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Ciampi L, Mantica F, López-Blanch L, Permanyer J, Rodriguez-Marín C, Zang J, Cianferoni D, Jiménez-Delgado S, Bonnal S, Miravet-Verde S, Ruprecht V, Neuhauss SCF, Banfi S, Carrella S, Serrano L, Head SA, Irimia M. Specialization of the photoreceptor transcriptome by Srrm3-dependent microexons is required for outer segment maintenance and vision. Proc Natl Acad Sci U S A 2022; 119:e2117090119. [PMID: 35858306 PMCID: PMC9303857 DOI: 10.1073/pnas.2117090119] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 05/28/2022] [Indexed: 01/14/2023] Open
Abstract
Retinal photoreceptors have a distinct transcriptomic profile compared to other neuronal subtypes, likely reflecting their unique cellular morphology and function in the detection of light stimuli by way of the ciliary outer segment. We discovered a layer of this molecular specialization by revealing that the vertebrate retina expresses the largest number of tissue-enriched microexons of all tissue types. A subset of these microexons is included exclusively in photoreceptor transcripts, particularly in genes involved in cilia biogenesis and vesicle-mediated transport. This microexon program is regulated by Srrm3, a paralog of the neural microexon regulator Srrm4. Despite the fact that both proteins positively regulate retina microexons in vitro, only Srrm3 is highly expressed in mature photoreceptors. Its deletion in zebrafish results in widespread down-regulation of microexon inclusion from early developmental stages, followed by other transcriptomic alterations, severe photoreceptor defects, and blindness. These results shed light on the transcriptomic specialization and functionality of photoreceptors, uncovering unique cell type-specific roles for Srrm3 and microexons with implications for retinal diseases.
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Affiliation(s)
- Ludovica Ciampi
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Federica Mantica
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Laura López-Blanch
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Jon Permanyer
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Cristina Rodriguez-Marín
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Jingjing Zang
- Department of Molecular Life Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Damiano Cianferoni
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Senda Jiménez-Delgado
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Sophie Bonnal
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Samuel Miravet-Verde
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Verena Ruprecht
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
- Universitat Pompeu Fabra, 08002 Barcelona, Spain
| | - Stephan C. F. Neuhauss
- Department of Molecular Life Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Sandro Banfi
- Medical Genetics, Department of Precision Medicine, University of Campania “L. Vanvitelli”, 80138 Naples, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Sabrina Carrella
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
- Ecosustainable Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy
| | - Luis Serrano
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
- Universitat Pompeu Fabra, 08002 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Sarah A. Head
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
| | - Manuel Irimia
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, 08036 Barcelona, Spain
- Universitat Pompeu Fabra, 08002 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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52
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Wright CJ, Smith CWJ, Jiggins CD. Alternative splicing as a source of phenotypic diversity. Nat Rev Genet 2022; 23:697-710. [PMID: 35821097 DOI: 10.1038/s41576-022-00514-4] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/27/2022]
Abstract
A major goal of evolutionary genetics is to understand the genetic processes that give rise to phenotypic diversity in multicellular organisms. Alternative splicing generates multiple transcripts from a single gene, enriching the diversity of proteins and phenotypic traits. It is well established that alternative splicing contributes to key innovations over long evolutionary timescales, such as brain development in bilaterians. However, recent developments in long-read sequencing and the generation of high-quality genome assemblies for diverse organisms has facilitated comparisons of splicing profiles between closely related species, providing insights into how alternative splicing evolves over shorter timescales. Although most splicing variants are probably non-functional, alternative splicing is nonetheless emerging as a dynamic, evolutionarily labile process that can facilitate adaptation and contribute to species divergence.
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Affiliation(s)
- Charlotte J Wright
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK. .,Department of Zoology, University of Cambridge, Cambridge, UK.
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge, UK.
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53
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Reixachs‐Solé M, Eyras E. Uncovering the impacts of alternative splicing on the proteome with current omics techniques. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1707. [PMID: 34979593 PMCID: PMC9542554 DOI: 10.1002/wrna.1707] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022]
Abstract
The high-throughput sequencing of cellular RNAs has underscored a broad effect of isoform diversification through alternative splicing on the transcriptome. Moreover, the differential production of transcript isoforms from gene loci has been recognized as a critical mechanism in cell differentiation, organismal development, and disease. Yet, the extent of the impact of alternative splicing on protein production and cellular function remains a matter of debate. Multiple experimental and computational approaches have been developed in recent years to address this question. These studies have unveiled how molecular changes at different steps in the RNA processing pathway can lead to differences in protein production and have functional effects. New and emerging experimental technologies open exciting new opportunities to develop new methods to fully establish the connection between messenger RNA expression and protein production and to further investigate how RNA variation impacts the proteome and cell function. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing Translation > Regulation RNA Evolution and Genomics > Computational Analyses of RNA.
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Affiliation(s)
- Marina Reixachs‐Solé
- The John Curtin School of Medical ResearchAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
- EMBL Australia Partner Laboratory Network and the Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Eduardo Eyras
- The John Curtin School of Medical ResearchAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
- EMBL Australia Partner Laboratory Network and the Australian National UniversityCanberraAustralian Capital TerritoryAustralia
- Catalan Institution for Research and Advanced StudiesBarcelonaSpain
- Hospital del Mar Medical Research Institute (IMIM)BarcelonaSpain
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54
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Wang J, Zhang L, Zeng A, Xia D, Yu J, Yu G. DeepIII: Predicting Isoform-Isoform Interactions by Deep Neural Networks and Data Fusion. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2022; 19:2177-2187. [PMID: 33764878 DOI: 10.1109/tcbb.2021.3068875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Alternative splicing enables a gene translating into different isoforms and into the corresponding proteoforms, which actually accomplish various biological functions of a living body. Isoform-isoform interactions (IIIs) provide a higher resolution interactome to explore the cellular processes and disease mechanisms than the canonically studied protein-protein interactions (PPIs), which are often recorded at the coarse gene level. The knowledge of IIIs is critical to map pathways, understand protein complexity and functional diversity, but the known IIIs are very scanty. In this paper, we propose a deep learning based method called DeepIII to systematically predict genome-wide IIIs by integrating diverse data sources, including RNA-seq datasets of different human tissues, exon array data, domain-domain interactions (DDIs) of proteins, nucleotide sequences and amino acid sequences. Particularly, DeepIII fuses these data to learn the representation of isoform pairs with a four-layer deep neural networks, and then performs binary classification on the learnt representation to achieve the prediction of IIIs. Experimental results show that DeepIII achieves a superior prediction performance to the state-of-the-art solutions and the III network constructed by DeepIII gives more accurate isoform function prediction. Case studies further confirm that DeepIII can differentiate the individual interaction partners of different isoforms spliced from the same gene. The code and datasets of DeepIII are available at http://mlda.swu.edu.cn/codes.php?name=DeepIII.
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55
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Zhou D, Tran Y, Abou Elela S, Scott MS. SAPFIR: A webserver for the identification of alternative protein features. BMC Bioinformatics 2022; 23:250. [PMID: 35751026 PMCID: PMC9229502 DOI: 10.1186/s12859-022-04804-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/20/2022] [Indexed: 11/29/2022] Open
Abstract
Background Alternative splicing can increase the diversity of gene functions by generating multiple isoforms with different sequences and functions. However, the extent to which splicing events have functional consequences remains unclear and predicting the impact of splicing events on protein activity is limited to gene-specific analysis. Results To accelerate the identification of functionally relevant alternative splicing events we created SAPFIR, a predictor of protein features associated with alternative splicing events. This webserver tool uses InterProScan to predict protein features such as functional domains, motifs and sites in the human and mouse genomes and link them to alternative splicing events. Alternative protein features are displayed as functions of the transcripts and splice sites. SAPFIR could be used to analyze proteins generated from a single gene or a group of genes and can directly identify alternative protein features in large sequence data sets. The accuracy and utility of SAPFIR was validated by its ability to rediscover previously validated alternative protein domains. In addition, our de novo analysis of public datasets using SAPFIR indicated that only a small portion of alternative protein domains was conserved between human and mouse, and that in human, genes involved in nervous system process, regulation of DNA-templated transcription and aging are more likely to produce isoforms missing functional domains due to alternative splicing. Conclusion Overall SAPFIR represents a new tool for the rapid identification of functional alternative splicing events and enables the identification of cellular functions affected by a defined splicing program. SAPFIR is freely available at https://bioinfo-scottgroup.med.usherbrooke.ca/sapfir/, a website implemented in Python, with all major browsers supported. The source code is available at https://github.com/DelongZHOU/SAPFIR. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-022-04804-w.
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Affiliation(s)
- Delong Zhou
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Yvan Tran
- Département de Biochimie et Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Sherif Abou Elela
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
| | - Michelle S Scott
- Département de Biochimie et Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
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56
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Huggett SB, Ikeda AS, McGeary JE, Kaun KR, Palmer RHC. Opioid Use Disorder and Alternative mRNA Splicing in Reward Circuitry. Genes (Basel) 2022; 13:1045. [PMID: 35741807 PMCID: PMC9222793 DOI: 10.3390/genes13061045] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 02/06/2023] Open
Abstract
Opiate/opioid use disorder (OUD) is a chronic relapsing brain disorder that has increased in prevalence in the last two decades in the United States. Understanding the molecular correlates of OUD may provide key insights into the pathophysiology of this syndrome. Using publicly available RNA-sequencing data, our study investigated the possible role of alternative mRNA splicing in human brain tissue (dorsal-lateral prefrontal cortex (dlPFC), nucleus accumbens (NAc), and midbrain) of 90 individuals with OUD or matched controls. We found a total of 788 differentially spliced genes across brain regions. Alternative mRNA splicing demonstrated mostly tissue-specific effects, but a functionally characterized splicing change in the clathrin and AP-2-binding (CLAP) domain of the Bridging Integrator 1 (BIN1) gene was significantly linked to OUD across all brain regions. We investigated two hypotheses that may underlie differential splicing in OUD. First, we tested whether spliceosome genes were disrupted in the brains of individuals with OUD. Pathway enrichment analyses indicated spliceosome perturbations in OUD across brain regions. Second, we tested whether alternative mRNA splicing regions were linked to genetic predisposition. Using a genome-wide association study (GWAS) of OUD, we found no evidence that DNA variants within or surrounding differentially spliced genes were implicated in the heritability of OUD. Altogether, our study contributes to the understanding of OUD pathophysiology by providing evidence of a possible role of alternative mRNA splicing in OUD.
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Affiliation(s)
- Spencer B. Huggett
- Behavioral Genetics of Addiction Laboratory, Department of Psychology at Emory University, Atlanta, GA 30322, USA; (S.B.H.); (A.S.I.)
| | - Ami S. Ikeda
- Behavioral Genetics of Addiction Laboratory, Department of Psychology at Emory University, Atlanta, GA 30322, USA; (S.B.H.); (A.S.I.)
| | - John E. McGeary
- Providence Veterans Affairs Medical Center, Department of Psychiatry and Human Behavior, Brown University, Providence, RI 02908, USA;
| | - Karla R. Kaun
- Department of Neuroscience, Brown University, Providence, RI 02912, USA;
| | - Rohan H. C. Palmer
- Behavioral Genetics of Addiction Laboratory, Department of Psychology at Emory University, Atlanta, GA 30322, USA; (S.B.H.); (A.S.I.)
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57
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Fagg WS, Liu N, Braunschweig U, Pereira de Castro K, Chen X, Ditmars F, Widen S, Donohue JP, Modis K, Russell W, Fair JH, Weirauch M, Blencowe B, Garcia-Blanco M. Definition of germ layer cell lineage alternative splicing programs reveals a critical role for Quaking in specifying cardiac cell fate. Nucleic Acids Res 2022; 50:5313-5334. [PMID: 35544276 PMCID: PMC9122611 DOI: 10.1093/nar/gkac327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/14/2022] [Accepted: 04/25/2022] [Indexed: 01/27/2023] Open
Abstract
Alternative splicing is critical for development; however, its role in the specification of the three embryonic germ layers is poorly understood. By performing RNA-Seq on human embryonic stem cells (hESCs) and derived definitive endoderm, cardiac mesoderm, and ectoderm cell lineages, we detect distinct alternative splicing programs associated with each lineage. The most prominent splicing program differences are observed between definitive endoderm and cardiac mesoderm. Integrative multi-omics analyses link each program with lineage-enriched RNA binding protein regulators, and further suggest a widespread role for Quaking (QKI) in the specification of cardiac mesoderm. Remarkably, knockout of QKI disrupts the cardiac mesoderm-associated alternative splicing program and formation of myocytes. These changes arise in part through reduced expression of BIN1 splice variants linked to cardiac development. Mechanistically, we find that QKI represses inclusion of exon 7 in BIN1 pre-mRNA via an exonic ACUAA motif, and this is concomitant with intron removal and cleavage from chromatin. Collectively, our results uncover alternative splicing programs associated with the three germ lineages and demonstrate an important role for QKI in the formation of cardiac mesoderm.
