1
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Wulff TF, Hahnke K, Lécrivain AL, Schmidt K, Ahmed-Begrich R, Finstermeier K, Charpentier E. Dynamics of diversified A-to-I editing in Streptococcus pyogenes is governed by changes in mRNA stability. Nucleic Acids Res 2024:gkae629. [PMID: 39087550 DOI: 10.1093/nar/gkae629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 07/01/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing plays an important role in the post-transcriptional regulation of eukaryotic cell physiology. However, our understanding of the occurrence, function and regulation of A-to-I editing in bacteria remains limited. Bacterial mRNA editing is catalysed by the deaminase TadA, which was originally described to modify a single tRNA in Escherichia coli. Intriguingly, several bacterial species appear to perform A-to-I editing on more than one tRNA. Here, we provide evidence that in the human pathogen Streptococcus pyogenes, tRNA editing has expanded to an additional tRNA substrate. Using RNA sequencing, we identified more than 27 editing sites in the transcriptome of S. pyogenes SF370 and demonstrate that the adaptation of S. pyogenes TadA to a second tRNA substrate has also diversified the sequence context and recoding scope of mRNA editing. Based on the observation that editing is dynamically regulated in response to several infection-relevant stimuli, such as oxidative stress, we further investigated the underlying determinants of editing dynamics and identified mRNA stability as a key modulator of A-to-I editing. Overall, our findings reveal the presence and diversification of A-to-I editing in S. pyogenes and provide novel insights into the plasticity of the editome and its regulation in bacteria.
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Affiliation(s)
- Thomas F Wulff
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | - Karin Hahnke
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | | | - Katja Schmidt
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | | | | | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
- Institute for Biology, Humboldt University Berlin, 10115 Berlin, Germany
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2
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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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3
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Xu Y, Liu J, Zhao T, Song F, Tian L, Cai W, Li H, Duan Y. Identification and Interpretation of A-to-I RNA Editing Events in Insect Transcriptomes. Int J Mol Sci 2023; 24:17126. [PMID: 38138955 PMCID: PMC10742984 DOI: 10.3390/ijms242417126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/01/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing is the most prevalent RNA modification in the nervous systems of metazoans. To study the biological significance of RNA editing, we first have to accurately identify these editing events from the transcriptome. The genome-wide identification of RNA editing sites remains a challenging task. In this review, we will first introduce the occurrence, regulation, and importance of A-to-I RNA editing and then describe the established bioinformatic procedures and difficulties in the accurate identification of these sit esespecially in small sized non-model insects. In brief, (1) to obtain an accurate profile of RNA editing sites, a transcriptome coupled with the DNA resequencing of a matched sample is favorable; (2) the single-cell sequencing technique is ready to be applied to RNA editing studies, but there are a few limitations to overcome; (3) during mapping and variant calling steps, various issues, like mapping and base quality, soft-clipping, and the positions of mismatches on reads, should be carefully considered; (4) Sanger sequencing of both RNA and the matched DNA is the best verification of RNA editing sites, but other auxiliary evidence, like the nonsynonymous-to-synonymous ratio or the linkage information, is also helpful for judging the reliability of editing sites. We have systematically reviewed the understanding of the biological significance of RNA editing and summarized the methodology for identifying such editing events. We also raised several promising aspects and challenges in this field. With insightful perspectives on both scientific and technical issues, our review will benefit the researchers in the broader RNA editing community.
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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; (Y.X.); (J.L.); (T.Z.); (F.S.); (L.T.); (W.C.); (H.L.)
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4
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Frezza V, Chellini L, Del Verme A, Paronetto MP. RNA Editing in Cancer Progression. Cancers (Basel) 2023; 15:5277. [PMID: 37958449 PMCID: PMC10648226 DOI: 10.3390/cancers15215277] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
Coding and noncoding RNA molecules play their roles in ensuring cell function and tissue homeostasis in an ordered and systematic fashion. RNA chemical modifications can occur both at bases and ribose sugar, and, similarly to DNA and histone modifications, can be written, erased, and recognized by the corresponding enzymes, thus modulating RNA activities and fine-tuning gene expression programs. RNA editing is one of the most prevalent and abundant forms of post-transcriptional RNA modification in normal physiological processes. By altering the sequences of mRNAs, it makes them different from the corresponding genomic template. Hence, edited mRNAs can produce protein isoforms that are functionally different from the corresponding genome-encoded variants. Abnormalities in regulatory enzymes and changes in RNA-modification patterns are closely associated with the occurrence and development of various human diseases, including cancer. To date, the roles played by RNA modifications in cancer are gathering increasing interest. In this review, we focus on the role of RNA editing in cancer transformation and provide a new perspective on its impact on tumorigenesis, by regulating cell proliferation, differentiation, invasion, migration, stemness, metabolism, and drug resistance.
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Affiliation(s)
- Valentina Frezza
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, Via del Fosso di Fiorano, 64, 00143 Rome, Italy; (V.F.); (L.C.); (A.D.V.)
| | - Lidia Chellini
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, Via del Fosso di Fiorano, 64, 00143 Rome, Italy; (V.F.); (L.C.); (A.D.V.)
| | - Arianna Del Verme
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, Via del Fosso di Fiorano, 64, 00143 Rome, Italy; (V.F.); (L.C.); (A.D.V.)
| | - Maria Paola Paronetto
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, Via del Fosso di Fiorano, 64, 00143 Rome, Italy; (V.F.); (L.C.); (A.D.V.)
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, Piazza Lauro de Bosis, 15, 00135 Rome, Italy
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5
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Kleinova R, Rajendra V, Leuchtenberger AF, Lo Giudice C, Vesely C, Kapoor U, Tanzer A, Derdak S, Picardi E, Jantsch MF. The ADAR1 editome reveals drivers of editing-specificity for ADAR1-isoforms. Nucleic Acids Res 2023; 51:4191-4207. [PMID: 37026479 PMCID: PMC10201426 DOI: 10.1093/nar/gkad265] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 03/10/2023] [Accepted: 04/06/2023] [Indexed: 04/08/2023] Open
Abstract
Adenosine deaminase acting on RNA ADAR1 promotes A-to-I conversion in double-stranded and structured RNAs. ADAR1 has two isoforms transcribed from different promoters: cytoplasmic ADAR1p150 is interferon-inducible while ADAR1p110 is constitutively expressed and primarily localized in the nucleus. Mutations in ADAR1 cause Aicardi - Goutières syndrome (AGS), a severe autoinflammatory disease associated with aberrant IFN production. In mice, deletion of ADAR1 or the p150 isoform leads to embryonic lethality driven by overexpression of interferon-stimulated genes. This phenotype is rescued by deletion of the cytoplasmic dsRNA-sensor MDA5 indicating that the p150 isoform is indispensable and cannot be rescued by ADAR1p110. Nevertheless, editing sites uniquely targeted by ADAR1p150 remain elusive. Here, by transfection of ADAR1 isoforms into ADAR-less mouse cells we detect isoform-specific editing patterns. Using mutated ADAR variants, we test how intracellular localization and the presence of a Z-DNA binding domain-α affect editing preferences. These data show that ZBDα only minimally contributes to p150 editing-specificity while isoform-specific editing is primarily directed by the intracellular localization of ADAR1 isoforms. Our study is complemented by RIP-seq on human cells ectopically expressing tagged-ADAR1 isoforms. Both datasets reveal enrichment of intronic editing and binding by ADAR1p110 while ADAR1p150 preferentially binds and edits 3'UTRs.
