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Fisher AJ, Beal PA. Structural perspectives on adenosine to inosine RNA editing by ADARs. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102284. [PMID: 39165563 PMCID: PMC11334849 DOI: 10.1016/j.omtn.2024.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Adenosine deaminases acting on RNA (ADARs) are enzymes that catalyze the hydrolytic deamination of adenosine to inosine. The editing feature of ADARs has garnered much attention as a therapeutic tool to repurpose ADARs to correct disease-causing mutations at the mRNA level in a technique called site-directed RNA editing (SDRE). Administering a short guide RNA oligonucleotide that hybridizes to a mutant sequence forms the requisite dsRNA substrate, directing ADARs to edit the desired adenosine. However, much is still unknown about ADARs' selectivity and sequence-specific effects on editing. Atomic-resolution structures can help provide additional insight to ADARs' selectivity and lead to novel guide RNA designs. Indeed, recent structures of ADAR domains have expanded our understanding on RNA binding and the base-flipping catalytic mechanism. These efforts have enabled the rational design of improved ADAR guide strands and advanced the therapeutic potential of the SDRE approach. While no full-length structure of any ADAR is known, this review presents an exposition of the structural basis for function of the different ADAR domains, focusing on human ADAR2. Key insights are extrapolated to human ADAR1, which is of substantial interest because of its widespread expression in most human tissues.
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Affiliation(s)
- Andrew J. Fisher
- Department of Chemistry, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - Peter A. Beal
- Department of Chemistry, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
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2
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Eliad B, Schneider N, Ben-Naim Zgayer O, Amichan Y, Glaser F, Erdmann EA, Rajendren S, Hundley HA, Lamm AT. ADBP-1 regulates ADR-2 nuclear localization to control editing substrate selection. Nucleic Acids Res 2024; 52:9501-9518. [PMID: 39036970 PMCID: PMC11381337 DOI: 10.1093/nar/gkae641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/05/2024] [Accepted: 07/09/2024] [Indexed: 07/23/2024] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a prevalent and conserved RNA modification. While A-to-I RNA editing is essential in mammals, in Caenorhabditis elegans, it is not, making them invaluable for RNA editing research. In C. elegans, ADR-2 is the sole catalytic A-to-I editing enzyme, and ADR-1 is an RNA editing regulator. ADAR localization is well-studied in humans but not well-established in C. elegans. In this study, we examine the cellular and tissue-specific localization of ADR-2. We show that while ADR-2 is present in most cells in the embryo, at later developmental stages, its expression is both tissue- and cell-type-specific. Additionally, both ADARs are mainly in the nucleus. ADR-2 is adjacent to the chromosomes during the cell cycle. We show that the nuclear localization of endogenous ADR-2 depends on ADBP-1, not ADR-1. In adbp-1 mutant worms, ADR-2 is mislocalized, while ADR-1 is not, leading to decreased editing levels and de-novo editing, mostly in exons, suggesting that ADR-2 is also functional in the cytoplasm. Besides, mutated ADBP-1 affects gene expression. Furthermore, we show that ADR-2 targets adenosines with different surrounding nucleotides in exons and introns. Our findings indicate that ADR-2 cellular localization is highly regulated and affects its function.
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Affiliation(s)
- Berta Eliad
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Noa Schneider
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Orna Ben-Naim Zgayer
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Yarden Amichan
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Fabian Glaser
- Technion Center for Structural Biology, Technion Human Health Initiative, Technion, Haifa 32000, Israel
| | - Emily A Erdmann
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Suba Rajendren
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Heather A Hundley
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Ayelet T Lamm
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
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3
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Eliad B, Schneider N, Zgayer OBN, Amichan Y, Glaser F, Erdmann EA, Rajendren S, Hundley HA, Lamm AT. ADBP-1 regulates ADR-2 nuclear localization to control editing substrate selection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.14.540679. [PMID: 38895382 PMCID: PMC11185548 DOI: 10.1101/2023.05.14.540679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a prevalent and conserved RNA modification. While A-to-I RNA editing is essential in mammals, in Caenorhabditis elegans , it is not, making them invaluable for RNA editing research. In C. elegans , ADR-2 is the sole catalytic A-to-I editing enzyme, and ADR-1 is an RNA editing regulator. ADAR localization is well-studied in humans but not well-established in C. elegans . In this study, we examine the cellular and tissue-specific localization of ADR-2. We show that while ADR-2 is present in most cells in the embryo, at later developmental stages, its expression is both tissue- and cell-type-specific. Additionally, both ADARs are mainly in the nucleus. ADR-2 is adjacent to the chromosomes during the cell cycle. We show that the nuclear localization of endogenous ADR-2 depends on ADBP-1, not ADR-1. In adbp-1 mutant worms, ADR-2 is mislocalized, while ADR-1 is not, leading to decreased editing levels and de-novo editing, mostly in exons, suggesting that ADR-2 is also functional in the cytoplasm. Besides, mutated ADBP-1 affects gene expression. Furthermore, we show that ADR-2 targets adenosines with different surrounding nucleotides in exons and introns. Our findings indicate that ADR-2 cellular localization is highly regulated and affects its function.
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Zawisza-Álvarez M, Peñuela-Melero J, Vegas E, Reverter F, Garcia-Fernàndez J, Herrera-Úbeda C. Exploring functional conservation in silico: a new machine learning approach to RNA-editing. Brief Bioinform 2024; 25:bbae332. [PMID: 38980372 PMCID: PMC11232462 DOI: 10.1093/bib/bbae332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/09/2024] [Accepted: 06/25/2024] [Indexed: 07/10/2024] Open
Abstract
Around 50 years ago, molecular biology opened the path to understand changes in forms, adaptations, complexity, or the basis of human diseases through myriads of reports on gene birth, gene duplication, gene expression regulation, and splicing regulation, among other relevant mechanisms behind gene function. Here, with the advent of big data and artificial intelligence (AI), we focus on an elusive and intriguing mechanism of gene function regulation, RNA editing, in which a single nucleotide from an RNA molecule is changed, with a remarkable impact in the increase of the complexity of the transcriptome and proteome. We present a new generation approach to assess the functional conservation of the RNA-editing targeting mechanism using two AI learning algorithms, random forest (RF) and bidirectional long short-term memory (biLSTM) neural networks with an attention layer. These algorithms, combined with RNA-editing data coming from databases and variant calling from same-individual RNA and DNA-seq experiments from different species, allowed us to predict RNA-editing events using both primary sequence and secondary structure. Then, we devised a method for assessing conservation or divergence in the molecular mechanisms of editing completely in silico: the cross-testing analysis. This novel method not only helps to understand the conservation of the editing mechanism through evolution but could set the basis for achieving a better understanding of the adenosine-targeting mechanism in other fields.
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Affiliation(s)
- Michał Zawisza-Álvarez
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
| | - Jesús Peñuela-Melero
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
| | - Esteban Vegas
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Calle Sinesio Delgado 4, 28029 Madrid, Spain
| | - Ferran Reverter
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
| | - Jordi Garcia-Fernàndez
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
| | - Carlos Herrera-Úbeda
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
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5
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Crane AB, Jetti SK, Littleton JT. A stochastic RNA editing process targets a limited number of sites in individual Drosophila glutamatergic motoneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594696. [PMID: 38798345 PMCID: PMC11118563 DOI: 10.1101/2024.05.17.594696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
RNA editing is a post-transcriptional source of protein diversity and occurs across the animal kingdom. Given the complete profile of mRNA targets and their editing rate in individual cells is unclear, we analyzed single cell RNA transcriptomes from Drosophila larval tonic and phasic glutamatergic motoneuron subtypes to determine the most highly edited targets and identify cell-type specific editing. From ∼15,000 genes encoded in the genome, 316 high confidence A-to-I canonical RNA edit sites were identified, with 102 causing missense amino acid changes in proteins regulating membrane excitability, synaptic transmission, and cellular function. Some sites showed 100% editing in single neurons as observed with mRNAs encoding mammalian AMPA receptors. However, most sites were edited at lower levels and generated variable expression of edited and unedited mRNAs within individual neurons. Together, these data provide insights into how the RNA editing landscape alters protein function to modulate the properties of two well-characterized neuronal populations in Drosophila .
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6
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Liu J, Zheng C, Duan Y. New comparative genomic evidence supporting the proteomic diversification role of A-to-I RNA editing in insects. Mol Genet Genomics 2024; 299:46. [PMID: 38642133 DOI: 10.1007/s00438-024-02141-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/29/2023] [Indexed: 04/22/2024]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, resembling A-to-G mutation, confers adaptiveness by increasing proteomic diversity in a temporal-spatial manner. This evolutionary theory named "proteomic diversifying hypothesis" has only partially been tested in very few organisms like Drosophila melanogaster, mainly by observing the positive selection on nonsynonymous editing events. To find additional genome-wide evidences supporting this interesting assumption, we retrieved the genomes of four Drosophila species and collected 20 deep-sequenced transcriptomes of different developmental stages and neuron populations of D. melanogaster. We systematically profiled the RNA editomes in these samples and performed meticulous comparative genomic analyses. Further evidences were found to support the diversifying hypothesis. (1) None of the nonsynonymous editing sites in D. melanogaster had ancestral G-alleles, while the silent editing sites had an unignorable fraction of ancestral G-alleles; (2) Only very few nonsynonymous editing sites in D. melanogaster had corresponding G-alleles derived in the genomes of sibling species, and the fraction of such situation was significantly lower than that of silent editing sites; (3) The few nonsynonymous editing with corresponding G-alleles had significantly more variable editing levels (across samples) than other nonsynonymous editing sites in D. melanogaster. The proteomic diversifying nature of RNA editing in Drosophila excludes the restorative role which favors an ancestral G-allele. The few fixed G-alleles in sibling species might facilitate the adaptation to particular environment and the corresponding nonsynonymous editing in D. melanogaster would introduce stronger advantage of flexible proteomic diversification. With multi-Omics data, our study consolidates the nature of evolutionary significance of A-to-I RNA editing sites in model insects.
