1
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Iruzubieta P, Damborenea A, Ioghen M, Bajew S, Fernandez-Torrón R, Töpf A, Herrero-Reiriz Á, Epure D, Vill K, Hernández-Laín A, Manterola M, Azkargorta M, Pikatza-Menoio O, Pérez-Fernandez L, García-Puga M, Gaina G, Bastian A, Streata I, Walter MC, Müller-Felber W, Thiele S, Moragón S, Bastida-Lertxundi N, López-Cortajarena A, Elortza F, Gereñu G, Alonso-Martin S, Straub V, de Sancho D, Teleanu R, López de Munain A, Blázquez L. Biallelic variants in SNUPN cause a limb girdle muscular dystrophy with myofibrillar-like features. Brain 2024; 147:2867-2883. [PMID: 38366623 PMCID: PMC11292911 DOI: 10.1093/brain/awae046] [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: 09/08/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 02/18/2024] Open
Abstract
Alterations in RNA-splicing are a molecular hallmark of several neurological diseases, including muscular dystrophies, where mutations in genes involved in RNA metabolism or characterized by alterations in RNA splicing have been described. Here, we present five patients from two unrelated families with a limb-girdle muscular dystrophy (LGMD) phenotype carrying a biallelic variant in SNUPN gene. Snurportin-1, the protein encoded by SNUPN, plays an important role in the nuclear transport of small nuclear ribonucleoproteins (snRNPs), essential components of the spliceosome. We combine deep phenotyping, including clinical features, histopathology and muscle MRI, with functional studies in patient-derived cells and muscle biopsies to demonstrate that variants in SNUPN are the cause of a new type of LGMD according to current definition. Moreover, an in vivo model in Drosophila melanogaster further supports the relevance of Snurportin-1 in muscle. SNUPN patients show a similar phenotype characterized by proximal weakness starting in childhood, restrictive respiratory dysfunction and prominent contractures, although inter-individual variability in terms of severity even in individuals from the same family was found. Muscle biopsy showed myofibrillar-like features consisting of myotilin deposits and Z-disc disorganization. MRI showed predominant impairment of paravertebral, vasti, sartorius, gracilis, peroneal and medial gastrocnemius muscles. Conservation and structural analyses of Snurportin-1 p.Ile309Ser variant suggest an effect in nuclear-cytosol snRNP trafficking. In patient-derived fibroblasts and muscle, cytoplasmic accumulation of snRNP components is observed, while total expression of Snurportin-1 and snRNPs remains unchanged, which demonstrates a functional impact of SNUPN variant in snRNP metabolism. Furthermore, RNA-splicing analysis in patients' muscle showed widespread splicing deregulation, in particular in genes relevant for muscle development and splicing factors that participate in the early steps of spliceosome assembly. In conclusion, we report that SNUPN variants are a new cause of limb girdle muscular dystrophy with specific clinical, histopathological and imaging features, supporting SNUPN as a new gene to be included in genetic testing of myopathies. These results further support the relevance of splicing-related proteins in muscle disorders.
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Affiliation(s)
- Pablo Iruzubieta
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Alberto Damborenea
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Mihaela Ioghen
- Clinical Neurosciences Department, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Paediatric Neurology, 020021 Bucharest, Romania
| | - Simon Bajew
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Roberto Fernandez-Torrón
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, NE4 5NR Newcastle Upon Tyne, UK
| | - Álvaro Herrero-Reiriz
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Diana Epure
- Department of Paediatric Neurology, Doctor Victor Gomoiu Children’s Hospital, 022102 Bucharest, Romania
| | - Katharina Vill
- Department of Pediatric Neurology and Developmental Medicine and LMU Center for Children with Medical Complexity, Dr. von Hauner Children’s Hospital, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Aurelio Hernández-Laín
- Neuropathology Unit, Department of Pathology, 12 de Octubre University Hospital, 28041 Madrid, Spain
- Department of Neuro-oncology, Instituto de Investigación Sanitaria imas12, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
- Universidad Complutense de Madrid, Facultad de Medicina, 28040 Madrid, Spain
| | - María Manterola
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Mikel Azkargorta
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Centre for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Oihane Pikatza-Menoio
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Laura Pérez-Fernandez
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), 20014 San Sebastián, Spain
| | - Mikel García-Puga
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Gisela Gaina
- Department of Cell Biology, Neurosciences and Experimental Myology, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Alexandra Bastian
- Department of Pathology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Ioana Streata
- Human Genomics Laboratory, Regional Centre of Medical Genetics, Craiova University of Medicine and Pharmacy, 200349 Dolj, Romania
| | - Maggie C Walter
- Friedrich Baur Institute at the Department of Neurology, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
| | - Wolfgang Müller-Felber
- Institute of Human Genetics, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Simone Thiele
- Friedrich Baur Institute at the Department of Neurology, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
| | - Saioa Moragón
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Nerea Bastida-Lertxundi
- Department of Clinical Genetics, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
| | - Aitziber López-Cortajarena
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), 20014 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Felix Elortza
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Centre for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Gorka Gereñu
