snRNA gene localization sites, but with other sites of active transcription by PolII. We also revealed that Sgf11 was present at many active transcription sites in interbands and puffs on polytene chromosomes, Sgf11 was localized at all Brf1 (the component of the RNA polymerase III basal transcription complex) sites. We concluded that SAGA coactivated transcription of both the PolII and PolIII-dependent snRNA genes.
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16
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Karam A, Trottier Y. Molecular Mechanisms and Therapeutic Strategies in Spinocerebellar Ataxia Type 7. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:197-218. [DOI: 10.1007/978-3-319-71779-1_9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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17
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Intrinsic Disorder in Proteins with Pathogenic Repeat Expansions. Molecules 2017; 22:molecules22122027. [PMID: 29186753 PMCID: PMC6149999 DOI: 10.3390/molecules22122027] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/18/2017] [Accepted: 11/21/2017] [Indexed: 11/18/2022] Open
Abstract
Intrinsically disordered proteins and proteins with intrinsically disordered regions have been shown to be highly prevalent in disease. Furthermore, disease-causing expansions of the regions containing tandem amino acid repeats often push repetitive proteins towards formation of irreversible aggregates. In fact, in disease-relevant proteins, the increased repeat length often positively correlates with the increased aggregation efficiency and the increased disease severity and penetrance, being negatively correlated with the age of disease onset. The major categories of repeat extensions involved in disease include poly-glutamine and poly-alanine homorepeats, which are often times located in the intrinsically disordered regions, as well as repeats in non-coding regions of genes typically encoding proteins with ordered structures. Repeats in such non-coding regions of genes can be expressed at the mRNA level. Although they can affect the expression levels of encoded proteins, they are not translated as parts of an affected protein and have no effect on its structure. However, in some cases, the repetitive mRNAs can be translated in a non-canonical manner, generating highly repetitive peptides of different length and amino acid composition. The repeat extension-caused aggregation of a repetitive protein may represent a pivotal step for its transformation into a proteotoxic entity that can lead to pathology. The goals of this article are to systematically analyze molecular mechanisms of the proteinopathies caused by the poly-glutamine and poly-alanine homorepeat expansion, as well as by the polypeptides generated as a result of the microsatellite expansions in non-coding gene regions and to examine the related proteins. We also present results of the analysis of the prevalence and functional roles of intrinsic disorder in proteins associated with pathological repeat expansions.
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18
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Fiszer A, Wroblewska JP, Nowak BM, Krzyzosiak WJ. Mutant CAG Repeats Effectively Targeted by RNA Interference in SCA7 Cells. Genes (Basel) 2016; 7:genes7120132. [PMID: 27999335 PMCID: PMC5192508 DOI: 10.3390/genes7120132] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/06/2016] [Accepted: 12/09/2016] [Indexed: 02/08/2023] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a human neurodegenerative polyglutamine (polyQ) disease caused by a CAG repeat expansion in the open reading frame of the ATXN7 gene. The allele-selective silencing of mutant transcripts using a repeat-targeting strategy has previously been used for several polyQ diseases. Herein, we demonstrate that the selective targeting of a repeat tract in a mutant ATXN7 transcript by RNA interference is a feasible approach and results in an efficient decrease of mutant ataxin-7 protein in patient-derived cells. Oligonucleotides (ONs) containing specific base substitutions cause the downregulation of the ATXN7 mutant allele together with the upregulation of its normal allele. The A2 ON shows high allele selectivity at a broad range of concentrations and also restores UCHL1 expression, which is downregulated in SCA7.