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Affiliation(s)
- Jiyao Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Caiqing Zheng
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Yuange Duan
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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7
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Szabo B, Mandl TC, Woldrich B, Diensthuber G, Martin D, Jantsch MF, Licht K. RNA Pol II-dependent transcription efficiency fine-tunes A-to-I editing levels. Genome Res 2024; 34:231-242. [PMID: 38471738 PMCID: PMC10984384 DOI: 10.1101/gr.277686.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024]
Abstract
A-to-I RNA editing is a widespread epitranscriptomic phenomenon leading to the conversion of adenosines to inosines, which are primarily interpreted as guanosines by cellular machines. Consequently, A-to-I editing can alter splicing or lead to recoding of transcripts. As misregulation of editing can cause a variety of human diseases, A-to-I editing requires tight regulation of the extent of deamination, particularly in protein-coding regions. The bulk of A-to-I editing occurs cotranscriptionally. Thus, we studied A-to-I editing regulation in the context of transcription and pre-mRNA processing. We show that stimulation of transcription impacts editing levels. Activation of the transcription factor MYC leads to an up-regulation of A-to-I editing, particularly in transcripts that are suppressed upon MYC activation. Moreover, low pre-mRNA synthesis rates and low pre-mRNA expression levels support high levels of editing. We also show that editing levels greatly differ between nascent pre-mRNA and mRNA in a cellular system, as well as in mouse tissues. Editing levels can increase or decrease from pre-mRNA to mRNA and can vary across editing targets and across tissues, showing that pre-mRNA processing is an important layer of editing regulation. Several lines of evidence suggest that the differences emerge during pre-mRNA splicing. Moreover, actinomycin D treatment of primary neuronal cells and editing level analysis suggests that regulation of editing levels also depends on transcription.
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Affiliation(s)
- Brigitta Szabo
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Therese C Mandl
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Bernhard Woldrich
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Gregor Diensthuber
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - David Martin
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael F Jantsch
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Konstantin Licht
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
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8
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Liu J, Zhao T, Zheng C, Ma L, Song F, Tian L, Cai W, Li H, Duan Y. An orthology-based methodology as a complementary approach to retrieve evolutionarily conserved A-to-I RNA editing sites. RNA Biol 2024; 21:29-45. [PMID: 39256954 PMCID: PMC11404581 DOI: 10.1080/15476286.2024.2397757] [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] [Revised: 08/14/2024] [Accepted: 08/19/2024] [Indexed: 09/12/2024] Open
Abstract
Adar-mediated adenosine-to-inosine (A-to-I) mRNA editing is a conserved mechanism that exerts diverse regulatory functions during the development, evolution, and adaptation of metazoans. The accurate detection of RNA editing sites helps us understand their biological significance. In this work, with an improved genome assembly of honeybee (Apis mellifera), we used a new orthology-based methodology to complement the traditional pipeline of (de novo) RNA editing detection. Compared to the outcome of traditional pipeline, we retrieved many novel editing sites in CDS that are deeply conserved between honeybee and other distantly related insects. The newly retrieved sites were missed by the traditional de novo identification due to the stringent criteria for controlling false-positive rate. Caste-specific editing sites are identified, including an Ile>Met auto-recoding site in Adar. This recoding was even conserved between honeybee and bumblebee, suggesting its putative regulatory role in shaping the phenotypic plasticity of eusocial Hymenoptera. In summary, we proposed a complementary approach to the traditional pipeline and retrieved several previously unnoticed CDS editing sites. From both technical and biological aspects, our works facilitate future researches on finding the functional editing sites and advance our understanding on the connection between RNA editing and the great phenotypic diversity of organisms.
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Affiliation(s)
- Jiyao Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Tianyou Zhao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Caiqing Zheng
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Ling Ma
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Fan Song
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Li Tian
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Wanzhi Cai
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Hu Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
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9
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Nguyen TA, Heng JWJ, Ng YT, Sun R, Fisher S, Oguz G, Kaewsapsak P, Xue S, Reversade B, Ramasamy A, Eisenberg E, Tan MH. Deep transcriptome profiling reveals limited conservation of A-to-I RNA editing in Xenopus. BMC Biol 2023; 21:251. [PMID: 37946231 PMCID: PMC10636886 DOI: 10.1186/s12915-023-01756-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Xenopus has served as a valuable model system for biomedical research over the past decades. Notably, ADAR was first detected in frog oocytes and embryos as an activity that unwinds RNA duplexes. However, the scope of A-to-I RNA editing by the ADAR enzymes in Xenopus remains underexplored. RESULTS Here, we identify millions of editing events in Xenopus with high accuracy and systematically map the editome across developmental stages, adult organs, and species. We report diverse spatiotemporal patterns of editing with deamination activity highest in early embryogenesis before zygotic genome activation and in the ovary. Strikingly, editing events are poorly conserved across different Xenopus species. Even sites that are detected in both X. laevis and X. tropicalis show largely divergent editing levels or developmental profiles. In protein-coding regions, only a small subset of sites that are found mostly in the brain are well conserved between frogs and mammals. CONCLUSIONS Collectively, our work provides fresh insights into ADAR activity in vertebrates and suggest that species-specific editing may play a role in each animal's unique physiology or environmental adaptation.
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Affiliation(s)
- Tram Anh Nguyen
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Jia Wei Joel Heng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Yan Ting Ng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Rui Sun
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Shira Fisher
- Faculty of Life Sciences, The Mina and Everard Goodman, Bar-Ilan University, Ramat Gan, Israel
| | - Gokce Oguz
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Pornchai Kaewsapsak
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Shifeng Xue
- Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Bruno Reversade
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Medical Genetics, School of Medicine (KUSoM), Koç University, Istanbul, Turkey
| | - Adaikalavan Ramasamy
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
| | - Meng How Tan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore.
- HP-NTU Digital Manufacturing Corporate Lab, Nanyang Technological University, Singapore, Singapore.
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10
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Zhang Y, Duan Y. Genome-Wide Analysis on Driver and Passenger RNA Editing Sites Suggests an Underestimation of Adaptive Signals in Insects. Genes (Basel) 2023; 14:1951. [PMID: 37895300 PMCID: PMC10606203 DOI: 10.3390/genes14101951] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing leads to a similar effect to A-to-G mutations. RNA editing provides a temporo-spatial flexibility for organisms. Nonsynonymous (Nonsyn) RNA editing in insects is over-represented compared with synonymous (Syn) editing, suggesting adaptive signals of positive selection on Nonsyn editing during evolution. We utilized the brain RNA editome of Drosophila melanogaster to systematically study the LD (r2) between editing sites and infer its impact on the adaptive signals of RNA editing. Pairs of editing sites (PESs) were identified from the transcriptome. For CDS PESs of two consecutive editing sites, their occurrence was significantly biased to type-3 PES (Syn-Nonsyn). The haplotype frequency of type-3 PES exhibited a significantly higher abundance of AG than GA, indicating that the rear Nonsyn site is the driver that promotes the editing of the front Syn site (passenger). The exclusion of passenger Syn sites dramatically amplifies the adaptive signal of Nonsyn RNA editing. Our study for the first time quantitatively demonstrates that the linkage between RNA editing events comes from hitchhiking effects and leads to the underestimation of adaptive signals for Nonsyn editing. Our work provides novel insights for studying the evolutionary significance of RNA editing events.
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Affiliation(s)
| | - Yuange Duan
- MOA Key Lab of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
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11
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Patrasso EA, Raikundalia S, Arango D. Regulation of the epigenome through RNA modifications. Chromosoma 2023; 132:231-246. [PMID: 37138119 PMCID: PMC10524150 DOI: 10.1007/s00412-023-00794-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 05/05/2023]
Abstract
Chemical modifications of nucleotides expand the complexity and functional properties of genomes and transcriptomes. A handful of modifications in DNA bases are part of the epigenome, wherein DNA methylation regulates chromatin structure, transcription, and co-transcriptional RNA processing. In contrast, more than 150 chemical modifications of RNA constitute the epitranscriptome. Ribonucleoside modifications comprise a diverse repertoire of chemical groups, including methylation, acetylation, deamination, isomerization, and oxidation. Such RNA modifications regulate all steps of RNA metabolism, including folding, processing, stability, transport, translation, and RNA's intermolecular interactions. Initially thought to influence all aspects of the post-transcriptional regulation of gene expression exclusively, recent findings uncovered a crosstalk between the epitranscriptome and the epigenome. In other words, RNA modifications feedback to the epigenome to transcriptionally regulate gene expression. The epitranscriptome achieves this feat by directly or indirectly affecting chromatin structure and nuclear organization. This review highlights how chemical modifications in chromatin-associated RNAs (caRNAs) and messenger RNAs (mRNAs) encoding factors involved in transcription, chromatin structure, histone modifications, and nuclear organization affect gene expression transcriptionally.
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Affiliation(s)
- Emmely A Patrasso
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Medical and Pharmaceutical Biotechnology Program, IMC University of Applied Sciences, Krems, Austria
| | - Sweta Raikundalia
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Daniel Arango
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, USA.
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12
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Duan Y, Xu Y, Song F, Tian L, Cai W, Li H. Differential adaptive RNA editing signals between insects and plants revealed by a new measurement termed haplotype diversity. Biol Direct 2023; 18:47. [PMID: 37592344 PMCID: PMC10433597 DOI: 10.1186/s13062-023-00404-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND C-to-U RNA editing in plants is believed to confer its evolutionary adaptiveness by reversing unfavorable DNA mutations. This "restorative hypothesis" has not yet been tested genome-wide. In contrast, A-to-I RNA editing in insects like Drosophila and honeybee is already known to benefit the host by increasing proteomic diversity in a spatial-temporal manner (namely "diversifying hypothesis"). METHODS We profiled the RNA editomes of multiple tissues of Arabidopsis thaliana, Drosophila melanogaster, and Apis melifera. We unprecedentedly defined the haplotype diversity (HD) of RNA molecules based on nonsynonymous editing events (recoding sites). RESULTS Signals of adaptation is confirmed in Arabidopsis by observing higher frequencies and levels at nonsynonymous editing sites over synonymous sites. Compared to A-to-I recoding sites in Drosophila, the C-to-U recoding sites in Arabidopsis show significantly lower HD, presumably due to the stronger linkage between C-to-U events. CONCLUSIONS C-to-U RNA editing in Arabidopsis is adaptive but it is not designed for diversifying the proteome like A-to-I editing in Drosophila. Instead, C-to-U recoding sites resemble DNA mutations. Our observation supports the restorative hypothesis of plant C-to-U editing which claims that editing is used for fixing unfavorable genomic sequences.