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Affiliation(s)
- W Samuel Fagg
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Naiyou Liu
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | | | | | - Xiaoting Chen
- Center for Autoimmune Genomics and Etiology (CAGE), Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Frederick S Ditmars
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - John Paul Donohue
- Sinsheimer Labs, RNA Center for Molecular Biology, Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Katalin Modis
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jeffrey H Fair
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology (CAGE), Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
- Divisions of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Benjamin J Blencowe
- Donnelly Centre, University of Toronto, Toronto, ONM5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, ONM5S 1A8, Canada
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
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58
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Co-transcriptional splicing efficiency is a gene-specific feature that can be regulated by TGFβ. Commun Biol 2022; 5:277. [PMID: 35347226 PMCID: PMC8960766 DOI: 10.1038/s42003-022-03224-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/03/2022] [Indexed: 11/26/2022] Open
Abstract
Differential splicing efficiency of specific introns is a mechanism that dramatically increases protein diversity, based on selection of alternative exons for the final mature mRNA. However, it is unclear whether splicing efficiency of introns within the same gene is coordinated and eventually regulated as a mechanism to control mature mRNA levels. Based on nascent chromatin-associated RNA-sequencing data, we now find that co-transcriptional splicing (CTS) efficiency tends to be similar between the different introns of a gene. We establish that two well-differentiated strategies for CTS efficiency exist, at the extremes of a gradient: short genes that produce high levels of pre-mRNA undergo inefficient splicing, while long genes with relatively low levels of pre-mRNA have an efficient splicing. Notably, we observe that genes with efficient CTS display a higher level of mature mRNA relative to their pre-mRNA levels. Further, we show that the TGFβ signal transduction pathway regulates the general CTS efficiency, causing changes in mature mRNA levels. Taken together, our data indicate that CTS efficiency is a gene-specific characteristic that can be regulated to control gene expression. Co-transcriptional splicing efficiency is a gene-specific characteristic that can be regulated by TGFβ to modulate gene expression.
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59
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Guillaudeux N, Belleannée C, Blanquart S. Identifying genes with conserved splicing structure and orthologous isoforms in human, mouse and dog. BMC Genomics 2022; 23:216. [PMID: 35303798 PMCID: PMC8933948 DOI: 10.1186/s12864-022-08429-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 02/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In eukaryote transcriptomes, a significant amount of transcript diversity comes from genes' capacity to generate different transcripts through alternative splicing. Identifying orthologous alternative transcripts across multiple species is of particular interest for genome annotators. However, there is no formal definition of transcript orthology based on the splicing structure conservation. Likewise there is no public dataset benchmark providing groups of orthologous transcripts sharing a conserved splicing structure. RESULTS We introduced a formal definition of splicing structure orthology and we predicted transcript orthologs in human, mouse and dog. Applying a selective strategy, we analyzed 2,167 genes and their 18,109 known transcripts and identified a set of 253 gene orthologs that shared a conserved splicing structure in all three species. We predicted 6,861 transcript CDSs (coding sequence), mainly for dog, an emergent model species. Each predicted transcript was an ortholog of a known transcript: both share the same CDS splicing structure. Evidence for the existence of the predicted CDSs was found in external data. CONCLUSIONS We generated a dataset of 253 gene triplets, structurally conserved and sharing all their CDSs in human, mouse and dog, which correspond to 879 triplets of spliced CDS orthologs. We have released the dataset both as an SQL database and as tabulated files. The data consists of the 879 CDS orthology groups with their detailed splicing structures, and the predicted CDSs, associated with their experimental evidence. The 6,861 predicted CDSs are provided in GTF files. Our data may contribute to compare highly conserved genes across three species, for comparative transcriptomics at the isoform level, or for benchmarking splice aligners and methods focusing on the identification of splicing orthologs. The data is available at https://data-access.cesgo.org/index.php/s/V97GXxOS66NqTkZ .
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60
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Pervasive occurrence of splice-site-creating mutations and their possible involvement in genetic disorders. NPJ Genom Med 2022; 7:22. [PMID: 35304488 PMCID: PMC8933504 DOI: 10.1038/s41525-022-00294-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 02/15/2022] [Indexed: 01/06/2023] Open
Abstract
The search for causative mutations in human genetic disorders has mainly focused on mutations that disrupt coding regions or splice sites. Recently, however, it has been reported that mutations creating splice sites can also cause a range of genetic disorders. In this study, we identified 5656 candidate splice-site-creating mutations (SCMs), of which 3942 are likely to be pathogenic, in 4054 genes responsible for genetic disorders. Reanalysis of exome data obtained from ciliopathy patients led us to identify 38 SCMs as candidate causative mutations. We estimate that, by focusing on SCMs, the increase in diagnosis rate is approximately 5.9–8.5% compared to the number of already known pathogenic variants. This finding suggests that SCMs are mutations worth focusing on in the search for causative mutations of genetic disorders.
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61
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Clinical Significance and Regulation of ERK5 Expression and Function in Cancer. Cancers (Basel) 2022; 14:cancers14020348. [PMID: 35053510 PMCID: PMC8773716 DOI: 10.3390/cancers14020348] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/08/2022] [Accepted: 01/08/2022] [Indexed: 02/06/2023] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5) is a unique kinase among MAPKs family members, given its large structure characterized by the presence of a unique C-terminal domain. Despite increasing data demonstrating the relevance of the ERK5 pathway in the growth, survival, and differentiation of normal cells, ERK5 has recently attracted the attention of several research groups given its relevance in inflammatory disorders and cancer. Accumulating evidence reported its role in tumor initiation and progression. In this review, we explore the gene expression profile of ERK5 among cancers correlated with its clinical impact, as well as the prognostic value of ERK5 and pERK5 expression levels in tumors. We also summarize the importance of ERK5 in the maintenance of a cancer stem-like phenotype and explore the major known contributions of ERK5 in the tumor-associated microenvironment. Moreover, although several questions are still open concerning ERK5 molecular regulation, different ERK5 isoforms derived from the alternative splicing process are also described, highlighting the potential clinical relevance of targeting ERK5 pathways.
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62
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Gohr A, Mantica F, Hermoso-Pulido A, Tapial J, Márquez Y, Irimia M. Computational Analysis of Alternative Splicing Using VAST-TOOLS and the VastDB Framework. Methods Mol Biol 2022; 2537:97-128. [PMID: 35895261 DOI: 10.1007/978-1-0716-2521-7_7] [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] [Indexed: 06/15/2023]
Abstract
Alternative splicing (AS) can vastly expand animal transcriptomes and proteomes. Two main open questions in the field are how AS is regulated across cell/tissue types and disease, and what roles different AS events play. To facilitate AS research, we have created the computational VastDB framework, which comprises a series of complementary software and resources that we describe in this chapter. The VastDB framework is especially designed to aid biomedical researchers without a strong computational background. It offers tools and resources to: (a) quantify AS and identify differentially spliced AS events using RNA-seq data (vast-tools), (b) perform multiple genomic and sequence analyses for investigating AS events (Matt), (c) identify AS events with genomic and regulatory conservation among species (ExOrthist), and (d) help with the biological interpretation of the results, and, ultimately, with the identification of interesting AS events to design wet-lab experiments (VastDB and PastDB).
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Affiliation(s)
- André Gohr
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Federica Mantica
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Antonio Hermoso-Pulido
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Javier Tapial
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Yamile Márquez
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Manuel Irimia
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- ICREA, Barcelona, Spain.
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63
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Malard F, Mackereth CD, Campagne S. Principles and correction of 5'-splice site selection. RNA Biol 2022; 19:943-960. [PMID: 35866748 PMCID: PMC9311317 DOI: 10.1080/15476286.2022.2100971] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/06/2022] [Indexed: 11/04/2022] Open
Abstract
In Eukarya, immature mRNA transcripts (pre-mRNA) often contain coding sequences, or exons, interleaved by non-coding sequences, or introns. Introns are removed upon splicing, and further regulation of the retained exons leads to alternatively spliced mRNA. The splicing reaction requires the stepwise assembly of the spliceosome, a macromolecular machine composed of small nuclear ribonucleoproteins (snRNPs). This review focuses on the early stage of spliceosome assembly, when U1 snRNP defines each intron 5'-splice site (5'ss) in the pre-mRNA. We first introduce the splicing reaction and the impact of alternative splicing on gene expression regulation. Thereafter, we extensively discuss splicing descriptors that influence the 5'ss selection by U1 snRNP, such as sequence determinants, and interactions mediated by U1-specific proteins or U1 small nuclear RNA (U1 snRNA). We also include examples of diseases that affect the 5'ss selection by U1 snRNP, and discuss recent therapeutic advances that manipulate U1 snRNP 5'ss selectivity with antisense oligonucleotides and small-molecule splicing switches.
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Affiliation(s)
- Florian Malard
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Cameron D Mackereth
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
| | - Sébastien Campagne
- Inserm U1212, CNRS UMR5320, ARNA Laboratory, University of Bordeaux, Bordeaux Cedex, France
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Desai J, Francis C, Longo K, Hoss A. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3128-3141. [PMID: 35286381 PMCID: PMC8989546 DOI: 10.1093/nar/gkac155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/14/2022] [Accepted: 02/26/2022] [Indexed: 11/13/2022] Open
Abstract
Alternative splicing is frequently involved in the diversification of protein function and can also be modulated for therapeutic purposes. Here we develop a predictive model, called Exon ByPASS (predicting Exon skipping Based on Protein amino acid SequenceS), to assess the criticality of exon inclusion based solely on information contained in the amino acid sequence upstream and downstream of the exon junctions. By focusing on protein sequence, Exon ByPASS predicts exon skipping independent of tissue and species in the absence of any intronic information. We validate model predictions using transcriptomic and proteomic data and show that the model can capture exon skipping in different tissues and species. Additionally, we reveal potential therapeutic opportunities by predicting synthetically skippable exons and neo-junctions arising in cancer cells.
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Affiliation(s)
- Jigar Desai
- To whom correspondence should be addressed. Tel: +1 704 214 7914;
| | | | | | - Andrew Hoss
- Wave Life Sciences, Cambridge, MA 02138, USA
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65
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Louadi Z, Elkjaer ML, Klug M, Lio CT, Fenn A, Illes Z, Bongiovanni D, Baumbach J, Kacprowski T, List M, Tsoy O. Functional enrichment of alternative splicing events with NEASE reveals insights into tissue identity and diseases. Genome Biol 2021; 22:327. [PMID: 34857024 PMCID: PMC8638120 DOI: 10.1186/s13059-021-02538-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/10/2021] [Indexed: 01/27/2023] Open
Abstract
Alternative splicing (AS) is an important aspect of gene regulation. Nevertheless, its role in molecular processes and pathobiology is far from understood. A roadblock is that tools for the functional analysis of AS-set events are lacking. To mitigate this, we developed NEASE, a tool integrating pathways with structural annotations of protein-protein interactions to functionally characterize AS events. We show in four application cases how NEASE can identify pathways contributing to tissue identity and cell type development, and how it highlights splicing-related biomarkers. With a unique view on AS, NEASE generates unique and meaningful biological insights complementary to classical pathways analysis.
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Affiliation(s)
- Zakaria Louadi
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Maria L Elkjaer
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Melissa Klug
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Department of Internal Medicine I, School of Medicine, University hospital rechts der Isar, Technical University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Chit Tong Lio
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Amit Fenn
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Zsolt Illes
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Dario Bongiovanni
- Department of Internal Medicine I, School of Medicine, University hospital rechts der Isar, Technical University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Cardiovascular Medicine, Humanitas Clinical and Research Center IRCCS and Humanitas University, Rozzano, Milan, Italy
| | - Jan Baumbach
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
- Institute of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, 5000, Odense, Denmark
| | - Tim Kacprowski
- Division Data Science in Biomedicine, Peter L. Reichertz Institute for Medical Informatics of Technische Universität Braunschweig and Hannover Medical School, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology (BRICS), TU Braunschweig, Braunschweig, Germany
| | - Markus List
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
| | - Olga Tsoy
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany.