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Affiliation(s)
- Agnieszka Fiszer
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
| | - Joanna P Wroblewska
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
| | - Bartosz M Nowak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
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19
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Sgf73, a subunit of SAGA complex, is required for the assembly of RITS complex in fission yeast. Sci Rep 2015; 5:14707. [PMID: 26443059 PMCID: PMC4595766 DOI: 10.1038/srep14707] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/07/2015] [Indexed: 02/04/2023] Open
Abstract
RNA interference (RNAi) is a widespread gene-silencing mechanism and is required for heterochromatin assembly in a variety of organisms. The RNA-induced transcriptional silencing complex (RITS), composed of Ago1, Tas3 and Chp1, is a key component of RNAi machinery in fission yeast that connects short interference RNA (siRNA) and heterochromatin formation. However, the process by which RITS is assembled is not well understood. Here, we identified Sgf73, a subunit of the SAGA co-transcriptional complex, is required for pericentromeric heterochromatin silencing and the generation of siRNA. This novel role of Sgf73 is independent of enzymatic activities or structural integrity of SAGA. Instead, Sgf73 is physically associated with Ago1 and Chp1. The interactions among the subunits of the RITS, including those between Tas3 and Chp1, between Chp1 and Ago1, between Ago1 and Tas3, were all impaired by the deletion of sgf73+. Consistently, the recruitment of Ago1 and Chp1 to the pericentromeric region was abolished in sgf73Δ cells. Our study unveils a moonlighting function of a SAGA subunit. It suggests Sgf73 is a novel factor that promotes assembly of RITS and RNAi-mediated heterochromatin formation.
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20
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Ajayi A, Yu X, Wahlo-Svedin C, Tsirigotaki G, Karlström V, Ström AL. Altered p53 and NOX1 activity cause bioenergetic defects in a SCA7 polyglutamine disease model. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:418-428. [PMID: 25647692 DOI: 10.1016/j.bbabio.2015.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/12/2014] [Accepted: 01/26/2015] [Indexed: 01/09/2023]
Abstract
Spinocerebellar ataxia type 7 (SCA7) is one of the nine neurodegenerative disorders caused by expanded polyglutamine (polyQ) domains. Common pathogenic mechanisms, including bioenergetics defects, have been suggested for these so called polyQ diseases. However, the exact molecular mechanism(s) behind the metabolic dysfunction is still unclear. In this study we identified a previously unreported mechanism, involving disruption of p53 and NADPH oxidase 1 (NOX1) activity, by which the expanded SCA7 disease protein ATXN7 causes metabolic dysregulation. The NOX1 protein is known to promote glycolytic activity, whereas the transcription factor p53 inhibits this process and instead promotes mitochondrial respiration. In a stable inducible PC12 model of SCA7, p53 and mutant ATXN7 co-aggregated and the transcriptional activity of p53 was reduced, resulting in a 50% decrease of key p53 target proteins, like AIF and TIGAR. In contrast, the expression of NOX1 was increased approximately 2 times in SCA7 cells. Together these alterations resulted in a decreased respiratory capacity, an increased reliance on glycolysis for energy production and a subsequent 20% reduction of ATP in SCA7 cells. Restoring p53 function, or suppressing NOX1 activity, both reversed the metabolic dysfunction and ameliorated mutant ATXN7 toxicity. These results hence not only enhance the understanding of the mechanisms causing metabolic dysfunction in SCA7 disease, but also identify NOX1 as a novel potential therapeutic target in SCA7 and possibly other polyQ diseases.