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Affiliation(s)
- Yuange Duan
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
| | - Ye Xu
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Fan Song
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Li Tian
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Wanzhi Cai
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Hu Li
- Key Laboratory of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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13
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Booth BJ, Nourreddine S, Katrekar D, Savva Y, Bose D, Long TJ, Huss DJ, Mali P. RNA editing: Expanding the potential of RNA therapeutics. Mol Ther 2023; 31:1533-1549. [PMID: 36620962 PMCID: PMC9824937 DOI: 10.1016/j.ymthe.2023.01.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/06/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
RNA therapeutics have had a tremendous impact on medicine, recently exemplified by the rapid development and deployment of mRNA vaccines to combat the COVID-19 pandemic. In addition, RNA-targeting drugs have been developed for diseases with significant unmet medical needs through selective mRNA knockdown or modulation of pre-mRNA splicing. Recently, RNA editing, particularly antisense RNA-guided adenosine deaminase acting on RNA (ADAR)-based programmable A-to-I editing, has emerged as a powerful tool to manipulate RNA to enable correction of disease-causing mutations and modulate gene expression and protein function. Beyond correcting pathogenic mutations, the technology is particularly well suited for therapeutic applications that require a transient pharmacodynamic effect, such as the treatment of acute pain, obesity, viral infection, and inflammation, where it would be undesirable to introduce permanent alterations to the genome. Furthermore, transient modulation of protein function, such as altering the active sites of enzymes or the interface of protein-protein interactions, opens the door to therapeutic avenues ranging from regenerative medicine to oncology. These emerging RNA-editing-based toolsets are poised to broadly impact biotechnology and therapeutic applications. Here, we review the emerging field of therapeutic RNA editing, highlight recent laboratory advancements, and discuss the key challenges on the path to clinical development.
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Affiliation(s)
| | - Sami Nourreddine
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | | | | | | | | | | | - Prashant Mali
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
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14
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Santos F, Capela AM, Mateus F, Nóbrega-Pereira S, Bernardes de Jesus B. Non-coding antisense transcripts: fine regulation of gene expression in cancer. Comput Struct Biotechnol J 2022; 20:5652-5660. [PMID: 36284703 PMCID: PMC9579725 DOI: 10.1016/j.csbj.2022.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 11/14/2022] Open
Abstract
Natural antisense transcripts (NATs) are coding or non-coding RNA sequences transcribed on the opposite direction from the same genomic locus. NATs are widely distributed throughout the human genome and seem to play crucial roles in physiological and pathological processes, through newly described and targeted mechanisms. NATs represent the intricate complexity of the genome organization and constitute another layer of potential targets in disease. Here, we focus on the interesting and unique role of non-coding NATs in cancer, paying particular attention to those acting as miRNA sponges.
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Affiliation(s)
| | | | | | | | - Bruno Bernardes de Jesus
- Corresponding author at: Department of Medical Sciences and Institute of Biomedicine – iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal.
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15
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Li D, Liu Y, Yi P, Zhu Z, Li W, Zhang QC, Li JB, Ou G. RNA editing restricts hyperactive ciliary kinases. Science 2021; 373:984-991. [PMID: 34446600 DOI: 10.1126/science.abd8971] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 04/01/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022]
Abstract
Protein kinase activity must be precisely regulated, but how a cell governs hyperactive kinases remains unclear. In this study, we generated a constitutively active mitogen-activated protein kinase DYF-5 (DYF-5CA) in Caenorhabditis elegans that disrupted sensory cilia. Genetic suppressor screens identified that mutations of ADR-2, an RNA adenosine deaminase, rescued ciliary phenotypes of dyf-5CA We found that dyf-5CA animals abnormally transcribed antisense RNAs that pair with dyf-5CA messenger RNA (mRNA) to form double-stranded RNA, recruiting ADR-2 to edit the region ectopically. RNA editing impaired dyf-5CA mRNA splicing, and the resultant intron retentions blocked DYF-5CA protein translation and activated nonsense-mediated dyf-5CA mRNA decay. The kinase RNA editing requires kinase hyperactivity. The similar RNA editing-dependent feedback regulation restricted the other ciliary kinases NEKL-4/NEK10 and DYF-18/CCRK, which suggests a widespread mechanism that underlies kinase regulation.
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Affiliation(s)
- Dongdong Li
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Yufan Liu
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Peishan Yi
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Zhiwen Zhu
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Wei Li
- School of Medicine, Tsinghua University, Beijing, China
| | - Qiangfeng Cliff Zhang
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China
| | - Jin Billy Li
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China. .,Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.,McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
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16
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Frassinelli L, Orecchini E, Al-Wardat S, Tripodi M, Mancone C, Doria M, Galardi S, Ciafrè SA, Michienzi A. The RNA editing enzyme ADAR2 restricts L1 mobility. RNA Biol 2021; 18:75-87. [PMID: 34224323 PMCID: PMC8677026 DOI: 10.1080/15476286.2021.1940020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) are enzymes that convert adenosines to inosines in double-stranded RNAs (RNA editing A-to-I). ADAR1 and ADAR2 were previously reported as HIV-1 proviral factors. The aim of this study was to investigate the composition of the ADAR2 ribonucleoprotein complex during HIV-1 expression. By using a dual-tag affinity purification procedure in cells expressing HIV-1 followed by mass spectrometry analysis, we identified 10 non-ribosomal ADAR2-interacting factors. A significant fraction of these proteins was previously found associated to the Long INterspersed Element 1 (LINE1 or L1) ribonucleoparticles and to regulate the life cycle of L1 retrotransposons. Considering that we previously demonstrated that ADAR1 is an inhibitor of LINE-1 retrotransposon activity, we investigated whether also ADAR2 played a similar function. To reach this goal, we performed specific cell culture retrotransposition assays in cells overexpressing or ablated for ADAR2. These experiments unveil a novel function of ADAR2 as suppressor of L1 retrotransposition. Furthermore, we showed that ADAR2 binds the basal L1 RNP complex. Overall, these data support the role of ADAR2 as regulator of L1 life cycle.
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Affiliation(s)
- Loredana Frassinelli
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
| | - Elisa Orecchini
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
| | - Sofian Al-Wardat
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
| | - Marco Tripodi
- National Institute for Infectious Diseases L. Spallanzani, IRCCS, Rome, Italy.,Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Carmine Mancone
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Margherita Doria
- Unit of Primary Immunodeficiency, Bambino Gesu` Children's Hospital, IRCCS, Rome, Italy
| | - Silvia Galardi
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
| | - Silvia Anna Ciafrè
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
| | - Alessandro Michienzi
- Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy
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17
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Sapiro AL, Freund EC, Restrepo L, Qiao HH, Bhate A, Li Q, Ni JQ, Mosca TJ, Li JB. Zinc Finger RNA-Binding Protein Zn72D Regulates ADAR-Mediated RNA Editing in Neurons. Cell Rep 2021; 31:107654. [PMID: 32433963 PMCID: PMC7306179 DOI: 10.1016/j.celrep.2020.107654] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/11/2020] [Accepted: 04/23/2020] [Indexed: 12/14/2022] Open
Abstract
Adenosine-to-inosine RNA editing, catalyzed by adenosine deaminase acting on RNA (ADAR) enzymes, alters RNA sequences from those encoded by DNA. These editing events are dynamically regulated, but few trans regulators of ADARs are known in vivo. Here, we screen RNA-binding proteins for roles in editing regulation with knockdown experiments in the Drosophila brain. We identify zinc-finger protein at 72D (Zn72D) as a regulator of editing levels at a majority of editing sites in the brain. Zn72D both regulates ADAR protein levels and interacts with ADAR in an RNA-dependent fashion, and similar to ADAR, Zn72D is necessary to maintain proper neuromuscular junction architecture and fly mobility. Furthermore, Zn72D’s regulatory role in RNA editing is conserved because the mammalian homolog of Zn72D, Zfr, regulates editing in mouse primary neurons. The broad and conserved regulation of ADAR editing by Zn72D in neurons sustains critically important editing events. Sapiro et al. identify Drosophila Zn72D as an influential regulator of neuronal A-to-I RNA editing and synaptic morphology. Zn72D regulates ADAR levels and editing at a large subset of editing sites, providing insight into the maintenance of critical tissue-specific RNA editing events.
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Affiliation(s)
- Anne L Sapiro
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Emily C Freund
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Lucas Restrepo
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Huan-Huan Qiao
- Tianjin Key Laboratory of Brain Science and Neural Engineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Amruta Bhate
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Qin Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Jian-Quan Ni
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Timothy J Mosca
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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18
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Duan Y, Tang X, Lu J. Evolutionary driving forces of A-to-I editing in metazoans. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1666. [PMID: 33998151 DOI: 10.1002/wrna.1666] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/12/2021] [Accepted: 04/24/2021] [Indexed: 11/05/2022]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing is an evolutionarily conserved mechanism that converts adenosines to inosines in metazoans' transcriptomes. However, the landscapes of editomes have considerably changed during evolution. Here, we review some of our current knowledge of A-to-I editing in the metazoan transcriptomes, focusing on the possible evolutionary driving forces underlying the editing events. First, we review the evolution of ADAR gene family in animals. Then, we summarize the recent advances in characterizing the editomes of various metazoan species. Next, we highlight several factors contributing to the interspecies differences in editomes, including variations in copy number and expression patterns of ADAR genes, the differences in genomic architectures and contents, and the differences in the efficacy of natural selection. After that, we review the possible diversifying and restorative effects of the editing (recoding) events that change the protein sequences. Finally, we discuss the possible convergent evolution of RNA editing in distantly related clades. This article is categorized under: RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Processing > RNA Editing and Modification.
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Affiliation(s)
- Yuange Duan
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
| | - Xiaolu Tang
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
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19
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O'Loughlin SM, Forster AJ, Fuchs S, Dottorini T, Nolan T, Crisanti A, Burt A. Ultra-conserved sequences in the genomes of highly diverse Anopheles mosquitoes, with implications for malaria vector control. G3-GENES GENOMES GENETICS 2021; 11:6175102. [PMID: 33730159 PMCID: PMC8495744 DOI: 10.1093/g3journal/jkab086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/08/2021] [Indexed: 12/30/2022]
Abstract
DNA sequences that are exactly conserved over long evolutionary time scales have been observed in a variety of taxa. Such sequences are likely under strong functional constraint and they have been useful in the field of comparative genomics for identifying genome regions with regulatory function. A potential new application for these ultra-conserved elements (UCEs) has emerged in the development of gene drives to control mosquito populations. Many gene drives work by recognizing and inserting at a specific target sequence in the genome, often imposing a reproductive load as a consequence. They can therefore select for target sequence variants that provide resistance to the drive. Focusing on highly conserved, highly constrained sequences lowers the probability that variant, gene drive-resistant alleles can be tolerated. Here, we search for conserved sequences of 18 bp and over in an alignment of 21 Anopheles genomes, spanning an evolutionary timescale of 100 million years, and characterize the resulting sequences according to their location and function. Over 8000 UCEs were found across the alignment, with a maximum length of 164 bp. Length-corrected gene ontology analysis revealed that genes containing Anopheles UCEs were over-represented in categories with structural or nucleotide-binding functions. Known insect transcription factor binding sites were found in 48% of intergenic Anopheles UCEs. When we looked at the genome sequences of 1142 wild-caught mosquitoes, we found that 15% of the Anopheles UCEs contained no polymorphisms. Our list of Anopheles UCEs should provide a valuable starting point for the selection and testing of new targets for gene-drive modification in the mosquitoes that transmit malaria.
