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Mendoza HG, Beal PA. Structural and functional effects of inosine modification in mRNA. RNA (NEW YORK, N.Y.) 2024; 30:512-520. [PMID: 38531652 PMCID: PMC11019749 DOI: 10.1261/rna.079977.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/09/2024] [Indexed: 03/28/2024]
Abstract
Inosine (I), resulting from the deamination of adenosine (A), is a prominent modification in the human transcriptome. The enzymes responsible for the conversion of adenosine to inosine in human mRNAs are the ADARs (adenosine deaminases acting on RNA). Inosine modification introduces a layer of complexity to mRNA processing and function, as it can impact various aspects of RNA biology, including mRNA stability, splicing, translation, and protein binding. The relevance of this process is emphasized in the growing number of human disorders associated with dysregulated A-to-I editing pathways. Here, we describe the impact of the A-to-I conversion on the structure and stability of duplex RNA and on the consequences of this modification at different locations in mRNAs. Furthermore, we highlight specific open questions regarding the interplay between inosine formation in duplex RNA and the innate immune response.
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Affiliation(s)
- Herra G Mendoza
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Peter A Beal
- Department of Chemistry, University of California, Davis, California 95616, USA
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2
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Bass BL. Adenosine deaminases that act on RNA, then and now. RNA (NEW YORK, N.Y.) 2024; 30:521-529. [PMID: 38531651 PMCID: PMC11019741 DOI: 10.1261/rna.079990.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 02/11/2024] [Indexed: 03/28/2024]
Abstract
In this article, I recount my memories of key experiments that led to my entry into the RNA editing/modification field. I highlight initial observations made by the pioneers in the ADAR field, and how they fit into our current understanding of this family of enzymes. I discuss early mysteries that have now been solved, as well as those that still linger. Finally, I discuss important, outstanding questions and acknowledge my hope for the future of the RNA editing/modification field.
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Affiliation(s)
- Brenda L Bass
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112, USA
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3
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Jarmoskaite I, Li JB. Multifaceted roles of RNA editing enzyme ADAR1 in innate immunity. RNA (NEW YORK, N.Y.) 2024; 30:500-511. [PMID: 38531645 PMCID: PMC11019752 DOI: 10.1261/rna.079953.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/09/2024] [Indexed: 03/28/2024]
Abstract
Innate immunity must be tightly regulated to enable sensitive pathogen detection while averting autoimmunity triggered by pathogen-like host molecules. A hallmark of viral infection, double-stranded RNAs (dsRNAs) are also abundantly encoded in mammalian genomes, necessitating surveillance mechanisms to distinguish "self" from "nonself." ADAR1, an RNA editing enzyme, has emerged as an essential safeguard against dsRNA-induced autoimmunity. By converting adenosines to inosines (A-to-I) in long dsRNAs, ADAR1 covalently marks endogenous dsRNAs, thereby blocking the activation of the cytoplasmic dsRNA sensor MDA5. Moreover, beyond its editing function, ADAR1 binding to dsRNA impedes the activation of innate immune sensors PKR and ZBP1. Recent landmark studies underscore the utility of silencing ADAR1 for cancer immunotherapy, by exploiting the ADAR1-dependence developed by certain tumors to unleash an antitumor immune response. In this perspective, we summarize the genetic and mechanistic evidence for ADAR1's multipronged role in suppressing dsRNA-mediated autoimmunity and explore the evolving roles of ADAR1 as an immuno-oncology target.