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Sonia Alonso-Martin
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, NE4 5NR Newcastle Upon Tyne, UK
| | - David de Sancho
- Donostia International Physics Center, 20018 San Sebastián, Spain
- Faculty of Chemistry, University of the Basque Country, 20018 San Sebastián, Spain
| | - Raluca Teleanu
- Clinical Neurosciences Department, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Paediatric Neurology, 020021 Bucharest, Romania
| | - Adolfo López de Munain
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Faculty of Medicine, University of the Basque Country, 20014 San Sebastián, Spain
- Faculty of Medicine, University of Deusto, 48007 Bilbao, Spain
| | - Lorea Blázquez
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
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2
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Sumitha MK, Kalimuthu M, Aarthy M, Paramasivan R, Kumar A, Gupta B. In silico identification, characterization, and expression analysis of RNA recognition motif (RRM) containing RNA-binding proteins in Aedes aegypti. Parasitol Res 2023; 122:2847-2857. [PMID: 37735272 DOI: 10.1007/s00436-023-07969-2] [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: 01/14/2023] [Accepted: 09/04/2023] [Indexed: 09/23/2023]
Abstract
RNA-binding proteins (RBPs) are the proteins that bind RNAs and regulate their functioning. RBPs in mosquitoes are gaining attention due to their ability to bind flaviviruses and regulate their replication and transmission. Despite their relevance, RBPs in mosquitoes are not explored much. In this study, we screened the whole genome of Aedes aegypti, the primary vector of several pathogenic viruses, and identified the proteins containing RNA recognition motif (RRM), the most abundant protein domain in eukaryotes. Using several in silico strategies, a total of 135 RRM-containing RBPs were identified in Ae. aegypti. The proteins were characterized based on their available annotations and the sequence similarity with Drosophila melanogaster. Ae. aegypti RRM-containing RBPs included serine/arginine-rich (SR) proteins, polyadenylate-binding proteins (PABP), heteronuclear ribonucleoproteins (hnRNP), small nuclear ribonucleoproteins (snRNP), splicing factors, eukaryotic initiation factors, transformers, and nucleolysins. Phylogenetic analysis revealed that the proteins and the domain organization are conserved among Ae. aegypti, Bombyx mori, and Drosophila melanogaster. However, the gene length and the intron-exon organization varied across the insect species. Expression analysis of the genes encoding RBPs using publicly available RNA sequencing data for different developmental time points of the mosquito life cycle starting from the ovary and eggs up to the adults revealed stage-specific expression with several genes preferentially expressed in early embryonic stages and blood-fed female ovaries. This is the first database for the Ae. aegypti RBPs that can serve as the reference base for future investigations. Stage-specific genes can be further explored to determine their role in mosquito growth and development with a focus on developing novel mosquito control strategies.
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Affiliation(s)
- Melveettil Kishor Sumitha
- ICMR-Vector Control Research Centre (VCRC), Field Station, 4, Sarojini Street Chinna Chokkikulam, Madurai, 625002, India
| | - Mariapillai Kalimuthu
- ICMR-Vector Control Research Centre (VCRC), Field Station, 4, Sarojini Street Chinna Chokkikulam, Madurai, 625002, India
| | - Murali Aarthy
- ICMR-Vector Control Research Centre (VCRC), Field Station, 4, Sarojini Street Chinna Chokkikulam, Madurai, 625002, India
| | - Rajaiah Paramasivan
- ICMR-Vector Control Research Centre (VCRC), Field Station, 4, Sarojini Street Chinna Chokkikulam, Madurai, 625002, India
| | - Ashwani Kumar
- ICMR-Vector Control Research Centre (VCRC), Puducherry, India
| | - Bhavna Gupta
- ICMR-Vector Control Research Centre (VCRC), Field Station, 4, Sarojini Street Chinna Chokkikulam, Madurai, 625002, India.
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3
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Nameki N, Takizawa M, Suzuki T, Tani S, Kobayashi N, Sakamoto T, Muto Y, Kuwasako K. Structural basis for the interaction between the first SURP domain of the SF3A1 subunit in U2 snRNP and the human splicing factor SF1. Protein Sci 2022; 31:e4437. [PMID: 36173164 PMCID: PMC9514218 DOI: 10.1002/pro.4437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/24/2022] [Accepted: 08/28/2022] [Indexed: 11/08/2022]
Abstract
SURP domains are exclusively found in splicing-related proteins in all eukaryotes. SF3A1, a component of the U2 snRNP, has two tandem SURP domains, SURP1, and SURP2. SURP2 is permanently associated with a specific short region of SF3A3 within the SF3A protein complex whereas, SURP1 binds to the splicing factor SF1 for recruitment of U2 snRNP to the early spliceosomal complex, from which SF1 is dissociated during complex conversion. Here, we determined the solution structure of the complex of SURP1 and the human SF1 fragment using nuclear magnetic resonance (NMR) methods. SURP1 adopts the canonical topology of α1-α2-310 -α3, in which α1 and α2 are connected by a single glycine residue in a particular backbone conformation, allowing the two α-helices to be fixed at an acute angle. A hydrophobic patch, which is part of the characteristic surface formed by α1 and α2, specifically contacts a hydrophobic cluster on a 16-residue α-helix of the SF1 fragment. Furthermore, whereas only hydrophobic interactions occurred between SURP2 and the SF3A3 fragment, several salt bridges and hydrogen bonds were found between the residues of SURP1 and the SF1 fragment. This finding was confirmed through mutational studies using bio-layer interferometry. The study also revealed that the dissociation constant between SURP1 and the SF1 fragment peptide was approximately 20 μM, indicating a weak or transient interaction. Collectively, these results indicate that the interplay between U2 snRNP and SF1 involves a transient interaction of SURP1, and this transient interaction appears to be common to most SURP domains, except for SURP2.