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Affiliation(s)
- Samantha M O'Loughlin
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK
| | - Annie J Forster
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK
| | - Silke Fuchs
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK
| | - Tania Dottorini
- School of Veterinary Medicine and Science, Sutton Bonington Campus, University of Nottingham, Leicestershire, LE12 5RD, UK
| | - Tony Nolan
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK.,Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK
| | - Austin Burt
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, SL5 7PY, UK
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20
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Saldi T, Riemondy K, Erickson B, Bentley DL. Alternative RNA structures formed during transcription depend on elongation rate and modify RNA processing. Mol Cell 2021; 81:1789-1801.e5. [PMID: 33631106 DOI: 10.1016/j.molcel.2021.01.040] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/24/2022]
Abstract
Most RNA processing occurs co-transcriptionally. We interrogated nascent pol II transcripts by chemical and enzymatic probing and determined how the "nascent RNA structureome" relates to splicing, A-I editing and transcription speed. RNA folding within introns and steep structural transitions at splice sites are associated with efficient co-transcriptional splicing. A slow pol II mutant elicits extensive remodeling into more folded conformations with increased A-I editing. Introns that become more structured at their 3' splice sites get co-transcriptionally excised more efficiently. Slow pol II altered folding of intronic Alu elements where cryptic splicing and intron retention are stimulated, an outcome mimicked by UV, which decelerates transcription. Slow transcription also remodeled RNA folding around alternative exons in distinct ways that predict whether skipping or inclusion is favored, even though it occurs post-transcriptionally. Hence, co-transcriptional RNA folding modulates post-transcriptional alternative splicing. In summary, the plasticity of nascent transcripts has widespread effects on RNA processing.
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Affiliation(s)
- Tassa Saldi
- RNA Bioscience Initiative, Department Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - Kent Riemondy
- RNA Bioscience Initiative, Department Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - Benjamin Erickson
- RNA Bioscience Initiative, Department Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - David L Bentley
- RNA Bioscience Initiative, Department Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA.
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21
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Duan Y, Dou S, Porath HT, Huang J, Eisenberg E, Lu J. A-to-I RNA editing in honeybees shows signals of adaptation and convergent evolution. iScience 2021; 24:101983. [PMID: 33458624 PMCID: PMC7797907 DOI: 10.1016/j.isci.2020.101983] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/18/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
Social insects exhibit extensive phenotypic diversities among the genetically similar individuals, suggesting a role for the epigenetic regulations beyond the genome level. The ADAR-mediated adenosine-to-inosine (A-to-I) RNA editing, an evolutionarily conserved mechanism, facilitates adaptive evolution by expanding proteomic diversities. Here, we characterize the A-to-I RNA editome of honeybees (Apis mellifera), identifying 407 high-confidence A-to-I editing sites. Editing is most abundant in the heads and shows signatures for positive selection. Editing behavior differs between foragers and nurses, suggesting a role for editing in caste differentiation. Although only five sites are conserved between bees and flies, an unexpectedly large number of genes exhibit editing in both species, albeit at different locations, including the nonsynonymous auto-editing of Adar. This convergent evolution, where the same target genes independently acquire recoding events in distant diverged clades, together with the signals of adaptation observed in honeybees alone, further supports the notion of recoding being adaptive. Nonsynonymous editing sites in honeybees were under positive selection Differential editing may contribute to the phenotypic diversity between sub-castes Target genes acquire editing in different clades, suggesting convergent evolution
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Affiliation(s)
- Yuange Duan
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, 100871, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Shengqian Dou
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Hagit T Porath
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 52900, Israel
| | - Jiaxing Huang
- Key Laboratory for Insect-Pollinator Biology of the Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100093, China
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, 100871, China
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22
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Vallecillo-Viejo IC, Liscovitch-Brauer N, Diaz Quiroz JF, Montiel-Gonzalez MF, Nemes SE, Rangan KJ, Levinson SR, Eisenberg E, Rosenthal JJC. Spatially regulated editing of genetic information within a neuron. Nucleic Acids Res 2020; 48:3999-4012. [PMID: 32201888 PMCID: PMC7192619 DOI: 10.1093/nar/gkaa172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/14/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022] Open
Abstract
In eukaryotic cells, with the exception of the specialized genomes of mitochondria and plastids, all genetic information is sequestered within the nucleus. This arrangement imposes constraints on how the information can be tailored for different cellular regions, particularly in cells with complex morphologies like neurons. Although messenger RNAs (mRNAs), and the proteins that they encode, can be differentially sorted between cellular regions, the information itself does not change. RNA editing by adenosine deamination can alter the genome's blueprint by recoding mRNAs; however, this process too is thought to be restricted to the nucleus. In this work, we show that ADAR2 (adenosine deaminase that acts on RNA), an RNA editing enzyme, is expressed outside of the nucleus in squid neurons. Furthermore, purified axoplasm exhibits adenosine-to-inosine activity and can specifically edit adenosines in a known substrate. Finally, a transcriptome-wide analysis of RNA editing reveals that tens of thousands of editing sites (>70% of all sites) are edited more extensively in the squid giant axon than in its cell bodies. These results indicate that within a neuron RNA editing can recode genetic information in a region-specific manner.
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Affiliation(s)
| | - Noa Liscovitch-Brauer
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
| | - Juan F Diaz Quiroz
- The Eugene Bell Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02540, USA
| | | | - Sonya E Nemes
- The Eugene Bell Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02540, USA
| | - Kavita J Rangan
- The Eugene Bell Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02540, USA
| | - Simon R Levinson
- Department of Physiology and Biophysics, University of Colorado at Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
| | - Joshua J C Rosenthal
- The Eugene Bell Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02540, USA
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23
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Kawamura Y, Koyama S, Yoshida R. Statistical inference of the rate of RNA polymerase II elongation by total RNA sequencing. Bioinformatics 2020; 35:1877-1884. [PMID: 30376061 PMCID: PMC6546130 DOI: 10.1093/bioinformatics/bty886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 08/03/2018] [Accepted: 10/29/2018] [Indexed: 12/25/2022] Open
Abstract
Motivation Sequencing total RNA without poly-A selection enables us to obtain a transcriptomic profile of nascent RNAs undergoing transcription with co-transcriptional splicing. In general, the RNA-seq reads exhibit a sawtooth pattern in a gene, which is characterized by a monotonically decreasing gradient across introns in the 5’–3’ direction, and by substantially higher levels of RNA-seq reads present in exonic regions. Such patterns result from the process of underlying transcription elongation by RNA polymerase II, which traverses the DNA strand in a 5’–3’ direction as it performs a complex series of mRNA synthesis and processing. Therefore, data of sequenced total RNAs could be utilized to infer the rate of transcription elongation by solving the inverse problem. Results Though solving the inverse problem in total RNA-seq has the great potential, statistical methods have not yet been fully developed. We demonstrate what extent the newly developed method can be useful. The objective is to reconstruct the spatial distribution of transcription elongation rates in a gene from a given noisy, sawtooth-like profile. It is necessary to recover the signal source of the elongation rates separately from several types of nuisance factors, such as unobserved modes of co-transcriptionally occurring mRNA splicing, which exert significant influences on the sawtooth shape. The present method was tested using published total RNA-seq data derived from mouse embryonic stem cells. We investigated the spatial characteristics of the estimated elongation rates, focusing especially on the relation to promoter-proximal pausing of RNA polymerase II, nucleosome occupancy and histone modification patterns. Availability and implementation A C implementation of PolSter and sample data are available at https://github.com/yoshida-lab/PolSter. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Yumi Kawamura
- Department of Statistical Science, The Graduate University for Advanced Studies (SOKENDAI), Tachikawa, Japan
| | - Shinsuke Koyama
- Department of Statistical Science, The Graduate University for Advanced Studies (SOKENDAI), Tachikawa, Japan.,Department of Statistical Modeling, The Institute of Statistical Mathematics, Research Organization of Information and Systems, Tachikawa, Japan
| | - Ryo Yoshida
- Department of Statistical Science, The Graduate University for Advanced Studies (SOKENDAI), Tachikawa, Japan.,Department of Statistical Data Science, The Institute of Statistical Mathematics, Research Organization of Information and Systems, Tachikawa, Japan
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24
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Herzog JJ, Xu W, Deshpande M, Rahman R, Suib H, Rodal AA, Rosbash M, Paradis S. TDP-43 dysfunction restricts dendritic complexity by inhibiting CREB activation and altering gene expression. Proc Natl Acad Sci U S A 2020; 117:11760-11769. [PMID: 32393629 PMCID: PMC7260973 DOI: 10.1073/pnas.1917038117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two related neurodegenerative diseases that present with similar TDP-43 pathology in patient tissue. TDP-43 is an RNA-binding protein which forms aggregates in neurons of ALS and FTD patients as well as in a subset of patients diagnosed with other neurodegenerative diseases. Despite our understanding that TDP-43 is essential for many aspects of RNA metabolism, it remains obscure how TDP-43 dysfunction contributes to neurodegeneration. Interestingly, altered neuronal dendritic morphology is a common theme among several neurological disorders and is thought to precede neurodegeneration. We previously found that both TDP-43 overexpression (OE) and knockdown (KD) result in reduced dendritic branching of cortical neurons. In this study, we used TRIBE (targets of RNA-binding proteins identified by editing) as an approach to identify signaling pathways that regulate dendritic branching downstream of TDP-43. We found that TDP-43 RNA targets are enriched for pathways that signal to the CREB transcription factor. We further found that TDP-43 dysfunction inhibits CREB activation and CREB transcriptional output, and restoring CREB signaling rescues defects in dendritic branching. Finally, we demonstrate, using RNA sequencing, that TDP-43 OE and KD cause similar changes in the abundance of specific messenger RNAs, consistent with their ability to produce similar morphological defects. Our data therefore provide a mechanism by which TDP-43 dysfunction interferes with dendritic branching, and may define pathways for therapeutic intervention in neurodegenerative diseases.
