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Aich M, Ansari AH, Ding L, Iesmantavicius V, Paul D, Choudhary C, Maiti S, Buchholz F, Chakraborty D. TOBF1 modulates mouse embryonic stem cell fate through regulating alternative splicing of pluripotency genes. Cell Rep 2023; 42:113177. [PMID: 37751355 DOI: 10.1016/j.celrep.2023.113177] [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: 02/08/2023] [Revised: 06/28/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023] Open
Abstract
Embryonic stem cells (ESCs) can undergo lineage-specific differentiation, giving rise to different cell types that constitute an organism. Although roles of transcription factors and chromatin modifiers in these cells have been described, how the alternative splicing (AS) machinery regulates their expression has not been sufficiently explored. Here, we show that the long non-coding RNA (lncRNA)-associated protein TOBF1 modulates the AS of transcripts necessary for maintaining stem cell identity in mouse ESCs. Among the genes affected is serine/arginine splicing factor 1 (SRSF1), whose AS leads to global changes in splicing and expression of a large number of downstream genes involved in the maintenance of ESC pluripotency. By overlaying information derived from TOBF1 chromatin occupancy, the distribution of its pluripotency-associated OCT-SOX binding motifs, and transcripts undergoing differential expression and AS upon its knockout, we describe local nuclear territories where these distinct events converge. Collectively, these contribute to the maintenance of mouse ESC identity.
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Affiliation(s)
- Meghali Aich
- CSIR- Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Asgar Hussain Ansari
- CSIR- Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Li Ding
- Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
| | - Vytautas Iesmantavicius
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Deepanjan Paul
- CSIR- Institute of Genomics and Integrative Biology, New Delhi 110025, India
| | - Chunaram Choudhary
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Souvik Maiti
- CSIR- Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Frank Buchholz
- Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
| | - Debojyoti Chakraborty
- CSIR- Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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2
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Sharma A, Mistriel-Zerbib S, Najar RA, Engal E, Bentata M, Taqatqa N, Dahan S, Cohen K, Jaffe-Herman S, Geminder O, Baker M, Nevo Y, Plaschkes I, Kay G, Drier Y, Berger M, Salton M. Isoforms of the TAL1 transcription factor have different roles in hematopoiesis and cell growth. PLoS Biol 2023; 21:e3002175. [PMID: 37379322 DOI: 10.1371/journal.pbio.3002175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/30/2023] [Indexed: 06/30/2023] Open
Abstract
T-cell acute lymphoblastic leukemia (T-ALL) protein 1 (TAL1) is a central transcription factor in hematopoiesis. The timing and level of TAL1 expression orchestrate the differentiation to specialized blood cells and its overexpression is a common cause of T-ALL. Here, we studied the 2 protein isoforms of TAL1, short and long, which are generated by the use of alternative promoters as well as by alternative splicing. We analyzed the expression of each isoform by deleting an enhancer or insulator, or by opening chromatin at the enhancer location. Our results show that each enhancer promotes expression from a specific TAL1 promoter. Expression from a specific promoter gives rise to a unique 5' UTR with differential regulation of translation. Moreover, our study suggests that the enhancers regulate TAL1 exon 3 alternative splicing by inducing changes in the chromatin at the splice site, which we demonstrate is mediated by KMT2B. Furthermore, our results indicate that TAL1-short binds more strongly to TAL1 E-protein partners and functions as a stronger transcription factor than TAL1-long. Specifically TAL1-short has a unique transcription signature promoting apoptosis. Finally, when we expressed both isoforms in mice bone marrow, we found that while overexpression of both isoforms prevents lymphoid differentiation, expression of TAL-short alone leads to hematopoietic stem cell exhaustion. Furthermore, we found that TAL1-short promoted erythropoiesis and reduced cell survival in the CML cell line K562. While TAL1 and its partners are considered promising therapeutic targets in the treatment of T-ALL, our results show that TAL1-short could act as a tumor suppressor and suggest that altering TAL1 isoform's ratio could be a preferred therapeutic approach.
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Affiliation(s)
- Aveksha Sharma
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shani Mistriel-Zerbib
- Faculty of Medicine, The Lautenberg Center for Immunology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rauf Ahmad Najar
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eden Engal
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mercedes Bentata
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nadeen Taqatqa
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sara Dahan
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Klil Cohen
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shiri Jaffe-Herman
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ophir Geminder
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mai Baker
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Nevo
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Inbar Plaschkes
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gillian Kay
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yotam Drier
- Faculty of Medicine, The Lautenberg Center for Immunology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michael Berger
- Faculty of Medicine, The Lautenberg Center for Immunology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maayan Salton
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
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3
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Terrone S, Valat J, Fontrodona N, Giraud G, Claude JB, Combe E, Lapendry A, Polvèche H, Ameur LB, Duvermy A, Modolo L, Bernard P, Mortreux F, Auboeuf D, Bourgeois C. RNA helicase-dependent gene looping impacts messenger RNA processing. Nucleic Acids Res 2022; 50:9226-9246. [PMID: 36039747 PMCID: PMC9458439 DOI: 10.1093/nar/gkac717] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 07/25/2022] [Accepted: 08/25/2022] [Indexed: 12/24/2022] Open
Abstract
DDX5 and DDX17 are DEAD-box RNA helicase paralogs which regulate several aspects of gene expression, especially transcription and splicing, through incompletely understood mechanisms. A transcriptome analysis of DDX5/DDX17-depleted human cells confirmed the large impact of these RNA helicases on splicing and revealed a widespread deregulation of 3' end processing. In silico analyses and experiments in cultured cells showed the binding and functional contribution of the genome organizing factor CTCF to chromatin sites at or near a subset of DDX5/DDX17-dependent exons that are characterized by a high GC content and a high density of RNA Polymerase II. We propose the existence of an RNA helicase-dependent relationship between CTCF and the dynamics of transcription across DNA and/or RNA structured regions, that contributes to the processing of internal and terminal exons. Moreover, local DDX5/DDX17-dependent chromatin loops spatially connect RNA helicase-regulated exons with their cognate promoter, and we provide the first direct evidence that de novo gene looping modifies alternative splicing and polyadenylation. Overall our findings uncover the impact of DDX5/DDX17-dependent chromatin folding on pre-messenger RNA processing.