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Affiliation(s)
- Nobukazu Nameki
- Division of Molecular ScienceGraduate School of Science and Technology, Gunma UniversityKiryuGunmaJapan
| | - Masayuki Takizawa
- Faculty of Pharmacy and Research Institute of Pharmaceutical SciencesMusashino UniversityNishitokyoTokyoJapan
| | - Takayuki Suzuki
- Faculty of Pharmacy and Research Institute of Pharmaceutical SciencesMusashino UniversityNishitokyoTokyoJapan
| | - Shoko Tani
- Faculty of Pharmacy and Research Institute of Pharmaceutical SciencesMusashino UniversityNishitokyoTokyoJapan
| | | | - Taiichi Sakamoto
- Department of Life Science, Faculty of Advanced EngineeringChiba Institute of TechnologyNarashinoChibaJapan
| | - Yutaka Muto
- Faculty of Pharmacy and Research Institute of Pharmaceutical SciencesMusashino UniversityNishitokyoTokyoJapan
| | - Kanako Kuwasako
- Faculty of Pharmacy and Research Institute of Pharmaceutical SciencesMusashino UniversityNishitokyoTokyoJapan
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4
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Zhan J, Li J, Wu Y, Wu P, Yu Z, Cui P, Zhou M, Xu Y, Jin T, Du Z, Luo M, Liu C. Chromatin-Associated Protein Sugp2 Involved in mRNA Alternative Splicing During Mouse Spermatogenesis. Front Vet Sci 2021; 8:754021. [PMID: 34733907 PMCID: PMC8558236 DOI: 10.3389/fvets.2021.754021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
Mammalian spermatogenesis is a highly ordered process that is determined by chromatin-associated moderators which still remain poorly understood. Through a multi-control group proteomics strategy, we confirmed that Sugp2 was a chromatin-associated candidate protein, and its signal arose along spermatogenesis. The expression results showed that Sugp2, which is mainly expressed in the testis, had two transcripts, encoding one protein. During spermatogenesis, Sugp2 was enriched in the nucleus of male germ cells. With the depletion of Sugp2 by CRISPER-Cas9 technology, we found that Sugp2 controlled a network of genes on metal ion and ATP binding, suggesting that alternative splicing regulation by Sugp2 is involved in cellular ion and energy metabolism during spermatogenesis, while it had a little effect on meiotic progression and male fertility. Collectively, these data demonstrated that, as a chromatin-associated protein, Sugp2 mediated the alternative splicing regulatory network during spermatogenesis.
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Affiliation(s)
- Junfeng Zhan
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.,Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Jianbo Li
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Yuerong Wu
- Center for Animal Experiment, Wuhan University, Wuhan, China
| | - Panfeng Wu
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Ziqi Yu
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Peng Cui
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Mofan Zhou
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yumin Xu
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Tingyu Jin
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Ziye Du
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Mengcheng Luo
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Cong Liu
- Department of Tissue and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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5
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Zhang J, Ali AM, Lieu YK, Liu Z, Gao J, Rabadan R, Raza A, Mukherjee S, Manley JL. Disease-Causing Mutations in SF3B1 Alter Splicing by Disrupting Interaction with SUGP1. Mol Cell 2019; 76:82-95.e7. [PMID: 31474574 PMCID: PMC7065273 DOI: 10.1016/j.molcel.2019.07.017] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/27/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022]
Abstract
SF3B1, which encodes an essential spliceosomal protein, is frequently mutated in myelodysplastic syndromes (MDS) and many cancers. However, the defect of mutant SF3B1 is unknown. Here, we analyzed RNA sequencing data from MDS patients and confirmed that SF3B1 mutants use aberrant 3' splice sites. To elucidate the underlying mechanism, we purified complexes containing either wild-type or the hotspot K700E mutant SF3B1 and found that levels of a poorly studied spliceosomal protein, SUGP1, were reduced in mutant spliceosomes. Strikingly, SUGP1 knockdown completely recapitulated the splicing errors, whereas SUGP1 overexpression drove the protein, which our data suggest plays an important role in branchsite recognition, into the mutant spliceosome and partially rescued splicing. Other hotspot SF3B1 mutants showed similar altered splicing and diminished interaction with SUGP1. Our study demonstrates that SUGP1 loss is a common defect of spliceosomes with disease-causing SF3B1 mutations and, because this defect can be rescued, suggests possibilities for therapeutic intervention.