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Affiliation(s)
- Inga Jarmoskaite
- Department of Genetics, Stanford University, Stanford, California 94305, USA
- AIRNA Corporation, Cambridge, Massachusetts 02142, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, California 94305, USA
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4
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de Reuver R, Maelfait J. Novel insights into double-stranded RNA-mediated immunopathology. Nat Rev Immunol 2024; 24:235-249. [PMID: 37752355 DOI: 10.1038/s41577-023-00940-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2023] [Indexed: 09/28/2023]
Abstract
Recent progress in human and mouse genetics has transformed our understanding of the molecular mechanisms by which recognition of self double-stranded RNA (self-dsRNA) causes immunopathology. Novel mouse models recapitulate loss-of-function mutations in the RNA editing enzyme ADAR1 that are found in patients with Aicardi-Goutières syndrome (AGS) - a monogenic inflammatory disease associated with increased levels of type I interferon. Extensive analyses of the genotype-phenotype relationships in these mice have now firmly established a causal relationship between increased intracellular concentrations of endogenous immunostimulatory dsRNA and type I interferon-driven immunopathology. Activation of the dsRNA-specific immune sensor MDA5 perpetuates the overproduction of type I interferons, and chronic engagement of the interferon-inducible innate immune receptors PKR and ZBP1 by dsRNA drives immunopathology by activating an integrated stress response or by inducing excessive cell death. Biochemical and genetic data support a role for the p150 isoform of ADAR1 in the cytosol in suppressing the spontaneous, pathological response to self-dsRNA.
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Affiliation(s)
- Richard de Reuver
- VIB-UGent Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jonathan Maelfait
- VIB-UGent Center for Inflammation Research, Ghent, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
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5
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Yin Q, Qu Z, Mathew R, Zeng L, Du Z, Xue Y, Liu D, Zheng X. Epitranscriptomic orchestrations: Unveiling the regulatory paradigm of m6A, A-to-I editing, and m5C in breast cancer via long noncoding RNAs and microRNAs. Cell Biochem Funct 2024; 42:e3996. [PMID: 38561942 DOI: 10.1002/cbf.3996] [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: 01/31/2024] [Revised: 03/09/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Breast cancer (BC) poses a persistent global health challenge, particularly in countries with elevated human development indices linked to factors such as increased life expectancy, education, and wealth. Despite therapeutic progress, challenges persist, and the role of epitranscriptomic RNA modifications in BC remains inadequately understood. The epitranscriptome, comprising diverse posttranscriptional modifications on RNA molecules, holds the potential to intricately modulate RNA function and regulation, implicating dysregulation in various diseases, including BC. Noncoding RNAs (ncRNAs), acting as posttranscriptional regulators, influence physiological and pathological processes, including cancer. RNA modifications in long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) add an extra layer to gene expression control. This review delves into recent insights into epitranscriptomic RNA modifications, such as N-6-methyladenosine (m6A), adenine-to-inosine (A-to-I) editing, and 5-methylcytosine (m5C), specifically in the context of lncRNA and miRNAs in BC, highlighting their potential implications in BC development and progression. Understanding this intricate regulatory landscape is vital for deciphering the molecular mechanisms underlying BC and identifying potential therapeutic targets.
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Affiliation(s)
- Qinan Yin
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Zhifeng Qu
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Regina Mathew
- Department of Chemistry and Biochemistry, California State University, Los Angeles, California, USA
| | - Li Zeng
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Zhe Du
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Yun Xue
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Dechun Liu
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Xuewei Zheng
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
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6
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Levanon EY, Cohen-Fultheim R, Eisenberg E. In search of critical dsRNA targets of ADAR1. Trends Genet 2024; 40:250-259. [PMID: 38160061 DOI: 10.1016/j.tig.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
Recent studies have underscored the pivotal role of adenosine-to-inosine RNA editing, catalyzed by ADAR1, in suppressing innate immune interferon responses triggered by cellular double-stranded RNA (dsRNA). However, the specific ADAR1 editing targets crucial for this regulatory function remain elusive. We review analyses of transcriptome-wide ADAR1 editing patterns and their evolutionary dynamics, which offer valuable insights into this unresolved query. The growing appreciation of the significance of immunogenic dsRNAs and their editing in inflammatory and autoimmune diseases and cancer calls for a more comprehensive understanding of dsRNA immunogenicity, which may promote our understanding of these diseases and open doors to therapeutic avenues.
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Affiliation(s)
- Erez Y Levanon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel.
| | - Roni Cohen-Fultheim
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv, University, Tel Aviv 6997801, Israel.