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66
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Shields EJ, Sorida M, Sheng L, Sieriebriennikov B, Ding L, Bonasio R. Genome annotation with long RNA reads reveals new patterns of gene expression and improves single-cell analyses in an ant brain. BMC Biol 2021; 19:254. [PMID: 34838024 PMCID: PMC8626913 DOI: 10.1186/s12915-021-01188-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 11/10/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Functional genomic analyses rely on high-quality genome assemblies and annotations. Highly contiguous genome assemblies have become available for a variety of species, but accurate and complete annotation of gene models, inclusive of alternative splice isoforms and transcription start and termination sites, remains difficult with traditional approaches. RESULTS Here, we utilized full-length isoform sequencing (Iso-Seq), a long-read RNA sequencing technology, to obtain a comprehensive annotation of the transcriptome of the ant Harpegnathos saltator. The improved genome annotations include additional splice isoforms and extended 3' untranslated regions for more than 4000 genes. Reanalysis of RNA-seq experiments using these annotations revealed several genes with caste-specific differential expression and tissue- or caste-specific splicing patterns that were missed in previous analyses. The extended 3' untranslated regions afforded great improvements in the analysis of existing single-cell RNA-seq data, resulting in the recovery of the transcriptomes of 18% more cells. The deeper single-cell transcriptomes obtained with these new annotations allowed us to identify additional markers for several cell types in the ant brain, as well as genes differentially expressed across castes in specific cell types. CONCLUSIONS Our results demonstrate that Iso-Seq is an efficient and effective approach to improve genome annotations and maximize the amount of information that can be obtained from existing and future genomic datasets in Harpegnathos and other organisms.
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Affiliation(s)
- Emily J Shields
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Department of Urology and Institute of Neuropathology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Masato Sorida
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Lihong Sheng
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Bogdan Sieriebriennikov
- Department of Biology, New York University, New York, NY, USA
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, USA
| | - Long Ding
- Department of Biology, New York University, New York, NY, USA
| | - Roberto Bonasio
- Epigenetics Institute and Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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67
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Karakulak T, Moch H, von Mering C, Kahraman A. Probing Isoform Switching Events in Various Cancer Types: Lessons From Pan-Cancer Studies. Front Mol Biosci 2021; 8:726902. [PMID: 34888349 PMCID: PMC8650491 DOI: 10.3389/fmolb.2021.726902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/01/2021] [Indexed: 12/03/2022] Open
Abstract
Alternative splicing is an essential regulatory mechanism for gene expression in mammalian cells contributing to protein, cellular, and species diversity. In cancer, alternative splicing is frequently disturbed, leading to changes in the expression of alternatively spliced protein isoforms. Advances in sequencing technologies and analysis methods led to new insights into the extent and functional impact of disturbed alternative splicing events. In this review, we give a brief overview of the molecular mechanisms driving alternative splicing, highlight the function of alternative splicing in healthy tissues and describe how alternative splicing is disrupted in cancer. We summarize current available computational tools for analyzing differential transcript usage, isoform switching events, and the pathogenic impact of cancer-specific splicing events. Finally, the strategies of three recent pan-cancer studies on isoform switching events are compared. Their methodological similarities and discrepancies are highlighted and lessons learned from the comparison are listed. We hope that our assessment will lead to new and more robust methods for cancer-specific transcript detection and help to produce more accurate functional impact predictions of isoform switching events.
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Affiliation(s)
- Tülay Karakulak
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
- Swiss Informatics Institute, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Holger Moch
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Christian von Mering
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Swiss Informatics Institute, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Abdullah Kahraman
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
- Swiss Informatics Institute, Swiss Institute of Bioinformatics, Lausanne, Switzerland
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68
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Kawachi T, Masuda A, Yamashita Y, Takeda JI, Ohkawara B, Ito M, Ohno K. Regulated splicing of large exons is linked to phase-separation of vertebrate transcription factors. EMBO J 2021; 40:e107485. [PMID: 34605568 DOI: 10.15252/embj.2020107485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 09/06/2021] [Accepted: 09/14/2021] [Indexed: 12/30/2022] Open
Abstract
Although large exons cannot be readily recognized by the spliceosome, many are evolutionarily conserved and constitutively spliced for inclusion in the processed transcript. Furthermore, whether large exons may be enriched in a certain subset of proteins, or mediate specific functions, has remained unclear. Here, we identify a set of nearly 3,000 SRSF3-dependent large constitutive exons (S3-LCEs) in human and mouse cells. These exons are enriched for cytidine-rich sequence motifs, which bind and recruit the splicing factors hnRNP K and SRSF3. We find that hnRNP K suppresses S3-LCE splicing, an effect that is mitigated by SRSF3 to thus achieve constitutive splicing of S3-LCEs. S3-LCEs are enriched in genes for components of transcription machineries, including mediator and BAF complexes, and frequently contain intrinsically disordered regions (IDRs). In a subset of analyzed S3-LCE-containing transcription factors, SRSF3 depletion leads to deletion of the IDRs due to S3-LCE exon skipping, thereby disrupting phase-separated assemblies of these factors. Cytidine enrichment in large exons introduces proline/serine codon bias in intrinsically disordered regions and appears to have been evolutionarily acquired in vertebrates. We propose that layered splicing regulation by hnRNP K and SRSF3 ensures proper phase-separation of these S3-LCE-containing transcription factors in vertebrates.
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Affiliation(s)
- Toshihiko Kawachi
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akio Masuda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihiro Yamashita
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Jun-Ichi Takeda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mikako Ito
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
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69
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Manet E, Polvèche H, Mure F, Mrozek-Gorska P, Roisné-Hamelin F, Hammerschmidt W, Auboeuf D, Gruffat H. Modulation of alternative splicing during early infection of human primary B lymphocytes with Epstein-Barr virus (EBV): a novel function for the viral EBNA-LP protein. Nucleic Acids Res 2021; 49:10657-10676. [PMID: 34530456 PMCID: PMC8501971 DOI: 10.1093/nar/gkab787] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 08/27/2021] [Accepted: 09/01/2021] [Indexed: 12/29/2022] Open
Abstract
Epstein-Barr virus (EBV) is a human herpesvirus associated with human cancers worldwide. Ex vivo, the virus efficiently infects resting human B lymphocytes and induces their continuous proliferation. This process is accompanied by a global reprogramming of cellular gene transcription. However, very little is known on the impact of EBV infection on the regulation of alternative splicing, a pivotal mechanism that plays an essential role in cell fate determination and is often deregulated in cancer. In this study, we have developed a systematic time-resolved analysis of cellular mRNA splice variant expression during EBV infection of resting B lymphocytes. Our results reveal that major modifications of alternative splice variant expression appear as early as day 1 post-infection and suggest that splicing regulation provides—besides transcription—an additional mechanism of gene expression regulation at the onset of B cell activation and proliferation. We also report a role for the viral proteins, EBNA2 and EBNA-LP, in the modulation of specific alternative splicing events and reveal a previously unknown function for EBNA-LP—together with the RBM4 splicing factor—in the alternative splicing regulation of two important modulators of cell proliferation and apoptosis respectively, NUMB and BCL-X.
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Affiliation(s)
- Evelyne Manet
- CIRI, Centre International de Recherche en Infectiologie, RNA Expression in Viruses and Eukaryotes Group, Univ Lyon, Université Claude Bernard Lyon I, INSERM U1111, CNRS UMR5308, ENS Lyon, Lyon F-69007, France
| | | | - Fabrice Mure
- CIRI, Centre International de Recherche en Infectiologie, RNA Expression in Viruses and Eukaryotes Group, Univ Lyon, Université Claude Bernard Lyon I, INSERM U1111, CNRS UMR5308, ENS Lyon, Lyon F-69007, France
| | - Paulina Mrozek-Gorska
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research, D-81377 Munich, Germany
| | - Florian Roisné-Hamelin
- CIRI, Centre International de Recherche en Infectiologie, RNA Expression in Viruses and Eukaryotes Group, Univ Lyon, Université Claude Bernard Lyon I, INSERM U1111, CNRS UMR5308, ENS Lyon, Lyon F-69007, France
| | - Wolfgang Hammerschmidt
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health and German Center for Infection Research, D-81377 Munich, Germany
| | | | - Henri Gruffat
- CIRI, Centre International de Recherche en Infectiologie, RNA Expression in Viruses and Eukaryotes Group, Univ Lyon, Université Claude Bernard Lyon I, INSERM U1111, CNRS UMR5308, ENS Lyon, Lyon F-69007, France
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70
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Olivieri JE, Dehghannasiri R, Wang PL, Jang S, de Morree A, Tan SY, Ming J, Ruohao Wu A, Quake SR, Krasnow MA, Salzman J. RNA splicing programs define tissue compartments and cell types at single-cell resolution. eLife 2021; 10:e70692. [PMID: 34515025 PMCID: PMC8563012 DOI: 10.7554/elife.70692] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/10/2021] [Indexed: 02/05/2023] Open
Abstract
The extent splicing is regulated at single-cell resolution has remained controversial due to both available data and methods to interpret it. We apply the SpliZ, a new statistical approach, to detect cell-type-specific splicing in >110K cells from 12 human tissues. Using 10X Chromium data for discovery, 9.1% of genes with computable SpliZ scores are cell-type-specifically spliced, including ubiquitously expressed genes MYL6 and RPS24. These results are validated with RNA FISH, single-cell PCR, and Smart-seq2. SpliZ analysis reveals 170 genes with regulated splicing during human spermatogenesis, including examples conserved in mouse and mouse lemur. The SpliZ allows model-based identification of subpopulations indistinguishable based on gene expression, illustrated by subpopulation-specific splicing of classical monocytes involving an ultraconserved exon in SAT1. Together, this analysis of differential splicing across multiple organs establishes that splicing is regulated cell-type-specifically.
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Affiliation(s)
- Julia Eve Olivieri
- Institute for Computational and Mathematical Engineering, Stanford UniversityStanfordUnited States
- Department of Biomedical Data Science, Stanford UniversityStanfordUnited States
- Department of Biochemistry, Stanford UniversityStanfordUnited States
| | - Roozbeh Dehghannasiri
- Department of Biomedical Data Science, Stanford UniversityStanfordUnited States
- Department of Biochemistry, Stanford UniversityStanfordUnited States
| | - Peter L Wang
- Department of Biochemistry, Stanford UniversityStanfordUnited States
| | - SoRi Jang
- Department of Biochemistry, Stanford UniversityStanfordUnited States
| | - Antoine de Morree
- Department of Neurology and Neurological Sciences, Stanford University School of MedicineStanfordUnited States
| | - Serena Y Tan
- Department of Pathology, Stanford University Medical CenterStanfordUnited States
| | - Jingsi Ming
- Academy for Statistics and Interdisciplinary Sciences, Faculty of Economics and Management,East China Normal UniversityShanghaiChina
- Department of Mathematics, The Hong Kong University of Science and TechnologyHong KongChina
| | - Angela Ruohao Wu
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and TechnologyHong KongChina
| | - Stephen R Quake
- Chan Zuckerberg BiohubSan FranciscoUnited States
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Mark A Krasnow
- Department of Biochemistry, Stanford UniversityStanfordUnited States
| | - Julia Salzman
- Department of Biomedical Data Science, Stanford UniversityStanfordUnited States
- Department of Biochemistry, Stanford UniversityStanfordUnited States
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71
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Hollander M, Do T, Will T, Helms V. Detecting Rewiring Events in Protein-Protein Interaction Networks Based on Transcriptomic Data. FRONTIERS IN BIOINFORMATICS 2021; 1:724297. [PMID: 36303788 PMCID: PMC9581068 DOI: 10.3389/fbinf.2021.724297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/23/2021] [Indexed: 12/25/2022] Open
Abstract
Proteins rarely carry out their cellular functions in isolation. Instead, eukaryotic proteins engage in about six interactions with other proteins on average. The aggregated protein interactome of an organism forms a “hairy ball”-type protein-protein interaction (PPI) network. Yet, in a typical human cell, only about half of all proteins are expressed at a particular time. Hence, it has become common practice to prune the full PPI network to the subset of expressed proteins. If RNAseq data is available, one can further resolve the specific protein isoforms present in a cell or tissue. Here, we review various approaches, software tools and webservices that enable users to construct context-specific or tissue-specific PPI networks and how these are rewired between two cellular conditions. We illustrate their different functionalities on the example of the interactions involving the human TNR6 protein. In an outlook, we describe how PPI networks may be integrated with epigenetic data or with data on the activity of splicing factors.