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Affiliation(s)
- Jian Zhang
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Abdullah M Ali
- Irving Cancer Research Center, Columbia University, New York, NY 10032, USA
| | - Yen K Lieu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Irving Cancer Research Center, Columbia University, New York, NY 10032, USA
| | - Zhaoqi Liu
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biomedical Informatics, Columbia University, New York, NY 10032, USA
| | - Jianchao Gao
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Raul Rabadan
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biomedical Informatics, Columbia University, New York, NY 10032, USA
| | - Azra Raza
- Irving Cancer Research Center, Columbia University, New York, NY 10032, USA; Division of Hematology/Oncology, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Siddhartha Mukherjee
- Irving Cancer Research Center, Columbia University, New York, NY 10032, USA; Division of Hematology/Oncology, Department of Medicine, Columbia University, New York, NY 10032, USA.
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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6
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Haselbach D, Komarov I, Agafonov DE, Hartmuth K, Graf B, Dybkov O, Urlaub H, Kastner B, Lührmann R, Stark H. Structure and Conformational Dynamics of the Human Spliceosomal B act Complex. Cell 2018; 172:454-464.e11. [PMID: 29361316 DOI: 10.1016/j.cell.2018.01.010] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/23/2017] [Accepted: 01/05/2018] [Indexed: 11/19/2022]
Abstract
The spliceosome is a highly dynamic macromolecular complex that precisely excises introns from pre-mRNA. Here we report the cryo-EM 3D structure of the human Bact spliceosome at 3.4 Å resolution. In the Bact state, the spliceosome is activated but not catalytically primed, so that it is functionally blocked prior to the first catalytic step of splicing. The spliceosomal core is similar to the yeast Bact spliceosome; important differences include the presence of the RNA helicase aquarius and peptidyl prolyl isomerases. To examine the overall dynamic behavior of the purified spliceosome, we developed a principal component analysis-based approach. Calculating the energy landscape revealed eight major conformational states, which we refined to higher resolution. Conformational differences of the highly flexible structural components between these eight states reveal how spliceosomal components contribute to the assembly of the spliceosome, allowing it to generate a dynamic interaction network required for its subsequent catalytic activation.
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Affiliation(s)
- David Haselbach
- Department for Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ilya Komarov
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Dmitry E Agafonov
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Klaus Hartmuth
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Benjamin Graf
- Department for Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Olexandr Dybkov
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytic Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37073 Göttingen, Germany
| | - Berthold Kastner
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Reinhard Lührmann
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Holger Stark
- Department for Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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7
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Chen M, Xu R, Ji H, Greening DW, Rai A, Izumikawa K, Ishikawa H, Takahashi N, Simpson RJ. Transcriptome and long noncoding RNA sequencing of three extracellular vesicle subtypes released from the human colon cancer LIM1863 cell line. Sci Rep 2016; 6:38397. [PMID: 27917920 PMCID: PMC5137021 DOI: 10.1038/srep38397] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/08/2016] [Indexed: 12/24/2022] Open
Abstract
Previously we reported that LIM1863 colorectal cancer (CRC) cells secrete three distinct extracellular vesicle subtypes – two subpopulations of exosomes (apical EpCAM-Exos and basolateral A33-Exos) and shed microvesicles (sMVs) – with distinct protein and miRNA signatures. Here, we extend our omics approach to understand the fundamental role of LIM1863-derived EVs by performing a comprehensive analysis of their mRNAs and long non-coding RNAs (lncRNAs) using RNA-Seq. We show that 2,389 mRNAs, 317 pseudogene transcripts, 1,028 lncRNAs and 206 short non-coding RNAs selectively distributed to (i.e., are enriched in) LIM1863 EVs, relative to the parent cell. An Ensembl/UniProtKB analysis revealed 1,937 mRNAs encode canonical proteins, 348 isoforms (including splice-variant proteins), and 119 ‘missing proteins’ (i.e., annotated in Ensembl but not UniProtKB). Further dissection of our protein/RNA data revealed that 6/151 observed RNA binding proteins have the potential to interact with ~75% of EV-enriched RNAs. Intriguingly, the co-existence of U1 and U2 ribonucleoproteins and their cognate snRNAs in LIM1863 EVs suggests a possible association of CRC EVs with recipient cell splicing events. Our data reveal several potential lncRNA CRC biomarkers and novel splicing/fusion genes that, collectively, will advance our understanding of EV biology in CRC and accelerate the development of EV-based diagnostics and therapeutics.