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Hong X, Wei Z, He L, Bu Q, Wu G, Chen G, He W, Deng Q, Huang S, Huang Y, Yu C, Luo X, Lin Y. High-throughput virtual screening to identify potential small molecule inhibitors of the Zα domain of the adenosine deaminases acting on RNA 1(ADAR1). Eur J Pharm Sci 2024; 193:106672. [PMID: 38103658 DOI: 10.1016/j.ejps.2023.106672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Changes in RNA editing are closely associated with diseases such as cancer, viral infections, and autoimmune disorders. Adenosine deaminase (ADAR1), which acts on RNA 1, plays a key role in adenosine to inosine editing and is a potential therapeutic target for these various diseases. The p150 subtype of ADAR1 is the only one that contains a Zα domain that binds to both Z-DNA and Z-RNA. The Zα domain modulates immune responses and may be suitable targets for antiviral therapy and cancer immunotherapy. In this study, we attempted to utilize molecular docking to identify potential inhibitors that bind to the ADAR1 Zα domain. The virtual docking method screened the potential activity of more than 100,000 compounds on the Zα domain of ADAR1 and filtered to obtain the highest scoring results.We identified 71 compounds promising to bind to ADAR1 and confirmed that two of them, lithospermic acid and Regaloside B, interacts with the ADAR1 Zα domain by surface plasmonic resonance technique. The molecular dynamics calculation of the complex of lithospermic acid and ADAR1 also showed that the binding effect of lithospermic acid to ADAR1 was stable.This study provides a new perspective for the search of ADAR1 inhibitors, and further studies on the anti-ADAR11 activity of these compounds have broad prospects.
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Affiliation(s)
- Xiaoshan Hong
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China
| | - Zhifu Wei
- Department of gynecology, The Affiliated Shunde Hospital of Jinan University, Foshan 528300, China
| | - Lulu He
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China
| | - Qiaowen Bu
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China
| | - Guosong Wu
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China
| | - Guanqiao Chen
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China
| | - Wanshan He
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China
| | - Qiuhua Deng
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China
| | - Shiqi Huang
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China
| | - Yongmei Huang
- Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China.
| | - Cai Yu
- College of Pharmacy, Jinan University, Guangzhou 511436, China.
| | - Xiping Luo
- Department of gynecology, Guangdong Women and Children Medical Hospital, Guangzhou 511400, China.
| | - Yu Lin
- Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China; Baiyun Branch, Nanfang Hospital, Southern Medical University, Guangzhou 510006, China.
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8
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Xiang J, Xu W, Wu J, Luo Y, Yang B, Chen J. Nucleoside deaminases: the key players in base editing toolkit. BIOPHYSICS REPORTS 2023; 9:325-337. [PMID: 38524700 PMCID: PMC10960570 DOI: 10.52601/bpr.2023.230029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 11/28/2023] [Indexed: 03/26/2024] Open
Abstract
The development of nucleoside deaminase-containing base editors realized targeted single base change with high efficiency and precision. Such nucleoside deaminases include adenosine and cytidine deaminases, which can catalyze adenosine-to-inosine (A-to-I) and cytidine-to-uridine (C-to-U) conversion respectively. These nucleoside deaminases are under the spotlight because of their vast application potential in gene editing. Recent advances in the engineering of current nucleoside deaminases and the discovery of new nucleoside deaminases greatly broaden the application scope and improve the editing specificity of base editors. In this review, we cover current knowledge about the deaminases used in base editors, including their key structural features, working mechanisms, optimization, and evolution.