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72
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He C, Guo J, Tian W, Wong CCL. Proteogenomics Integrating Novel Junction Peptide Identification Strategy Discovers Three Novel Protein Isoforms of Human NHSL1 and EEF1B2. J Proteome Res 2021; 20:5294-5303. [PMID: 34420305 DOI: 10.1021/acs.jproteome.1c00373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In eukaryotes, alternative pre-mRNA splicing allows a single gene to encode different protein isoforms that function in many biological processes, and they are used as biomarkers or therapeutic targets for diseases. Although protein isoforms in the human genome are well annotated, we speculate that some low-abundance protein isoforms may still be under-annotated because most genes have a primary coding product and alternative protein isoforms tend to be under-expressed. A peptide coencoded by a novel exon and an annotated exon separated by an intron is known as a novel junction peptide. In the absence of known transcripts and homologous proteins, traditional whole-genome six-frame translation-based proteogenomics cannot identify novel junction peptides, and it cannot capture novel alternative splice sites. In this article, we first propose a strategy and tool for identifying novel junction peptides, called CJunction, which we then integrate into a proteogenomics process specifically designed for novel protein isoform discovery and apply to the analysis of a deep-coverage HeLa mass spectrometry data set with identifier PXD004452 in ProteomeXchange. We succeeded in identifying and validating three novel protein isoforms of two functionally important genes, NHSL1 (causative gene of Nance-Horan syndrome) and EEF1B2 (translation elongation factor), which validate our hypothesis. These novel protein isoforms have significant sequence differences from the annotated gene-coding products introduced by the novel N-terminal, suggesting that they may play importantly different functions.
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Affiliation(s)
- Cuitong He
- Peking-Tsinghua Centre for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, 100871 Beijing, China.,Center for Precision Medicine Multi-Omics Research, Peking University Health Science Center, 100191 Beijing, China
| | - Jiangtao Guo
- Center for Precision Medicine Multi-Omics Research, Peking University Health Science Center, 100191 Beijing, China
| | - Wenmin Tian
- Center for Precision Medicine Multi-Omics Research, Peking University Health Science Center, 100191 Beijing, China.,School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Catherine C L Wong
- Peking-Tsinghua Centre for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, 100871 Beijing, China.,Center for Precision Medicine Multi-Omics Research, Peking University Health Science Center, 100191 Beijing, China.,School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China.,Peking University First Hospital, 100034 Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, 100069 Beijing, China
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73
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Skinnider MA, Scott NE, Prudova A, Kerr CH, Stoynov N, Stacey RG, Chan QWT, Rattray D, Gsponer J, Foster LJ. An atlas of protein-protein interactions across mouse tissues. Cell 2021; 184:4073-4089.e17. [PMID: 34214469 DOI: 10.1016/j.cell.2021.06.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/05/2021] [Accepted: 06/01/2021] [Indexed: 12/20/2022]
Abstract
Cellular processes arise from the dynamic organization of proteins in networks of physical interactions. Mapping the interactome has therefore been a central objective of high-throughput biology. However, the dynamics of protein interactions across physiological contexts remain poorly understood. Here, we develop a quantitative proteomic approach combining protein correlation profiling with stable isotope labeling of mammals (PCP-SILAM) to map the interactomes of seven mouse tissues. The resulting maps provide a proteome-scale survey of interactome rewiring across mammalian tissues, revealing more than 125,000 unique interactions at a quality comparable to the highest-quality human screens. We identify systematic suppression of cross-talk between the evolutionarily ancient housekeeping interactome and younger, tissue-specific modules. Rewired proteins are tightly regulated by multiple cellular mechanisms and are implicated in disease. Our study opens up new avenues to uncover regulatory mechanisms that shape in vivo interactome responses to physiological and pathophysiological stimuli in mammalian systems.
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Affiliation(s)
- Michael A Skinnider
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Nichollas E Scott
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Peter Doherty Institute, Department of Microbiology and Immunology, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Anna Prudova
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Craig H Kerr
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Nikolay Stoynov
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - R Greg Stacey
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Queenie W T Chan
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - David Rattray
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Jörg Gsponer
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Leonard J Foster
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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74
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Ho JSY, Di Tullio F, Schwarz M, Low D, Incarnato D, Gay F, Tabaglio T, Zhang J, Wollmann H, Chen L, An O, Chan THM, Hall Hickman A, Zheng S, Roudko V, Chen S, Karz A, Ahmed M, He HH, Greenbaum BD, Oliviero S, Serresi M, Gargiulo G, Mann KM, Hernando E, Mulholland D, Marazzi I, Wee DKB, Guccione E. HNRNPM controls circRNA biogenesis and splicing fidelity to sustain cancer cell fitness. eLife 2021; 10:e59654. [PMID: 34075878 PMCID: PMC8346284 DOI: 10.7554/elife.59654] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 05/30/2021] [Indexed: 12/25/2022] Open
Abstract
High spliceosome activity is a dependency for cancer cells, making them more vulnerable to perturbation of the splicing machinery compared to normal cells. To identify splicing factors important for prostate cancer (PCa) fitness, we performed pooled shRNA screens in vitro and in vivo. Our screens identified heterogeneous nuclear ribonucleoprotein M (HNRNPM) as a regulator of PCa cell growth. RNA- and eCLIP-sequencing identified HNRNPM binding to transcripts of key homeostatic genes. HNRNPM binding to its targets prevents aberrant exon inclusion and backsplicing events. In both linear and circular mis-spliced transcripts, HNRNPM preferentially binds to GU-rich elements in long flanking proximal introns. Mimicry of HNRNPM-dependent linear-splicing events using splice-switching-antisense-oligonucleotides was sufficient to inhibit PCa cell growth. This suggests that PCa dependence on HNRNPM is likely a result of mis-splicing of key homeostatic coding and non-coding genes. Our results have further been confirmed in other solid tumors. Taken together, our data reveal a role for HNRNPM in supporting cancer cell fitness. Inhibition of HNRNPM activity is therefore a potential therapeutic strategy in suppressing growth of PCa and other solid tumors.
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Affiliation(s)
- Jessica SY Ho
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
- Department of Microbiology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Federico Di Tullio
- Center for Therapeutics Discovery, department of Oncological Sciences and Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Megan Schwarz
- Center for Therapeutics Discovery, department of Oncological Sciences and Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Diana Low
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Danny Incarnato
- IIGM (Italian Institute for Genomic Medicine)TorinoItaly
- Dipartimento di Scienze della Vita e Biologia dei Sistemi Università di TorinoTorinoItaly
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of GroningenGroningenNetherlands
| | - Florence Gay
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Tommaso Tabaglio
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - JingXian Zhang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Heike Wollmann
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Leilei Chen
- Cancer Science Institute of Singapore, National University of SingaporeSingaporeSingapore
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Omer An
- Cancer Science Institute of Singapore, National University of SingaporeSingaporeSingapore
| | - Tim Hon Man Chan
- Cancer Science Institute of Singapore, National University of SingaporeSingaporeSingapore
| | - Alexander Hall Hickman
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Simin Zheng
- Department of Microbiology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- NTU Institute of Structural Biology, Nanyang Technological UniversitySingaporeSingapore
| | - Vladimir Roudko
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Sujun Chen
- Department of Medical Biophysics, University of TorontoTorontoCanada
- Princess Margaret Cancer Center, University Health NetworkTorontoCanada
- Ontario Institute for Cancer ResearchTorontoCanada
| | - Alcida Karz
- Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical CenterNew YorkUnited States
- Department of Pathology, New York University Langone Medical CenterNew YorkUnited States
| | - Musaddeque Ahmed
- Princess Margaret Cancer Center, University Health NetworkTorontoCanada
| | - Housheng Hansen He
- Department of Medical Biophysics, University of TorontoTorontoCanada
- Princess Margaret Cancer Center, University Health NetworkTorontoCanada
| | - Benjamin D Greenbaum
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Pathology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Salvatore Oliviero
- IIGM (Italian Institute for Genomic Medicine)TorinoItaly
- Dipartimento di Scienze della Vita e Biologia dei Sistemi Università di TorinoTorinoItaly
| | - Michela Serresi
- Max Delbruck Center for Molecular MedicineBerlin-BuchGermany
| | | | - Karen M Mann
- Department of Molecular Oncology, Moffitt Cancer CenterTampaUnited States
| | - Eva Hernando
- Interdisciplinary Melanoma Cooperative Group, New York University Langone Medical CenterNew YorkUnited States
- Department of Pathology, New York University Langone Medical CenterNew YorkUnited States
| | - David Mulholland
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Ivan Marazzi
- Department of Microbiology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Dave Keng Boon Wee
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
| | - Ernesto Guccione
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR)SingaporeSingapore
- Center for Therapeutics Discovery, department of Oncological Sciences and Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Department of Oncological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
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75
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Nanjundaiah S, Chidambaram H, Chandrashekar M, Chinnathambi S. Role of Microglia in Regulating Cholesterol and Tau Pathology in Alzheimer's Disease. Cell Mol Neurobiol 2021; 41:651-668. [PMID: 32468440 PMCID: PMC11448617 DOI: 10.1007/s10571-020-00883-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 05/19/2020] [Indexed: 01/21/2023]
Abstract
Cholesterol, a principal constituent of the cell membrane, plays a crucial role in the brain by regulating the synaptic transmission, neuronal signaling, as well as neurodegenerative diseases. Defects in the cholesterol trafficking are associated with enhanced generation of hyperphosphorylated Tau and Amyloid-β protein. Tau, a major microtubule-associated protein in the brain, is the key regulator of the mature neuron. Abnormally hyperphosphorylated Tau hampers the major functions related to microtubule assembly by promoting neurofibrillary tangles of paired helical filaments, twisted ribbons, and straight filaments. The observed pathological changes due to impaired cholesterol and Tau protein accumulation cause Alzheimer's disease. Thus, in order to regulate the pathogenesis of Alzheimer's disease, regulation of cholesterol metabolism, as well as Tau phosphorylation, is essential. The current review provides an overview of (1) cholesterol synthesis in the brain, neurons, astrocytes, and microglia; (2) the mechanism involved in modulating cholesterol concentration between the astrocytes and brain; (3) major mechanisms involved in the hyperphosphorylation of Tau and amyloid-β protein; and (4) microglial involvement in its regulation. Thus, the answering key questions will provide an in-depth information on microglia involvement in managing the pathogenesis of cholesterol-modulated hyperphosphorylated Tau protein.
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Affiliation(s)
- Shwetha Nanjundaiah
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India
| | - Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Madhura Chandrashekar
- School of Biomedical Engineering and Sciences, MIT University, Loni Kalbhor, Pune, 412201, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India.
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76
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An extended catalogue of tandem alternative splice sites in human tissue transcriptomes. PLoS Comput Biol 2021; 17:e1008329. [PMID: 33826604 PMCID: PMC8055015 DOI: 10.1371/journal.pcbi.1008329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 04/19/2021] [Accepted: 03/22/2021] [Indexed: 12/18/2022] Open
Abstract
Tandem alternative splice sites (TASS) is a special class of alternative splicing events that are characterized by a close tandem arrangement of splice sites. Most TASS lack functional characterization and are believed to arise from splicing noise. Based on the RNA-seq data from the Genotype Tissue Expression project, we present an extended catalogue of TASS in healthy human tissues and analyze their tissue-specific expression. The expression of TASS is usually dominated by one major splice site (maSS), while the expression of minor splice sites (miSS) is at least an order of magnitude lower. Among 46k miSS with sufficient read support, 9k (20%) are significantly expressed above the expected noise level, and among them 2.5k are expressed tissue-specifically. We found significant correlations between tissue-specific expression of RNA-binding proteins (RBP), tissue-specific expression of miSS, and miSS response to RBP inactivation by shRNA. In combination with RBP profiling by eCLIP, this allowed prediction of novel cases of tissue-specific splicing regulation including a miSS in QKI mRNA that is likely regulated by PTBP1. The analysis of human primary cell transcriptomes suggested that both tissue-specific and cell-type-specific factors contribute to the regulation of miSS expression. More than 20% of tissue-specific miSS affect structured protein regions and may adjust protein-protein interactions or modify the stability of the protein core. The significantly expressed miSS evolve under the same selection pressure as maSS, while other miSS lack signatures of evolutionary selection and conservation. Using mixture models, we estimated that not more than 15% of maSS and not more than 54% of tissue-specific miSS are noisy, while the proportion of noisy splice sites among non-significantly expressed miSS is above 63%. Pre-mRNA splicing is an important step in the processing of the genomic information during gene expression. During splicing, introns are excised from a gene transcript, and the remaining exons are ligated. Our work concerns one its particular subtype, which involves the so-called tandem alternative splice sites, a group of closely located exon borders that are used alternatively. We analyzed RNA-seq measurements of gene expression provided by the Genotype-Tissue Expression (GTEx) project, the largest to-date collection of such measurements in healthy human tissues, and constructed a detailed catalogue of tandem alternative splice sites. Within this catalogue, we characterized patterns of tissue-specific expression, regulation, impact on protein structure, and evolutionary selection acting on tandem alternative splice sites. In a number of genes, we predicted regulatory mechanisms that could be responsible for choosing one of many tandem alternative splice sites. The results of this study provide an invaluable resource for molecular biologists studying alternative splicing.