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Affiliation(s)
- Maoshan Chen
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia
| | - Rong Xu
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia
| | - Hong Ji
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia
| | - David W Greening
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia
| | - Alin Rai
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia
| | - Keiichi Izumikawa
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.,Global Innovation Research Organisation, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Hideaki Ishikawa
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.,Global Innovation Research Organisation, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Nobuhiro Takahashi
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.,Global Innovation Research Organisation, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Richard J Simpson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia.,Global Innovation Research Organisation, Tokyo University of Agriculture and Technology, Tokyo, Japan
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8
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Kuwasako K, Nameki N, Tsuda K, Takahashi M, Sato A, Tochio N, Inoue M, Terada T, Kigawa T, Kobayashi N, Shirouzu M, Ito T, Sakamoto T, Wakamatsu K, Güntert P, Takahashi S, Yokoyama S, Muto Y. Solution structure of the first RNA recognition motif domain of human spliceosomal protein SF3b49 and its mode of interaction with a SF3b145 fragment. Protein Sci 2016; 26:280-291. [PMID: 27862552 PMCID: PMC5275738 DOI: 10.1002/pro.3080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 01/17/2023]
Abstract
The spliceosomal protein SF3b49, a component of the splicing factor 3b (SF3b) protein complex in the U2 small nuclear ribonucleoprotein, contains two RNA recognition motif (RRM) domains. In yeast, the first RRM domain (RRM1) of Hsh49 protein (yeast orthologue of human SF3b49) reportedly interacts with another component, Cus1 protein (orthologue of human SF3b145). Here, we solved the solution structure of the RRM1 of human SF3b49 and examined its mode of interaction with a fragment of human SF3b145 using NMR methods. Chemical shift mapping showed that the SF3b145 fragment spanning residues 598–631 interacts with SF3b49 RRM1, which adopts a canonical RRM fold with a topology of β1‐α1‐β2‐β3‐α2‐β4. Furthermore, a docking model based on NOESY measurements suggests that residues 607–616 of the SF3b145 fragment adopt a helical structure that binds to RRM1 predominantly via α1, consequently exhibiting a helix–helix interaction in almost antiparallel. This mode of interaction was confirmed by a mutational analysis using GST pull‐down assays. Comparison with structures of all RRM domains when complexed with a peptide found that this helix–helix interaction is unique to SF3b49 RRM1. Additionally, all amino acid residues involved in the interaction are well conserved among eukaryotes, suggesting evolutionary conservation of this interaction mode between SF3b49 RRM1 and SF3b145. PDB Code(s): 5GVQ
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Affiliation(s)
- Kanako Kuwasako
- Faculty of Pharmacy and Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo, Tokyo, 202-8585, Japan.,RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Nobukazu Nameki
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515, Japan
| | - Kengo Tsuda
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Mari Takahashi
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Atsuko Sato
- Department of Chemical & Biological Sciences, Japan Women's University, Mejirodai, Bunkyo, Tokyo, 112-8681, Japan
| | - Naoya Tochio
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan
| | - Makoto Inoue
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Takaho Terada
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Takanori Kigawa
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Naohiro Kobayashi
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Mikako Shirouzu
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Takuhiro Ito
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Taiichi Sakamoto
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba, 275-0016, Japan
| | - Kaori Wakamatsu
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515, Japan
| | - Peter Güntert
- Tatsuo Miyazawa Memorial Program, RIKEN Genomic Sciences Center, Yokohama, 230-0045, Japan.,Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, and Frankfurt Institute of Advanced Studies, Goethe University Frankfurt, Max-von-Laue-Str, Frankfurt am Main, 60438, Germany
| | - Seizo Takahashi
- Department of Chemical & Biological Sciences, Japan Women's University, Mejirodai, Bunkyo, Tokyo, 112-8681, Japan
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Yutaka Muto
- Faculty of Pharmacy and Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo, Tokyo, 202-8585, Japan.,RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.,RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
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9
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Zuo ZH, Yu YP, Martin A, Luo JH. Cellular stress response 1 down-regulates the expression of epidermal growth factor receptor and platelet-derived growth factor receptor through inactivation of splicing factor 3A3. Mol Carcinog 2016; 56:315-324. [PMID: 27148859 DOI: 10.1002/mc.22494] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/19/2016] [Accepted: 04/13/2016] [Indexed: 12/19/2022]
Abstract