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Affiliation(s)
- Josiah J Herzog
- Department of Biology, Brandeis University, Waltham, MA 02453
- Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453
| | - Weijin Xu
- Department of Biology, Brandeis University, Waltham, MA 02453
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02453
| | - Mugdha Deshpande
- Department of Biology, Brandeis University, Waltham, MA 02453
- Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453
| | - Reazur Rahman
- Department of Biology, Brandeis University, Waltham, MA 02453
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02453
| | - Hannah Suib
- Department of Biology, Brandeis University, Waltham, MA 02453
- Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453
| | - Avital A Rodal
- Department of Biology, Brandeis University, Waltham, MA 02453
| | - Michael Rosbash
- Department of Biology, Brandeis University, Waltham, MA 02453;
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02453
| | - Suzanne Paradis
- Department of Biology, Brandeis University, Waltham, MA 02453;
- Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453
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25
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De los Santos H, Collins EJ, Mann C, Sagan AW, Jankowski MS, Bennett KP, Hurley JM. ECHO: an application for detection and analysis of oscillators identifies metabolic regulation on genome-wide circadian output. Bioinformatics 2020; 36:773-781. [PMID: 31384918 PMCID: PMC7523678 DOI: 10.1093/bioinformatics/btz617] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 07/24/2019] [Accepted: 08/02/2019] [Indexed: 01/07/2023] Open
Abstract
MOTIVATION Time courses utilizing genome scale data are a common approach to identifying the biological pathways that are controlled by the circadian clock, an important regulator of organismal fitness. However, the methods used to detect circadian oscillations in these datasets are not able to accommodate changes in the amplitude of the oscillations over time, leading to an underestimation of the impact of the clock on biological systems. RESULTS We have created a program to efficaciously identify oscillations in large-scale datasets, called the Extended Circadian Harmonic Oscillator application, or ECHO. ECHO utilizes an extended solution of the fixed amplitude oscillator that incorporates the amplitude change coefficient. Employing synthetic datasets, we determined that ECHO outperforms existing methods in detecting rhythms with decreasing oscillation amplitudes and in recovering phase shift. Rhythms with changing amplitudes identified from published biological datasets revealed distinct functions from those oscillations that were harmonic, suggesting purposeful biologic regulation to create this subtype of circadian rhythms. AVAILABILITY AND IMPLEMENTATION ECHO's full interface is available at https://github.com/delosh653/ECHO. An R package for this functionality, echo.find, can be downloaded at https://CRAN.R-project.org/package=echo.find. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Hannah De los Santos
- Department of Computer Science, Troy, NY 12180, USA,Institute for Data Exploration and Applications, Troy, NY 12180, USA
| | | | | | - April W Sagan
- Department of Mathematical Sciences, Troy, NY 12180, USA
| | | | - Kristin P Bennett
- Department of Computer Science, Troy, NY 12180, USA,Institute for Data Exploration and Applications, Troy, NY 12180, USA,Department of Mathematical Sciences, Troy, NY 12180, USA
| | - Jennifer M Hurley
- Department of Biological Sciences, Troy, NY 12180, USA,Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA,To whom correspondence should be addressed.
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26
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Pillman KA, Scheer KG, Hackett-Jones E, Saunders K, Bert AG, Toubia J, Whitfield HJ, Sapkota S, Sourdin L, Pham H, Le TD, Cursons J, Davis MJ, Gregory PA, Goodall GJ, Bracken CP. Extensive transcriptional responses are co-ordinated by microRNAs as revealed by Exon-Intron Split Analysis (EISA). Nucleic Acids Res 2019; 47:8606-8619. [PMID: 31372646 PMCID: PMC6895270 DOI: 10.1093/nar/gkz664] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 07/16/2019] [Accepted: 07/30/2019] [Indexed: 12/29/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) has been a subject of intense scrutiny as it facilitates metastasis and alters drug sensitivity. Although EMT-regulatory roles for numerous miRNAs and transcription factors are known, their functions can be difficult to disentangle, in part due to the difficulty in identifying direct miRNA targets from complex datasets and in deciding how to incorporate 'indirect' miRNA effects that may, or may not, represent biologically relevant information. To better understand how miRNAs exert effects throughout the transcriptome during EMT, we employed Exon-Intron Split Analysis (EISA), a bioinformatic technique that separates transcriptional and post-transcriptional effects through the separate analysis of RNA-Seq reads mapping to exons and introns. We find that in response to the manipulation of miRNAs, a major effect on gene expression is transcriptional. We also find extensive co-ordination of transcriptional and post-transcriptional regulatory mechanisms during both EMT and mesenchymal to epithelial transition (MET) in response to TGF-β or miR-200c respectively. The prominent transcriptional influence of miRNAs was also observed in other datasets where miRNA levels were perturbed. This work cautions against a narrow approach that is limited to the analysis of direct targets, and demonstrates the utility of EISA to examine complex regulatory networks involving both transcriptional and post-transcriptional mechanisms.
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Affiliation(s)
- Katherine A Pillman
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia.,ACRF Cancer Genomics Facility, Centre for Cancer Biology, SA Pathology, Adelaide, Australia
| | - Kaitlin G Scheer
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - Emily Hackett-Jones
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - Klay Saunders
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - Andrew G Bert
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - John Toubia
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia.,ACRF Cancer Genomics Facility, Centre for Cancer Biology, SA Pathology, Adelaide, Australia
| | - Holly J Whitfield
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Sunil Sapkota
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - Laura Sourdin
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia
| | - Hoang Pham
- School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia
| | - Thuc D Le
- School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia
| | - Joseph Cursons
- School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia.,Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Melissa J Davis
- School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia.,Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Philip A Gregory
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia.,School of Medicine, Discipline of Medicine, University of Adelaide, SA, Australia
| | - Gregory J Goodall
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia.,School of Medicine, Discipline of Medicine, University of Adelaide, SA, Australia
| | - Cameron P Bracken
- Centre for Cancer Biology, an alliance of SA Pathology and University of South Australia, Adelaide, SA, Australia.,School of Medicine, Discipline of Medicine, University of Adelaide, SA, Australia
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27
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Wissink EM, Vihervaara A, Tippens ND, Lis JT. Nascent RNA analyses: tracking transcription and its regulation. Nat Rev Genet 2019; 20:705-723. [PMID: 31399713 PMCID: PMC6858503 DOI: 10.1038/s41576-019-0159-6] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2019] [Indexed: 12/19/2022]
Abstract
The programmes that direct an organism's development and maintenance are encoded in its genome. Decoding of this information begins with regulated transcription of genomic DNA into RNA. Although transcription and its control can be tracked indirectly by measuring stable RNAs, it is only by directly measuring nascent RNAs that the immediate regulatory changes in response to developmental, environmental, disease and metabolic signals are revealed. Multiple complementary methods have been developed to quantitatively track nascent transcription genome-wide at nucleotide resolution, all of which have contributed novel insights into the mechanisms of gene regulation and transcription-coupled RNA processing. Here we critically evaluate the array of strategies used for investigating nascent transcription and discuss the recent conceptual advances they have provided.
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Affiliation(s)
- Erin M Wissink
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Anniina Vihervaara
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Nathaniel D Tippens
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, New York, NY, USA
| | - John T Lis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
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28
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Jain M, Jantsch MF, Licht K. The Editor's I on Disease Development. Trends Genet 2019; 35:903-913. [PMID: 31648814 DOI: 10.1016/j.tig.2019.09.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/12/2022]
Abstract
Adenosine-to-inosine (A-to-I) editing of RNA leads to deamination of adenosine to inosine. Inosine is interpreted as guanosine by the cellular machinery, thus altering the coding, folding, splicing, or transport of transcripts. A-to-I editing is tightly regulated. Altered editing has severe consequences for human health and can cause interferonopathies, neurological disorders, and cardiovascular disease, as well as impacting on cancer progression. ADAR1-mediated RNA editing plays an important role in antiviral immunity and is essential for distinguishing between endogenous and viral RNA, thereby preventing autoimmune disorders. Interestingly, A-to-I editing can be used not only to correct genomic mutations at the RNA level but also to modulate tumor antigenicity with large therapeutic potential. We highlight recent developments in the field, focusing on cancer and other human diseases.
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Affiliation(s)
- Mamta Jain
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Michael F Jantsch
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria.
| | - Konstantin Licht
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
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29
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Jiang D, Zhang J. The preponderance of nonsynonymous A-to-I RNA editing in coleoids is nonadaptive. Nat Commun 2019; 10:5411. [PMID: 31776345 PMCID: PMC6881472 DOI: 10.1038/s41467-019-13275-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/31/2019] [Indexed: 01/24/2023] Open
Abstract
A-to-I editing enzymatically converts the base adenosine (A) in RNA molecules to inosine (I), which is recognized as guanine (G) in translation. Exceptionally abundant A-to-I editing was recently discovered in the neural tissues of coleoids (octopuses, squids, and cuttlefishes), with a greater fraction of nonsynonymous sites than synonymous sites subject to high levels of editing. Although this phenomenon is thought to indicate widespread adaptive editing, its potential advantage is unknown. Here we propose an alternative, nonadaptive explanation. Specifically, increasing the cellular editing activity permits some otherwise harmful G-to-A nonsynonymous substitutions, because the As are edited to Is at sufficiently high levels. These high editing levels are constrained upon substitutions, resulting in the predominance of nonsynonymous editing at highly edited sites. Our evidence for this explanation suggests that the prevalent nonsynonymous editing in coleoids is generally nonadaptive, as in species with much lower editing activities. The neural tissues of coleoids have a greater fraction of nonsynonymous sites than synonymous sites subject to high levels of A-to-I RNA editing, a pattern thought to indicate widespread adaptive editing. Here the authors propose and provide evidence for an alternative, nonadaptive explanation.
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Affiliation(s)
- Daohan Jiang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA.
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30
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Maita H, Nakagawa S. What is the switch for coupling transcription and splicing? RNA Polymerase II C‐terminal domain phosphorylation, phase separation and beyond. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1574. [DOI: 10.1002/wrna.1574] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 01/12/2023]
Affiliation(s)
- Hiroshi Maita
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences Hokkaido University Sapporo Japan
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences Hokkaido University Sapporo Japan
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31
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Hong H, An O, Chan THM, Ng VHE, Kwok HS, Lin JS, Qi L, Han J, Tay DJT, Tang SJ, Yang H, Song Y, Bellido Molias F, Tenen DG, Chen L. Bidirectional regulation of adenosine-to-inosine (A-to-I) RNA editing by DEAH box helicase 9 (DHX9) in cancer. Nucleic Acids Res 2019; 46:7953-7969. [PMID: 29796672 PMCID: PMC6125626 DOI: 10.1093/nar/gky396] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/30/2018] [Indexed: 12/25/2022] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing entails the enzymatic deamination of adenosines to inosines by adenosine deaminases acting on RNA (ADARs). Dysregulated A-to-I editing has been implicated in various diseases, including cancers. However, the precise factors governing the A-to-I editing and their physiopathological implications remain as a long-standing question. Herein, we unravel that DEAH box helicase 9 (DHX9), at least partially dependent of its helicase activity, functions as a bidirectional regulator of A-to-I editing in cancer cells. Intriguingly, the ADAR substrate specificity determines the opposing effects of DHX9 on editing as DHX9 silencing preferentially represses editing of ADAR1-specific substrates, whereas augments ADAR2-specific substrate editing. Analysis of 11 cancer types from The Cancer Genome Atlas (TCGA) reveals a striking overexpression of DHX9 in tumors. Further, tumorigenicity studies demonstrate a helicase-dependent oncogenic role of DHX9 in cancer development. In sum, DHX9 constitutes a bidirectional regulatory mode in A-to-I editing, which is in part responsible for the dysregulated editome profile in cancer.