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Affiliation(s)
- Renata Kleinova
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Vinod Rajendra
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Alina F Leuchtenberger
- Center for Integrative Bioinformatics Vienna (CIBIV) Max Perutz Labs, University of Vienna and Medical University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Claudio Lo Giudice
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, University Campus “Ernesto Quagliariello”, Via Orabona 4, Bari, Italy
| | - Cornelia Vesely
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Utkarsh Kapoor
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Andrea Tanzer
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Sophia Derdak
- Core Facilities Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria
| | - Ernesto Picardi
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, University Campus “Ernesto Quagliariello”, Via Orabona 4, Bari, Italy
- Institute of Biomembranes and Bioenergetics (IBBE), National Research Council (CNR), Via Amendola 122, Bari, Italy
| | - Michael F Jantsch
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
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6
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Crews LA, Ma W, Ladel L, Pham J, Balaian L, Steel SK, Mondala PK, Diep RH, Wu CN, Mason CN, van der Werf I, Oliver I, Reynoso E, Pineda G, Whisenant TC, Wentworth P, La Clair JJ, Jiang Q, Burkart MD, Jamieson CHM. Reversal of malignant ADAR1 splice isoform switching with Rebecsinib. Cell Stem Cell 2023; 30:250-263.e6. [PMID: 36803553 PMCID: PMC10134781 DOI: 10.1016/j.stem.2023.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/15/2022] [Accepted: 01/20/2023] [Indexed: 02/18/2023]
Abstract
Adenosine deaminase acting on RNA1 (ADAR1) preserves genomic integrity by preventing retroviral integration and retrotransposition during stress responses. However, inflammatory-microenvironment-induced ADAR1p110 to p150 splice isoform switching drives cancer stem cell (CSC) generation and therapeutic resistance in 20 malignancies. Previously, predicting and preventing ADAR1p150-mediated malignant RNA editing represented a significant challenge. Thus, we developed lentiviral ADAR1 and splicing reporters for non-invasive detection of splicing-mediated ADAR1 adenosine-to-inosine (A-to-I) RNA editing activation; a quantitative ADAR1p150 intracellular flow cytometric assay; a selective small-molecule inhibitor of splicing-mediated ADAR1 activation, Rebecsinib, which inhibits leukemia stem cell (LSC) self-renewal and prolongs humanized LSC mouse model survival at doses that spare normal hematopoietic stem and progenitor cells (HSPCs); and pre-IND studies showing favorable Rebecsinib toxicokinetic and pharmacodynamic (TK/PD) properties. Together, these results lay the foundation for developing Rebecsinib as a clinical ADAR1p150 antagonist aimed at obviating malignant microenvironment-driven LSC generation.
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Affiliation(s)
- Leslie A Crews
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wenxue Ma
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Luisa Ladel
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Jessica Pham
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Larisa Balaian
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - S Kathleen Steel
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Phoebe K Mondala
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Raymond H Diep
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Christina N Wu
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Cayla N Mason
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Inge van der Werf
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Isabelle Oliver
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Eduardo Reynoso
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Gabriel Pineda
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Thomas C Whisenant
- Center for Computational Biology & Bioinformatics (CCBB), Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Peggy Wentworth
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - James J La Clair
- Departments of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qingfei Jiang
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA
| | - Michael D Burkart
- Departments of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Catriona H M Jamieson
- Department of Medicine, Division of Regenerative Medicine, Sanford Stem Cell Institute, University of California, San Diego, La Jolla, CA 92037, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.
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7
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Fu T, Chan TW, Bahn JH, Kim TH, Rowat AC, Xiao X. Multifaceted role of RNA editing in promoting loss-of-function of PODXL in cancer. iScience 2022; 25:104836. [PMID: 35992085 PMCID: PMC9382340 DOI: 10.1016/j.isci.2022.104836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/16/2022] [Accepted: 07/20/2022] [Indexed: 12/03/2022] Open
Abstract
PODXL, a protein that is dysregulated in multiple cancers, plays an important role in promoting cancer metastasis. In this study, we report that RNA editing promotes the inclusion of a PODXL alternative exon. The resulting edited PODXL long isoform is more prone to protease digestion and has the strongest effects on reducing cell migration and cisplatin chemoresistance among the three PODXL isoforms (short, unedited long, and edited long isoforms). Importantly, the editing level of the PODXL recoding site and the inclusion level of the PODXL alternative exon are strongly associated with overall patient survival in Kidney Renal Clear Cell Carcinoma (KIRC). Supported by significant enrichment of exonic RNA editing sites in alternatively spliced exons, we hypothesize that exonic RNA editing sites may enhance proteomic diversity through alternative splicing, in addition to amino acid changes, a previously under-appreciated aspect of RNA editing function.
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Affiliation(s)
- Ting Fu
- Molecular, Cellular, and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tracey W. Chan
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jae Hoon Bahn
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tae-Hyung Kim
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Amy C. Rowat
- Molecular, Cellular, and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xinshu Xiao
- Molecular, Cellular, and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
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8
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Gaidin SG, Kosenkov AM. mRNA editing of kainate receptor subunits: what do we know so far? Rev Neurosci 2022; 33:641-655. [DOI: 10.1515/revneuro-2021-0144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/18/2022] [Indexed: 11/15/2022]
Abstract
Abstract
Kainate receptors (KARs) are considered one of the key modulators of synaptic activity in the mammalian central nervous system. These receptors were discovered more than 30 years ago, but their role in brain functioning remains unclear due to some peculiarities. One such feature of these receptors is the editing of pre-mRNAs encoding GluK1 and GluK2 subunits. Despite the long history of studying this phenomenon, numerous questions remain unanswered. This review summarizes the current data about the mechanism and role of pre-mRNA editing of KAR subunits in the mammalian brain and proposes a perspective of future investigations.
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Affiliation(s)
- Sergei G. Gaidin
- Institute of Cell Biophysics of the Russian Academy of Sciences , 142290 , Pushchino , Russia
| | - Artem M. Kosenkov
- Institute of Cell Biophysics of the Russian Academy of Sciences , 142290 , Pushchino , Russia
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9
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Song B, Shiromoto Y, Minakuchi M, Nishikura K. The role of RNA editing enzyme ADAR1 in human disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1665. [PMID: 34105255 PMCID: PMC8651834 DOI: 10.1002/wrna.1665] [Citation(s) in RCA: 65] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 03/02/2021] [Accepted: 04/22/2021] [Indexed: 12/19/2022]
Abstract
Adenosine deaminase acting on RNA (ADAR) catalyzes the posttranscriptional conversion of adenosine to inosine in double-stranded RNA (dsRNA), which can lead to the creation of missense mutations in coding sequences. Recent studies show that editing-dependent functions of ADAR1 protect dsRNA from dsRNA-sensing molecules and inhibit innate immunity and the interferon-mediated response. Deficiency in these ADAR1 functions underlie the pathogenesis of autoinflammatory diseases such as the type I interferonopathies Aicardi-Goutieres syndrome and dyschromatosis symmetrica hereditaria. ADAR1-mediated editing of endogenous coding and noncoding RNA as well as ADAR1 editing-independent interactions with DICER can also have oncogenic or tumor suppressive effects that affect tumor proliferation, invasion, and response to immunotherapy. The combination of proviral and antiviral roles played by ADAR1 in repressing the interferon response and editing viral RNAs alters viral morphogenesis and cell susceptibility to infection. This review analyzes the structure and function of ADAR1 with a focus on its position in human disease pathways and the mechanisms of its disease-associated effects. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > RNA Editing and Modification RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Brian Song
- Department of Gene Expression and Regulation, The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Yusuke Shiromoto
- Department of Gene Expression and Regulation, The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Moeko Minakuchi
- Department of Gene Expression and Regulation, The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Kazuko Nishikura
- Department of Gene Expression and Regulation, The Wistar Institute, Philadelphia, Pennsylvania, USA
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10
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Hofmann CS, Carrington S, Keller AN, Gregory KJ, Niswender CM. Regulation and functional consequences of mGlu 4 RNA editing. RNA (NEW YORK, N.Y.) 2021; 27:1220-1240. [PMID: 34244459 PMCID: PMC8457003 DOI: 10.1261/rna.078729.121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Metabotropic glutamate receptor 4 (mGlu4) is one of eight mGlu receptors within the Class C G protein-coupled receptor superfamily. mGlu4 is primarily localized to the presynaptic membrane of neurons where it functions as an auto and heteroreceptor controlling synaptic release of neurotransmitter. mGlu4 is implicated in numerous disorders and is a promising drug target; however, more remains to be understood about its regulation and pharmacology. Using high-throughput sequencing, we have validated and quantified an adenosine-to-inosine (A-to-I) RNA editing event that converts glutamine 124 to arginine in mGlu4; additionally, we have identified a rare but novel K129R site. Using an in vitro editing assay, we then validated the pre-mRNA duplex that allows for editing by ADAR enzymes and predicted its conservation across the mammalian species. Structural modeling of the mGlu4 protein predicts the Q124R substitution to occur in the B helix of the receptor that is critical for receptor dimerization and activation. Interestingly, editing of a receptor homodimer does not disrupt G protein activation in response to the endogenous agonist, glutamate. Using an assay designed to specifically measure heterodimer populations at the surface, however, we found that Q124R substitution decreased the propensity of mGlu4 to heterodimerize with mGlu2 and mGlu7 Our study is the first to extensively describe the extent and regulatory factors of RNA editing of mGlu4 mRNA transcripts. In addition, we have proposed a novel functional consequence of this editing event that provides insights regarding its effects in vivo and expands the regulatory capacity for mGlu receptors.