Cellular stress response 1 (CSR1) is a tumor suppressor gene that plays an important role in regulating cell death. In this report, we show that the N-terminus of CSR1 interacts with splicing factor 3A, subunit 3 (SF3A3). The SF3A3 binding motif was identified in the region of amino acids 62-91 of CSR1 through cell-free binding analyses. The interaction between CSR1 and SF3A3 led to migration of SF3A3 from nucleus to cytoplasm. The cytoplasmic redistribution of SF3A3 significantly reduced the splicing efficiency of epidermal growth factor receptor and platelet-derived growth factor receptor. Induction of CSR1 or down-regulation of SF3A3 also significantly reduced the splicing activity of oxytocin reporter gene both in vivo and in vitro. Mutant CSR1 that lacks the SF3A3 binding motif contained no RNA splicing regulatory activity, while the peptide corresponding to the SF3A3 binding motif in CSR1 interfered with the wild-type CSR1 mediated inhibition of RNA splicing. Interaction of CSR1 and SF3A3 is essential for CSR1 mediated cell death. To our knowledge, this is the first report demonstrating that RNA splicing is negatively regulated by redistribution of a splicing factor. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ze-Hua Zuo
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Yan P Yu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Amantha Martin
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jian-Hua Luo
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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10
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Crisci A, Raleff F, Bagdiul I, Raabe M, Urlaub H, Rain JC, Krämer A. Mammalian splicing factor SF1 interacts with SURP domains of U2 snRNP-associated proteins. Nucleic Acids Res 2015; 43:10456-73. [PMID: 26420826 PMCID: PMC4666396 DOI: 10.1093/nar/gkv952] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 09/10/2015] [Indexed: 02/03/2023] Open
Abstract
Splicing factor 1 (SF1) recognizes the branch point sequence (BPS) at the 3′ splice site during the formation of early complex E, thereby pre-bulging the BPS adenosine, thought to facilitate subsequent base-pairing of the U2 snRNA with the BPS. The 65-kDa subunit of U2 snRNP auxiliary factor (U2AF65) interacts with SF1 and was shown to recruit the U2 snRNP to the spliceosome. Co-immunoprecipitation experiments of SF1-interacting proteins from HeLa cell extracts shown here are consistent with the presence of SF1 in early splicing complexes. Surprisingly almost all U2 snRNP proteins were found associated with SF1. Yeast two-hybrid screens identified two SURP domain-containing U2 snRNP proteins as partners of SF1. A short, evolutionarily conserved region of SF1 interacts with the SURP domains, stressing their role in protein–protein interactions. A reduction of A complex formation in SF1-depleted extracts could be rescued with recombinant SF1 containing the SURP-interaction domain, but only partial rescue was observed with SF1 lacking this sequence. Thus, SF1 can initially recruit the U2 snRNP to the spliceosome during E complex formation, whereas U2AF65 may stabilize the association of the U2 snRNP with the spliceosome at later times. In addition, these findings may have implications for alternative splicing decisions.
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Affiliation(s)
- Angela Crisci
- Department of Cell Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Flore Raleff
- Department of Cell Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Ivona Bagdiul
- Department of Cell Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Monika Raabe
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany Bioanalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, D-37075 Göttingen, Germany
| | | | - Angela Krämer
- Department of Cell Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
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11
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Kuwasako K, Takahashi M, Unzai S, Tsuda K, Yoshikawa S, He F, Kobayashi N, Güntert P, Shirouzu M, Ito T, Tanaka A, Yokoyama S, Hagiwara M, Kuroyanagi H, Muto Y. RBFOX and SUP-12 sandwich a G base to cooperatively regulate tissue-specific splicing. Nat Struct Mol Biol 2014; 21:778-86. [DOI: 10.1038/nsmb.2870] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/14/2014] [Indexed: 12/25/2022]
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12
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Nyambega B, Helbig C, Masiga DK, Clayton C, Levin MJ. Proteins associated with SF3a60 in T. brucei. PLoS One 2014; 9:e91956. [PMID: 24651488 PMCID: PMC3961280 DOI: 10.1371/journal.pone.0091956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 02/18/2014] [Indexed: 12/29/2022] Open
Abstract
Trypanosoma brucei relies on Spliced leader trans splicing to generate functional messenger RNAs. Trans splicing joins the specialized SL exon from the SL RNA to pre-mRNAs and is mediated by the trans-spliceosome, which is made up of small nuclear ribonucleoprotein particles and non-snRNP factors. Although the trans spliceosome is essential for trypanosomatid gene expression, not all spliceosomal protein factors are known and of these, only a few are completely characterized. In this study, we have characterized the trypanosome Splicing Factor, SF3a60, the only currently annotated SF3a component. As expected, epitope-tagged SF3a60 localizes in the trypanosome nucleus. SF3a60 is essential for cell viability but its depletion seem to have no detectable effect on trans-splicing. In addition, we used SF3a60 as bait in a Yeast-2-hybrid system screen and identified its interacting protein factors. The interactions with SF3a120, SF3a66 and SAP130 were confirmed by tandem affinity purification and mass spectrometry.