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Affiliation(s)
| | | | - Nicolas Fontrodona
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | | | - Jean-Baptiste Claude
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | | | - Audrey Lapendry
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Hélène Polvèche
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France,CECS/AFM, I-STEM, 28 rue Henri Desbruères, F-91100, Corbeil-Essonnes, France
| | - Lamya Ben Ameur
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Arnaud Duvermy
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Laurent Modolo
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Pascal Bernard
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Franck Mortreux
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Didier Auboeuf
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Cyril F Bourgeois
- To whom correspondence should be addressed. Tel: +33 47272 8663; Fax: +33 47272 8674;
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4
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Gañez-Zapater A, Mackowiak SD, Guo Y, Tarbier M, Jordán-Pla A, Friedländer MR, Visa N, Östlund Farrants AK. The SWI/SNF subunit BRG1 affects alternative splicing by changing RNA binding factor interactions with nascent RNA. Mol Genet Genomics 2022; 297:463-484. [PMID: 35187582 PMCID: PMC8960663 DOI: 10.1007/s00438-022-01863-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/23/2022] [Indexed: 11/29/2022]
Abstract
BRG1 and BRM are ATPase core subunits of the human SWI/SNF chromatin remodelling complexes mainly associated with transcriptional initiation. They also have a role in alternative splicing, which has been shown for BRM-containing SWI/SNF complexes at a few genes. Here, we have identified a subset of genes which harbour alternative exons that are affected by SWI/SNF ATPases by expressing the ATPases BRG1 and BRM in C33A cells, a BRG1- and BRM-deficient cell line, and analysed the effect on splicing by RNA sequencing. BRG1- and BRM-affected sub-sets of genes favouring both exon inclusion and exon skipping, with only a minor overlap between the ATPase. Some of the changes in alternative splicing induced by BRG1 and BRM expression did not require the ATPase activity. The BRG1-ATPase independent included exons displayed an exon signature of a high GC content. By investigating three genes with exons affected by the BRG-ATPase-deficient variant, we show that these exons accumulated phosphorylated RNA pol II CTD, both serine 2 and serine 5 phosphorylation, without an enrichment of the RNA polymerase II. The ATPases were recruited to the alternative exons, together with both core and signature subunits of SWI/SNF complexes, and promoted the binding of RNA binding factors to chromatin and RNA at the alternative exons. The interaction with the nascent RNP, however, did not reflect the association to chromatin. The hnRNPL, hnRNPU and SAM68 proteins associated with chromatin in cells expressing BRG1 and BRM wild type, but the binding of hnRNPU to the nascent RNP was excluded. This suggests that SWI/SNF can regulate alternative splicing by interacting with splicing-RNA binding factor and influence their binding to the nascent pre-mRNA particle.
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Affiliation(s)
- Antoni Gañez-Zapater
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, The Arrhenius Laboratories F4, 106 91, Stockholm, Sweden
- Center for Genomic Regulation, 08003, Barcelona, Spain
| | - Sebastian D Mackowiak
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91, Stockholm, Sweden
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195, Berlin, Germany
| | - Yuan Guo
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, The Arrhenius Laboratories F4, 106 91, Stockholm, Sweden
| | - Marcel Tarbier
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91, Stockholm, Sweden
| | - Antonio Jordán-Pla
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, The Arrhenius Laboratories F4, 106 91, Stockholm, Sweden
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencies Biológicas, Valencia University, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - Marc R Friedländer
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91, Stockholm, Sweden
| | - Neus Visa
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, The Arrhenius Laboratories F4, 106 91, Stockholm, Sweden
| | - Ann-Kristin Östlund Farrants
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, The Arrhenius Laboratories F4, 106 91, Stockholm, Sweden.
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5
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Alharbi AB, Schmitz U, Bailey CG, Rasko JEJ. CTCF as a regulator of alternative splicing: new tricks for an old player. Nucleic Acids Res 2021; 49:7825-7838. [PMID: 34181707 PMCID: PMC8373115 DOI: 10.1093/nar/gkab520] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/01/2021] [Accepted: 06/10/2021] [Indexed: 12/15/2022] Open
Abstract
Three decades of research have established the CCCTC-binding factor (CTCF) as a ubiquitously expressed chromatin organizing factor and master regulator of gene expression. A new role for CTCF as a regulator of alternative splicing (AS) has now emerged. CTCF has been directly and indirectly linked to the modulation of AS at the individual transcript and at the transcriptome-wide level. The emerging role of CTCF-mediated regulation of AS involves diverse mechanisms; including transcriptional elongation, DNA methylation, chromatin architecture, histone modifications, and regulation of splicing factor expression and assembly. CTCF thereby appears to not only co-ordinate gene expression regulation but contributes to the modulation of transcriptomic complexity. In this review, we highlight previous discoveries regarding the role of CTCF in AS. In addition, we summarize detailed mechanisms by which CTCF mediates AS regulation. We propose opportunities for further research designed to examine the possible fate of CTCF-mediated alternatively spliced genes and associated biological consequences. CTCF has been widely acknowledged as the 'master weaver of the genome'. Given its multiple connections, further characterization of CTCF's emerging role in splicing regulation might extend its functional repertoire towards a 'conductor of the splicing orchestra'.