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Affiliation(s)
- Abiodun Ajayi
- Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Xin Yu
- Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
| | | | - Galateia Tsirigotaki
- Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Victor Karlström
- Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Anna-Lena Ström
- Department of Neurochemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
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21
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Scripko P, Oaklander AL, Koeppen AH, Frosch MP, Schmahmann JD. A 40-year-old woman with difficulty going down stairs in high-heeled shoes. Ann Neurol 2015; 77:1-7. [PMID: 25380064 DOI: 10.1002/ana.24301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 10/30/2014] [Accepted: 11/02/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Patricia Scripko
- Department of Neurology, Massachusetts General Hospital, Boston, MA
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22
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Alves S, Cormier-Dequaire F, Marinello M, Marais T, Muriel MP, Beaumatin F, Charbonnier-Beaupel F, Tahiri K, Seilhean D, El Hachimi K, Ruberg M, Stevanin G, Barkats M, den Dunnen W, Priault M, Brice A, Durr A, Corvol JC, Sittler A. The autophagy/lysosome pathway is impaired in SCA7 patients and SCA7 knock-in mice. Acta Neuropathol 2014; 128:705-22. [PMID: 24859968 DOI: 10.1007/s00401-014-1289-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 04/18/2014] [Accepted: 04/26/2014] [Indexed: 01/11/2023]
Abstract
There is still no treatment for polyglutamine disorders, but clearance of mutant proteins might represent a potential therapeutic strategy. Autophagy, the major pathway for organelle and protein turnover, has been implicated in these diseases. To determine whether the autophagy/lysosome system contributes to the pathogenesis of spinocerebellar ataxia type 7 (SCA7), caused by expansion of a polyglutamine tract in the ataxin-7 protein, we looked for biochemical, histological and transcriptomic abnormalities in components of the autophagy/lysosome pathway in a knock-in mouse model of the disease, postmortem brain and peripheral blood mononuclear cells (PBMC) from patients. In the mouse model, mutant ataxin-7 accumulated in inclusions immunoreactive for the autophagy-associated proteins mTOR, beclin-1, p62 and ubiquitin. Atypical accumulations of the autophagosome/lysosome markers LC3, LAMP-1, LAMP2 and cathepsin-D were also found in the cerebellum of the SCA7 knock-in mice. In patients, abnormal accumulations of autophagy markers were detected in the cerebellum and cerebral cortex of patients, but not in the striatum that is spared in SCA7, suggesting that autophagy might be impaired by the selective accumulation of mutant ataxin-7. In vitro studies demonstrated that the autophagic flux was impaired in cells overexpressing full-length mutant ataxin-7. Interestingly, the expression of the early autophagy-associated gene ATG12 was increased in PBMC from SCA7 patients in correlation with disease severity. These results provide evidence that the autophagy/lysosome pathway is impaired in neurons undergoing degeneration in SCA7. Autophagy/lysosome-associated molecules might, therefore, be useful markers for monitoring the effects of potential therapeutic approaches using modulators of autophagy in SCA7 and other autophagy/lysosome-associated neurodegenerative disorders.
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23
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Vishweswaraiah S, Veerappa AM, Mahesh PA, Jayaraju BS, Krishnarao CS, Ramachandra NB. Molecular interaction network and pathway studies of ADAM33 potentially relevant to asthma. Ann Allergy Asthma Immunol 2014; 113:418-24.e1. [PMID: 25155083 DOI: 10.1016/j.anai.2014.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 07/10/2014] [Accepted: 07/12/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND Asthma is a complex disease caused by gene-gene, gene-protein, and protein-protein interactions and the influence of environment, which plays a significant role in causing asthma pathogenesis. ADAM33 is known to be an important gene involved in asthma pathogenesis. No one single gene is a causal factor of asthma; rather, asthma is caused by a complex interaction of multiple genes having pathogenetic and protective effects. OBJECTIVE To identify and understand the interacting genes and proteins of ADAM33. METHODS The Ingenuity Pathway Analysis and GeneMANIA tools and a literature survey were used to identify the interacting candidates of ADAM33 and the WEB-based GEne SeT AnaLysis Toolkit was used to perform enrichment analysis of the proteins identified. RESULTS Keeping ADAM33 as a major hub, the authors identified some proteins whose interaction with ADAM33 had been associated with asthma and they recognized some proteins, such as amyloid β (A4) precursor protein, ataxin-7, α4-integrin, α5-integrin, α9-integrin, tissue inhibitor of metalloproteinase-4, and ubiquilin-4, that had not been previously associated with asthma. CONCLUSION The proteins identified in this study were enriched for various mechanisms that are involved in airway hyperresponsiveness, and through the interaction with ADAM33, they may have potential relevance in asthma.
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Affiliation(s)
- Sangeetha Vishweswaraiah
- Genetics and Genomics Laboratory, Department of Studies in Zoology, University of Mysore, Mysore, Karnataka, India
| | - Avinash M Veerappa
- Genetics and Genomics Laboratory, Department of Studies in Zoology, University of Mysore, Mysore, Karnataka, India
| | | | | | | | - Nallur B Ramachandra
- Genetics and Genomics Laboratory, Department of Studies in Zoology, University of Mysore, Mysore, Karnataka, India.