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Affiliation(s)
- Benson Nyambega
- Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigacíones en Ingeniería Genética y Biología Molecular (INGEBI), Buenos Aires, Argentina
- Molecular Biology and Biotechnology Department, International Center for Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Claudia Helbig
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Daniel K. Masiga
- Molecular Biology and Biotechnology Department, International Center for Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Mariano J. Levin
- Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigacíones en Ingeniería Genética y Biología Molecular (INGEBI), Buenos Aires, Argentina
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13
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Lin-Moshier Y, Sebastian PJ, Higgins L, Sampson ND, Hewitt JE, Marchant JS. Re-evaluation of the role of calcium homeostasis endoplasmic reticulum protein (CHERP) in cellular calcium signaling. J Biol Chem 2013; 288:355-67. [PMID: 23148228 PMCID: PMC3537033 DOI: 10.1074/jbc.m112.405761] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/31/2012] [Indexed: 11/06/2022] Open
Abstract
Changes in cytoplasmic Ca(2+) concentration, resulting from activation of intracellular Ca(2+) channels within the endoplasmic reticulum, regulate several aspects of cellular growth and differentiation. Ca(2+) homeostasis endoplasmic reticulum protein (CHERP) is a ubiquitously expressed protein that has been proposed as a regulator of both major families of endoplasmic reticulum Ca(2+) channels, inositol 1,4,5-trisphosphate receptors (IP(3)Rs) and ryanodine receptors (RyRs), with resulting effects on mitotic cycling. However, the manner by which CHERP regulates intracellular Ca(2+) channels to impact cellular growth is unknown. Here, we challenge previous findings that CHERP acts as a direct cytoplasmic regulator of IP(3)Rs and RyRs and propose that CHERP acts in the nucleus to impact cellular proliferation by regulating the function of the U2 snRNA spliceosomal complex. The previously reported effects of CHERP on cellular growth therefore are likely indirect effects of altered spliceosomal function, consistent with prior data showing that loss of function of U2 snRNP components can interfere with cell growth and induce cell cycle arrest.
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Affiliation(s)
| | | | - LeeAnn Higgins
- Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455 and
| | - Natalie D. Sampson
- the School of Biology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Jane E. Hewitt
- the School of Biology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom
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14
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Korneta I, Bujnicki JM. Intrinsic disorder in the human spliceosomal proteome. PLoS Comput Biol 2012; 8:e1002641. [PMID: 22912569 PMCID: PMC3415423 DOI: 10.1371/journal.pcbi.1002641] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 06/16/2012] [Indexed: 12/11/2022] Open
Abstract
The spliceosome is a molecular machine that performs the excision of introns from eukaryotic pre-mRNAs. This macromolecular complex comprises in human cells five RNAs and over one hundred proteins. In recent years, many spliceosomal proteins have been found to exhibit intrinsic disorder, that is to lack stable native three-dimensional structure in solution. Building on the previous body of proteomic, structural and functional data, we have carried out a systematic bioinformatics analysis of intrinsic disorder in the proteome of the human spliceosome. We discovered that almost a half of the combined sequence of proteins abundant in the spliceosome is predicted to be intrinsically disordered, at least when the individual proteins are considered in isolation. The distribution of intrinsic order and disorder throughout the spliceosome is uneven, and is related to the various functions performed by the intrinsic disorder of the spliceosomal proteins in the complex. In particular, proteins involved in the secondary functions of the spliceosome, such as mRNA recognition, intron/exon definition and spliceosomal assembly and dynamics, are more disordered than proteins directly involved in assisting splicing catalysis. Conserved disordered regions in spliceosomal proteins are evolutionarily younger and less widespread than ordered domains of essential spliceosomal proteins at the core of the spliceosome, suggesting that disordered regions were added to a preexistent ordered functional core. Finally, the spliceosomal proteome contains a much higher amount of intrinsic disorder predicted to lack secondary structure than the proteome of the ribosome, another large RNP machine. This result agrees with the currently recognized different functions of proteins in these two complexes.
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Affiliation(s)
- Iga Korneta
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Janusz M. Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Bioinformatics Laboratory, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
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15
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Structure and assembly of the SF3a splicing factor complex of U2 snRNP. EMBO J 2012; 31:1579-90. [PMID: 22314233 DOI: 10.1038/emboj.2012.7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 01/03/2012] [Indexed: 11/08/2022] Open
Abstract
SF3a is an evolutionarily conserved heterotrimeric complex essential for pre-mRNA splicing. It functions in spliceosome assembly within the mature U2 snRNP (small nuclear ribonucleoprotein particle), and its displacement from the spliceosome initiates the first step of the splicing reaction. We have identified a core domain of the yeast SF3a complex required for complex assembly and determined its crystal structure. The structure shows a bifurcated assembly of three subunits, Prp9, Prp11 and Prp21, with Prp9 interacting with Prp21 via a bidentate-binding mode, and Prp21 wrapping around Prp11. Structure-guided biochemical analysis also shows that Prp9 harbours a major binding site for stem-loop IIa of U2 snRNA. These findings provide mechanistic insights into the assembly of U2 snRNP.