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77
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Elorza A, Márquez Y, Cabrera JR, Sánchez-Trincado JL, Santos-Galindo M, Hernández IH, Picó S, Díaz-Hernández JI, García-Escudero R, Irimia M, Lucas JJ. Huntington's disease-specific mis-splicing unveils key effector genes and altered splicing factors. Brain 2021; 144:2009-2023. [PMID: 33725094 PMCID: PMC8370404 DOI: 10.1093/brain/awab087] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 12/21/2020] [Accepted: 12/24/2020] [Indexed: 12/31/2022] Open
Abstract
Correction of mis-splicing events is a growing therapeutic approach for neurological diseases such as spinal muscular atrophy or neuronal ceroid lipofuscinosis 7, which are caused by splicing-affecting mutations. Mis-spliced effector genes that do not harbour mutations are also good candidate therapeutic targets in diseases with more complex aetiologies such as cancer, autism, muscular dystrophies or neurodegenerative diseases. Next-generation RNA sequencing (RNA-seq) has boosted investigation of global mis-splicing in diseased tissue to identify such key pathogenic mis-spliced genes. Nevertheless, while analysis of tumour or dystrophic muscle biopsies can be informative on early stage pathogenic mis-splicing, for neurodegenerative diseases, these analyses are intrinsically hampered by neuronal loss and neuroinflammation in post-mortem brains. To infer splicing alterations relevant to Huntington’s disease pathogenesis, here we performed intersect-RNA-seq analyses of human post-mortem striatal tissue and of an early symptomatic mouse model in which neuronal loss and gliosis are not yet present. Together with a human/mouse parallel motif scan analysis, this approach allowed us to identify the shared mis-splicing signature triggered by the Huntington’s disease-causing mutation in both species and to infer upstream deregulated splicing factors. Moreover, we identified a plethora of downstream neurodegeneration-linked mis-spliced effector genes that—together with the deregulated splicing factors—become new possible therapeutic targets. In summary, here we report pathogenic global mis-splicing in Huntington’s disease striatum captured by our new intersect-RNA-seq approach that can be readily applied to other neurodegenerative diseases for which bona fide animal models are available.
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Affiliation(s)
- Ainara Elorza
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - Yamile Márquez
- Centre for Genomic Regulation (CRG), Barcelona Institute for Science and Technology, 08003 Barcelona, Spain
| | - Jorge R Cabrera
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - José Luis Sánchez-Trincado
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - María Santos-Galindo
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - Ivó H Hernández
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain.,Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - Sara Picó
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - Juan I Díaz-Hernández
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
| | - Ramón García-Escudero
- Molecular Oncology Unit, CIEMAT, Madrid 28040, Spain.,Biomedical Research Institute i+12, Hospital 12 de Octubre, Madrid 28041, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Manuel Irimia
- Centre for Genomic Regulation (CRG), Barcelona Institute for Science and Technology, 08003 Barcelona, Spain.,Universitat Pompeu Fabra, 08003, Barcelona, Spain.,ICREA, Barcelona, Spain
| | - José J Lucas
- Center for Molecular Biology 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid 28049, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid 28031, Spain
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78
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Lam SD, Babu MM, Lees J, Orengo CA. Biological impact of mutually exclusive exon switching. PLoS Comput Biol 2021; 17:e1008708. [PMID: 33651795 PMCID: PMC7954323 DOI: 10.1371/journal.pcbi.1008708] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 03/12/2021] [Accepted: 01/14/2021] [Indexed: 12/27/2022] Open
Abstract
Alternative splicing can expand the diversity of proteomes. Homologous mutually exclusive exons (MXEs) originate from the same ancestral exon and result in polypeptides with similar structural properties but altered sequence. Why would some genes switch homologous exons and what are their biological impact? Here, we analyse the extent of sequence, structural and functional variability in MXEs and report the first large scale, structure-based analysis of the biological impact of MXE events from different genomes. MXE-specific residues tend to map to single domains, are highly enriched in surface exposed residues and cluster at or near protein functional sites. Thus, MXE events are likely to maintain the protein fold, but alter specificity and selectivity of protein function. This comprehensive resource of MXE events and their annotations is available at: http://gene3d.biochem.ucl.ac.uk/mxemod/. These findings highlight how small, but significant changes at critical positions on a protein surface are exploited in evolution to alter function.
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Affiliation(s)
- Su Datt Lam
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
- * E-mail: (SDL); (JL); (CO)
| | - M. Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jonathan Lees
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom
- * E-mail: (SDL); (JL); (CO)
| | - Christine A. Orengo
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- * E-mail: (SDL); (JL); (CO)
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79
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Akkaya C, Atak D, Kamacioglu A, Akarlar BA, Guner G, Bayam E, Taskin AC, Ozlu N, Ince-Dunn G. Roles of developmentally regulated KIF2A alternative isoforms in cortical neuron migration and differentiation. Development 2021; 148:dev.192674. [PMID: 33531432 DOI: 10.1242/dev.192674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 01/18/2021] [Indexed: 11/20/2022]
Abstract
KIF2A is a kinesin motor protein with essential roles in neural progenitor division and axonal pruning during brain development. However, how different KIF2A alternative isoforms function during development of the cerebral cortex is not known. Here, we focus on three Kif2a isoforms expressed in the developing cortex. We show that Kif2a is essential for dendritic arborization in mice and that the functions of all three isoforms are sufficient for this process. Interestingly, only two of the isoforms can sustain radial migration of cortical neurons; a third isoform, lacking a key N-terminal region, is ineffective. By proximity-based interactome mapping for individual isoforms, we identify previously known KIF2A interactors, proteins localized to the mitotic spindle poles and, unexpectedly, also translation factors, ribonucleoproteins and proteins that are targeted to organelles, prominently to the mitochondria. In addition, we show that a KIF2A mutation, which causes brain malformations in humans, has extensive changes to its proximity-based interactome, with depletion of mitochondrial proteins identified in the wild-type KIF2A interactome. Our data raises new insights about the importance of alternative splice variants during brain development.
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Affiliation(s)
- Cansu Akkaya
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Dila Atak
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Altug Kamacioglu
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Busra Aytul Akarlar
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Gokhan Guner
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Efil Bayam
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Ali Cihan Taskin
- Embryo Manipulation Laboratory, Animal Research Facility, Translational Medicine Research Center, Koç University, 34450 Istanbul, Turkey
| | - Nurhan Ozlu
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey
| | - Gulayse Ince-Dunn
- Department of Molecular Biology and Genetics, Koç University, 34450 Istanbul, Turkey .,Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
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80
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Chandra S, Srinivasan S, Batra J. Hepatocyte nuclear factor 1 beta: A perspective in cancer. Cancer Med 2021; 10:1791-1804. [PMID: 33580750 PMCID: PMC7940219 DOI: 10.1002/cam4.3676] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 12/17/2022] Open
Abstract
Hepatocyte nuclear factor 1 beta (HNF1 β/B) exists as a homeobox transcription factor having a vital role in the embryonic development of organs mainly liver, kidney and pancreas. Initially described as a gene causing maturity‐onset diabetes of the young (MODY), HNF1β expression deregulation and single nucleotide polymorphisms in HNF1β have now been associated with several tumours including endometrial, prostate, ovarian, hepatocellular, renal and colorectal cancers. Its function has been studied either as homodimer or heterodimer with HNF1α. In this review, the role of HNF1B in different cancers will be discussed along with the role of its splice variants, and its emerging role as a potential biomarker in cancer.
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Affiliation(s)
- Shubhra Chandra
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
| | - Srilakshmi Srinivasan
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
| | - Jyotsna Batra
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
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81
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Schwenzer H, Abdel Mouti M, Neubert P, Morris J, Stockton J, Bonham S, Fellermeyer M, Chettle J, Fischer R, Beggs AD, Blagden SP. LARP1 isoform expression in human cancer cell lines. RNA Biol 2021; 18:237-247. [PMID: 32286153 PMCID: PMC7928056 DOI: 10.1080/15476286.2020.1744320] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/09/2020] [Accepted: 03/14/2020] [Indexed: 01/07/2023] Open
Abstract
LARP1 is an oncogenic RNA-binding protein required for ribosome biogenesis and cancer cell survival. From published in vitro studies, there is disparity over which of two different LARP1 protein isoforms (termed the long LI-LARP1 and short SI-LARP1) is the canonical. Here, after conducting a series of biochemical and cellular assays, we conclude that LI-LARP1 (NM_033551.3 > NP_056130.2) is the dominantly expressed form. We observe that SI-LARP1 (NM_015315.5> NP_056130.2) is epigenetically repressed and that this repression is evolutionarily conserved in all but a small subclade of mammalian species. As with other LARP family members, there are multiple potential LARP1 mRNA isoforms that appear to be censored within the nucleus. The capacity of the cell to modulate splicing and expression of these apparently 'redundant' mRNAs hints at contextually specific mechanisms of LARP1 expression.
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Affiliation(s)
| | | | - Pia Neubert
- Department of Oncology, University of Oxford, Oxford, UK
| | | | - Joanne Stockton
- Institute of Cancer & Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Sarah Bonham
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - James Chettle
- Department of Oncology, University of Oxford, Oxford, UK
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrew D. Beggs
- Institute of Cancer & Genomic Sciences, University of Birmingham, Birmingham, UK
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82
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Louadi Z, Yuan K, Gress A, Tsoy O, Kalinina OV, Baumbach J, Kacprowski T, List M. DIGGER: exploring the functional role of alternative splicing in protein interactions. Nucleic Acids Res 2021; 49:D309-D318. [PMID: 32976589 PMCID: PMC7778957 DOI: 10.1093/nar/gkaa768] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/20/2022] Open
Abstract
Alternative splicing plays a major role in regulating the functional repertoire of the proteome. However, isoform-specific effects to protein-protein interactions (PPIs) are usually overlooked, making it impossible to judge the functional role of individual exons on a systems biology level. We overcome this barrier by integrating protein-protein interactions, domain-domain interactions and residue-level interactions information to lift exon expression analysis to a network level. Our user-friendly database DIGGER is available at https://exbio.wzw.tum.de/digger and allows users to seamlessly switch between isoform and exon-centric views of the interactome and to extract sub-networks of relevant isoforms, making it an essential resource for studying mechanistic consequences of alternative splicing.
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Affiliation(s)
- Zakaria Louadi
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Kevin Yuan
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Alexander Gress
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), 66123 Saarbrücken, Germany
| | - Olga Tsoy
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Olga V Kalinina
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), 66123 Saarbrücken, Germany.,Faculty of Medicine, Saarland University, 66421 Homburg, Germany
| | - Jan Baumbach
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany.,Department of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense M, Denmark
| | - Tim Kacprowski
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Markus List
- Chair of Experimental Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
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83
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Ha KCH, Sterne-Weiler T, Morris Q, Weatheritt RJ, Blencowe BJ. Differential contribution of transcriptomic regulatory layers in the definition of neuronal identity. Nat Commun 2021; 12:335. [PMID: 33436550 PMCID: PMC7804943 DOI: 10.1038/s41467-020-20483-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/25/2020] [Indexed: 12/23/2022] Open
Abstract
Previous transcriptomic profiling studies have typically focused on separately analyzing mRNA expression, alternative splicing and alternative polyadenylation differences between cell and tissue types. However, the relative contribution of these three transcriptomic regulatory layers to cell type specification is poorly understood. This question is particularly relevant to neurons, given their extensive heterogeneity associated with brain location, morphology and function. In the present study, we generated profiles for the three regulatory layers from developmentally and regionally distinct subpopulations of neurons from the mouse hippocampus and broader nervous system. Multi-omics factor analyses revealed differing contributions of each transcriptomic layer in the discrimination of neurons based on their stage of development, region, and function. Importantly, profiles of differential alternative splicing and polyadenylation better discriminated specific neuronal subtype populations than gene expression patterns. These results provide evidence for differential relative contributions of coordinated gene regulatory layers in the specification of neuronal subtypes.