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Kang MS, Yu SL, Kim HY, Gorospe CM, Choi BH, Lee SH, Lee SK. Yeast RAD2, a homolog of human XPG, plays a key role in the regulation of the cell cycle and actin dynamics. Biol Open 2014; 3:29-41. [PMID: 24326185 PMCID: PMC3892158 DOI: 10.1242/bio.20136403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mutations in the human XPG gene cause Cockayne syndrome (CS) and xeroderma pigmentosum (XP). Transcription defects have been suggested as the fundamental cause of CS; however, defining CS as a transcription syndrome is inconclusive. In particular, the function of XPG in transcription has not been clearly demonstrated. Here, we provide evidence for the involvement of RAD2, the Saccharomyces cerevisiae counterpart of XPG, in cell cycle regulation and efficient actin assembly following ultraviolet irradiation. RAD2 C-terminal deletion, which resembles the XPG mutation found in XPG/CS cells, caused cell growth arrest, the cell cycle stalling, a defective α-factor response, shortened lifespan, cell polarity defect, and misregulated actin-dynamics after DNA damage. Overexpression of the C-terminal 65 amino acids of Rad2p was sufficient to induce hyper-cell polarization. In addition, RAD2 genetically interacts with TPM1 during cell polarization. These results provide insights into the role of RAD2 in post-UV irradiation cell cycle regulation and actin assembly, which may be an underlying cause of XPG/CS.
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Affiliation(s)
- Mi-Sun Kang
- Department of Pharmacology, College of Medicine, Inha University, Incheon, Korea 400-712
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25
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Lei B, Zhou N, Guo Y, Zhao W, Tan YW, Yu Y, Lu H. Septin ring assembly is regulated by Spt20, a structural subunit of SAGA complex. J Cell Sci 2014; 127:4024-36. [DOI: 10.1242/jcs.151910] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Accurate cell division requires proper assembly of high-order septin structures. In fission yeast, Spn1-4 are assembled into a primary septin ring at the division site, and the subsequent recruitment of Mid2 to the structure results in a stable septin ring. However, not much is known about the regulation of this key process. Here, we found deletion of Spt20, a structural subunit of SAGA transcriptional activation complex, caused a severe cell separation defect. The defect is mainly due to impaired septin ring assembly, as 80% of spt20Δ cells lost septin rings at the division sites. Spt20 regulates septin ring assembly partially through the transcriptional activation of mid2+. Spt20 also interacts with Spn2 and Mid2 in vitro and is associated with other components of the ring in vivo. Spt20 is co-localized with the septin ring, but does not separate when the septin ring splits. Importantly, Spt20 regulates the stability of the septin ring and is required for the recruitment of Mid2. The transcription-dependent and -independent roles of Spt20 in the septin ring assembly highlight a multifaceted regulation of one process by a SAGA subunit.
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26
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Gurskiy DY, Kopytova DV, Georgieva SG, Nabirochkina EN. SAGA complex: Role in viability and development. Mol Biol 2013. [DOI: 10.1134/s0026893313060071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Kikuchi M, Ogishima S, Miyamoto T, Miyashita A, Kuwano R, Nakaya J, Tanaka H. Identification of unstable network modules reveals disease modules associated with the progression of Alzheimer's disease. PLoS One 2013; 8:e76162. [PMID: 24348898 PMCID: PMC3858171 DOI: 10.1371/journal.pone.0076162] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 08/20/2013] [Indexed: 11/18/2022] Open
Abstract
Alzheimer's disease (AD), the most common cause of dementia, is associated with aging, and it leads to neuron death. Deposits of amyloid β and aberrantly phosphorylated tau protein are known as pathological hallmarks of AD, but the underlying mechanisms have not yet been revealed. A high-throughput gene expression analysis previously showed that differentially expressed genes accompanying the progression of AD were more down-regulated than up-regulated in the later stages of AD. This suggested that the molecular networks and their constituent modules collapsed along with AD progression. In this study, by using gene expression profiles and protein interaction networks (PINs), we identified the PINs expressed in three brain regions: the entorhinal cortex (EC), hippocampus (HIP) and superior frontal gyrus (SFG). Dividing the expressed PINs into modules, we examined the stability of the modules with AD progression and with normal aging. We found that in the AD modules, the constituent proteins, interactions and cellular functions were not maintained between consecutive stages through all brain regions. Interestingly, the modules were collapsed with AD progression, specifically in the EC region. By identifying the modules that were affected by AD pathology, we found the transcriptional regulation-associated modules that interact with the proteasome-associated module via UCHL5 hub protein, which is a deubiquitinating enzyme. Considering PINs as a system made of network modules, we found that the modules relevant to the transcriptional regulation are disrupted in the EC region, which affects the ubiquitin-proteasome system.