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16
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Huang CJ, Ferfoglia F, Raleff F, Krämer A. Interaction domains and nuclear targeting signals in subunits of the U2 small nuclear ribonucleoprotein particle-associated splicing factor SF3a. J Biol Chem 2011; 286:13106-14. [PMID: 21349847 DOI: 10.1074/jbc.m110.201491] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Human splicing factor SF3a is a component of the mature U2 small nuclear ribonucleoprotein particle (snRNP) and its three subunits of 60, 66, and 120 kDa are essential for splicing in vitro and in vivo. The SF3a heterotrimer forms in the cytoplasm and enters the nucleus independently of the U2 snRNP. Here, we have analyzed domains required for in vitro interactions between the SF3a subunits. Our results indicate that the SF3a66-SF3a120 interaction is mediated by a 27-amino acid region in SF3a120 C-terminal to the second suppressor-of-white-apricot and prp21/spp91 domain and amino acids 108-210 of SF3a66. Neither of these sequences contains known structural motifs, suggesting that the interaction domains are novel. Moreover, an ∼100-amino acid region, including the SURP2 domain of SF3a120 but extending into neighboring regions, is sufficient for binding to SF3a60. Analysis of determinants for nuclear import of SF3a demonstrates that SF3a120 provides the major nuclear localization signal and SF3a60 contributes to nuclear import.
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Affiliation(s)
- Ching-Jung Huang
- Department of Cell Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
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17
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Jurica MS. Detailed close-ups and the big picture of spliceosomes. Curr Opin Struct Biol 2008; 18:315-20. [PMID: 18550358 DOI: 10.1016/j.sbi.2008.05.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 05/08/2008] [Accepted: 05/13/2008] [Indexed: 02/04/2023]
Abstract
The spliceosome is the huge macromolecular assembly responsible for the removal of introns from pre-mRNA transcripts. The size and complexity of this dynamic cellular machine dictate that structural analysis of the spliceosome is best served by a combination of techniques. Electron microscopy is providing a more global, albeit less detailed, view of spliceosome assemblies. X-ray crystallographers and NMR spectroscopists are steadily reporting more atomic resolution structures of individual spliceosome components and fragments. Increasingly, structures of these individual pieces in complex with binding partners are yielding insights into the interfaces that hold the entire spliceosome assembly together. Although the information arising from the various structural studies of splicing machinery has not yet fully converged into a complete model, we can expect that a detailed understanding of spliceosome structure will arise at the juncture of structural and computational modeling methods.
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Affiliation(s)
- Melissa S Jurica
- Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California Santa Cruz, CA 95064, United States.
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18
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Bonet R, Ramirez-Espain X, Macias MJ. Solution structure of the yeast URN1 splicing factor FF domain: Comparative analysis of charge distributions in FF domain structures-FFs and SURPs, two domains with a similar fold. Proteins 2008; 73:1001-9. [DOI: 10.1002/prot.22127] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Kuwasako K, Takahashi M, Tochio N, Abe C, Tsuda K, Inoue M, Terada T, Shirouzu M, Kobayashi N, Kigawa T, Taguchi S, Tanaka A, Hayashizaki Y, Güntert P, Muto Y, Yokoyama S. Solution structure of the second RNA recognition motif (RRM) domain of murine T cell intracellular antigen-1 (TIA-1) and its RNA recognition mode. Biochemistry 2008; 47:6437-50. [PMID: 18500819 DOI: 10.1021/bi7024723] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
T cell intracellular antigen-1 (TIA-1), an apoptosis promoting factor, functions as a splicing regulator for the Fas pre-mRNA. TIA-1 possesses three RNA recognition motifs (RRMs) and a glutamine-rich domain. The second RRM (RRM2) is necessary and sufficient for tight, sequence-specific binding to the uridine-rich sequences buried around the 5' splice sites. In the present study, we solved the solution structure of the murine TIA-1 RRM2 by heteronuclear-nuclear magnetic resonance spectroscopy. The TIA-1 RRM2 adopts the RRM fold (betaalphabetabetaalphabeta) and possesses an extra beta-strand between beta2 and beta3, which forms an additional beta-sheet with the C-terminal part of beta2. We refer to this structure as the beta2-beta2' beta-loop. Interestingly, this characteristic beta-loop structure is conserved among a number of RRMs, including the U2AF65 RRM2 and the Sex-lethal RRM1 and RRM2, which also bind to uridine-rich RNAs. Furthermore, we identified a new sequence motif in the beta2-beta2' beta-loop, the DxxT motif. Chemical shift perturbation analyses of both the main and side chains upon binding to the uridine pentamer RNA revealed that most of the beta-sheet surface, including the beta2-beta2' beta-loop, is involved in the RNA binding. An investigation of the chemical shift perturbation revealed similarity in the RNA recognition modes between the TIA-1 and U2AF65 RRMs.
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Affiliation(s)
- Kanako Kuwasako
- Protein Research Group, Genomic Sciences Center, Yokohama Institute, RIKEN, Tsurumi-ku, Yokohama 230-0045, Japan
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20
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Kuwasako K, Dohmae N, Inoue M, Shirouzu M, Taguchi S, Güntert P, Séraphin B, Muto Y, Yokoyama S. Complex assembly mechanism and an RNA-binding mode of the human p14-SF3b155 spliceosomal protein complex identified by NMR solution structure and functional analyses. Proteins 2007; 71:1617-36. [DOI: 10.1002/prot.21839] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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