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Affiliation(s)
- Adel B Alharbi
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Computational BioMedicine Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Faculty of Medicine & Health, The University of Sydney, NSW 2006, Australia
- Cancer & Gene Regulation Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
| | - Ulf Schmitz
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Computational BioMedicine Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Faculty of Medicine & Health, The University of Sydney, NSW 2006, Australia
| | - Charles G Bailey
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Faculty of Medicine & Health, The University of Sydney, NSW 2006, Australia
- Cancer & Gene Regulation Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
| | - John E J Rasko
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW 2050, Australia
- Faculty of Medicine & Health, The University of Sydney, NSW 2006, Australia
- Cell & Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
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6
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Devailly G, Joshi A. Comprehensive analysis of epigenetic signatures of human transcription control. Mol Omics 2021; 17:692-705. [PMID: 34291238 DOI: 10.1039/d0mo00130a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Advances in sequencing technologies have enabled exploration of epigenetic and transcriptional profiles at a genome-wide level. The epigenetic and transcriptional landscapes are now available in hundreds of mammalian cell and tissue contexts. Many studies have performed multi-omics analyses using these datasets to enhance our understanding of relationships between epigenetic modifications and transcription regulation. Nevertheless, most studies so far have focused on the promoters/enhancers and transcription start sites, and other features of transcription control including exons, introns and transcription termination remain underexplored. We investigated the interplay between epigenetic modifications and diverse transcription features using the data generated by the Roadmap Epigenomics project. A comprehensive analysis of histone modifications, DNA methylation, and RNA-seq data of thirty-three human cell lines and tissue types allowed us to confirm the generality of previously described relationships, as well as to generate new hypotheses about the interplay between epigenetic modifications and transcription features. Importantly, our analysis included previously under-explored features of transcription control, namely, transcription termination sites, exon-intron boundaries, and the exon inclusion ratio. We have made the analyses freely available to the scientific community at joshiapps.cbu.uib.no/perepigenomics_app/ for easy exploration, validation and hypothesis generation.
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Affiliation(s)
- Guillaume Devailly
- GenPhySE, Université de Toulouse, INRAE, ENVT, 31326, Castanet Tolosan, France.
| | - Anagha Joshi
- Computational Biology Unit, Department of Clinical Science, University of Bergen, 5021, Bergen, Norway.
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7
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Agirre E, Oldfield AJ, Bellora N, Segelle A, Luco RF. Splicing-associated chromatin signatures: a combinatorial and position-dependent role for histone marks in splicing definition. Nat Commun 2021; 12:682. [PMID: 33514745 PMCID: PMC7846797 DOI: 10.1038/s41467-021-20979-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/05/2021] [Indexed: 12/14/2022] Open
Abstract
Alternative splicing relies on the combinatorial recruitment of splicing regulators to specific RNA binding sites. Chromatin has been shown to impact this recruitment. However, a limited number of histone marks have been studied at a global level. In this work, a machine learning approach, applied to extensive epigenomics datasets in human H1 embryonic stem cells and IMR90 foetal fibroblasts, has identified eleven chromatin modifications that differentially mark alternatively spliced exons depending on the level of exon inclusion. These marks act in a combinatorial and position-dependent way, creating characteristic splicing-associated chromatin signatures (SACS). In support of a functional role for SACS in coordinating splicing regulation, changes in the alternative splicing of SACS-marked exons between ten different cell lines correlate with changes in SACS enrichment levels and recruitment of the splicing regulators predicted by RNA motif search analysis. We propose the dynamic nature of chromatin modifications as a mechanism to rapidly fine-tune alternative splicing when necessary. Chromatin is known to regulate splicing by modulating recruitment of splicing factors. Using machine learning approaches, the authors have underlined a chromatin code for alternative splicing regulation that is conserved amongst cell lines.
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Affiliation(s)
- E Agirre
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34000, Montpellier, France.,Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - A J Oldfield
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34000, Montpellier, France
| | - N Bellora
- Institute of Nuclear Technologies for Health (INTECNUS), National Scientific and Technical Research Council (CONICET), Bariloche, 8400, Argentina
| | - A Segelle
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34000, Montpellier, France
| | - R F Luco
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34000, Montpellier, France.
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Sun X, Tian Y, Wang J, Sun Z, Zhu Y. Genome-wide analysis reveals the association between alternative splicing and DNA methylation across human solid tumors. BMC Med Genomics 2020; 13:4. [PMID: 31906954 PMCID: PMC6945449 DOI: 10.1186/s12920-019-0654-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 12/24/2019] [Indexed: 12/13/2022] Open
Abstract
Background Dysregulation of alternative splicing (AS) is a critical signature of cancer. However, the regulatory mechanisms of cancer-specific AS events, especially the impact of DNA methylation, are poorly understood. Methods By using The Cancer Genome Atlas (TCGA) SpliceSeq and TCGA data for ten solid tumor types, association analysis was performed to characterize the potential link between cancer-specific AS and DNA methylation. Functional and pathway enrichment analyses were performed, and the protein-protein interaction (PPI) network was constructed with the String website. The prognostic analysis was carried out with multivariate Cox regressions models. Results 15,818 AS events in 3955 annotated genes were identified across ten solid tumor types. The different DNA methylation patterns between tumor and normal tissues at the corresponding alternative spliced exon boundaries were shown, and 51.3% of CpG sites (CpGs) revealed hypomethylated in tumors. Notably, 607 CpGs were found to be highly correlated with 369 cancer-specific AS events after permutation tests. Among them, the hypomethylated CpGs account for 52.7%, and the number of down-regulated exons was 173. Furthermore, we found 38 AS events in 35 genes could serve as new molecular biomarkers to predict patient survival. Conclusions Our study described the relationship between DNA methylation and AS events across ten human solid tumor types and provided new insights into intragenic DNA methylation and exon usage during the AS process.