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Affiliation(s)
- Masataka Kikuchi
- Department of Bioinformatics, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Soichi Ogishima
- Department of Bioclinical Informatics, Tohoku Medical Megabank Organization, Tohoku University, Sendai-shi, Miyagi, Japan
- * E-mail:
| | - Tadashi Miyamoto
- Department of Bioinformatics, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Akinori Miyashita
- Bioresource Science Branch, Center for Bioresources, Brain Research Institute, Niigata University, Niigata-shi, Niigata, Japan
| | - Ryozo Kuwano
- Bioresource Science Branch, Center for Bioresources, Brain Research Institute, Niigata University, Niigata-shi, Niigata, Japan
| | - Jun Nakaya
- Department of Bioclinical Informatics, Tohoku Medical Megabank Organization, Tohoku University, Sendai-shi, Miyagi, Japan
| | - Hiroshi Tanaka
- Department of Bioinformatics, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
- Department of Bioclinical Informatics, Tohoku Medical Megabank Organization, Tohoku University, Sendai-shi, Miyagi, Japan
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Yu X, Muñoz-Alarcón A, Ajayi A, Webling KE, Steinhof A, Langel Ü, Ström AL. Inhibition of autophagy via p53-mediated disruption of ULK1 in a SCA7 polyglutamine disease model. J Mol Neurosci 2013; 50:586-99. [PMID: 23592174 DOI: 10.1007/s12031-013-0012-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 04/01/2013] [Indexed: 02/07/2023]
Abstract
Spinocerebellar ataxia type 7 (SCA7) is one of nine neurodegenerative disorders caused by expanded polyglutamine domains. These so-called polyglutamine (polyQ) diseases are all characterized by aggregation. Reducing the level of aggregating polyQ proteins via pharmacological activation of autophagy has been suggested as a therapeutic approach. However, recently, evidence implicating autophagic dysfunction in these disorders has also been reported. In this study, we show that the SCA7 polyglutamine protein ataxin-7 (ATXN7) reduces the autophagic activity via a previously unreported mechanism involving p53-mediated disruption of two key proteins involved in autophagy initiation. We show that in mutant ATXN7 cells, an increased p53-FIP200 interaction and co-aggregation of p53-FIP200 into ATXN7 aggregates result in decreased soluble FIP200 levels and subsequent destabilization of ULK1. Together, this leads to a decreased capacity for autophagy induction via the ULK1-FIP200-Atg13-Atg101 complex. We also show that treatment with a p53 inhibitor, or a blocker of ATXN7 aggregation, can restore the soluble levels of FIP200 and ULK1, as well as increase the autophagic activity and reduce ATXN7 toxicity. Understanding the mechanism behind polyQ-mediated inhibition of autophagy is of importance if therapeutic approaches based on autophagy stimulation should be developed for these disorders.
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Affiliation(s)
- Xin Yu
- Department of Neurochemistry, Stockholm University, 106 91, Stockholm, Sweden.