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MESH Headings
- Adenosine Deaminase/genetics
- Adenosine Deaminase/metabolism
- Amino Acid Sequence
- Animals
- Base Pairing
- Base Sequence
- Birds
- Cerebral Cortex/cytology
- Cerebral Cortex/metabolism
- Corpus Striatum/cytology
- Corpus Striatum/metabolism
- HEK293 Cells
- Hippocampus/cytology
- Hippocampus/metabolism
- Humans
- Models, Molecular
- Neurons/cytology
- Neurons/metabolism
- Nucleic Acid Conformation
- Point Mutation
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- RNA Editing
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Metabotropic Glutamate/chemistry
- Receptors, Metabotropic Glutamate/genetics
- Receptors, Metabotropic Glutamate/metabolism
- Reptiles
- Sequence Homology, Amino Acid
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Affiliation(s)
- Christopher S Hofmann
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, USA
| | - Sheridan Carrington
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, USA
| | - Andrew N Keller
- Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Karen J Gregory
- Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37203, USA
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11
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Vesely C, Jantsch MF. An I for an A: Dynamic Regulation of Adenosine Deamination-Mediated RNA Editing. Genes (Basel) 2021; 12:1026. [PMID: 34356042 PMCID: PMC8304401 DOI: 10.3390/genes12071026] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
RNA-editing by adenosine deaminases acting on RNA (ADARs) converts adenosines to inosines in structured RNAs. Inosines are read as guanosines by most cellular machineries. A to I editing has two major functions: first, marking endogenous RNAs as "self", therefore helping the innate immune system to distinguish repeat- and endogenous retrovirus-derived RNAs from invading pathogenic RNAs; and second, recoding the information of the coding RNAs, leading to the translation of proteins that differ from their genomically encoded versions. It is obvious that these two important biological functions of ADARs will differ during development, in different tissues, upon altered physiological conditions or after exposure to pathogens. Indeed, different levels of ADAR-mediated editing have been observed in different tissues, as a response to altered physiology or upon pathogen exposure. In this review, we describe the dynamics of A to I editing and summarize the known and likely mechanisms that will lead to global but also substrate-specific regulation of A to I editing.
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Affiliation(s)
| | - Michael F. Jantsch
- Division of Cell & Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria;
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12
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Li J, Li Q, Yu CP, Chang S, Xie LL, Wang S. Genome-wide expression changes mediated by A-to-I RNA editing correlate with hepatic oncogenesis. Transl Cancer Res 2021; 10:2725-2737. [PMID: 35116583 PMCID: PMC8798912 DOI: 10.21037/tcr-21-236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/06/2021] [Indexed: 12/31/2022]
Abstract
Background Adenosine-to-inosine (A-to-I) RNA editing is one of the most prevalent RNA modifications in the animal kingdom. Since inosine is recognized as guanosines, the A-to-I process mimics A-to-G DNA mutations but can be controlled in a more flexible manner compared to DNA alterations. Methods We parsed the transcriptomes and translatomes of liver cancer and normal tissues from ten patients. We profiled the landscape of the A-to-I RNA editome in these samples and interrogated whether the A-to-I processes participated in the gene expression regulation in oncogenesis. Results Globally, editing activity was enhanced in all tumor samples compared to that in normal samples. Accordingly, expression of the gene encoding the RNA editing enzyme ADAR (adenosine deaminase acting on RNA) was elevated. Two intronic self-editing sites in ADAR mRNAs controlled its splicing pattern and may regulate its translation efficiency (TE). Moreover, the expression of oncogenes was generally upregulated in tumors, whereas tumor suppressor genes (TSG) were downregulated, possibly due to alterations to microRNA binding sites or RNA splicing defects caused by A-to-I editing. Conclusions A-to-I RNA editing plays a crucial role in the oncogenesis of liver cancer. ADAR regulates its own expression via self-editing, and it also affects global transcriptomes and translatomes involving cancer-related genes by RNA editing and changing their expression patterns.
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Affiliation(s)
- Jian Li
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qun Li
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chun-Peng Yu
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shuai Chang
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ling-Ling Xie
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Song Wang
- Department of Interventional Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
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13
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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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14
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Srinivasan S, Torres AG, Ribas de Pouplana L. Inosine in Biology and Disease. Genes (Basel) 2021; 12:600. [PMID: 33921764 PMCID: PMC8072771 DOI: 10.3390/genes12040600] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 02/06/2023] Open
Abstract
The nucleoside inosine plays an important role in purine biosynthesis, gene translation, and modulation of the fate of RNAs. The editing of adenosine to inosine is a widespread post-transcriptional modification in transfer RNAs (tRNAs) and messenger RNAs (mRNAs). At the wobble position of tRNA anticodons, inosine profoundly modifies codon recognition, while in mRNA, inosines can modify the sequence of the translated polypeptide or modulate the stability, localization, and splicing of transcripts. Inosine is also found in non-coding and exogenous RNAs, where it plays key structural and functional roles. In addition, molecular inosine is an important secondary metabolite in purine metabolism that also acts as a molecular messenger in cell signaling pathways. Here, we review the functional roles of inosine in biology and their connections to human health.
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Affiliation(s)
- Sundaramoorthy Srinivasan
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
| | - Adrian Gabriel Torres
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
| | - Lluís Ribas de Pouplana
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
- Catalan Institution for Research and Advanced Studies, 08010 Barcelona, Catalonia, Spain
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15
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Wu D, Zang YY, Shi YY, Ye C, Cai WM, Tang XH, Zhao L, Liu Y, Gan Z, Chen GQ, Xu Y, Yang JJ, Shi YS. Distant coupling between RNA editing and alternative splicing of the osmosensitive cation channel Tmem63b. J Biol Chem 2020; 295:18199-18212. [PMID: 33100268 PMCID: PMC7939439 DOI: 10.1074/jbc.ra120.016049] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/17/2020] [Indexed: 11/06/2022] Open
Abstract
Post-transcriptional modifications of pre-mRNAs expand the diversity of proteomes in higher eukaryotes. In the brain, these modifications diversify the functional output of many critical neuronal signal molecules. In this study, we identified a brain-specific A-to-I RNA editing that changed glutamine to arginine (Q/R) at exon 20 and an alternative splicing of exon 4 in Tmem63b, which encodes a ubiquitously expressed osmosensitive cation channel. The channel isoforms lacking exon 4 occurred in ∼80% of Tmem63b mRNAs in the brain but were not detected in other tissues, suggesting a brain-specific splicing. We found that the Q/R editing was catalyzed by Adar2 (Adarb1) and required an editing site complementary sequence located in the proximal 5' end of intron 20. Moreover, the Q/R editing was almost exclusively identified in the splicing isoform lacking exon 4, indicating a coupling between the editing and the splicing. Elimination of the Q/R editing in brain-specific Adar2 knockout mice did not affect the splicing efficiency of exon 4. Furthermore, transfection with the splicing isoform containing exon 4 suppressed the Q/R editing in primary cultured cerebellar granule neurons. Thus, our study revealed a coupling between an RNA editing and a distant alternative splicing in the Tmem63b pre-mRNA, in which the splicing plays a dominant role. Finally, physiological analysis showed that the splicing and the editing coordinately regulate Ca2+ permeability and osmosensitivity of channel proteins, which may contribute to their functions in the brain.