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Affiliation(s)
- Xiaohui Sun
- Department of Epidemiology & Biostatistics, School of Public Health, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Yiping Tian
- Department of Pathology, Zhejiang Cancer Hospital, Hangzhou, 310022, China
| | - Jianming Wang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, 08901, USA
| | - Zeyuan Sun
- Department of Health Related Social and Behavioral Science, West China School of Public Health, Sichuan University, Chengdu, 610041, China
| | - Yimin Zhu
- Department of Epidemiology & Biostatistics, School of Public Health, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
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9
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Krchňáková Z, Thakur PK, Krausová M, Bieberstein N, Haberman N, Müller-McNicoll M, Staněk D. Splicing of long non-coding RNAs primarily depends on polypyrimidine tract and 5' splice-site sequences due to weak interactions with SR proteins. Nucleic Acids Res 2019; 47:911-928. [PMID: 30445574 PMCID: PMC6344860 DOI: 10.1093/nar/gky1147] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 10/26/2018] [Accepted: 10/30/2018] [Indexed: 12/20/2022] Open
Abstract
Many nascent long non-coding RNAs (lncRNAs) undergo the same maturation steps as pre-mRNAs of protein-coding genes (PCGs), but they are often poorly spliced. To identify the underlying mechanisms for this phenomenon, we searched for putative splicing inhibitory sequences using the ncRNA-a2 as a model. Genome-wide analyses of intergenic lncRNAs (lincRNAs) revealed that lincRNA splicing efficiency positively correlates with 5'ss strength while no such correlation was identified for PCGs. In addition, efficiently spliced lincRNAs have higher thymidine content in the polypyrimidine tract (PPT) compared to efficiently spliced PCGs. Using model lincRNAs, we provide experimental evidence that strengthening the 5'ss and increasing the T content in PPT significantly enhances lincRNA splicing. We further showed that lincRNA exons contain less putative binding sites for SR proteins. To map binding of SR proteins to lincRNAs, we performed iCLIP with SRSF2, SRSF5 and SRSF6 and analyzed eCLIP data for SRSF1, SRSF7 and SRSF9. All examined SR proteins bind lincRNA exons to a much lower extent than expression-matched PCGs. We propose that lincRNAs lack the cooperative interaction network that enhances splicing, which renders their splicing outcome more dependent on the optimality of splice sites.
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Affiliation(s)
- Zuzana Krchňáková
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Prasoon Kumar Thakur
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Michaela Krausová
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Nicole Bieberstein
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Nejc Haberman
- Computational Regulatory Genomics, MRC London Institute of Medical Sciences, London W12 0NN, UK
| | | | - David Staněk
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
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10
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Sasagawa Y, Hayashi T, Nikaido I. Strategies for Converting RNA to Amplifiable cDNA for Single-Cell RNA Sequencing Methods. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1129:1-17. [PMID: 30968357 DOI: 10.1007/978-981-13-6037-4_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This review describes the features of molecular biology techniques for single-cell RNA sequencing (scRNA-seq), including methods developed in our laboratory. Existing scRNA-seq methods require the conversion of first-strand cDNA to amplifiable cDNA followed by whole-transcript amplification. There are three primary strategies for this conversion: poly-A tagging, template switching, and RNase H-DNA polymerase I-mediated second-strand cDNA synthesis for in vitro transcription. We discuss the merits and limitations of these strategies and describe our Reverse Transcription with Random Displacement Amplification technology that allows for direct first-strand cDNA amplification from RNA without the need for conversion to an amplifiable cDNA. We believe that this review provides all users of single-cell transcriptome technologies with an understanding of the relationship between the quantitative performance of various methods and their molecular features.
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Affiliation(s)
- Yohei Sasagawa
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, Wako, Saitama, Japan
| | - Tetsutaro Hayashi
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, Wako, Saitama, Japan
| | - Itoshi Nikaido
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, Wako, Saitama, Japan.
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Xu Y, Zhao W, Olson SD, Prabhakara KS, Zhou X. Alternative splicing links histone modifications to stem cell fate decision. Genome Biol 2018; 19:133. [PMID: 30217220 PMCID: PMC6138936 DOI: 10.1186/s13059-018-1512-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/20/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Understanding the embryonic stem cell (ESC) fate decision between self-renewal and proper differentiation is important for developmental biology and regenerative medicine. Attention has focused on mechanisms involving histone modifications, alternative pre-messenger RNA splicing, and cell-cycle progression. However, their intricate interrelations and joint contributions to ESC fate decision remain unclear. RESULTS We analyze the transcriptomes and epigenomes of human ESC and five types of differentiated cells. We identify thousands of alternatively spliced exons and reveal their development and lineage-dependent characterizations. Several histone modifications show dynamic changes in alternatively spliced exons and three are strongly associated with 52.8% of alternative splicing events upon hESC differentiation. The histone modification-associated alternatively spliced genes predominantly function in G2/M phases and ATM/ATR-mediated DNA damage response pathway for cell differentiation, whereas other alternatively spliced genes are enriched in the G1 phase and pathways for self-renewal. These results imply a potential epigenetic mechanism by which some histone modifications contribute to ESC fate decision through the regulation of alternative splicing in specific pathways and cell-cycle genes. Supported by experimental validations and extended datasets from Roadmap/ENCODE projects, we exemplify this mechanism by a cell-cycle-related transcription factor, PBX1, which regulates the pluripotency regulatory network by binding to NANOG. We suggest that the isoform switch from PBX1a to PBX1b links H3K36me3 to hESC fate determination through the PSIP1/SRSF1 adaptor, which results in the exon skipping of PBX1. CONCLUSION We reveal the mechanism by which alternative splicing links histone modifications to stem cell fate decision.
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Affiliation(s)
- Yungang Xu
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
- Center for Bioinformatics and Systems Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157 USA
| | - Weiling Zhao
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
- Center for Bioinformatics and Systems Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157 USA
| | - Scott D. Olson
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
| | - Karthik S. Prabhakara
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
| | - Xiaobo Zhou
- Center for Computational Systems Medicine, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030 USA
- Center for Bioinformatics and Systems Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157 USA
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12
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Martínez-Bueno M, Oparina N, Dozmorov MG, Marion MC, Comeau ME, Gilkeson G, Kamen D, Weisman M, Salmon J, McCune JW, Harley JB, Kimberly R, James JA, Merrill J, Montgomery C, Langefeld CD, Alarcón-Riquelme ME. Trans-Ethnic Mapping of BANK1 Identifies Two Independent SLE-Risk Linkage Groups Enriched for Co-Transcriptional Splicing Marks. Int J Mol Sci 2018; 19:ijms19082331. [PMID: 30096841 PMCID: PMC6121630 DOI: 10.3390/ijms19082331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 11/17/2022] Open
Abstract
BANK1 is a susceptibility gene for several systemic autoimmune diseases in several populations. Using the genome-wide association study (GWAS) data from Europeans (EUR) and African Americans (AA), we performed an extensive fine mapping of ankyrin repeats 1 (BANK1). To increase the SNP density, we used imputation followed by univariate and conditional analysis, combined with a haplotypic and expression quantitative trait locus (eQTL) analysis. The data from Europeans showed that the associated region was restricted to a minimal and dependent set of SNPs covering introns two and three, and exon two. In AA, the signal found in the Europeans was split into two independent effects. All of the major risk associated SNPs were eQTLs, and the risks were associated with an increased BANK1 gene expression. Functional annotation analysis revealed the enrichment of repressive B cell epigenomic marks (EZH2 and H3K27me3) and a strong enrichment of splice junctions. Furthermore, one eQTL located in intron two, rs13106926, was found within the binding site for RUNX3, a transcriptional activator. These results connect the local genome topography, chromatin structure, and the regulatory landscape of BANK1 with co-transcriptional splicing of exon two. Our data defines a minimal set of risk associated eQTLs predicted to be involved in the expression of BANK1 modulated through epigenetic regulation and splicing. These findings allow us to suggest that the increased expression of BANK1 will have an impact on B-cell mediated disease pathways.