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29
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Berdasco M, Esteller M. Genetic syndromes caused by mutations in epigenetic genes. Hum Genet 2013; 132:359-83. [PMID: 23370504 DOI: 10.1007/s00439-013-1271-x] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 01/18/2013] [Indexed: 12/21/2022]
Abstract
The orchestrated organization of epigenetic factors that control chromatin dynamism, including DNA methylation, histone marks, non-coding RNAs (ncRNAs) and chromatin-remodeling proteins, is essential for the proper function of tissue homeostasis, cell identity and development. Indeed, deregulation of epigenetic profiles has been described in several human pathologies, including complex diseases (such as cancer, cardiovascular and neurological diseases), metabolic pathologies (type 2 diabetes and obesity) and imprinting disorders. Over the last decade it has become increasingly clear that mutations of genes involved in epigenetic mechanism, such as DNA methyltransferases, methyl-binding domain proteins, histone deacetylases, histone methylases and members of the SWI/SNF family of chromatin remodelers are linked to human disorders, including Immunodeficiency Centromeric instability Facial syndrome 1, Rett syndrome, Rubinstein-Taybi syndrome, Sotos syndrome or alpha-thalassemia/mental retardation X-linked syndrome, among others. As new members of the epigenetic machinery are described, the number of human syndromes associated with epigenetic alterations increases. As recent examples, mutations of histone demethylases and members of the non-coding RNA machinery have recently been associated with Kabuki syndrome, Claes-Jensen X-linked mental retardation syndrome and Goiter syndrome. In this review, we describe the variety of germline mutations of epigenetic modifiers that are known to be associated with human disorders, and discuss the therapeutic potential of epigenetic drugs as palliative care strategies in the treatment of such disorders.
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Affiliation(s)
- María Berdasco
- Cancer Epigenetics Group, Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 3rd Floor, Hospital Duran i Reynals, Av. Gran Via 199-203, 08908 L'Hospitalet de LLobregat, Barcelona, Catalonia, Spain
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30
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Galán A, Rodríguez-Navarro S. Sus1/ENY2: a multitasking protein in eukaryotic gene expression. Crit Rev Biochem Mol Biol 2012; 47:556-68. [PMID: 23057668 DOI: 10.3109/10409238.2012.730498] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The purpose of this review is to provide a complete overview on the functions of the transcription/export factor Sus1. Sus1 is a tiny conserved factor in sequence and functions through the eukaryotic kingdom. Although it was discovered recently, research done to address the role of Sus1/ENY2 has provided in deep description of different mechanisms influencing gene expression. Initially found to interact with the transcription and mRNA export machinery in yeast, it is now clear that it has a broad role in mRNA biogenesis. Sus1 is necessary for histone H2B deubiquitination, mRNA export and gene gating. Moreover, interesting observations also suggest a link with the cytoplasmatic mRNP fate. Although the role of Sus1 in human cells is largely unknown, preliminary results suggest interesting links to pathological states that range from rare diseases to diabetes. We will describe what is known about Sus1/ENY2 in yeast and other eukaryotes and discuss some exciting open questions to be solved in the future.
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Affiliation(s)
- Amparo Galán
- Centro de Investigación Príncipe Felipe, CIPF. Gene Expression coupled to RNA Transport Laboratory, Eduardo Primo Yúfera, Valencia, Spain
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31
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Gurskiy D, Orlova A, Vorobyeva N, Nabirochkina E, Krasnov A, Shidlovskii Y, Georgieva S, Kopytova D. The DUBm subunit Sgf11 is required for mRNA export and interacts with Cbp80 in Drosophila. Nucleic Acids Res 2012; 40:10689-700. [PMID: 22989713 PMCID: PMC3510517 DOI: 10.1093/nar/gks857] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
SAGA/TFTC is a histone acetyltransferase complex that has a second enzymatic activity because of the presence of a deubiquitination module (DUBm). Drosophila DUBm consists of Sgf11, ENY2 and Nonstop proteins. We show that Sgf11 has other DUBm-independent functions. It associates with Cbp80 component of the cap-binding complex and is thereby recruited onto growing messenger ribonucleic acid (mRNA); it also interacts with the AMEX mRNA export complex and is essential for hsp70 mRNA export, as well as for general mRNA export from the nucleus. Thus, Sgf11 functions as a component of both SAGA DUBm and the mRNA biogenesis machinery.
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Affiliation(s)
- Dmitriy Gurskiy
- Department of Regulation of Gene Expression, Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 32, Moscow 119991, Russia
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