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Affiliation(s)
- Dan Wu
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China
| | - Yan-Yu Zang
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China
| | - Yong-Yun Shi
- Department of Orthopaedics, Luhe People's Hospital Affiliated to Yangzhou University, Nanjing, China
| | - Chang Ye
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China
| | - Wen-Min Cai
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China
| | - Xiao-Hui Tang
- Department of Anesthesiology and Perioperative Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; School of Medicine, Southeast University, Nanjing, China
| | - Liyun Zhao
- Translational Science and Clinical Biomarker, BeiGene (Shanghai) Co., Ltd., Shanghai, China
| | - Yong Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan, China
| | - Zhenji Gan
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China
| | - Gui-Quan Chen
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China; Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Yun Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China; Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Jian-Jun Yang
- Department of Anesthesiology and Perioperative Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
| | - Yun Stone Shi
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing University, Nanjing, China; Institute for Brain Sciences, Nanjing University, Nanjing, China; Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing, China.
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16
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Rajendren S, Dhakal A, Vadlamani P, Townsend J, Deffit SN, Hundley HA. Profiling neural editomes reveals a molecular mechanism to regulate RNA editing during development. Genome Res 2020; 31:27-39. [PMID: 33355311 PMCID: PMC7849389 DOI: 10.1101/gr.267575.120] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/18/2020] [Indexed: 12/18/2022]
Abstract
Adenosine (A) to inosine (I) RNA editing contributes to transcript diversity and modulates gene expression in a dynamic, cell type–specific manner. During mammalian brain development, editing of specific adenosines increases, whereas the expression of A-to-I editing enzymes remains unchanged, suggesting molecular mechanisms that mediate spatiotemporal regulation of RNA editing exist. Herein, by using a combination of biochemical and genomic approaches, we uncover a molecular mechanism that regulates RNA editing in a neural- and development-specific manner. Comparing editomes during development led to the identification of neural transcripts that were edited only in one life stage. The stage-specific editing is largely regulated by differential gene expression during neural development. Proper expression of nearly one-third of the neurodevelopmentally regulated genes is dependent on adr-2, the sole A-to-I editing enzyme in C. elegans. However, we also identified a subset of neural transcripts that are edited and expressed throughout development. Despite a neural-specific down-regulation of adr-2 during development, the majority of these sites show increased editing in adult neural cells. Biochemical data suggest that ADR-1, a deaminase-deficient member of the adenosine deaminase acting on RNA (ADAR) family, is competing with ADR-2 for binding to specific transcripts early in development. Our data suggest a model in which during neural development, ADR-2 levels overcome ADR-1 repression, resulting in increased ADR-2 binding and editing of specific transcripts. Together, our findings reveal tissue- and development-specific regulation of RNA editing and identify a molecular mechanism that regulates ADAR substrate recognition and editing efficiency.
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Affiliation(s)
- Suba Rajendren
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| | - Alfa Dhakal
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, Indiana 47405, USA
| | - Pranathi Vadlamani
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, Indiana 47405, USA
| | - Jack Townsend
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, Indiana 47405, USA
| | - Sarah N Deffit
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, Indiana 47405, USA
| | - Heather A Hundley
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, Indiana 47405, USA
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17
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Marina RJ, Brannan KW, Dong KD, Yee BA, Yeo GW. Evaluation of Engineered CRISPR-Cas-Mediated Systems for Site-Specific RNA Editing. Cell Rep 2020; 33:108350. [PMID: 33147453 PMCID: PMC8985550 DOI: 10.1016/j.celrep.2020.108350] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/30/2020] [Accepted: 10/13/2020] [Indexed: 12/17/2022] Open
Abstract
Site-directed RNA editing approaches offer great potential to correct genetic mutations in somatic cells while avoiding permanent off-target genomic edits. Nuclease-dead RNA-targeting CRISPR-Cas systems recruit functional effectors to RNA molecules in a programmable fashion. Here, we demonstrate a Streptococcus pyogenes Cas9-ADAR2 fusion system that uses a 3' modified guide RNA (gRNA) to enable adenosine-to-inosine (A-to-I) editing of specific bases on reporter and endogenously expressed mRNAs. Due to the sufficient nature of the 3' gRNA extension sequence, we observe that Cas9 gRNA spacer sequences are dispensable for directed RNA editing, revealing that Cas9 can act as an RNA-aptamer-binding protein. We demonstrate that Cas9-based A-to-I editing is comparable in on-target efficiency and off-target specificity with Cas13 RNA editing versions. This study provides a systematic benchmarking of RNA-targeting CRISPR-Cas designs for reversible nucleotide-level conversion at the transcriptome level.
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Affiliation(s)
- Ryan J Marina
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Stem Cell Program, University of California San Diego, La Jolla, CA 92093, USA; Institute for Genomic Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Kristopher W Brannan
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Stem Cell Program, University of California San Diego, La Jolla, CA 92093, USA; Institute for Genomic Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Kevin D Dong
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Stem Cell Program, University of California San Diego, La Jolla, CA 92093, USA; Institute for Genomic Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Stem Cell Program, University of California San Diego, La Jolla, CA 92093, USA; Institute for Genomic Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Stem Cell Program, University of California San Diego, La Jolla, CA 92093, USA; Institute for Genomic Medicine, University of California at San Diego, La Jolla, CA 92093, USA.
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18
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Kapoor U, Licht K, Amman F, Jakobi T, Martin D, Dieterich C, Jantsch MF. ADAR-deficiency perturbs the global splicing landscape in mouse tissues. Genome Res 2020; 30:1107-1118. [PMID: 32727871 PMCID: PMC7462079 DOI: 10.1101/gr.256933.119] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 07/10/2020] [Indexed: 02/06/2023]
Abstract
Adenosine-to-inosine RNA editing and pre-mRNA splicing largely occur cotranscriptionally and influence each other. Here, we use mice deficient in either one of the two editing enzymes ADAR (ADAR1) or ADARB1 (ADAR2) to determine the transcriptome-wide impact of RNA editing on splicing across different tissues. We find that ADAR has a 100× higher impact on splicing than ADARB1, although both enzymes target a similar number of substrates with a large common overlap. Consistently, differentially spliced regions frequently harbor ADAR editing sites. Moreover, catalytically dead ADAR also impacts splicing, demonstrating that RNA binding of ADAR affects splicing. In contrast, ADARB1 editing sites are found enriched 5′ of differentially spliced regions. Several of these ADARB1-mediated editing events change splice consensus sequences, therefore strongly influencing splicing of some mRNAs. A significant overlap between differentially edited and differentially spliced sites suggests evolutionary selection toward splicing being regulated by editing in a tissue-specific manner.
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Affiliation(s)
- Utkarsh Kapoor
- Center of Anatomy and Cell Biology, Department of Cell and Developmental Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Konstantin Licht
- Center of Anatomy and Cell Biology, Department of Cell and Developmental Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Fabian Amman
- Center of Anatomy and Cell Biology, Department of Cell and Developmental Biology, Medical University of Vienna, A-1090 Vienna, Austria.,Institute of Theoretical Biochemistry, University of Vienna, A-1090 Vienna, Austria
| | - Tobias Jakobi
- Department of Internal Medicine III and Klaus Tschira Institute for Computational Cardiology, Section of Bioinformatics and Systems Cardiology, University Hospital, D-96120 Heidelberg, Germany
| | - David Martin
- Center of Anatomy and Cell Biology, Department of Cell and Developmental Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Christoph Dieterich
- Department of Internal Medicine III and Klaus Tschira Institute for Computational Cardiology, Section of Bioinformatics and Systems Cardiology, University Hospital, D-96120 Heidelberg, Germany
| | - Michael F Jantsch
- Center of Anatomy and Cell Biology, Department of Cell and Developmental Biology, Medical University of Vienna, A-1090 Vienna, Austria
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19
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Costa Cruz PH, Kato Y, Nakahama T, Shibuya T, Kawahara Y. A comparative analysis of ADAR mutant mice reveals site-specific regulation of RNA editing. RNA (NEW YORK, N.Y.) 2020; 26:454-469. [PMID: 31941663 PMCID: PMC7075269 DOI: 10.1261/rna.072728.119] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 01/09/2020] [Indexed: 05/03/2023]
Abstract
Adenosine-to-inosine RNA editing is an essential post-transcriptional modification catalyzed by adenosine deaminase acting on RNA (ADAR)1 and ADAR2 in mammals. For numerous sites in coding sequences (CDS) and microRNAs, editing is highly conserved and has significant biological consequences, for example, by altering amino acid residues and target recognition. However, no comprehensive and quantitative studies have been undertaken to determine how specific ADARs contribute to conserved sites in vivo. Here, we amplified each RNA region with editing site(s) separately and combined these for deep sequencing. Then, we compared the editing ratios of all sites that were conserved in CDS and microRNAs in the cerebral cortex and spleen of wild-type mice, Adar1E861A/E861AIfih-/- mice expressing inactive ADAR1 (Adar1 KI) and Adar2-/-Gria2R/R (Adar2 KO) mice. We found that most of the sites showed a preference for one ADAR. In contrast, some sites, such as miR-3099-3p, showed no ADAR preference. In addition, we found that the editing ratio for several sites, such as DACT3 R/G, was up-regulated in either Adar mutant mouse strain, whereas a coordinated interplay between ADAR1 and ADAR2 was required for the efficient editing of specific sites, such as the 5-HT2CR B site. We further created double mutant Adar1 KI Adar2 KO mice and observed viable and fertile animals with the complete absence of editing, demonstrating that ADAR1 and ADAR2 are the sole enzymes responsible for all editing sites in vivo. Collectively, these findings indicate that editing is regulated in a site-specific manner by the different interplay between ADAR1 and ADAR2.