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Affiliation(s)
- Jiangchao Xiang
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wenchao Xu
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jing Wu
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yaxin Luo
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Bei Yang
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
| | - Jia Chen
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
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9
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Budzko L, Hoffa-Sobiech K, Jackowiak P, Figlerowicz M. Engineered deaminases as a key component of DNA and RNA editing tools. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102062. [PMID: 38028200 PMCID: PMC10661471 DOI: 10.1016/j.omtn.2023.102062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Over recent years, zinc-dependent deaminases have attracted increasing interest as key components of nucleic acid editing tools that can generate point mutations at specific sites in either DNA or RNA by combining a targeting module (such as a catalytically impaired CRISPR-Cas component) and an effector module (most often a deaminase). Deaminase-based molecular tools are already being utilized in a wide spectrum of therapeutic and research applications; however, their medical and biotechnological potential seems to be much greater. Recent reports indicate that the further development of nucleic acid editing systems depends largely on our ability to engineer the substrate specificity and catalytic activity of the editors themselves. In this review, we summarize the current trends and achievements in deaminase engineering. The presented data indicate that the potential of these enzymes has not yet been fully revealed or understood. Several examples show that even relatively minor changes in the structure of deaminases can give them completely new and unique properties.
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Affiliation(s)
- Lucyna Budzko
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Karolina Hoffa-Sobiech
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Paulina Jackowiak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Marek Figlerowicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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10
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Keegan LP, Hajji K, O’Connell MA. Adenosine Deaminase Acting on RNA (ADAR) Enzymes: A Journey from Weird to Wondrous. Acc Chem Res 2023; 56:3165-3174. [PMID: 37906879 PMCID: PMC10666284 DOI: 10.1021/acs.accounts.3c00433] [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: 07/27/2023] [Indexed: 11/02/2023]
Abstract
ConspectusThe adenosine deaminase acting on RNA (ADAR) enzymes that catalyze the conversion of adenosine to inosine in double-stranded (ds)RNA are evolutionarily conserved and are essential for many biological functions including nervous system function, hematopoiesis, and innate immunity. Initially it was assumed that the wide-ranging biological roles of ADARs are due to inosine in mRNA being read as guanosine by the translational machinery, allowing incomplete RNA editing in a target codon to generate two different proteins from the same primary transcript. In humans, there are approximately seventy-six positions that undergo site-specific editing in tissues at greater than 20% efficiency that result in recoding. Many of these transcripts are expressed in the central nervous system (CNS) and edited by ADAR2. Exploiting mouse genetic models revealed that transgenic mice lacking the gene encoding Adar2 die within 3 weeks of birth. Therefore, the role of ADAR2 in generating protein diversity in the nervous system is clear, but why is ADAR RNA editing activity essential in other biological processes, particularly editing mainly involving ADAR1? ADAR1 edits human transcripts having embedded Alu element inverted repeats (AluIRs), but the link from this activity to innate immunity activation was elusive. Mice lacking the gene encoding Adar1 are embryonically lethal, and a major breakthrough was the discovery that the role of Adar1 in innate immunity is due to its ability to edit such repetitive element inverted repeats which have the ability to form dsRNA in transcripts. The presence of inosine prevents activation of the dsRNA sensor melanoma differentiation-associated protein 5 (Mda5). Thus, inosine helps the cell discriminate self from non-self RNA, acting like a barcode on mRNA. As innate immunity is key to many different biological processes, the basis for this widespread biological role of the ADAR1 enzyme became evident.Our group has been studying ADARs from the outset of research on these enzymes. In this Account, we give a historical perspective, moving from the initial purification of ADAR1 and ADAR2 and cloning of their encoding genes up to the current research focus in the field and what questions still remain to be addressed. We discuss the characterizations of the proteins, their localizations, posttranslational modifications, and dimerization, and how all of these affect their biological activities. Another aspect we explore is the use of mouse and Drosophila genetic models to study ADAR functions and how these were crucial in determining the biological functions of the ADAR proteins. Finally, we describe the severe consequences of rare mutations found in the human genes encoding ADAR1 and ADAR2.