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Affiliation(s)
- Kevin C H Ha
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada
- Vector Institute, Toronto, ON, M5G 1M1, Canada
- BioSymetrics, Inc., Huntington, New York, NY, USA
| | - Timothy Sterne-Weiler
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Quaid Morris
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada
- Vector Institute, Toronto, ON, M5G 1M1, Canada
- Department of Computer Science, University of Toronto, Toronto, ON, M5S 4G4, Canada
| | - Robert J Weatheritt
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia.
- St. Vincent Clinical School, University of New South Wales, Darlinghurst, NSW, 2010, Australia.
| | - Benjamin J Blencowe
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada.
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84
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Tsang B, Pritišanac I, Scherer SW, Moses AM, Forman-Kay JD. Phase Separation as a Missing Mechanism for Interpretation of Disease Mutations. Cell 2020; 183:1742-1756. [DOI: 10.1016/j.cell.2020.11.050] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/04/2020] [Accepted: 11/25/2020] [Indexed: 02/08/2023]
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85
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Zhang N, Zhang P, Chen Y, Lou S, Zeng H, Deng J. Clusterization in acute myeloid leukemia based on prognostic alternative splicing signature to reveal the clinical characteristics in the bone marrow microenvironment. Cell Biosci 2020; 10:118. [DOI: 5.doi: 10.1186/s13578-020-00481-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/06/2020] [Indexed: 05/14/2025] Open
Abstract
Abstract
Background
Alternative splicing (AS), a crucial post-transcriptional regulatory mechanism in expanding the coding capacities of genomes and increasing the diversity of proteins, still faces various challenges in the splicing regulation mechanism of acute myeloid leukemia (AML) and microenvironmental changes.
Results
A total of 27,833 AS events were detected in 8337 genes in 178 AML patients, with exon skip being the predominant type. Approximately 11% of the AS events were significantly related to prognosis, and the prediction models based on various events demonstrated high classification efficiencies. Splicing factors correlation networks further altered the diversity of AS events through epigenetic regulation and clarified the potential mechanism of the splicing pathway. Unsupervised cluster analysis revealed significant correlations between AS and immune features, molecular mutations, immune checkpoints and clinical outcome. The results suggested that AS clusters could be used to identify patient subgroups with different survival outcomes in AML, among which C1 was both associated with good outcome in overall survival. Interestingly, C1 was associated with lower immune scores compared with C2 and C3, and favorable-risk cytogenetics was rarely distributed in C2, but much more common in C1.
Conclusions
This study revealed a comprehensive landscape of AS events, and provides new insight into molecular targeted therapy and immunotherapy strategy for AML.
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86
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Chong S, Mir M. Towards Decoding the Sequence-Based Grammar Governing the Functions of Intrinsically Disordered Protein Regions. J Mol Biol 2020; 433:166724. [PMID: 33248138 DOI: 10.1016/j.jmb.2020.11.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/14/2020] [Accepted: 11/19/2020] [Indexed: 01/03/2023]
Abstract
A substantial portion of the proteome consists of intrinsically disordered regions (IDRs) that do not fold into well-defined 3D structures yet perform numerous biological functions and are associated with a broad range of diseases. It has been a long-standing enigma how different IDRs successfully execute their specific functions. Further putting a spotlight on IDRs are recent discoveries of functionally relevant biomolecular assemblies, which in some cases form through liquid-liquid phase separation. At the molecular level, the formation of biomolecular assemblies is largely driven by weak, multivalent, but selective IDR-IDR interactions. Emerging experimental and computational studies suggest that the primary amino acid sequences of IDRs encode a variety of their interaction behaviors. In this review, we focus on findings and insights that connect sequence-derived features of IDRs to their conformations, propensities to form biomolecular assemblies, selectivity of interaction partners, functions in the context of physiology and disease, and regulation of function. We also discuss directions of future research to facilitate establishing a comprehensive sequence-function paradigm that will eventually allow prediction of selective interactions and specificity of function mediated by IDRs.
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Affiliation(s)
- Shasha Chong
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, United States; The Howard Hughes Medical Institute, University of California Berkeley, Berkeley, CA 94720, United States.
| | - Mustafa Mir
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, United States
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87
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Prokic I, Cowling BS, Kutchukian C, Kretz C, Tasfaout H, Gache V, Hergueux J, Wendling O, Ferry A, Toussaint A, Gavriilidis C, Nattarayan V, Koch C, Lainé J, Combe R, Tiret L, Jacquemond V, Pilot-Storck F, Laporte J. Differential physiological roles for BIN1 isoforms in skeletal muscle development, function and regeneration. Dis Model Mech 2020; 13:dmm044354. [PMID: 32994313 PMCID: PMC7710016 DOI: 10.1242/dmm.044354] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/27/2020] [Indexed: 01/09/2023] Open
Abstract
Skeletal muscle development and regeneration are tightly regulated processes. How the intracellular organization of muscle fibers is achieved during these steps is unclear. Here, we focus on the cellular and physiological roles of amphiphysin 2 (BIN1), a membrane remodeling protein mutated in both congenital and adult centronuclear myopathies (CNM), that is ubiquitously expressed and has skeletal muscle-specific isoforms. We created and characterized constitutive muscle-specific and inducible Bin1 homozygous and heterozygous knockout mice targeting either ubiquitous or muscle-specific isoforms. Constitutive Bin1-deficient mice died at birth from lack of feeding due to a skeletal muscle defect. T-tubules and other organelles were misplaced and altered, supporting a general early role for BIN1 in intracellular organization, in addition to membrane remodeling. Although restricted deletion of Bin1 in unchallenged adult muscles had no impact, the forced switch from the muscle-specific isoforms to the ubiquitous isoforms through deletion of the in-frame muscle-specific exon delayed muscle regeneration. Thus, ubiquitous BIN1 function is necessary for muscle development and function, whereas its muscle-specific isoforms fine tune muscle regeneration in adulthood, supporting that BIN1 CNM with congenital onset are due to developmental defects, whereas later onset may be due to regeneration defects.
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Affiliation(s)
- Ivana Prokic
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Belinda S Cowling
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Candice Kutchukian
- Université Lyon, Université Claude Bernard Lyon 1, CNRS UMR-5310, INSERM U-1217, Institut NeuroMyoGène, 8 Avenue Rockefeller, 69373 Lyon, France
| | - Christine Kretz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Hichem Tasfaout
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Vincent Gache
- Université Lyon, Université Claude Bernard Lyon 1, CNRS UMR-5310, INSERM U-1217, Institut NeuroMyoGène, 8 Avenue Rockefeller, 69373 Lyon, France
| | - Josiane Hergueux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Olivia Wendling
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Arnaud Ferry
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, Unité Mixte de Recherche (UMRS) 794, 75013 Paris, France
| | - Anne Toussaint
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Christos Gavriilidis
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Vasugi Nattarayan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Catherine Koch
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
| | - Jeanne Lainé
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, Department of Physiology, UMRS 974, 75013 Paris, France
- Sorbonne Université, Department of Physiology, Université Paris 06, Pitié-Salpêtrière Hospital, 75013 Paris, France
| | - Roy Combe
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
- CELPHEDIA-PHENOMIN, Institut Clinique de la Souris (ICS), 67404 Illkirch, France
| | - Laurent Tiret
- Université Paris Est Creteil, INSERM, EnvA, EFS, AP-HP, IMRB, BNMS Team, 94700 Maisons-Alfort, France
| | - Vincent Jacquemond
- Université Lyon, Université Claude Bernard Lyon 1, CNRS UMR-5310, INSERM U-1217, Institut NeuroMyoGène, 8 Avenue Rockefeller, 69373 Lyon, France
| | - Fanny Pilot-Storck
- Université Paris Est Creteil, INSERM, EnvA, EFS, AP-HP, IMRB, BNMS Team, 94700 Maisons-Alfort, France
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Translational Medicine, 67404 Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
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88
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Brito DVC, Gulmez Karaca K, Kupke J, Frank L, Oliveira AMM. MeCP2 gates spatial learning-induced alternative splicing events in the mouse hippocampus. Mol Brain 2020; 13:156. [PMID: 33203444 PMCID: PMC7672966 DOI: 10.1186/s13041-020-00695-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/06/2020] [Indexed: 12/31/2022] Open
Abstract
Long-term memory formation is supported by functional and structural changes of neuronal networks, which rely on de novo gene transcription and protein synthesis. The modulation of the neuronal transcriptome in response to learning depends on transcriptional and post-transcriptional mechanisms. DNA methylation writers and readers regulate the activity-dependent genomic program required for memory consolidation. The most abundant DNA methylation reader, the Methyl CpG binding domain protein 2 (MeCP2), has been shown to regulate alternative splicing, but whether it establishes splicing events important for memory consolidation has not been investigated. In this study, we identified the alternative splicing profile of the mouse hippocampus in basal conditions and after a spatial learning experience, and investigated the requirement of MeCP2 for these processes. We observed that spatial learning triggers a wide-range of alternative splicing events in transcripts associated with structural and functional remodeling and that virus-mediated knockdown of MeCP2 impairs learning-dependent post-transcriptional responses of mature hippocampal neurons. Furthermore, we found that MeCP2 preferentially affected the splicing modalities intron retention and exon skipping and guided the alternative splicing of distinct set of genes in baseline conditions and after learning. Lastly, comparative analysis of the MeCP2-regulated transcriptome with the alternatively spliced mRNA pool, revealed that MeCP2 disruption alters the relative abundance of alternatively spliced isoforms without affecting the overall mRNA levels. Taken together, our findings reveal that adult hippocampal MeCP2 is required to finetune alternative splicing events in basal conditions, as well as in response to spatial learning. This study provides new insight into how MeCP2 regulates brain function, particularly cognitive abilities, and sheds light onto the pathophysiological mechanisms of Rett syndrome, that is characterized by intellectual disability and caused by mutations in the Mecp2 gene.
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Affiliation(s)
- David V C Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
| | - Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany.,Department of Cognitive Neuroscience, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
| | - Janina Kupke
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
| | - Lukas Frank
- Division of Chromatin Networks, German Cancer Research Center (DKFZ) and Bioquant (Heidelberg University), Heidelberg, Germany
| | - Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany.
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89
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Koterniak B, Pilaka PP, Gracida X, Schneider LM, Pritišanac I, Zhang Y, Calarco JA. Global regulatory features of alternative splicing across tissues and within the nervous system of C. elegans. Genome Res 2020; 30:1766-1780. [PMID: 33127752 PMCID: PMC7706725 DOI: 10.1101/gr.267328.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/28/2020] [Indexed: 12/27/2022]
Abstract
Alternative splicing plays a major role in shaping tissue-specific transcriptomes. Among the broad tissue types present in metazoans, the central nervous system contains some of the highest levels of alternative splicing. Although many documented examples of splicing differences between broad tissue types exist, there remains much to be understood about the splicing factors and the cis sequence elements controlling tissue and neuron subtype-specific splicing patterns. By using translating ribosome affinity purification coupled with deep-sequencing (TRAP-seq) in Caenorhabditis elegans, we have obtained high coverage profiles of ribosome-associated mRNA for three broad tissue classes (nervous system, muscle, and intestine) and two neuronal subtypes (dopaminergic and serotonergic neurons). We have identified hundreds of splice junctions that exhibit distinct splicing patterns between tissue types or within the nervous system. Alternative splicing events differentially regulated between tissues are more often frame-preserving, are more highly conserved across Caenorhabditis species, and are enriched in specific cis regulatory motifs, when compared with other types of exons. By using this information, we have identified a likely mechanism of splicing repression by the RNA-binding protein UNC-75/CELF via interactions with cis elements that overlap a 5′ splice site. Alternatively spliced exons also overlap more frequently with intrinsically disordered peptide regions than constitutive exons. Moreover, regulated exons are often shorter than constitutive exons but are flanked by longer intron sequences. Among these tissue-regulated exons are several highly conserved microexons <27 nt in length. Collectively, our results indicate a rich layer of tissue-specific gene regulation at the level of alternative splicing in C. elegans that parallels the evolutionary forces and constraints observed across metazoa.