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Affiliation(s)
- Pedro Henrique Costa Cruz
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yuki Kato
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Toshiharu Shibuya
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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20
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Lundin E, Wu C, Widmark A, Behm M, Hjerling-Leffler J, Daniel C, Öhman M, Nilsson M. Spatiotemporal mapping of RNA editing in the developing mouse brain using in situ sequencing reveals regional and cell-type-specific regulation. BMC Biol 2020; 18:6. [PMID: 31937309 PMCID: PMC6961268 DOI: 10.1186/s12915-019-0736-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/23/2019] [Indexed: 01/01/2023] Open
Abstract
Background Adenosine-to-inosine (A-to-I) RNA editing is a process that contributes to the diversification of proteins that has been shown to be essential for neurotransmission and other neuronal functions. However, the spatiotemporal and diversification properties of RNA editing in the brain are largely unknown. Here, we applied in situ sequencing to distinguish between edited and unedited transcripts in distinct regions of the mouse brain at four developmental stages, and investigate the diversity of the RNA landscape. Results We analyzed RNA editing at codon-altering sites using in situ sequencing at single-cell resolution, in combination with the detection of individual ADAR enzymes and specific cell type marker transcripts. This approach revealed cell-type-specific regulation of RNA editing of a set of transcripts, and developmental and regional variation in editing levels for many of the targeted sites. We found increasing editing diversity throughout development, which arises through regional- and cell type-specific regulation of ADAR enzymes and target transcripts. Conclusions Our single-cell in situ sequencing method has proved useful to study the complex landscape of RNA editing and our results indicate that this complexity arises due to distinct mechanisms of regulating individual RNA editing sites, acting both regionally and in specific cell types. Electronic supplementary material The online version of this article (10.1186/s12915-019-0736-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elin Lundin
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, SE-171 21, Solna, Sweden.
| | - Chenglin Wu
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, SE-171 21, Solna, Sweden
| | - Albin Widmark
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden
| | - Mikaela Behm
- German Cancer Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Jens Hjerling-Leffler
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Chammiran Daniel
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden
| | - Marie Öhman
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden
| | - Mats Nilsson
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, SE-171 21, Solna, Sweden.
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21
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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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22
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Nanopore native RNA sequencing of a human poly(A) transcriptome. Nat Methods 2019; 16:1297-1305. [PMID: 31740818 PMCID: PMC7768885 DOI: 10.1038/s41592-019-0617-2] [Citation(s) in RCA: 328] [Impact Index Per Article: 65.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 09/19/2019] [Indexed: 12/11/2022]
Abstract
High throughput cDNA sequencing technologies have advanced our understanding of transcriptome complexity and regulation. However, these methods lose information contained in biological RNA because the copied reads are often short and because modifications are not retained. We address these limitations using a native poly(A) RNA sequencing strategy developed by Oxford Nanopore Technologies (ONT). Our study generated 9.9 million aligned sequence reads for the human cell line GM12878, using thirty MinION flow cells at six institutions. These native RNA reads had a median length of 771 bases, and a maximum aligned length of over 21,000 bases. Mitochondrial poly(A) reads provided an internal measure of read length quality. We combined these long nanopore reads with higher accuracy short-reads and annotated GM12878 promoter regions, to identify 33,984 plausible RNA isoforms. We describe strategies for assessing 3′ poly(A) tail length, base modifications, and transcript haplotypes.
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23
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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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24
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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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25
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Perrone B, La Cognata V, Sprovieri T, Ungaro C, Conforti FL, Andò S, Cavallaro S. Alternative Splicing of ALS Genes: Misregulation and Potential Therapies. Cell Mol Neurobiol 2019; 40:1-14. [PMID: 31385134 DOI: 10.1007/s10571-019-00717-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/31/2019] [Indexed: 12/12/2022]
Abstract
Neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), Parkinson's, Alzheimer's, and Huntington's disease affect a rapidly increasing population worldwide. Although common pathogenic mechanisms have been identified (e.g., protein aggregation or dysfunction, immune response alteration and axonal degeneration), the molecular events underlying timing, dosage, expression, and location of RNA molecules are still not fully elucidated. In particular, the alternative splicing (AS) mechanism is a crucial player in RNA processing and represents a fundamental determinant for brain development, as well as for the physiological functions of neuronal circuits. Although in recent years our knowledge of AS events has increased substantially, deciphering the molecular interconnections between splicing and ALS remains a complex task and still requires considerable efforts. In the present review, we will summarize the current scientific evidence outlining the involvement of AS in the pathogenic processes of ALS. We will also focus on recent insights concerning the tuning of splicing mechanisms by epigenomic and epi-transcriptomic regulation, providing an overview of the available genomic technologies to investigate AS drivers on a genome-wide scale, even at a single-cell level resolution. In the future, gene therapy strategies and RNA-based technologies may be utilized to intercept or modulate the splicing mechanism and produce beneficial effects against ALS.
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Affiliation(s)
- Benedetta Perrone
- Institute for Biomedical Research and Innovation, National Research Council, Mangone, Cosenza, Italy
| | - Valentina La Cognata
- Institute for Biomedical Research and Innovation, National Research Council, Catania, Italy
| | - Teresa Sprovieri
- Institute for Biomedical Research and Innovation, National Research Council, Mangone, Cosenza, Italy
| | - Carmine Ungaro
- Institute for Biomedical Research and Innovation, National Research Council, Mangone, Cosenza, Italy
| | - Francesca Luisa Conforti
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Sebastiano Andò
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy.,Centro Sanitario, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Sebastiano Cavallaro
- Institute for Biomedical Research and Innovation, National Research Council, Catania, Italy.
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26
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Kung CP, Maggi LB, Weber JD. The Role of RNA Editing in Cancer Development and Metabolic Disorders. Front Endocrinol (Lausanne) 2018; 9:762. [PMID: 30619092 PMCID: PMC6305585 DOI: 10.3389/fendo.2018.00762] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/03/2018] [Indexed: 12/26/2022] Open
Abstract
Numerous human diseases arise from alterations of genetic information, most notably DNA mutations. Thought to be merely the intermediate between DNA and protein, changes in RNA sequence were an afterthought until the discovery of RNA editing 30 years ago. RNA editing alters RNA sequence without altering the sequence or integrity of genomic DNA. The most common RNA editing events are A-to-I changes mediated by adenosine deaminase acting on RNA (ADAR), and C-to-U editing mediated by apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1). Both A-to-I and C-to-U editing were first identified in the context of embryonic development and physiological homeostasis. The role of RNA editing in human disease has only recently started to be understood. In this review, the impact of RNA editing on the development of cancer and metabolic disorders will be examined. Distinctive functions of each RNA editase that regulate either A-to-I or C-to-U editing will be highlighted in addition to pointing out important regulatory mechanisms governing these processes. The potential of developing novel therapeutic approaches through intervention of RNA editing will be explored. As the role of RNA editing in human disease is elucidated, the clinical utility of RNA editing targeted therapies will be needed. This review aims to serve as a bridge of information between past findings and future directions of RNA editing in the context of cancer and metabolic disease.