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Affiliation(s)
- Manuel Martínez-Bueno
- GENYO, Centre for Genomics and Oncological Research: Pfizer, University of Granada, Andalusian Government, PTS, 18016 Granada, Spain.
| | - Nina Oparina
- Unit of Chronic Inflammatory Diseases, Institute for Environmental Medicine, Karolinska Institutet, 171 67 Solna, Sweden.
| | - Mikhail G Dozmorov
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23284, USA.
| | - Miranda C Marion
- Center for Public Health Genomics, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
| | - Mary E Comeau
- Center for Public Health Genomics, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
| | - Gary Gilkeson
- Division of Rheumatology, Medical University of South Carolina, Charleston, SC 29425, USA.
| | - Diane Kamen
- Division of Rheumatology, Medical University of South Carolina, Charleston, SC 29425, USA.
| | - Michael Weisman
- Division of Rheumatology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
| | - Jane Salmon
- Hospital for Special Surgery, New York, NY 10021, USA.
| | - Joseph W McCune
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
| | - John B Harley
- Cincinnati Children's Hospital Medical Center, OH and US Department of Veterans Affairs Medical Center, Cincinnati, OH 45229, USA.
| | - Robert Kimberly
- School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35205, USA.
| | - Judith A James
- Arthritis and Clinical Immunology and Clinical Pharmacology Programs, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Joan Merrill
- Arthritis and Clinical Immunology and Clinical Pharmacology Programs, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Courtney Montgomery
- Arthritis and Clinical Immunology and Clinical Pharmacology Programs, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Carl D Langefeld
- Center for Public Health Genomics, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
| | - Marta E Alarcón-Riquelme
- GENYO, Centre for Genomics and Oncological Research: Pfizer, University of Granada, Andalusian Government, PTS, 18016 Granada, Spain.
- Unit of Chronic Inflammatory Diseases, Institute for Environmental Medicine, Karolinska Institutet, 171 67 Solna, Sweden.
- Arthritis and Clinical Immunology and Clinical Pharmacology Programs, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
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13
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Sasagawa Y, Danno H, Takada H, Ebisawa M, Tanaka K, Hayashi T, Kurisaki A, Nikaido I. Quartz-Seq2: a high-throughput single-cell RNA-sequencing method that effectively uses limited sequence reads. Genome Biol 2018; 19:29. [PMID: 29523163 PMCID: PMC5845169 DOI: 10.1186/s13059-018-1407-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 02/14/2018] [Indexed: 12/14/2022] Open
Abstract
High-throughput single-cell RNA-seq methods assign limited unique molecular identifier (UMI) counts as gene expression values to single cells from shallow sequence reads and detect limited gene counts. We thus developed a high-throughput single-cell RNA-seq method, Quartz-Seq2, to overcome these issues. Our improvements in the reaction steps make it possible to effectively convert initial reads to UMI counts, at a rate of 30-50%, and detect more genes. To demonstrate the power of Quartz-Seq2, we analyzed approximately 10,000 transcriptomes from in vitro embryonic stem cells and an in vivo stromal vascular fraction with a limited number of reads.
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Affiliation(s)
- Yohei Sasagawa
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
| | - Hiroki Danno
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
| | - Hitomi Takada
- Laboratory of Stem Cell Technology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama-cho 8916-5, Ikoma, Nara, Japan
| | - Masashi Ebisawa
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
| | - Kaori Tanaka
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
| | - Tetsutaro Hayashi
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
| | - Akira Kurisaki
- Laboratory of Stem Cell Technology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama-cho 8916-5, Ikoma, Nara, Japan
| | - Itoshi Nikaido
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Hirosawa 2-1, Wako, Saitama, Japan
- Single-cell Omics Research Unit, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Japan
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14
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Ruiz-Velasco M, Kumar M, Lai MC, Bhat P, Solis-Pinson AB, Reyes A, Kleinsorg S, Noh KM, Gibson TJ, Zaugg JB. CTCF-Mediated Chromatin Loops between Promoter and Gene Body Regulate Alternative Splicing across Individuals. Cell Syst 2017; 5:628-637.e6. [DOI: 10.1016/j.cels.2017.10.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/02/2017] [Accepted: 10/27/2017] [Indexed: 12/20/2022]
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15
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Tilgner H, Jahanbani F, Gupta I, Collier P, Wei E, Rasmussen M, Snyder M. Microfluidic isoform sequencing shows widespread splicing coordination in the human transcriptome. Genome Res 2017; 28:231-242. [PMID: 29196558 PMCID: PMC5793787 DOI: 10.1101/gr.230516.117] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/30/2017] [Indexed: 12/21/2022]
Abstract
Understanding transcriptome complexity is crucial for understanding human biology and disease. Technologies such as Synthetic long-read RNA sequencing (SLR-RNA-seq) delivered 5 million isoforms and allowed assessing splicing coordination. Pacific Biosciences and Oxford Nanopore increase throughput also but require high input amounts or amplification. Our new droplet-based method, sparse isoform sequencing (spISO-seq), sequences 100k–200k partitions of 10–200 molecules at a time, enabling analysis of 10–100 million RNA molecules. SpISO-seq requires less than 1 ng of input cDNA, limiting or removing the need for prior amplification with its associated biases. Adjusting the number of reads devoted to each molecule reduces sequencing lanes and cost, with little loss in detection power. The increased number of molecules expands our understanding of isoform complexity. In addition to confirming our previously published cases of splicing coordination (e.g., BIN1), the greater depth reveals many new cases, such as MAPT. Coordination of internal exons is found to be extensive among protein coding genes: 23.5%–59.3% (95% confidence interval) of highly expressed genes with distant alternative exons exhibit coordination, showcasing the need for long-read transcriptomics. However, coordination is less frequent for noncoding sequences, suggesting a larger role of splicing coordination in shaping proteins. Groups of genes with coordination are involved in protein–protein interactions with each other, raising the possibility that coordination facilitates complex formation and/or function. We also find new splicing coordination types, involving initial and terminal exons. Our results provide a more comprehensive understanding of the human transcriptome and a general, cost-effective method to analyze it.