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Affiliation(s)
- Liam P. Keegan
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
| | - Khadija Hajji
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
| | - Mary A. O’Connell
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
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11
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Nguyen TA, Heng JWJ, Ng YT, Sun R, Fisher S, Oguz G, Kaewsapsak P, Xue S, Reversade B, Ramasamy A, Eisenberg E, Tan MH. Deep transcriptome profiling reveals limited conservation of A-to-I RNA editing in Xenopus. BMC Biol 2023; 21:251. [PMID: 37946231 PMCID: PMC10636886 DOI: 10.1186/s12915-023-01756-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Xenopus has served as a valuable model system for biomedical research over the past decades. Notably, ADAR was first detected in frog oocytes and embryos as an activity that unwinds RNA duplexes. However, the scope of A-to-I RNA editing by the ADAR enzymes in Xenopus remains underexplored. RESULTS Here, we identify millions of editing events in Xenopus with high accuracy and systematically map the editome across developmental stages, adult organs, and species. We report diverse spatiotemporal patterns of editing with deamination activity highest in early embryogenesis before zygotic genome activation and in the ovary. Strikingly, editing events are poorly conserved across different Xenopus species. Even sites that are detected in both X. laevis and X. tropicalis show largely divergent editing levels or developmental profiles. In protein-coding regions, only a small subset of sites that are found mostly in the brain are well conserved between frogs and mammals. CONCLUSIONS Collectively, our work provides fresh insights into ADAR activity in vertebrates and suggest that species-specific editing may play a role in each animal's unique physiology or environmental adaptation.
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Affiliation(s)
- Tram Anh Nguyen
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Jia Wei Joel Heng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Yan Ting Ng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Rui Sun
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Shira Fisher
- Faculty of Life Sciences, The Mina and Everard Goodman, Bar-Ilan University, Ramat Gan, Israel
| | - Gokce Oguz
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Pornchai Kaewsapsak
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Shifeng Xue
- Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Bruno Reversade
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Medical Genetics, School of Medicine (KUSoM), Koç University, Istanbul, Turkey
| | - Adaikalavan Ramasamy
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
| | - Meng How Tan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore.
- HP-NTU Digital Manufacturing Corporate Lab, Nanyang Technological University, Singapore, Singapore.
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12
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Tan MH. Identification of Bona Fide RNA Editing Sites: History, Challenges, and Opportunities. Acc Chem Res 2023; 56:3033-3044. [PMID: 37827987 DOI: 10.1021/acs.accounts.3c00462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by the adenosine deaminase acting on the RNA (ADAR) family of enzymes of which there are three members (ADAR1, ADAR2, and ADAR3), is a major gene regulatory mechanism that diversifies the transcriptome. It is widespread in many metazoans, including humans. As inosine is interpreted by cellular machineries mainly as guanosine, A-to-I editing effectively gives A-to-G nucleotide changes. Depending on its location, an editing event can generate new protein isoforms or influence other RNA processing pathways. Researchers have found that ADAR-mediated editing performs diverse functions. For example, it enables living organisms such as cephalopods to adapt rapidly to fluctuating environmental conditions such as water temperature. In development, the loss of ADAR1 is embryonically lethal partly because endogenous double-stranded RNAs (dsRNAs) are no longer marked by inosines, which signal "self", and thus cause the melanoma differentiation-associated protein 5 (MDA5) sensor to trigger a deleterious interferon response. Hence, ADAR1 plays a key role in preventing aberrant activation of the innate immune system. Furthermore, ADAR enzymes have been implicated in myriad human diseases. Intriguingly, some cancer cells are known to exploit ADAR1 activity to dodge immune responses. However, the exact identities of immunogenic RNAs in different biological contexts have remained elusive. Consequently, there is tremendous interest in identifying inosine-containing RNAs in the cell.The identification of A-to-I