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Affiliation(s)
- HuiQi Hong
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Omer An
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Tim H M Chan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Vanessa H E Ng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Hui Si Kwok
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Jaymie S Lin
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Lihua Qi
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
| | - Jian Han
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Daryl J T Tay
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Sze Jing Tang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Henry Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Yangyang Song
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Fernando Bellido Molias
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Daniel G Tenen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore.,Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Leilei Chen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore.,Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594, Singapore
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32
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Licht K, Kapoor U, Amman F, Picardi E, Martin D, Bajad P, Jantsch MF. A high resolution A-to-I editing map in the mouse identifies editing events controlled by pre-mRNA splicing. Genome Res 2019; 29:1453-1463. [PMID: 31427386 PMCID: PMC6724681 DOI: 10.1101/gr.242636.118] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 07/25/2019] [Indexed: 11/25/2022]
Abstract
Pre-mRNA-splicing and adenosine to inosine (A-to-I) RNA-editing occur mostly cotranscriptionally. During A-to-I editing, a genomically encoded adenosine is deaminated to inosine by adenosine deaminases acting on RNA (ADARs). Editing-competent stems are frequently formed between exons and introns. Consistently, studies using reporter assays have shown that splicing efficiency can affect editing levels. Here, we use Nascent-seq and identify ∼90,000 novel A-to-I editing events in the mouse brain transcriptome. Most novel sites are located in intronic regions. Unlike previously assumed, we show that both ADAR (ADAR1) and ADARB1 (ADAR2) can edit repeat elements and regular transcripts to the same extent. We find that inhibition of splicing primarily increases editing levels at hundreds of sites, suggesting that reduced splicing efficiency extends the exposure of intronic and exonic sequences to ADAR enzymes. Lack of splicing factors NOVA1 or NOVA2 changes global editing levels, demonstrating that alternative splicing factors can modulate RNA editing. Finally, we show that intron retention rates correlate with editing levels across different brain tissues. We therefore demonstrate that splicing efficiency is a major factor controlling tissue-specific differences in editing levels.
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Affiliation(s)
- Konstantin Licht
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Utkarsh Kapoor
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Fabian Amman
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria.,Institute of Theoretical Biochemistry, University of Vienna, A-1090 Vienna, Austria
| | - Ernesto Picardi
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, I-70126 Bari, Italy.,Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, I-70126 Bari, Italy
| | - David Martin
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Prajakta Bajad
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael F Jantsch
- Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
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33
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Rahman R, Xu W, Jin H, Rosbash M. Identification of RNA-binding protein targets with HyperTRIBE. Nat Protoc 2019; 13:1829-1849. [PMID: 30013039 DOI: 10.1038/s41596-018-0020-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
RNA-binding proteins (RBPs) accompany RNA from birth to death, affecting RNA biogenesis and functions. Identifying RBP-RNA interactions is essential to understanding their complex roles in different cellular processes. However, detecting in vivo RNA targets of RBPs, especially in a small number of discrete cells, has been a technically challenging task. We previously developed a novel technique called TRIBE (targets of RNA-binding proteins identified by editing) to overcome this problem. TRIBE expresses a fusion protein consisting of a queried RBP and the catalytic domain of the RNA-editing enzyme ADAR (adenosine deaminase acting on RNA) (ADARcd), which marks target RNA transcripts by converting adenosine to inosine near the RBP binding sites. These marks can be subsequently identified via high-throughput sequencing. In spite of its usefulness, TRIBE is constrained by a low editing efficiency and editing-sequence bias from the ADARcd. Therefore, we developed HyperTRIBE by incorporating a previously characterized hyperactive mutation, E488Q, into the ADARcd. This strategy increases the editing efficiency and reduces sequence bias, which markedly increases the sensitivity of this technique without sacrificing specificity. HyperTRIBE provides a more powerful strategy for identifying RNA targets of RBPs with an easy experimental and computational protocol at low cost, that can be performed not only in flies, but also in mammals. The HyperTRIBE experimental protocol described below can be carried out in cultured Drosophila S2 cells in 1 week, using tools available in a common molecular biology laboratory; the computational analysis requires 3 more days.
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Affiliation(s)
- Reazur Rahman
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, USA
| | - Weijin Xu
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, USA
| | - Hua Jin
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, USA
| | - Michael Rosbash
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, USA.
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34
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Zhang Y, Zhang L, Yue J, Wei X, Wang L, Liu X, Gao H, Hou X, Zhao F, Yan H, Wang L. Genome-wide identification of RNA editing in seven porcine tissues by matched DNA and RNA high-throughput sequencing. J Anim Sci Biotechnol 2019; 10:24. [PMID: 30911384 PMCID: PMC6415349 DOI: 10.1186/s40104-019-0326-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/24/2019] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND RNA editing is a co/posttranscriptional modification mechanism that increases the diversity of transcripts, with potential functional consequences. The advent of next-generation sequencing technologies has enabled the identification of RNA edits at unprecedented throughput and resolution. However, our knowledge of RNA editing in swine is still limited. RESULTS Here, we utilized RES-Scanner to identify RNA editing sites in the brain, subcutaneous fat, heart, liver, muscle, lung and ovary in three 180-day-old Large White gilts based on matched strand-specific RNA sequencing and whole-genome resequencing datasets. In total, we identified 74863 editing sites, and 92.1% of these sites caused adenosine-to-guanosine (A-to-G) conversion. Most A-to-G sites were located in noncoding regions and generally had low editing levels. In total, 151 A-to-G sites were detected in coding regions (CDS), including 94 sites that could lead to nonsynonymous amino acid changes. We provide further evidence supporting a previous observation that pig transcriptomes are highly editable at PRE-1 elements. The number of A-to-G editing sites ranged from 4155 (muscle) to 25001 (brain) across the seven tissues. The expression levels of the ADAR enzymes could explain some but not all of this variation across tissues. The functional analysis of the genes with tissue-specific editing sites in each tissue revealed that RNA editing might play important roles in tissue function. Specifically, more pathways showed significant enrichment in the fat and liver than in other tissues, while no pathway was enriched in the muscle. CONCLUSIONS This study identified a total of 74863 nonredundant RNA editing sites in seven tissues and revealed the potential importance of RNA editing in tissue function. Our findings largely extend the porcine editome and enhance our understanding of RNA editing in swine.
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Affiliation(s)
- Yuebo Zhang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Longchao Zhang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Jingwei Yue
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Xia Wei
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Ligang Wang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Xin Liu
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Hongmei Gao
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Xinhua Hou
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Fuping Zhao
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Hua Yan
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Lixian Wang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
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Abstract
A fundamental question in contemporary neuroscience is how the remarkable cellular diversity required for the intricate function of the nervous system is achieved. Here, we bridge the gap between a cellular machinery that is known to diversify the transcriptome and the existence of distinct neuronal populations that compose the Drosophila brain. Adenosine-to-inosine (A-to-I) RNA editing is a ubiquitous mechanism that generates transcriptomic diversity in cells by recoding certain adenosines within the pre-mRNA sequence into inosines. We present a spatial map of RNA editing across different neuronal populations in Drosophila brain. Each neuronal population has a distinct editing signature, with the majority of differential editing occurring in highly conserved regions of transcripts that encode ion channels and other essential neuronal genes. Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a ubiquitous mechanism that generates transcriptomic diversity. This process is particularly important for proper neuronal function; however, little is known about how RNA editing is dynamically regulated between the many functionally distinct neuronal populations of the brain. Here, we present a spatial RNA editing map in the Drosophila brain and show that different neuronal populations possess distinct RNA editing signatures. After purifying and sequencing RNA from genetically marked groups of neuronal nuclei, we identified a large number of editing sites and compared editing levels in hundreds of transcripts across nine functionally different neuronal populations. We found distinct editing repertoires for each population, including sites in repeat regions of the transcriptome and differential editing in highly conserved and likely functional regions of transcripts that encode essential neuronal genes. These changes are site-specific and not driven by changes in Adar expression, suggesting a complex, targeted regulation of editing levels in key transcripts. This fine-tuning of the transcriptome between different neurons by RNA editing may account for functional differences between distinct populations in the brain.
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Riemondy KA, Gillen AE, White EA, Bogren LK, Hesselberth JR, Martin SL. Dynamic temperature-sensitive A-to-I RNA editing in the brain of a heterothermic mammal during hibernation. RNA (NEW YORK, N.Y.) 2018; 24:1481-1495. [PMID: 30065024 PMCID: PMC6191720 DOI: 10.1261/rna.066522.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
RNA editing diversifies genomically encoded information to expand the complexity of the transcriptome. In ectothermic organisms, including Drosophila and Cephalopoda, where body temperature mirrors ambient temperature, decreases in environmental temperature lead to increases in A-to-I RNA editing and cause amino acid recoding events that are thought to be adaptive responses to temperature fluctuations. In contrast, endothermic mammals, including humans and mice, typically maintain a constant body temperature despite environmental changes. Here, A-to-I editing primarily targets repeat elements, rarely results in the recoding of amino acids, and plays a critical role in innate immune tolerance. Hibernating ground squirrels provide a unique opportunity to examine RNA editing in a heterothermic mammal whose body temperature varies over 30°C and can be maintained at 5°C for many days during torpor. We profiled the transcriptome in three brain regions at six physiological states to quantify RNA editing and determine whether cold-induced RNA editing modifies the transcriptome as a potential mechanism for neuroprotection at low temperature during hibernation. We identified 5165 A-to-I editing sites in 1205 genes with dynamically increased editing after prolonged cold exposure. The majority (99.6%) of the cold-increased editing sites are outside of previously annotated coding regions, 82.7% lie in SINE-derived repeats, and 12 sites are predicted to recode amino acids. Additionally, A-to-I editing frequencies increase with increasing cold-exposure, demonstrating that ADAR remains active during torpor. Our findings suggest that dynamic A-to-I editing at low body temperature may provide a neuroprotective mechanism to limit aberrant dsRNA accumulation during torpor in the mammalian hibernator.