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Affiliation(s)
- Hagen Tilgner
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10021, USA
| | - Fereshteh Jahanbani
- Department of Genetics, Stanford University, Stanford, California 94304, USA
| | - Ishaan Gupta
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10021, USA
| | - Paul Collier
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10021, USA
| | - Eric Wei
- Department of Genetics, Stanford University, Stanford, California 94304, USA
| | | | - Michael Snyder
- Department of Genetics, Stanford University, Stanford, California 94304, USA
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16
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Huang Y, Sanguinetti G. BRIE: transcriptome-wide splicing quantification in single cells. Genome Biol 2017; 18:123. [PMID: 28655331 PMCID: PMC5488362 DOI: 10.1186/s13059-017-1248-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/30/2017] [Indexed: 11/12/2022] Open
Abstract
Single-cell RNA-seq (scRNA-seq) provides a comprehensive measurement of stochasticity in transcription, but the limitations of the technology have prevented its application to dissect variability in RNA processing events such as splicing. Here, we present BRIE (Bayesian regression for isoform estimation), a Bayesian hierarchical model that resolves these problems by learning an informative prior distribution from sequence features. We show that BRIE yields reproducible estimates of exon inclusion ratios in single cells and provides an effective tool for differential isoform quantification between scRNA-seq data sets. BRIE, therefore, expands the scope of scRNA-seq experiments to probe the stochasticity of RNA processing.
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Affiliation(s)
- Yuanhua Huang
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK
| | - Guido Sanguinetti
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK. .,Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, Edinburgh, EH9 3BF, UK.
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17
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A saga of cancer epigenetics: linking epigenetics to alternative splicing. Biochem J 2017; 474:885-896. [PMID: 28270561 DOI: 10.1042/bcj20161047] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/29/2016] [Accepted: 01/05/2017] [Indexed: 12/14/2022]
Abstract
The discovery of an increasing number of alternative splicing events in the human genome highlighted that ∼94% of genes generate alternatively spliced transcripts that may produce different protein isoforms with diverse functions. It is now well known that several diseases are a direct and indirect consequence of aberrant splicing events in humans. In addition to the conventional mode of alternative splicing regulation by 'cis' RNA-binding sites and 'trans' RNA-binding proteins, recent literature provides enormous evidence for epigenetic regulation of alternative splicing. The epigenetic modifications may regulate alternative splicing by either influencing the transcription elongation rate of RNA polymerase II or by recruiting a specific splicing regulator via different chromatin adaptors. The epigenetic alterations and aberrant alternative splicing are known to be associated with various diseases individually, but this review discusses/highlights the latest literature on the role of epigenetic alterations in the regulation of alternative splicing and thereby cancer progression. This review also points out the need for further studies to understand the interplay between epigenetic modifications and aberrant alternative splicing in cancer progression.
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18
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Eckstein M, Eleazer R, Rea M, Fondufe-Mittendorf Y. Epigenomic reprogramming in inorganic arsenic-mediated gene expression patterns during carcinogenesis. REVIEWS ON ENVIRONMENTAL HEALTH 2017; 32:93-103. [PMID: 27701139 DOI: 10.1515/reveh-2016-0025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/08/2016] [Indexed: 05/22/2023]
Abstract
Arsenic is a ubiquitous metalloid that is not mutagenic but is carcinogenic. The mechanism(s) by which arsenic causes cancer remain unknown. To date, several mechanisms have been proposed, including the arsenic-induced generation of reactive oxygen species (ROS). However, it is also becoming evident that inorganic arsenic (iAs) may exert its carcinogenic effects by changing the epigenome, and thereby modifying chromatin structure and dynamics. These epigenetic changes alter the accessibility of gene regulatory factors to DNA, resulting in specific changes in gene expression both at the levels of transcription initiation and gene splicing. In this review, we discuss recent literature reports describing epigenetic changes induced by iAs exposure and the possible epigenetic mechanisms underlying these changes.
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19
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Fuchs A, Torroba M, Kinkley S. PHF13: A new player involved in RNA polymerase II transcriptional regulation and co-transcriptional splicing. Transcription 2017; 8:106-112. [PMID: 28102760 DOI: 10.1080/21541264.2016.1274813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
We recently identified PHF13 as an H3K4me2/3 chromatin reader and transcriptional co-regulator. We found that PHF13 interacts with RNAPIIS5P and PRC2 stabilizing their association with active and bivalent promoters. Furthermore, mass spectrometry analysis identified ∼50 spliceosomal proteins in PHF13s interactome. Here, we will discuss the potential role of PHF13 in RNAPII pausing and co-transcriptional splicing.