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Affiliation(s)
- Che-Pei Kung
- ICCE Institute, Washington University School of Medicine, Saint Louis, MO, United States
- Division of Molecular Oncology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Leonard B. Maggi
- ICCE Institute, Washington University School of Medicine, Saint Louis, MO, United States
- Division of Molecular Oncology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Jason D. Weber
- ICCE Institute, Washington University School of Medicine, Saint Louis, MO, United States
- Division of Molecular Oncology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
- Siteman Cancer Center, Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO, United States
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27
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Jain M, Mann TD, Stulić M, Rao SP, Kirsch A, Pullirsch D, Strobl X, Rath C, Reissig L, Moreth K, Klein-Rodewald T, Bekeredjian R, Gailus-Durner V, Fuchs H, Hrabě de Angelis M, Pablik E, Cimatti L, Martin D, Zinnanti J, Graier WF, Sibilia M, Frank S, Levanon EY, Jantsch MF. RNA editing of Filamin A pre-mRNA regulates vascular contraction and diastolic blood pressure. EMBO J 2018; 37:e94813. [PMID: 30087110 PMCID: PMC6166124 DOI: 10.15252/embj.201694813] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/25/2018] [Accepted: 06/27/2018] [Indexed: 12/26/2022] Open
Abstract
Epitranscriptomic events such as adenosine-to-inosine (A-to-I) RNA editing by ADAR can recode mRNAs to translate novel proteins. Editing of the mRNA that encodes actin crosslinking protein Filamin A (FLNA) mediates a Q-to-R transition in the interactive C-terminal region. While FLNA editing is conserved among vertebrates, its physiological function remains unclear. Here, we show that cardiovascular tissues in humans and mice show massive editing and that FLNA RNA is the most prominent substrate. Patient-derived RNA-Seq data demonstrate a significant drop in FLNA editing associated with cardiovascular diseases. Using mice with only impaired FLNA editing, we observed increased vascular contraction and diastolic hypertension accompanied by increased myosin light chain phosphorylation, arterial remodeling, and left ventricular wall thickening, which eventually causes cardiac remodeling and reduced systolic output. These results demonstrate a causal relationship between RNA editing and the development of cardiovascular disease indicating that a single epitranscriptomic RNA modification can maintain cardiovascular health.
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Affiliation(s)
- Mamta Jain
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Tomer D Mann
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
- Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Maja Stulić
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Shailaja P Rao
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Andrijana Kirsch
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dieter Pullirsch
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Xué Strobl
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Claus Rath
- Division of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Lukas Reissig
- Division of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Kristin Moreth
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Tanja Klein-Rodewald
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Raffi Bekeredjian
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Experimental Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Eleonore Pablik
- Section for Medical Statistics, CeMSIIS, Medical University of Vienna, Vienna, Austria
| | - Laura Cimatti
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - David Martin
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | | | - Wolfgang F Graier
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Maria Sibilia
- Department of Medicine I, Comprehensive Cancer Center, Institute for Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Saša Frank
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Michael F Jantsch
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
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28
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Czermak P, Amman F, Jantsch MF, Cimatti L. Organ-wide profiling in mouse reveals high editing levels of Filamin B mRNA in the musculoskeletal system. RNA Biol 2018; 15:877-885. [PMID: 30064337 PMCID: PMC6161736 DOI: 10.1080/15476286.2018.1480252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/15/2018] [Indexed: 01/24/2023] Open
Abstract
Adenosine to inosine RNA editing in protein-coding messenger RNAs (mRNAs) potentially leads to changes in the amino acid composition of the encoded proteins. The mRNAs encoding the ubiquitously expressed actin-crosslinking proteins Filamin A and Filamin B undergo RNA editing leading to a highly conserved glutamine to arginine exchange at the identical position in either protein. Here, by targeted amplicon sequencing we analysed the RNA editing of Filamin B across several mouse tissues during post-natal development. We find highest filamin B editing levels in skeletal muscles, cartilage and bones, tissues where Filamin B function seems most important. Through the analysis of Filamin B editing in mice deficient in either ADAR1 or 2, we identified ADAR2 as the enzyme responsible for Filamin B RNA editing. We show that in neuronal tissues Filamin B editing drops in spliced transcripts indicating regulated maturation of edited transcripts. We show further that the variability of Filamin B editing across several organs correlates with its mRNA expression.
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Affiliation(s)
- Philipp Czermak
- Center of Anatomy and Cell Biology, Division of Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Fabian Amman
- Institute of Theoretical Biochemistry, University of Vienna, Vienna, Austria
- Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna, Vienna, Austria
| | - Michael F. Jantsch
- Center of Anatomy and Cell Biology, Division of Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Laura Cimatti
- Center of Anatomy and Cell Biology, Division of Cell Biology, Medical University of Vienna, Vienna, Austria
- Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna, Vienna, Austria
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29
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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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30
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Coassin S, Erhart G, Weissensteiner H, Eca Guimarães de Araújo M, Lamina C, Schönherr S, Forer L, Haun M, Losso JL, Köttgen A, Schmidt K, Utermann G, Peters A, Gieger C, Strauch K, Finkenstedt A, Bale R, Zoller H, Paulweber B, Eckardt KU, Hüttenhofer A, Huber LA, Kronenberg F. A novel but frequent variant in LPA KIV-2 is associated with a pronounced Lp(a) and cardiovascular risk reduction. Eur Heart J 2018; 38:1823-1831. [PMID: 28444229 PMCID: PMC5837733 DOI: 10.1093/eurheartj/ehx174] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/21/2017] [Indexed: 01/21/2023] Open
Abstract
Aims Lp(a) concentrations represent a major cardiovascular risk factor and are almost entirely controlled by one single locus (LPA). However, many genetic factors in LPA governing the enormous variance of Lp(a) levels are still unknown. Since up to 70% of the LPA coding sequence are located in a difficult to access hypervariable copy number variation named KIV-2, we hypothesized that it may contain novel functional variants with pronounced effects on Lp(a) concentrations. We performed a large scale mutation analysis in the KIV-2 using an extreme phenotype approach. Methods and Results We compiled an discovery set of 123 samples showing discordance between LPA isoform phenotype and Lp(a) concentrations and controls. Using ultra-deep sequencing, we identified a splice site variant (G4925A) in preferential association with the smaller LPA isoforms. Follow-up in a European general population (n = 2892) revealed an exceptionally high carrier frequency of 22.1% in the general population. The variant explains 20.6% of the Lp(a) variance in carriers of low molecular weight (LMW) apo(a) isoforms (P = 5.75e-38) and reduces Lp(a) concentrations by 31.3 mg/dL. Accordingly the odds ratio for cardiovascular disease was reduced from 1.39 [95% confidence interval (CI): 1.17–1.66, P = 1.89e-04] for wildtype LMW individuals to 1.19 [95%CI: 0.92; 1.56, P = 0.19] in LMW individuals who were additionally positive for G4925A. Functional studies point towards a reduction of splicing efficiency by this novel variant. Conclusion A highly frequent but until now undetected variant in the LPA KIV-2 region is strongly associated with reduced Lp(a) concentrations and reduced cardiovascular risk in LMW individuals.