RNA editing sites is dependent on the sequencing of nucleic acids. Technological and algorithmic advancements over the past decades have revolutionized the way editing events are detected. At the beginning, the discovery of editing sites relies on Sanger sequencing, a first-generation technology. Both RNA, which is reverse transcribed into complementary DNA (cDNA), and genomic DNA (gDNA) from the same source are analyzed. After sequence alignment, one would require an adenosine to be present in the genome but a guanosine to be detected in the RNA sample for a position to be declared as an editing site. However, an issue with Sanger sequencing is its low throughput. Subsequently, Illumina sequencing, a second-generation technology, was invented. By permitting the simultaneous interrogation of millions of molecules, it enables many editing sites to be identified rapidly. However, a key challenge is that the Illumina platform produces short sequencing reads that can be difficult to map accurately. To tackle the challenge, we and others developed computational workflows with a series of filters to discard sites that are likely to be false positives. When Illumina sequencing data sets are properly analyzed, A-to-G variants should emerge as the most dominant mismatch type. Moreover, the quantitative nature of the data allows us to build a comprehensive atlas of editing-level measurements across different biological contexts, providing deep insights into the spatiotemporal dynamics of RNA editing. However, difficulties remain in identifying true A-to-I editing sites in short protein-coding exons or in organisms and diseases where DNA mutations and genomic polymorphisms are prevalent and mostly unknown. Nanopore sequencing, a third-generation technology, promises to address the difficulties, as it allows native RNAs to be sequenced without conversion to cDNA, preserving base modifications that can be directly detected through machine learning. We recently demonstrated that nanopore sequencing could be used to identify A-to-I editing sites in native RNA directly. Although further work is needed to enhance the detection accuracy in single molecules from fewer cells, the nanopore technology holds the potential to revolutionize epitranscriptomic studies.
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Affiliation(s)
- Meng How Tan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637459, Singapore
- HP-NTU Digital Manufacturing Corporate Laboratory, Nanyang Technological University, Singapore 637460, Singapore
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13
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Pfeiffer LS, Stafforst T. Precision RNA base editing with engineered and endogenous effectors. Nat Biotechnol 2023; 41:1526-1542. [PMID: 37735261 DOI: 10.1038/s41587-023-01927-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 07/26/2023] [Indexed: 09/23/2023]
Abstract
RNA base editing refers to the rewriting of genetic information within an intact RNA molecule and serves various functions, such as evasion of the endogenous immune system and regulation of protein function. To achieve this, certain enzymes have been discovered in human cells that catalyze the conversion of one nucleobase into another. This natural process could be exploited to manipulate and recode any base in a target transcript. In contrast to DNA base editing, analogous changes introduced in RNA are not permanent or inheritable but rather allow reversible and doseable effects that appeal to various therapeutic applications. The current practice of RNA base editing involves the deamination of adenosines and cytidines, which are converted to inosines and uridines, respectively. In this Review, we summarize current site-directed RNA base-editing strategies and highlight recent achievements to improve editing efficiency, precision, codon-targeting scope and in vivo delivery into disease-relevant tissues. Besides engineered editing effectors, we focus on strategies to harness endogenous adenosine deaminases acting on RNA (ADAR) enzymes and discuss limitations and future perspectives to apply the tools in basic research and as a therapeutic modality. We expect the field to realize the first RNA base-editing drug soon, likely on a well-defined genetic disease. However, the long-term challenge will be to carve out the sweet spot of the technology where its unique ability is exploited to modulate signaling cues, metabolism or other clinically relevant processes in a safe and doseable manner.
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Affiliation(s)
- Laura S Pfeiffer
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Thorsten Stafforst
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany.
- Gene and RNA Therapy Center, Faculty of Medicine, University of Tübingen, Tübingen, Germany.