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Affiliation(s)
- Alisa Fuchs
- a Max Planck Institute for Molecular Genetics , Berlin , Germany
| | - Marcos Torroba
- a Max Planck Institute for Molecular Genetics , Berlin , Germany
| | - Sarah Kinkley
- a Max Planck Institute for Molecular Genetics , Berlin , Germany
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20
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Double-target Antisense U1snRNAs Correct Mis-splicing Due to c.639+861C>T and c.639+919G>A GLA Deep Intronic Mutations. MOLECULAR THERAPY-NUCLEIC ACIDS 2016; 5:e380. [PMID: 27779620 PMCID: PMC5095687 DOI: 10.1038/mtna.2016.88] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 08/22/2016] [Indexed: 12/26/2022]
Abstract
Fabry disease is a rare X-linked lysosomal storage disorder caused by deficiency of the α-galactosidase A (α-Gal A) enzyme, which is encoded by the GLA gene. GLA transcription in humans produces a major mRNA encoding α-Gal A and a minor mRNA of unknown function, which retains a 57-nucleotide-long cryptic exon between exons 4 and 5, bearing a premature termination codon. NM_000169.2:c.639+861C>T and NM_000169.2:c.639+919G>A GLA deep intronic mutations have been described to cause Fabry disease by inducing overexpression of the alternatively spliced mRNA, along with a dramatic decrease in the major one. Here, we built a wild-type GLA minigene and two minigenes that carry mutations c.639+861C>T and c.639+919G>A. Once transfected into cells, the minigenes recapitulate the molecular patterns observed in patients, at the mRNA, protein, and enzymatic level. We constructed a set of specific double-target U1asRNAs to correct c.639+861C>T and c.639+919G>A GLA mutations. Efficacy of U1asRNAs in inducing the skipping of the cryptic exon was evaluated upon their transient co-transfection with the minigenes in COS-1 cells, by real-time polymerase chain reaction (PCR), western blot analysis, and α-Gal A enzyme assay. We identified a set of U1asRNAs that efficiently restored α-Gal A enzyme activity and the correct splicing pathways in reporter minigenes. We also identified a unique U1asRNA correcting both mutations as efficently as the mutation-specific U1asRNAs. Our study proves that an exon skipping-based approach recovering α-Gal A activity in the c.639+861C>T and c.639+919G>A GLA mutations is active.
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21
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Ferreira PG, Oti M, Barann M, Wieland T, Ezquina S, Friedländer MR, Rivas MA, Esteve-Codina A, Rosenstiel P, Strom TM, Lappalainen T, Guigó R, Sammeth M. Sequence variation between 462 human individuals fine-tunes functional sites of RNA processing. Sci Rep 2016; 6:32406. [PMID: 27617755 PMCID: PMC5019111 DOI: 10.1038/srep32406] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/03/2016] [Indexed: 12/23/2022] Open
Abstract
Recent advances in the cost-efficiency of sequencing technologies enabled the combined DNA- and RNA-sequencing of human individuals at the population-scale, making genome-wide investigations of the inter-individual genetic impact on gene expression viable. Employing mRNA-sequencing data from the Geuvadis Project and genome sequencing data from the 1000 Genomes Project we show that the computational analysis of DNA sequences around splice sites and poly-A signals is able to explain several observations in the phenotype data. In contrast to widespread assessments of statistically significant associations between DNA polymorphisms and quantitative traits, we developed a computational tool to pinpoint the molecular mechanisms by which genetic markers drive variation in RNA-processing, cataloguing and classifying alleles that change the affinity of core RNA elements to their recognizing factors. The in silico models we employ further suggest RNA editing can moonlight as a splicing-modulator, albeit less frequently than genomic sequence diversity. Beyond existing annotations, we demonstrate that the ultra-high resolution of RNA-Seq combined from 462 individuals also provides evidence for thousands of bona fide novel elements of RNA processing-alternative splice sites, introns, and cleavage sites-which are often rare and lowly expressed but in other characteristics similar to their annotated counterparts.
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Affiliation(s)
- Pedro G. Ferreira
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1211 Geneva, Switzerland
- Instituto de Investigação e Inovação em Saúde, (i3S) Universidade do Porto, 4200-625 Porto, Portugal
- Institute of Molecular Pathology and Immunology (IPATIMUP), University of Porto, 4200-625 Porto, Portugal
| | - Martin Oti
- Institute of Biophysics Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro (UFRJ), 21941-902 Rio de Janeiro, Brazil
| | - Matthias Barann
- Institute of Clinical Molecular Biology, Christians-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Thomas Wieland
- Institute of Human Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Suzana Ezquina
- Center for Human Genome and Stem-cell research (HUG-CELL), University of São Paulo (USP), 05508090 São Paulo, Brazil
| | - Marc R. Friedländer
- Science for Life Laboratory, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Manuel A. Rivas
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Anna Esteve-Codina
- Centre Nacional d’Anàlisi Genòmica, 08028 Barcelona, Catalonia, Spain
- Center for Research in Agricultural Genomics (CRAG), Autonome University of Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Christians-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Tim M Strom
- Institute of Human Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Tuuli Lappalainen
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1211 Geneva, Switzerland
- Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
- Swiss Institute of Bioinformatics, 1211 Geneva, Switzerland
| | - Roderic Guigó
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Pompeu Fabra University (UPF), 08003 Barcelona, Catalonia, Spain
| | - Michael Sammeth
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Institute of Biophysics Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro (UFRJ), 21941-902 Rio de Janeiro, Brazil
- National Center of Scientific Computing (LNCC), 2233-6000 Petrópolis, Rio de Janeiro, Brazil
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22
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Trivellin G, Bjelobaba I, Daly AF, Larco DO, Palmeira L, Faucz FR, Thiry A, Leal LF, Rostomyan L, Quezado M, Schernthaner-Reiter MH, Janjic MM, Villa C, Wu TJ, Stojilkovic SS, Beckers A, Feldman B, Stratakis CA. Characterization of GPR101 transcript structure and expression patterns. J Mol Endocrinol 2016; 57:97-111. [PMID: 27282544 PMCID: PMC4959428 DOI: 10.1530/jme-16-0045] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/09/2016] [Indexed: 12/25/2022]
Abstract
We recently showed that Xq26.3 microduplications cause X-linked acrogigantism (X-LAG). X-LAG patients mainly present with growth hormone and prolactin-secreting adenomas and share a minimal duplicated region containing at least four genes. GPR101 was the only gene highly expressed in their pituitary lesions, but little is known about its expression patterns. In this work, GPR101 transcripts were characterized in human tissues by 5'-Rapid Amplification of cDNA Ends (RACE) and RNAseq, while the putative promoter was bioinformatically predicted. We investigated GPR101 mRNA and protein expression by RT-quantitative PCR (qPCR), whole-mount in situ hybridization, and immunostaining, in human, rhesus monkey, rat and zebrafish. We identified four GPR101 isoforms characterized by different 5'-untranslated regions (UTRs) and a common 6.1kb long 3'UTR. GPR101 expression was very low or absent in almost all adult human tissues examined, except for specific brain regions. Strong GPR101 staining was observed in human fetal pituitary and during adolescence, whereas very weak/absent expression was detected during childhood and adult life. In contrast to humans, adult monkey and rat pituitaries expressed GPR101, but in different cell types. Gpr101 is expressed in the brain and pituitary during rat and zebrafish development; in rat pituitary, Gpr101 is expressed only after birth and shows sexual dimorphism. This study shows that different GPR101 transcripts exist and that the brain is the major site of GPR101 expression across different species, although divergent species- and temporal-specific expression patterns are evident. These findings suggest an important role for GPR101 in brain and pituitary development and likely reflect the very different growth, development and maturation patterns among species.