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Affiliation(s)
- Bina Koterniak
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Pallavi P Pilaka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Xicotencatl Gracida
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Lisa-Marie Schneider
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada.,Department of Chemistry, University of Bayreuth, 95447 Bayreuth, Germany
| | - Iva Pritišanac
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Yun Zhang
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - John A Calarco
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
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90
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Zhang N, Zhang P, Chen Y, Lou S, Zeng H, Deng J. Clusterization in acute myeloid leukemia based on prognostic alternative splicing signature to reveal the clinical characteristics in the bone marrow microenvironment. Cell Biosci 2020; 10:118. [PMID: 33062256 PMCID: PMC7552347 DOI: 10.1186/s13578-020-00481-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/06/2020] [Indexed: 12/29/2022] Open
Abstract
Background Alternative splicing (AS), a crucial post-transcriptional regulatory mechanism in expanding the coding capacities of genomes and increasing the diversity of proteins, still faces various challenges in the splicing regulation mechanism of acute myeloid leukemia (AML) and microenvironmental changes. Results A total of 27,833 AS events were detected in 8337 genes in 178 AML patients, with exon skip being the predominant type. Approximately 11% of the AS events were significantly related to prognosis, and the prediction models based on various events demonstrated high classification efficiencies. Splicing factors correlation networks further altered the diversity of AS events through epigenetic regulation and clarified the potential mechanism of the splicing pathway. Unsupervised cluster analysis revealed significant correlations between AS and immune features, molecular mutations, immune checkpoints and clinical outcome. The results suggested that AS clusters could be used to identify patient subgroups with different survival outcomes in AML, among which C1 was both associated with good outcome in overall survival. Interestingly, C1 was associated with lower immune scores compared with C2 and C3, and favorable-risk cytogenetics was rarely distributed in C2, but much more common in C1. Conclusions This study revealed a comprehensive landscape of AS events, and provides new insight into molecular targeted therapy and immunotherapy strategy for AML.
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Affiliation(s)
- Nan Zhang
- Department of Hematology, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Chongqing, 400010 People's Republic of China
| | - Ping Zhang
- Hematology Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 China
| | - Ying Chen
- Department of Hematology, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Chongqing, 400010 People's Republic of China
| | - Shifeng Lou
- Department of Hematology, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Chongqing, 400010 People's Republic of China
| | - Hanqing Zeng
- Department of Hematology, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Chongqing, 400010 People's Republic of China
| | - Jianchuan Deng
- Department of Hematology, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Chongqing, 400010 People's Republic of China
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91
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Rodriguez JM, Pozo F, di Domenico T, Vazquez J, Tress ML. An analysis of tissue-specific alternative splicing at the protein level. PLoS Comput Biol 2020; 16:e1008287. [PMID: 33017396 PMCID: PMC7561204 DOI: 10.1371/journal.pcbi.1008287] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 10/15/2020] [Accepted: 08/25/2020] [Indexed: 01/09/2023] Open
Abstract
The role of alternative splicing is one of the great unanswered questions in cellular biology. There is strong evidence for alternative splicing at the transcript level, and transcriptomics experiments show that many splice events are tissue specific. It has been suggested that alternative splicing evolved in order to remodel tissue-specific protein-protein networks. Here we investigated the evidence for tissue-specific splicing among splice isoforms detected in a large-scale proteomics analysis. Although the data supporting alternative splicing is limited at the protein level, clear patterns emerged among the small numbers of alternative splice events that we could detect in the proteomics data. More than a third of these splice events were tissue-specific and most were ancient: over 95% of splice events that were tissue-specific in both proteomics and RNAseq analyses evolved prior to the ancestors of lobe-finned fish, at least 400 million years ago. By way of contrast, three in four alternative exons in the human gene set arose in the primate lineage, so our results cannot be extrapolated to the whole genome. Tissue-specific alternative protein forms in the proteomics analysis were particularly abundant in nervous and muscle tissues and their genes had roles related to the cytoskeleton and either the structure of muscle fibres or cell-cell connections. Our results suggest that this conserved tissue-specific alternative splicing may have played a role in the development of the vertebrate brain and heart. We manually curated a set of 255 splice events detected in a large-scale tissue-based proteomics experiment and found that more than a third had evidence of significant tissue-specific differences. Events that were significantly tissue-specific at the protein level were highly conserved; almost 75% evolved over 400 million years ago. The tissues in which we found most evidence for tissue-specific splicing were nervous tissues and cardiac tissues. Genes with tissue-specific events in these two tissues had functions related to important cellular structures in brain and heart tissues. These splice events may have been essential for the development of vertebrate heart and muscle. However, our data set may not be representative of alternative exons as a whole. We found that most tissue specific splicing was strongly conserved, but just 5% of annotated alternative exons in the human gene set are ancient. More than three quarters of alternative exons are primate-derived. Although the analysis does not provide a definitive answer to the question of the functional role of alternative splicing, our results do indicate that alternative splice variants may have played a significant part in the evolution of brain and heart tissues in vertebrates.
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Affiliation(s)
- Jose Manuel Rodriguez
- Cardiovascular Proteomics Laboratory, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Calle Melchor Fernandez, Madrid, Spain
| | - Fernando Pozo
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), Calle Melchor Fernandez, Madrid, Spain
| | - Tomas di Domenico
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), Calle Melchor Fernandez, Madrid, Spain
| | - Jesus Vazquez
- Cardiovascular Proteomics Laboratory, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Calle Melchor Fernandez, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Michael L. Tress
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), Calle Melchor Fernandez, Madrid, Spain
- * E-mail:
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92
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Lau E, Han Y, Williams DR, Thomas CT, Shrestha R, Wu JC, Lam MPY. Splice-Junction-Based Mapping of Alternative Isoforms in the Human Proteome. Cell Rep 2020; 29:3751-3765.e5. [PMID: 31825849 PMCID: PMC6961840 DOI: 10.1016/j.celrep.2019.11.026] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/24/2019] [Accepted: 11/06/2019] [Indexed: 12/18/2022] Open
Abstract
The protein-level translational status and function of many alternative splicing events remain poorly understood. We use an RNA sequencing (RNA-seq)-guided proteomics method to identify protein alternative splicing isoforms in the human proteome by constructing tissue-specific protein databases that prioritize transcript splice junction pairs with high translational potential. Using the custom databases to reanalyze ~80 million mass spectra in public proteomics datasets, we identify more than 1,500 noncanonical protein isoforms across 12 human tissues, including ~400 sequences undocumented on TrEMBL and RefSeq databases. We apply the method to original quantitative mass spectrometry experiments and observe widespread isoform regulation during human induced pluripotent stem cell cardiomyocyte differentiation. On a proteome scale, alternative isoform regions overlap frequently with disordered sequences and post-translational modification sites, suggesting that alternative splicing may regulate protein function through modulating intrinsically disordered regions. The described approach may help elucidate functional consequences of alternative splicing and expand the scope of proteomics investigations in various systems. The translation and function of many alternative splicing events await confirmation at the protein level. Lau et al. use an integrated proteotranscriptomics approach to identify non-canonical and undocumented isoforms from 12 organs in the human proteome. Alternative isoforms interfere with functional sequence features and are differentially regulated during iPSC cardiomyocyte differentiation.
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Affiliation(s)
- Edward Lau
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Yu Han
- Consortium for Fibrosis Research and Translation, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA; Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA
| | - Damon R Williams
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Cody T Thomas
- Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA
| | - Rajani Shrestha
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA; Department of Radiology, School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Maggie P Y Lam
- Consortium for Fibrosis Research and Translation, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA; Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA.
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Kahraman A, Karakulak T, Szklarczyk D, von Mering C. Pathogenic impact of transcript isoform switching in 1,209 cancer samples covering 27 cancer types using an isoform-specific interaction network. Sci Rep 2020; 10:14453. [PMID: 32879328 PMCID: PMC7468103 DOI: 10.1038/s41598-020-71221-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/17/2020] [Indexed: 01/01/2023] Open
Abstract
Under normal conditions, cells of almost all tissue types express the same predominant canonical transcript isoform at each gene locus. In cancer, however, splicing regulation is often disturbed, leading to cancer-specific switches in the most dominant transcripts (MDT). To address the pathogenic impact of these switches, we have analyzed isoform-specific protein-protein interaction disruptions in 1,209 cancer samples covering 27 different cancer types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) project of the International Cancer Genomics Consortium (ICGC). Our study revealed large variations in the number of cancer-specific MDT (cMDT) with the highest frequency in cancers of female reproductive organs. Interestingly, in contrast to the mutational load, cancers arising from the same primary tissue had a similar number of cMDT. Some cMDT were found in 100% of all samples in a cancer type, making them candidates for diagnostic biomarkers. cMDT tend to be located at densely populated network regions where they disrupted protein interactions in the proximity of pathogenic cancer genes. A gene ontology enrichment analysis showed that these disruptions occurred mostly in protein translation and RNA splicing pathways. Interestingly, samples with mutations in the spliceosomal complex tend to have higher number of cMDT, while other transcript expressions correlated with mutations in non-coding splice-site and promoter regions of their genes. This work demonstrates for the first time the large extent of cancer-specific alterations in alternative splicing for 27 different cancer types. It highlights distinct and common patterns of cMDT and suggests novel pathogenic transcripts and markers that induce large network disruptions in cancers.
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Affiliation(s)
- Abdullah Kahraman
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tülay Karakulak
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Damian Szklarczyk
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Christian von Mering
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland. .,Swiss Institute of Bioinformatics, Lausanne, Switzerland.
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94
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Yu G, Wang K, Domeniconi C, Guo M, Wang J. Isoform function prediction based on bi-random walks on a heterogeneous network. Bioinformatics 2020; 36:303-310. [PMID: 31250882 DOI: 10.1093/bioinformatics/btz535] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 01/29/2023] Open
Abstract
MOTIVATION Alternative splicing contributes to the functional diversity of protein species and the proteoforms translated from alternatively spliced isoforms of a gene actually execute the biological functions. Computationally predicting the functions of genes has been studied for decades. However, how to distinguish the functional annotations of isoforms, whose annotations are essential for understanding developmental abnormalities and cancers, is rarely explored. The main bottleneck is that functional annotations of isoforms are generally unavailable and functional genomic databases universally store the functional annotations at the gene level. RESULTS We propose IsoFun to accomplish Isoform Function prediction based on bi-random walks on a heterogeneous network. IsoFun firstly constructs an isoform functional association network based on the expression profiles of isoforms derived from multiple RNA-seq datasets. Next, IsoFun uses the available Gene Ontology annotations of genes, gene-gene interactions and the relations between genes and isoforms to construct a heterogeneous network. After this, IsoFun performs a tailored bi-random walk on the heterogeneous network to predict the association between GO terms and isoforms, thus accomplishing the prediction of GO annotations of isoforms. Experimental results show that IsoFun significantly outperforms the state-of-the-art algorithms and improves the area under the receiver-operating curve (AUROC) and the area under the precision-recall curve (AUPRC) by 17% and 44% at the gene-level, respectively. We further validated the performance of IsoFun on the genes ADAM15 and BCL2L1. IsoFun accurately differentiates the functions of respective isoforms of these two genes. AVAILABILITY AND IMPLEMENTATION The code of IsoFun is available at http://mlda.swu.edu.cn/codes.php? name=IsoFun. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Guoxian Yu
- College of Computer and Information Science, Southwest University, Chongqing, China
| | - Keyao Wang
- College of Computer and Information Science, Southwest University, Chongqing, China
| | - Carlotta Domeniconi
- Department of Computer Science, George Mason University, Fairfax, VA 22030, USA
| | - Maozu Guo
- School of Electrical and Information Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China.,Beijing Key Laboratory of Intelligent Processing for Building Big Data, Beijing, China
| | - Jun Wang
- College of Computer and Information Science, Southwest University, Chongqing, China
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95
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Taga M, Petyuk VA, White C, Marsh G, Ma Y, Klein HU, Connor SM, Kroshilina A, Yung CJ, Khairallah A, Olah M, Schneider J, Karhohs K, Carpenter AE, Ransohoff R, Bennett DA, Crotti A, Bradshaw EM, De Jager PL. BIN1 protein isoforms are differentially expressed in astrocytes, neurons, and microglia: neuronal and astrocyte BIN1 are implicated in tau pathology. Mol Neurodegener 2020; 15:44. [PMID: 32727516 PMCID: PMC7389646 DOI: 10.1186/s13024-020-00387-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 06/08/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Identified as an Alzheimer's disease (AD) susceptibility gene by genome wide-association studies, BIN1 has 10 isoforms that are expressed in the Central Nervous System (CNS). The distribution of these isoforms in different cell types, as well as their role in AD pathology still remains unclear. METHODS Utilizing antibodies targeting specific BIN1 epitopes in human post-mortem tissue and analyzing mRNA expression data from purified microglia, we identified three isoforms expressed in neurons and astrocytes (isoforms 1, 2 and 3) and four isoforms expressed in microglia (isoforms 6, 9, 10 and 12). The abundance of selected peptides, which correspond to groups of BIN1 protein isoforms, was measured in dorsolateral prefrontal cortex, and their relation to neuropathological features of AD was assessed. RESULTS Peptides contained in exon 7 of BIN1's N-BAR domain were found to be significantly associated with AD-related traits and, particularly, tau tangles. Decreased expression of BIN1 isoforms containing exon 7 is associated with greater accumulation of tangles and subsequent cognitive decline, with astrocytic rather than neuronal BIN1 being the more likely culprit. These effects are independent of the BIN1 AD risk variant. CONCLUSIONS Exploring the molecular mechanisms of specific BIN1 isoforms expressed by astrocytes may open new avenues for modulating the accumulation of Tau pathology in AD.