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Affiliation(s)
- Stefan Coassin
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Gertraud Erhart
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Hansi Weissensteiner
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | | | - Claudia Lamina
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Sebastian Schönherr
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Lukas Forer
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Margot Haun
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Jamie Lee Losso
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Anna Köttgen
- Division of Genetic Epidemiology, Division of Genetic Epidemiology - Faculty of Medicine and Medical Center - University of Freiburg, Hugstetter Strasse 49, 79106 Freiburg, Germany
| | - Konrad Schmidt
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
| | - Gerd Utermann
- Division of Human Genetics, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Peter-Mayr-Strasse 1, 6020 Innsbruck, Austria
| | - Annette Peters
- German Center for Diabetes Research, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München - German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.,Munich Heart Alliance, German Center for Cardiovascular Disease Research, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Christian Gieger
- Institute of Epidemiology II, Helmholtz Zentrum München - German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Konstantin Strauch
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.,Institute of Medical Informatics, Biometry and Epidemiology, Chair of Genetic Epidemiology, Ludwig-Maximilians-Universität, Marchioninistrasse 15, 81377 Munich, Germany
| | - Armin Finkenstedt
- Internal Medicine I, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Reto Bale
- Section of Interventional Oncology - Microinvasive Therapy (SIP), Department of Radiology, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Heinz Zoller
- Internal Medicine I, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Bernhard Paulweber
- First Department of Internal Medicine, Paracelsus Private Medical University, Müllner Hauptstrasse 48, 5020 Salzburg, Austria
| | - Kai-Uwe Eckardt
- Department of Nephrology and Hypertension, University of Erlangen-Nürnberg, Ulmenweg 18, 91054 Erlangen, Germany
| | - Alexander Hüttenhofer
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Florian Kronenberg
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Schoepfstrasse 41, 6020 Innsbruck, Austria
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31
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Shevchenko G, Morris KV. All I's on the RADAR: role of ADAR in gene regulation. FEBS Lett 2018; 592:2860-2873. [PMID: 29770436 DOI: 10.1002/1873-3468.13093] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/26/2018] [Accepted: 05/05/2018] [Indexed: 12/12/2022]
Abstract
Adenosine to inosine (A-to-I) editing is the most abundant form of RNA modification in mammalian cells, which is catalyzed by adenosine deaminase acting on the double-stranded RNA (ADAR) protein family. A-to-I editing is currently known to be involved in the regulation of the immune system, RNA splicing, protein recoding, microRNA biogenesis, and formation of heterochromatin. Editing occurs within regions of double-stranded RNA, particularly within inverted Alu repeats, and is associated with many diseases including cancer, neurological disorders, and metabolic syndromes. However, the significance of RNA editing in a large portion of the transcriptome remains unknown. Here, we review the current knowledge about the prevalence and function of A-to-I editing by the ADAR protein family, focusing on its role in the regulation of gene expression. Furthermore, RNA editing-independent regulation of cellular processes by ADAR and the putative role(s) of this process in gene regulation will be discussed.
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Affiliation(s)
- Galina Shevchenko
- Hematological Malignancy and Stem Cell Transplantation Institute, Center for Gene Therapy, City of Hope-Beckman Research Institute, Duarte, CA, USA
| | - Kevin V Morris
- Hematological Malignancy and Stem Cell Transplantation Institute, Center for Gene Therapy, City of Hope-Beckman Research Institute, Duarte, CA, USA
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32
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Chen YT, Chang IYF, Liu H, Ma CP, Kuo YP, Shih CT, Shih YH, Kang L, Tan BCM. Tumor-associated intronic editing of HNRPLL generates a novel splicing variant linked to cell proliferation. J Biol Chem 2018; 293:10158-10171. [PMID: 29769310 DOI: 10.1074/jbc.ra117.001197] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/29/2018] [Indexed: 01/02/2023] Open
Abstract
Processing of the eukaryotic transcriptome is a dynamic regulatory mechanism that confers genetic diversity, and splicing and adenosine to inosine (A-to-I) RNA editing are well-characterized examples of such processing. Growing evidence reveals the cross-talk between the splicing and RNA editing, but there is a paucity of substantial evidence for its mechanistic details and contribution in a physiological context. Here, our findings demonstrate that tumor-associated differential RNA editing, in conjunction with splicing machinery, regulates the expression of variants of HNRPLL, a gene encoding splicing factor. We discovered an HNRPLL transcript variant containing an additional exon 12A (E12A), which is a substrate of ADAR1 and ADAR2. Adenosine deaminases acting on RNA (ADAR) direct deaminase-dependent expression of the E12A transcript, and ADAR-mediated regulation of E12A is largely splicing-based, and does not affect the stability or nucleocytoplasmic distribution of the transcript. Furthermore, ADAR-mediated modification of exon 12A generates an enhancer for the oncogenic splicing factor SRSF1 and consequently promotes the frequency of alternative splicing. Gene expression profiling by RNA-seq revealed that E12A acts distinctly from HNRPLL and regulates a set of growth-related genes, such as cyclin CCND1 and growth factor receptor TGFBR1 Accordingly, silencing E12A expression leads to impaired clonogenic ability and enhanced sensitivity to doxorubicin, thus highlighting the significance of this alternative isoform in tumor cell survival. In summary, we present the interplay of RNA editing and splicing as a regulatory mechanism of gene expression and also its physiological relevance. These findings extend our understanding of transcriptional dynamics and provide a mechanistic explanation to the link of RNA editors to tumorigenesis.
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Affiliation(s)
- Yi-Tung Chen
- From the Graduate Institute of Biomedical Sciences, College of Medicine.,the Department of Biomedical Sciences, College of Medicine
| | | | - Hsuan Liu
- From the Graduate Institute of Biomedical Sciences, College of Medicine.,Molecular Medicine Research Center.,Department of Biochemistry, College of Medicine, and.,the Division of Colon and Rectal Surgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| | - Chung-Pei Ma
- From the Graduate Institute of Biomedical Sciences, College of Medicine.,the Department of Biomedical Sciences, College of Medicine
| | - Yu-Ping Kuo
- From the Graduate Institute of Biomedical Sciences, College of Medicine.,the Department of Biomedical Sciences, College of Medicine
| | - Chieh-Tien Shih
- From the Graduate Institute of Biomedical Sciences, College of Medicine.,the Department of Biomedical Sciences, College of Medicine
| | - Ying-Hsin Shih
- the Department of Biomedical Sciences, College of Medicine
| | - Lin Kang
- the Edward Via College of Osteopathic Medicine, Blacksburg, Virginia 24060, and
| | - Bertrand Chin-Ming Tan
- From the Graduate Institute of Biomedical Sciences, College of Medicine, .,the Department of Biomedical Sciences, College of Medicine.,Molecular Medicine Research Center.,the Department of Neurosurgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
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33
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Schaefer M, Kapoor U, Jantsch MF. Understanding RNA modifications: the promises and technological bottlenecks of the 'epitranscriptome'. Open Biol 2018; 7:rsob.170077. [PMID: 28566301 PMCID: PMC5451548 DOI: 10.1098/rsob.170077] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/02/2017] [Indexed: 01/08/2023] Open
Abstract
The discovery of mechanisms that alter genetic information via RNA editing or introducing covalent RNA modifications points towards a complexity in gene expression that challenges long-standing concepts. Understanding the biology of RNA modifications represents one of the next frontiers in molecular biology. To this date, over 130 different RNA modifications have been identified, and improved mass spectrometry approaches are still adding to this list. However, only recently has it been possible to map selected RNA modifications at single-nucleotide resolution, which has created a number of exciting hypotheses about the biological function of RNA modifications, culminating in the proposition of the ‘epitranscriptome’. Here, we review some of the technological advances in this rapidly developing field, identify the conceptual challenges and discuss approaches that are needed to rigorously test the biological function of specific RNA modifications.
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Affiliation(s)
- Matthias Schaefer
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
| | - Utkarsh Kapoor
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
| | - Michael F Jantsch
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
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34
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Jiang Q, Crews LA, Holm F, Jamieson CHM. RNA editing-dependent epitranscriptome diversity in cancer stem cells. Nat Rev Cancer 2017; 17:381-392. [PMID: 28416802 PMCID: PMC5665169 DOI: 10.1038/nrc.2017.23] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cancer stem cells (CSCs) can regenerate all facets of a tumour as a result of their stem cell-like capacity to self-renew, survive and become dormant in protective microenvironments. CSCs evolve during tumour progression in a manner that conforms to Charles Darwin's principle of natural selection. Although somatic DNA mutations and epigenetic alterations promote evolution, post-transcriptional RNA modifications together with RNA binding protein activity (the 'epitranscriptome') might also contribute to clonal evolution through dynamic determination of RNA function and gene expression diversity in response to environmental stimuli. Deregulation of these epitranscriptomic events contributes to CSC generation and maintenance, which governs cancer progression and drug resistance. In this Review, we discuss the role of malignant RNA processing in CSC generation and maintenance, including mechanisms of RNA methylation, RNA editing and RNA splicing, and the functional consequences of their aberrant regulation in human malignancies. Finally, we highlight the potential of these events as novel CSC biomarkers as well as therapeutic targets.