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Affiliation(s)
- Kent A Riemondy
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Austin E Gillen
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Emily A White
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | | | - Jay R Hesselberth
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sandra L Martin
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- Department of Cell and Developmental Biology
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Kuznetsova KG, Kliuchnikova AA, Ilina IU, Chernobrovkin AL, Novikova SE, Farafonova TE, Karpov DS, Ivanov MV, Goncharov AO, Ilgisonis EV, Voronko OE, Nasaev SS, Zgoda VG, Zubarev RA, Gorshkov MV, Moshkovskii SA. Proteogenomics of Adenosine-to-Inosine RNA Editing in the Fruit Fly. J Proteome Res 2018; 17:3889-3903. [DOI: 10.1021/acs.jproteome.8b00553] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | - Anna A. Kliuchnikova
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | | | | | | | - Dmitry S. Karpov
- Institute of Biomedical Chemistry, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mark V. Ivanov
- Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia
| | - Anton O. Goncharov
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | | | - Shamsudin S. Nasaev
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | | | - Roman A. Zubarev
- Karolinska Institutet, Stockholm, Sweden
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Mikhail V. Gorshkov
- Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, Russia
| | - Sergei A. Moshkovskii
- Institute of Biomedical Chemistry, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
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NonA and CPX Link the Circadian Clockwork to Locomotor Activity in Drosophila. Neuron 2018; 99:768-780.e3. [PMID: 30057203 DOI: 10.1016/j.neuron.2018.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/27/2018] [Accepted: 07/01/2018] [Indexed: 11/20/2022]
Abstract
Drosophila NonA and its mammalian ortholog NONO are members of the Drosophila behavior and human splicing (DBHS) family. NONO also has a strong circadian connection: it associates with the circadian repressor protein PERIOD (PER) and contributes to circadian timekeeping. Here, we investigate NonA, which is required for proper levels of evening locomotor activity as well as a normal free-running period in Drosophila. NonA is associated with the positive transcription factor CLOCK/CYCLE (CLK/CYC), interacts directly with complexin (cpx) pre-mRNA, and upregulates gene expression, including the gene cpx. Downregulation of cpx expression in circadian neurons phenocopies NonA downregulation, whereas cpx overexpression rescues the nonA RNAi phenotypes, indicating that cpx is an important NonA target gene. As the cpx protein contributes to proper neurotransmitter and neuropeptide release in response to calcium, these results and others indicate that this control is important for the normal circadian regulation of locomotor activity.
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Beta RAA, Balatsos NAA. Tales around the clock: Poly(A) tails in circadian gene expression. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1484. [PMID: 29911349 DOI: 10.1002/wrna.1484] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 04/15/2018] [Accepted: 04/20/2018] [Indexed: 11/07/2022]
Abstract
Circadian rhythms are ubiquitous time-keeping processes in eukaryotes with a period of ~24 hr. Light is perhaps the main environmental cue (zeitgeber) that affects several aspects of physiology and behaviour, such as sleep/wake cycles, orientation of birds and bees, and leaf movements in plants. Temperature can serve as the main zeitgeber in the absence of light cycles, even though it does not lead to rhythmicity through the same mechanism as light. Additional cues include feeding patterns, humidity, and social rhythms. At the molecular level, a master oscillator orchestrates circadian rhythms and organizes molecular clocks located in most cells. The generation of the 24 hr molecular clock is based on transcriptional regulation, as it drives intrinsic rhythmic changes based on interlocked transcription/translation feedback loops that synchronize expression of genes. Thus, processes and factors that determine rhythmic gene expression are important to understand circadian rhythms. Among these, the poly(A) tails of RNAs play key roles in their stability, translational efficiency and degradation. In this article, we summarize current knowledge and discuss perspectives on the role and significance of poly(A) tails and associating factors in the context of the circadian clock. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability RNA Processing > 3' End Processing.
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Affiliation(s)
- Rafailia A A Beta
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Nikolaos A A Balatsos
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
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40
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Hsiao YHE, Bahn JH, Yang Y, Lin X, Tran S, Yang EW, Quinones-Valdez G, Xiao X. RNA editing in nascent RNA affects pre-mRNA splicing. Genome Res 2018; 28:812-823. [PMID: 29724793 PMCID: PMC5991522 DOI: 10.1101/gr.231209.117] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 04/26/2018] [Indexed: 12/21/2022]
Abstract
In eukaryotes, nascent RNA transcripts undergo an intricate series of RNA processing steps to achieve mRNA maturation. RNA editing and alternative splicing are two major RNA processing steps that can introduce significant modifications to the final gene products. By tackling these processes in isolation, recent studies have enabled substantial progress in understanding their global RNA targets and regulatory pathways. However, the interplay between individual steps of RNA processing, an essential aspect of gene regulation, remains poorly understood. By sequencing the RNA of different subcellular fractions, we examined the timing of adenosine-to-inosine (A-to-I) RNA editing and its impact on alternative splicing. We observed that >95% A-to-I RNA editing events occurred in the chromatin-associated RNA prior to polyadenylation. We report about 500 editing sites in the 3' acceptor sequences that can alter splicing of the associated exons. These exons are highly conserved during evolution and reside in genes with important cellular function. Furthermore, we identified a second class of exons whose splicing is likely modulated by RNA secondary structures that are recognized by the RNA editing machinery. The genome-wide analyses, supported by experimental validations, revealed remarkable interplay between RNA editing and splicing and expanded the repertoire of functional RNA editing sites.
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Affiliation(s)
| | - Jae Hoon Bahn
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Yun Yang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Xianzhi Lin
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Stephen Tran
- Bioinformatics Interdepartmental Program, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Ei-Wen Yang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California 90095, USA
| | | | - Xinshu Xiao
- Department of Bioengineering
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California 90095, USA
- Bioinformatics Interdepartmental Program, University of California Los Angeles, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA
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41
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Short cryptic exons mediate recursive splicing in Drosophila. Nat Struct Mol Biol 2018; 25:365-371. [PMID: 29632374 DOI: 10.1038/s41594-018-0052-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/02/2018] [Indexed: 01/11/2023]
Abstract
Many long Drosophila introns are processed by an unusual recursive strategy. The presence of ~200 adjacent splice acceptor and splice donor sites, termed ratchet points (RPs), were inferred to reflect 'zero-nucleotide exons', whose sequential processing subdivides removal of long host introns. We used CRISPR-Cas9 to disrupt several intronic RPs in Drosophila melanogaster, some of which recapitulated characteristic loss-of-function phenotypes. Unexpectedly, selective disruption of RP splice donors revealed constitutive retention of unannotated short exons. Assays using functional minigenes confirm that unannotated cryptic splice donor sites are critical for recognition of intronic RPs, demonstrating that recursive splicing involves the recognition of cryptic RP exons. This appears to be a general mechanism, because canonical, conserved splice donors are specifically enriched in a 40-80-nt window downstream of known and newly annotated intronic RPs and exhibit similar properties to a broadly expanded class of expressed RP exons. Overall, these studies unify the mechanism of Drosophila recursive splicing with that in mammals.
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42
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Reich DP, Tyc KM, Bass BL. C. elegans ADARs antagonize silencing of cellular dsRNAs by the antiviral RNAi pathway. Genes Dev 2018; 32:271-282. [PMID: 29483152 PMCID: PMC5859968 DOI: 10.1101/gad.310672.117] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/26/2018] [Indexed: 12/03/2022]
Abstract
In this study, Reich et al. researched the functions of Caenorhabditis elegans adenosine deaminases that act on RNA (ADARs), which catalyze A-to-I RNA editing in dsRNA. Using dsRNA immunoprecipitation (dsRIP) and RNA-seq, they identified 1523 regions of clustered A-to-I editing, termed editing-enriched regions (EERs), in four stages of C. elegans development, often with highest expression in embryos. Cellular dsRNAs are edited by adenosine deaminases that act on RNA (ADARs). While editing can alter mRNA-coding potential, most editing occurs in noncoding sequences, the function of which is poorly understood. Using dsRNA immunoprecipitation (dsRIP) and RNA sequencing (RNA-seq), we identified 1523 regions of clustered A-to-I editing, termed editing-enriched regions (EERs), in four stages of Caenorhabditis elegans development, often with highest expression in embryos. Analyses of small RNA-seq data revealed 22- to 23-nucleotide (nt) siRNAs, reminiscent of viral siRNAs, that mapped to EERs and were abundant in adr-1;adr-2 mutant animals. Consistent with roles for these siRNAs in silencing, EER-associated genes (EAGs) were down-regulated in adr-1;adr-2 embryos, and this was dependent on associated EERs and the RNAi factor RDE-4. We observed that ADARs genetically interact with the 26G endogenous siRNA (endo-siRNA) pathway, which likely competes for RNAi components; deletion of factors required for this pathway (rrf-3 or ergo-1) in adr-1;adr-2 mutant strains caused a synthetic phenotype that was rescued by deleting antiviral RNAi factors. Poly(A)+ RNA-seq revealed EAG down-regulation and antiviral gene induction in adr-1;adr-2;rrf-3 embryos, and these expression changes were dependent on rde-1 and rde-4. Our data suggest that ADARs restrict antiviral silencing of cellular dsRNAs.
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Affiliation(s)
- Daniel P Reich
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Katarzyna M Tyc
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Brenda L Bass
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112, USA
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Xu W, Rahman R, Rosbash M. Mechanistic implications of enhanced editing by a HyperTRIBE RNA-binding protein. RNA (NEW YORK, N.Y.) 2018; 24:173-182. [PMID: 29127211 PMCID: PMC5769745 DOI: 10.1261/rna.064691.117] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/10/2017] [Indexed: 05/21/2023]
Abstract
We previously developed TRIBE, a method for the identification of cell-specific RNA-binding protein targets. TRIBE expresses an RBP of interest fused to the catalytic domain (cd) of the RNA-editing enzyme ADAR and performs adenosine-to-inosine editing on RNA targets of the RBP. However, target identification is limited by the low editing efficiency of the ADARcd. Here we describe HyperTRIBE, which carries a previously characterized hyperactive mutation (E488Q) of the ADARcd. HyperTRIBE identifies dramatically more editing sites, many of which are also edited by TRIBE but at a much lower editing frequency. HyperTRIBE therefore more faithfully recapitulates the known binding specificity of its RBP than TRIBE. In addition, separating RNA binding from the enhanced editing activity of the HyperTRIBE ADAR catalytic domain sheds light on the mechanism of ADARcd editing as well as the enhanced activity of the HyperADARcd.