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Affiliation(s)
- Mariko Taga
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | | | - Charles White
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | | | - Yiyi Ma
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
| | - Hans-Ulrich Klein
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | - Sarah M. Connor
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | - Alexandra Kroshilina
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
| | - Christina J. Yung
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
| | - Anthony Khairallah
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
| | - Marta Olah
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | - Julie Schneider
- Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL USA
| | - Kyle Karhohs
- Imaging Platform, Broad Institute, Cambridge, MA USA
| | | | - Richard Ransohoff
- Third Rock Ventures, 29 Newbury Street, Suite 301, Boston, MA 02116 USA
- Department of Cell Biology, Harvard Medical School, Boston, MA USA
| | - David A. Bennett
- Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL USA
| | | | - Elizabeth M. Bradshaw
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
| | - Philip L. De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th st, PH19-311, New York, NY 10032 USA
- Cell Circuits Program, Broad Institute, Cambridge, MA USA
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96
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Sulakhe D, D'Souza M, Wang S, Balasubramanian S, Athri P, Xie B, Canzar S, Agam G, Gilliam TC, Maltsev N. Exploring the functional impact of alternative splicing on human protein isoforms using available annotation sources. Brief Bioinform 2020; 20:1754-1768. [PMID: 29931155 DOI: 10.1093/bib/bby047] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/02/2018] [Indexed: 12/30/2022] Open
Abstract
In recent years, the emphasis of scientific inquiry has shifted from whole-genome analyses to an understanding of cellular responses specific to tissue, developmental stage or environmental conditions. One of the central mechanisms underlying the diversity and adaptability of the contextual responses is alternative splicing (AS). It enables a single gene to encode multiple isoforms with distinct biological functions. However, to date, the functions of the vast majority of differentially spliced protein isoforms are not known. Integration of genomic, proteomic, functional, phenotypic and contextual information is essential for supporting isoform-based modeling and analysis. Such integrative proteogenomics approaches promise to provide insights into the functions of the alternatively spliced protein isoforms and provide high-confidence hypotheses to be validated experimentally. This manuscript provides a survey of the public databases supporting isoform-based biology. It also presents an overview of the potential global impact of AS on the human canonical gene functions, molecular interactions and cellular pathways.
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Affiliation(s)
- Dinanath Sulakhe
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
| | - Mark D'Souza
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA
| | - Sheng Wang
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Toyota Technological Institute at Chicago, 6045 S. Kenwood Avenue, Chicago, IL, USA
| | - Sandhya Balasubramanian
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Genentech, Inc. 1 DNA Way, Mail Stop: 35-6J, South San Francisco, CA, USA
| | - Prashanth Athri
- Department of Computer Science and Engineering, Amrita School of Engineering, Bengaluru, Amrita Vishwa Vidyapeetham, Kasavanahalli, Carmelaram P.O., Bengaluru, Karnataka, India
| | - Bingqing Xie
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Department of Computer Science, Illinois Institute of Technology, Chicago, IL, USA
| | - Stefan Canzar
- Toyota Technological Institute at Chicago, 6045 S. Kenwood Avenue, Chicago, IL, USA.,Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gady Agam
- Department of Computer Science, Illinois Institute of Technology, Chicago, IL, USA
| | - T Conrad Gilliam
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
| | - Natalia Maltsev
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
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97
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Association study based on topological constraints of protein-protein interaction networks. Sci Rep 2020; 10:10797. [PMID: 32612246 PMCID: PMC7329836 DOI: 10.1038/s41598-020-67875-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/15/2020] [Indexed: 12/17/2022] Open
Abstract
The non-random interaction pattern of a protein–protein interaction network (PIN) is biologically informative, but its potentials have not been fully utilized in omics studies. Here, we propose a network-permutation-based association study (NetPAS) method that gauges the observed interactions between two sets of genes based on the comparison between permutation null models and the empirical networks. This enables NetPAS to evaluate relationships, constrained by network topology, between gene sets related to different phenotypes. We demonstrated the utility of NetPAS in 50 well-curated gene sets and comparison of association studies using Z-scores, modified Zʹ-scores, p-values and Jaccard indices. Using NetPAS, a weighted human disease network was generated from the association scores of 19 gene sets from OMIM. We also applied NetPAS in gene sets derived from gene ontology and pathway annotations and showed that NetPAS uncovered functional terms missed by DAVID and WebGestalt. Overall, we show that NetPAS can take topological constraints of molecular networks into account and offer new perspectives than existing methods.
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98
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de la Fuente L, Arzalluz-Luque Á, Tardáguila M, Del Risco H, Martí C, Tarazona S, Salguero P, Scott R, Lerma A, Alastrue-Agudo A, Bonilla P, Newman JRB, Kosugi S, McIntyre LM, Moreno-Manzano V, Conesa A. tappAS: a comprehensive computational framework for the analysis of the functional impact of differential splicing. Genome Biol 2020; 21:119. [PMID: 32423416 PMCID: PMC7236505 DOI: 10.1186/s13059-020-02028-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 04/23/2020] [Indexed: 12/26/2022] Open
Abstract
Recent advances in long-read sequencing solve inaccuracies in alternative transcript identification of full-length transcripts in short-read RNA-Seq data, which encourages the development of methods for isoform-centered functional analysis. Here, we present tappAS, the first framework to enable a comprehensive Functional Iso-Transcriptomics (FIT) analysis, which is effective at revealing the functional impact of context-specific post-transcriptional regulation. tappAS uses isoform-resolved annotation of coding and non-coding functional domains, motifs, and sites, in combination with novel analysis methods to interrogate different aspects of the functional readout of transcript variants and isoform regulation. tappAS software and documentation are available at https://app.tappas.org.
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Affiliation(s)
- Lorena de la Fuente
- Genomics of Gene Expression Laboratory, Prince Felipe Research Center, Valencia, Spain
- Present Address: Bioinformatics Unit, IIS Fundación Jiménez Díaz, Madrid, Spain
| | - Ángeles Arzalluz-Luque
- Department of Statistics and Operational Research, Polytechnical University of Valencia, Valencia, Spain
| | - Manuel Tardáguila
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
- Present Address: Human Genetics Department, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Héctor Del Risco
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Cristina Martí
- Genomics of Gene Expression Laboratory, Prince Felipe Research Center, Valencia, Spain
| | - Sonia Tarazona
- Department of Statistics and Operational Research, Polytechnical University of Valencia, Valencia, Spain
| | - Pedro Salguero
- Genomics of Gene Expression Laboratory, Prince Felipe Research Center, Valencia, Spain
| | - Raymond Scott
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Alberto Lerma
- Genomics of Gene Expression Laboratory, Prince Felipe Research Center, Valencia, Spain
| | - Ana Alastrue-Agudo
- Present Address: Human Genetics Department, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Pablo Bonilla
- Present Address: Human Genetics Department, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Jeremy R B Newman
- Genetics Institute, University of Florida, Gainesville, FL, USA
- Department of Pathology, University of Florida, Gainesville, FL, USA
| | - Shunichi Kosugi
- Genetics Institute, University of Florida, Gainesville, FL, USA
- Laboratory for Statistical and Translational Genetics, Center for Integrative Medical Sciences, RIKEN, Wako, Japan
| | - Lauren M McIntyre
- Genetics Institute, University of Florida, Gainesville, FL, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | | | - Ana Conesa
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA.
- Genetics Institute, University of Florida, Gainesville, FL, USA.
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99
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Reixachs-Solé M, Ruiz-Orera J, Albà MM, Eyras E. Ribosome profiling at isoform level reveals evolutionary conserved impacts of differential splicing on the proteome. Nat Commun 2020; 11:1768. [PMID: 32286305 PMCID: PMC7156646 DOI: 10.1038/s41467-020-15634-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 03/11/2020] [Indexed: 12/14/2022] Open
Abstract
The differential production of transcript isoforms from gene loci is a key cellular mechanism. Yet, its impact in protein production remains an open question. Here, we describe ORQAS (ORF quantification pipeline for alternative splicing), a pipeline for the translation quantification of individual transcript isoforms using ribosome-protected mRNA fragments (ribosome profiling). We find evidence of translation for 40-50% of the expressed isoforms in human and mouse, with 53% of the expressed genes having more than one translated isoform in human, and 33% in mouse. Differential splicing analysis revealed that about 40% of the splicing changes at RNA level are concordant with changes in translation. Furthermore, orthologous cassette exons between human and mouse preserve the directionality of the change, and are enriched in microexons in a comparison between glia and glioma. ORQAS leverages ribosome profiling to uncover a widespread and evolutionarily conserved impact of differential splicing on translation, particularly of microexon-containing isoforms.
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Affiliation(s)
- Marina Reixachs-Solé
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, 2601, Australia
- EMBL Australia Partner Laboratory Network at the Australian National University, Canberra, ACT, 2601, Australia
| | - Jorge Ruiz-Orera
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany
| | - M Mar Albà
- IMIM - Hospital del Mar Medical Research Institute, E08003, Barcelona, Spain
- Catalan Institution for Research and Advanced Studies, E08010, Barcelona, Spain
- Pompeu Fabra University, E08003, Barcelona, Spain
| | - Eduardo Eyras
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, 2601, Australia.
- EMBL Australia Partner Laboratory Network at the Australian National University, Canberra, ACT, 2601, Australia.
- IMIM - Hospital del Mar Medical Research Institute, E08003, Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies, E08010, Barcelona, Spain.
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100
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Fochi S, Lorenzi P, Galasso M, Stefani C, Trabetti E, Zipeto D, Romanelli MG. The Emerging Role of the RBM20 and PTBP1 Ribonucleoproteins in Heart Development and Cardiovascular Diseases. Genes (Basel) 2020; 11:genes11040402. [PMID: 32276354 PMCID: PMC7230170 DOI: 10.3390/genes11040402] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing is a regulatory mechanism essential for cell differentiation and tissue organization. More than 90% of human genes are regulated by alternative splicing events, which participate in cell fate determination. The general mechanisms of splicing events are well known, whereas only recently have deep-sequencing, high throughput analyses and animal models provided novel information on the network of functionally coordinated, tissue-specific, alternatively spliced exons. Heart development and cardiac tissue differentiation require thoroughly regulated splicing events. The ribonucleoprotein RBM20 is a key regulator of the alternative splicing events required for functional and structural heart properties, such as the expression of TTN isoforms. Recently, the polypyrimidine tract-binding protein PTBP1 has been demonstrated to participate with RBM20 in regulating splicing events. In this review, we summarize the updated knowledge relative to RBM20 and PTBP1 structure and molecular function; their role in alternative splicing mechanisms involved in the heart development and function; RBM20 mutations associated with idiopathic dilated cardiovascular disease (DCM); and the consequences of RBM20-altered expression or dysfunction. Furthermore, we discuss the possible application of targeting RBM20 in new approaches in heart therapies.
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