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Affiliation(s)
- Giampaolo Trivellin
- Section on Endocrinology and GeneticsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ivana Bjelobaba
- Section on Cellular SignalingEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Adrian F Daly
- Department of EndocrinologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium
| | - Darwin O Larco
- Department of Obstetrics and GynecologyUniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Leonor Palmeira
- Department of EndocrinologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium
| | - Fabio R Faucz
- Section on Endocrinology and GeneticsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Albert Thiry
- Department of PathologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium
| | - Letícia F Leal
- Section on Endocrinology and GeneticsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA Department of PediatricsUniversity of Sao Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Liliya Rostomyan
- Department of EndocrinologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium
| | - Martha Quezado
- Laboratory of PathologyNational Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Marie Helene Schernthaner-Reiter
- Section on Endocrinology and GeneticsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Marija M Janjic
- Section on Cellular SignalingEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Chiara Villa
- Department of EndocrinologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium Hopital FochService d'Anatomie et Cytologie Pathologiques, Suresnes Cedex, France
| | - T John Wu
- Department of Obstetrics and GynecologyUniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Stanko S Stojilkovic
- Section on Cellular SignalingEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Albert Beckers
- Department of EndocrinologyUniversity of Liège, Domaine Universitaire du Sart-Tilman, Liège, Belgium
| | - Benjamin Feldman
- Division of Developmental BiologyEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Constantine A Stratakis
- Section on Endocrinology and GeneticsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
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23
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Jimeno-González S, Reyes JC. Chromatin structure and pre-mRNA processing work together. Transcription 2016; 7:63-8. [PMID: 27028548 PMCID: PMC4984687 DOI: 10.1080/21541264.2016.1168507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022] Open
Abstract
Chromatin is the natural context for transcription elongation. However, the elongating RNA polymerase II (RNAPII) is forced to pause by the positioned nucleosomes present in gene bodies. Here, we briefly discuss the current results suggesting that those pauses could serve as a mechanism to coordinate transcription elongation with pre-mRNA processing. Further, histone post-translational modifications have been found to regulate the recruitment of factors involved in pre-mRNA processing. This view highlights the important regulatory role of the chromatin context in the whole process of the mature mRNA synthesis.
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Affiliation(s)
- Silvia Jimeno-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Seville, Spain
| | - José C. Reyes
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Seville, Spain
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24
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Li YI, van de Geijn B, Raj A, Knowles DA, Petti AA, Golan D, Gilad Y, Pritchard JK. RNA splicing is a primary link between genetic variation and disease. Science 2016; 352:600-4. [PMID: 27126046 DOI: 10.1126/science.aad9417] [Citation(s) in RCA: 378] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/25/2016] [Indexed: 12/14/2022]
Abstract
Noncoding variants play a central role in the genetics of complex traits, but we still lack a full understanding of the molecular pathways through which they act. We quantified the contribution of cis-acting genetic effects at all major stages of gene regulation from chromatin to proteins, in Yoruba lymphoblastoid cell lines (LCLs). About ~65% of expression quantitative trait loci (eQTLs) have primary effects on chromatin, whereas the remaining eQTLs are enriched in transcribed regions. Using a novel method, we also detected 2893 splicing QTLs, most of which have little or no effect on gene-level expression. These splicing QTLs are major contributors to complex traits, roughly on a par with variants that affect gene expression levels. Our study provides a comprehensive view of the mechanisms linking genetic variation to variation in human gene regulation.
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Affiliation(s)
- Yang I Li
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | - Anil Raj
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - David A Knowles
- Department of Computer Science, Stanford University, Stanford, CA, USA. Department of Radiology, Stanford University, Stanford, CA, USA
| | - Allegra A Petti
- Genome Institute, Washington University in St. Louis, St. Louis, MO, USA
| | - David Golan
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL, USA.
| | - Jonathan K Pritchard
- Department of Genetics, Stanford University, Stanford, CA, USA. Department of Biology, Stanford University, Stanford, CA, USA. Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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25
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Curado J, Iannone C, Tilgner H, Valcárcel J, Guigó R. Erratum to: Promoter-like epigenetic signatures in exons displaying cell type-specific splicing. Genome Biol 2016; 17:52. [PMID: 26993099 PMCID: PMC4799591 DOI: 10.1186/s13059-016-0890-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 11/10/2022] Open
Affiliation(s)
- Joao Curado
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.,Graduate program in Areas of Basic and Applied Biology, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, 4099-003, Portugal
| | - Camilla Iannone
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.,Universitat Pompeu Fabra, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain
| | - Hagen Tilgner
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.,Department of Genetics, Stanford University, 300 Pasteur Dr., Stanford, 94305-5120, CA, USA
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.,Universitat Pompeu Fabra, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.,Institució Catalana de Recerca i Estudis Avançats, Pg Lluis Companys 23, Barcelona, 08010, Catalonia, Spain
| | - Roderic Guigó
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain. .,Universitat Pompeu Fabra, Dr. Aiguader, 88, Barcelona, 08003, Catalonia, Spain.
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