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Affiliation(s)
- Qingfei Jiang
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center and Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Leslie A Crews
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center and Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Frida Holm
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center and Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Catriona H M Jamieson
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center and Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California 92093, USA
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35
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Galipon J, Ishii R, Suzuki Y, Tomita M, Ui-Tei K. Differential Binding of Three Major Human ADAR Isoforms to Coding and Long Non-Coding Transcripts. Genes (Basel) 2017; 8:genes8020068. [PMID: 28208661 PMCID: PMC5333057 DOI: 10.3390/genes8020068] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/03/2017] [Accepted: 02/06/2017] [Indexed: 11/16/2022] Open
Abstract
RNA editing by deamination of adenosine to inosine is an evolutionarily conserved process involved in many cellular pathways, from alternative splicing to miRNA targeting. In humans, it is carried out by no less than three major adenosine deaminases acting on RNA (ADARs): ADAR1-p150, ADAR1-p110, and ADAR2. However, the first two derive from alternative splicing, so that it is currently impossible to delete ADAR1-p110 without also knocking out ADAR1-p150 expression. Furthermore, the expression levels of ADARs varies wildly among cell types, and no study has systematically explored the effect of each of these isoforms on the cell transcriptome. In this study, RNA immunoprecipitation (RIP)-sequencing on overexpressed ADAR isoforms tagged with green fluorescent protein (GFP) shows that each ADAR is associated with a specific set of differentially expressed genes, and that they each bind to distinct set of RNA targets. Our results show a good overlap with known edited transcripts, establishing RIP-seq as a valid method for the investigation of RNA editing biology.
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Affiliation(s)
- Josephine Galipon
- Keio University Institute for Advanced Biosciences, Tsuruoka 997-0017, Japan.
| | - Rintaro Ishii
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan.
| | - Yutaka Suzuki
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan.
| | - Masaru Tomita
- Keio University Institute for Advanced Biosciences, Tsuruoka 997-0017, Japan.
| | - Kumiko Ui-Tei
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan.
- Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
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36
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Oakes E, Anderson A, Cohen-Gadol A, Hundley HA. Adenosine Deaminase That Acts on RNA 3 (ADAR3) Binding to Glutamate Receptor Subunit B Pre-mRNA Inhibits RNA Editing in Glioblastoma. J Biol Chem 2017; 292:4326-4335. [PMID: 28167531 DOI: 10.1074/jbc.m117.779868] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 02/05/2017] [Indexed: 01/08/2023] Open
Abstract
RNA editing is a cellular process that precisely alters nucleotide sequences, thus regulating gene expression and generating protein diversity. Over 60% of human transcripts undergo adenosine to inosine RNA editing, and editing is required for normal development and proper neuronal function of animals. Editing of one adenosine in the transcript encoding the glutamate receptor subunit B, glutamate receptor ionotropic AMPA 2 (GRIA2), modifies a codon, replacing the genomically encoded glutamine (Q) with arginine (R); thus this editing site is referred to as the Q/R site. Editing at the Q/R site of GRIA2 is essential, and reduced editing of GRIA2 transcripts has been observed in patients suffering from glioblastoma. In glioblastoma, incorporation of unedited GRIA2 subunits leads to a calcium-permeable glutamate receptor, which can promote cell migration and tumor invasion. In this study, we identify adenosine deaminase that acts on RNA 3 (ADAR3) as an important regulator of Q/R site editing, investigate its mode of action, and detect elevated ADAR3 expression in glioblastoma tumors compared with adjacent brain tissue. Overexpression of ADAR3 in astrocyte and astrocytoma cell lines inhibits RNA editing at the Q/R site of GRIA2 Furthermore, the double-stranded RNA binding domains of ADAR3 are required for repression of RNA editing. As the Q/R site of GRIA2 is specifically edited by ADAR2, we suggest that ADAR3 directly competes with ADAR2 for binding to GRIA2 transcript, inhibiting RNA editing, as evidenced by the direct binding of ADAR3 to the GRIA2 pre-mRNA. Finally, we provide evidence that both ADAR2 and ADAR3 expression contributes to the relative level of GRIA2 editing in tumors from patients suffering from glioblastoma.
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Affiliation(s)
| | - Ashley Anderson
- Medical Sciences Program, Indiana University, Bloomington, Indiana 47405 and
| | - Aaron Cohen-Gadol
- Department of Neurological Surgery, Goodman Campbell Brain and Spine, Indianapolis, Indiana 46202
| | - Heather A Hundley
- Medical Sciences Program, Indiana University, Bloomington, Indiana 47405 and
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37
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Filippini A, Bonini D, La Via L, Barbon A. The Good and the Bad of Glutamate Receptor RNA Editing. Mol Neurobiol 2016; 54:6795-6805. [DOI: 10.1007/s12035-016-0201-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/11/2016] [Indexed: 12/15/2022]
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38
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Ferreira PG, Oti M, Barann M, Wieland T, Ezquina S, Friedländer MR, Rivas MA, Esteve-Codina A, Rosenstiel P, Strom TM, Lappalainen T, Guigó R, Sammeth M. Sequence variation between 462 human individuals fine-tunes functional sites of RNA processing. Sci Rep 2016; 6:32406. [PMID: 27617755 PMCID: PMC5019111 DOI: 10.1038/srep32406] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/03/2016] [Indexed: 12/23/2022] Open
Abstract
Recent advances in the cost-efficiency of sequencing technologies enabled the combined DNA- and RNA-sequencing of human individuals at the population-scale, making genome-wide investigations of the inter-individual genetic impact on gene expression viable. Employing mRNA-sequencing data from the Geuvadis Project and genome sequencing data from the 1000 Genomes Project we show that the computational analysis of DNA sequences around splice sites and poly-A signals is able to explain several observations in the phenotype data. In contrast to widespread assessments of statistically significant associations between DNA polymorphisms and quantitative traits, we developed a computational tool to pinpoint the molecular mechanisms by which genetic markers drive variation in RNA-processing, cataloguing and classifying alleles that change the affinity of core RNA elements to their recognizing factors. The in silico models we employ further suggest RNA editing can moonlight as a splicing-modulator, albeit less frequently than genomic sequence diversity. Beyond existing annotations, we demonstrate that the ultra-high resolution of RNA-Seq combined from 462 individuals also provides evidence for thousands of bona fide novel elements of RNA processing-alternative splice sites, introns, and cleavage sites-which are often rare and lowly expressed but in other characteristics similar to their annotated counterparts.
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Affiliation(s)
- Pedro G. Ferreira
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1211 Geneva, Switzerland
- Instituto de Investigação e Inovação em Saúde, (i3S) Universidade do Porto, 4200-625 Porto, Portugal
- Institute of Molecular Pathology and Immunology (IPATIMUP), University of Porto, 4200-625 Porto, Portugal
| | - Martin Oti
- Institute of Biophysics Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro (UFRJ), 21941-902 Rio de Janeiro, Brazil
| | - Matthias Barann
- Institute of Clinical Molecular Biology, Christians-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Thomas Wieland
- Institute of Human Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Suzana Ezquina
- Center for Human Genome and Stem-cell research (HUG-CELL), University of São Paulo (USP), 05508090 São Paulo, Brazil
| | - Marc R. Friedländer
- Science for Life Laboratory, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Manuel A. Rivas
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Anna Esteve-Codina
- Centre Nacional d’Anàlisi Genòmica, 08028 Barcelona, Catalonia, Spain
- Center for Research in Agricultural Genomics (CRAG), Autonome University of Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Christians-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Tim M Strom
- Institute of Human Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Tuuli Lappalainen
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1211 Geneva, Switzerland
- Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
- Swiss Institute of Bioinformatics, 1211 Geneva, Switzerland
| | - Roderic Guigó
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Pompeu Fabra University (UPF), 08003 Barcelona, Catalonia, Spain
| | - Michael Sammeth
- Bioinformatics and Genomics, Center for Genomic Regulation (CRG), 08003 Barcelona, Catalonia, Spain
- Institute of Biophysics Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro (UFRJ), 21941-902 Rio de Janeiro, Brazil
- National Center of Scientific Computing (LNCC), 2233-6000 Petrópolis, Rio de Janeiro, Brazil
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