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Affiliation(s)
- Weijin Xu
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Reazur Rahman
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Michael Rosbash
- Department of Biology, Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02453, USA
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Abstract
The molecular process of RNA editing allows changes in RNA transcripts that increase genomic diversity. These highly conserved RNA editing events are catalyzed by a group of enzymes known as adenosine deaminases acting on double-stranded RNA (ADARs). ADARs are necessary for normal development, they bind to over thousands of genes, impact millions of editing sites, and target critical components of the central nervous system (CNS) such as glutamate receptors, serotonin receptors, and potassium channels. Dysfunctional ADARs are known to cause alterations in CNS protein products and therefore play a role in chronic or acute neurodegenerative and psychiatric diseases as well as CNS cancer. Here, we review how RNA editing deficiency impacts CNS function and summarize its role during disease pathogenesis.
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Affiliation(s)
- Ileana Lorenzini
- Barrow Neurological Institute, Department of Neurobiology, Dignity Health, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Stephen Moore
- Barrow Neurological Institute, Department of Neurobiology, Dignity Health, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
- Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, USA
| | - Rita Sattler
- Department of Neurobiology and Neurology, Dignityhealth St. Joseph's Hospital, Barrow Neurological Institute, Phoenix, AZ, USA.
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45
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Duan Y, Dou S, Zhang H, Wu C, Wu M, Lu J. Linkage of A-to-I RNA Editing in Metazoans and the Impact on Genome Evolution. Mol Biol Evol 2018; 35:132-148. [PMID: 29048557 PMCID: PMC5850729 DOI: 10.1093/molbev/msx274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The adenosine-to-inosine (A-to-I) RNA editomes have been systematically characterized in various metazoan species, and many editing sites were found in clusters. However, it remains unclear whether the clustered editing sites tend to be linked in the same RNA molecules or not. By adopting a method originally designed to detect linkage disequilibrium of DNA mutations, we examined the editomes of ten metazoan species and detected extensive linkage of editing in Drosophila and cephalopods. The prevalent linkages of editing in these two clades, many of which are conserved between closely related species and might be associated with the adaptive proteomic recoding, are maintained by natural selection at the cost of genome evolution. Nevertheless, in worms and humans, we only detected modest proportions of linked editing events, the majority of which were not conserved. Furthermore, the linkage of editing in coding regions of worms and humans might be overall deleterious, which drives the evolution of DNA sites to escape promiscuous editing. Altogether, our results suggest that the linkage landscape of A-to-I editing has evolved during metazoan evolution. This present study also suggests that linkage of editing should be considered in elucidating the functional consequences of RNA editing.
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Affiliation(s)
- Yuange Duan
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Shengqian Dou
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Hong Zhang
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Changcheng Wu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Mingming Wu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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46
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Medd NC, Fellous S, Waldron FM, Xuéreb A, Nakai M, Cross JV, Obbard DJ. The virome of Drosophila suzukii, an invasive pest of soft fruit. Virus Evol 2018; 4:vey009. [PMID: 29644097 PMCID: PMC5888908 DOI: 10.1093/ve/vey009] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Drosophila suzukii (Matsumura) is one of the most damaging and costly pests to invade temperate horticultural regions in recent history. Conventional control of this pest is challenging, and an environmentally benign microbial biopesticide is highly desirable. A thorough exploration of the pathogens infecting this pest is not only the first step on the road to the development of an effective biopesticide, but also provides a valuable comparative dataset for the study of viruses in the model family Drosophilidae. Here we use a metatransciptomic approach to identify viruses infecting this fly in both its native (Japanese) and invasive (British and French) ranges. We describe eighteen new RNA viruses, including members of the Picornavirales, Mononegavirales, Bunyavirales, Chuviruses, Nodaviridae, Tombusviridae, Reoviridae, and Nidovirales, and discuss their phylogenetic relationships with previously known viruses. We also detect 18 previously described viruses of other Drosophila species that appear to be associated with D. suzukii in the wild.
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Affiliation(s)
- Nathan C Medd
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Simon Fellous
- Centre de Biologie pour la Gestion des Populations, INRA, 755 avenue du Campus Agropolis, 34988, Montferrier-sur-Lez cedex, France
| | - Fergal M Waldron
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Anne Xuéreb
- Centre de Biologie pour la Gestion des Populations, INRA, 755 avenue du Campus Agropolis, 34988, Montferrier-sur-Lez cedex, France
| | - Madoka Nakai
- Tokyo University of Agriculture and Technology, Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Jerry V Cross
- NIAB EMR, New Road, East Malling, Kent, ME19 6BJ, UK
| | - Darren J Obbard
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
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Li L, Song Y, Shi X, Liu J, Xiong S, Chen W, Fu Q, Huang Z, Gu N, Zhang R. The landscape of miRNA editing in animals and its impact on miRNA biogenesis and targeting. Genome Res 2017; 28:132-143. [PMID: 29233923 PMCID: PMC5749178 DOI: 10.1101/gr.224386.117] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 10/25/2017] [Indexed: 01/23/2023]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing regulates miRNA biogenesis and function. To date, fewer than 160 miRNA editing sites have been identified. Here, we present a quantitative atlas of miRNA A-to-I editing through the profiling of 201 pri-miRNA samples and 4694 mature miRNA samples in human, mouse, and Drosophila. We identified 4162 sites present in ∼80% of the pri-miRNAs and 574 sites in mature miRNAs. miRNA editing is prevalent in many tissue types in human. However, high-level editing is mostly found in neuronal tissues in mouse and Drosophila. Interestingly, the edited miRNAs in neuronal and non-neuronal tissues in human gain two distinct sets of new targets, which are significantly associated with cognitive and organ developmental functions, respectively. Furthermore, we reveal that miRNA editing profoundly affects asymmetric strand selection. Altogether, these data provide insight into the impact of RNA editing on miRNA biology and suggest that miRNA editing has recently gained non-neuronal functions in human.
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Affiliation(s)
- Lishi Li
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Yulong Song
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Xinrui Shi
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Jianheng Liu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Shaolei Xiong
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Wanying Chen
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Qiang Fu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Zichao Huang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Nannan Gu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | - Rui Zhang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
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Zimmerman JE, Chan MT, Lenz OT, Keenan BT, Maislin G, Pack AI. Glutamate Is a Wake-Active Neurotransmitter in Drosophila melanogaster. Sleep 2017; 40:2667755. [PMID: 28364503 DOI: 10.1093/sleep/zsw046] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Introduction In mammals, there is evidence that glutamate has a role as a wake-active neurotransmitter. So using video-based analysis of Drosophila behavior, we undertook a study to examine if glutamate, which has been previously shown to have an excitatory role in neuromuscular junctions in Drosophila, may have a conserved wake-active role in the adult brain. Aims and Methods Using 6- to 9-day-old female flies, we examined the effect of perturbations of the glutamatergic signaling on total wakefulness and wake bout architecture. We increased and decreased neuronal activity of glutamatergic neurons in the brains of adult flies using Upstream Activating Sequence (UAS) NaChBac and UAS EKO, respectively. We blocked neurotransmission from glutamatergic neurons in adult flies using the UAS-driven temperature-sensitive dynamin mutation shibirets. We examined the behavior of flies with loss of function mutations of individual subunits of brain-specific ionotropic glutamate receptors. Results Increasing the activity of glutamatergic neurons in the adult brain led to a significant increase in wakefulness compared to the control groups both in the daytime and nighttime and decreasing the activity of these same neurons reduced wakefulness in the nighttime. Blocking neurotransmitter release in glutamatergic neurons significantly reduced wake in the nighttime. The ionotropic receptor mutants had significantly less wake in the nighttime than their respective genetic background controls. Conclusion The results show the following: glutamate is indeed a wake-active neurotransmitter in Drosophila; there is a major time of day effect associated with loss of glutamatergic neurotransmission; and it is a major wake-active neurotransmitter in the nighttime.
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Affiliation(s)
- John E Zimmerman
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA
| | - May T Chan
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA
| | - Olivia T Lenz
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA
| | - Brendan T Keenan
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA
| | - Greg Maislin
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA.,Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.,Biomedical Statistical Consulting, 1357 Garden Rd, Wynnewood, PA
| | - Allan I Pack
- Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, 125 S. 31st St., Philadelphia, PA.,Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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Porath HT, Knisbacher BA, Eisenberg E, Levanon EY. Massive A-to-I RNA editing is common across the Metazoa and correlates with dsRNA abundance. Genome Biol 2017; 18:185. [PMID: 28969707 PMCID: PMC5625713 DOI: 10.1186/s13059-017-1315-y] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 09/07/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Adenosine to inosine (A-to-I) RNA editing is a post-transcriptional modification catalyzed by the ADAR (adenosine deaminase that acts on RNA) enzymes, which are ubiquitously expressed among metazoans. Technical requirements have limited systematic mapping of editing sites to a small number of organisms. Thus, the extent of editing across the metazoan lineage is largely unknown. RESULTS Here, we apply a computational procedure to search for RNA-sequencing reads containing clusters of editing sites in 21 diverse organisms. Clusters of editing sites are abundant in repetitive genomic regions that putatively form double-stranded RNA (dsRNA) structures and are rarely seen in coding regions. The method reveals a considerable variation in hyper-editing levels across species, which is partly explained by differences in the potential of sequences to form dsRNA structures and the variability of ADAR proteins. Several commonly used model animals exhibit low editing levels and editing levels in primates is not exceptionally high, as previously suggested. CONCLUSIONS Editing by ADARs is highly prevalent across the Metazoa, mostly targeting dsRNA structures formed by genomic repeats. The degree to which the transcriptome of a given species undergoes hyper-editing is governed by the repertoire of repeats in the underlying genome. The strong association of RNA editing with the long dsRNA regions originating from non-coding repetitive elements is contrasted by the almost non-existing signal seen in coding regions. Hyper-edited regions are rarely expressed in a non-edited form. These results support the notion that the main role of ADAR is to suppress the cellular response to endogenous dsRNA structures.
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Affiliation(s)
- Hagit T Porath
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Binyamin A Knisbacher
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 69978, Israel.
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
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50
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Licht K, Jantsch MF. The Other Face of an Editor: ADAR1 Functions in Editing-Independent Ways. Bioessays 2017; 39. [DOI: 10.1002/bies.201700129] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/29/2017] [Indexed: 02/04/2023]
Affiliation(s)
- Konstantin Licht
- Department of Cell and Developmental Biology Center for Anatomy and Cell Biology; Medical University of Vienna; Schwarzspanierstrasse 17 A-1090 Vienna Austria
| | - Michael F. Jantsch
- Department of Cell and Developmental Biology Center for Anatomy and Cell Biology; Medical University of Vienna; Schwarzspanierstrasse 17 A-1090 Vienna Austria
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