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14
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Lin W, Luo Y, Wu J, Zhang H, Jin G, Guo C, Zhou H, Liang H, Xu X. Loss of ADAR1 in macrophages in combination with interferon gamma suppresses tumor growth by remodeling the tumor microenvironment. J Immunother Cancer 2023; 11:e007402. [PMID: 37935565 PMCID: PMC10649901 DOI: 10.1136/jitc-2023-007402] [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] [Accepted: 09/18/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND ADAR1, the major enzyme for RNA editing, has emerged as a tumor-intrinsic key determinant for cancer immunotherapy efficacy through modulating interferon-mediated innate immunity. However, the role of ADAR1 in innate immune cells such as macrophages remains unknown. METHODS We first analyzed publicly accessible patient-derived single-cell RNA-sequencing and perturbed RNA sequencing data to elucidate the ADAR1 expression and function in macrophages. Subsequently, we evaluated the combined effects of ADAR1 conditional knockout in macrophages and interferon (IFN)-γ treatment on tumor growth in three distinct disease mouse models: LLC for lung cancer, B16-F10 for melanoma, and MC38 for colon cancer. To gain the mechanistic insights, we performed human cytokine arrays to identify differentially secreted cytokines in response to ADAR1 perturbations in THP-1 cells. Furthermore, we examined the effects of ADAR1 loss and IFN-γ treatment on vessel formation through immunohistochemical staining of mouse tumor sections and tube-forming experiments using HUVEC and SVEC4-10 cells. We also assessed the effects on CD8+ T cells using immunofluorescent and immunohistochemical staining and flow cytometry. To explore the translational potential, we examined the consequences of injecting ADAR1-deficient macrophages alongside IFN-γ treatment on tumor growth in LLC-tumor-bearing mice. RESULTS Our analysis on public data suggests that ADAR1 loss in macrophages promotes antitumor immunity as in cancer cells. Indeed, ADAR1 loss in macrophages combined with IFN-γ treatment results in tumor regression in diverse disease mouse models. Mechanistically, the loss of ADAR1 in macrophages leads to the differential secretion of key cytokines: it inhibits the translation of CCL20, GDF15, IL-18BP, and TIM-3 by activating PKR/EIF2α signaling but increases the secretion of IFN-γ through transcriptional upregulation and interleukin (IL)-18 due to the 5'UTR uORF. Consequently, decreased CCL20 and GDF15 and increased IFN-γ suppress angiogenesis, while decreased IL-18BP and TIM-3 and increased IL-18 induce antitumor immunity by enhancing cytotoxicity of CD8+ T cells. We further demonstrate that combination therapy of injecting ADAR1-deficient macrophages and IFN-γ effectively suppresses tumors in vivo. CONCLUSION This study provides a comprehensive elucidation of how ADAR1 loss within macrophages contributes to the establishment of an antitumor microenvironment, suggesting the therapeutic potential of targeting ADAR1 beyond the scope of cancer cells.
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Affiliation(s)
- Weiwei Lin
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Yikai Luo
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, Texas, USA
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jie Wu
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Haowan Zhang
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Ge Jin
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Chahua Guo
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Hang Zhou
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
| | - Han Liang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xiaoyan Xu
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning Province, China
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15
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Burdick JT, Comai A, Bruzel A, Sun G, Dedon PC, Cheung VG. Nanopore-based direct sequencing of RNA transcripts with 10 different modified nucleotides reveals gaps in existing technology. G3 (BETHESDA, MD.) 2023; 13:jkad200. [PMID: 37655917 PMCID: PMC10627276 DOI: 10.1093/g3journal/jkad200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 06/14/2023] [Accepted: 08/23/2023] [Indexed: 09/02/2023]
Abstract
RNA undergoes complex posttranscriptional processing including chemical modifications of the nucleotides. The resultant-modified nucleotides are an integral part of RNA sequences that must be considered in studying the biology of RNA and in the design of RNA therapeutics. However, the current "RNA-sequencing" methods primarily sequence complementary DNA rather than RNA itself, which means that the modifications present in RNA are not captured in the sequencing results. Emerging direct RNA-sequencing technologies, such as those offered by Oxford Nanopore, aim to address this limitation. In this study, we synthesized and used Nanopore technology to sequence RNA transcripts consisting of canonical nucleotides and 10 different modifications in various concentrations. The results show that direct RNA sequencing still has a baseline error rate of >10%, and although some modifications can be detected, many remain unidentified. Thus, there is a need to develop sequencing technologies and analysis methods that can comprehensively capture the total complexity of RNA. The RNA sequences obtained through this project are made available for benchmarking analysis methods.
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Affiliation(s)
- Joshua T Burdick
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Annelise Comai
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alan Bruzel
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Guangxin Sun
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Peter C Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vivian G Cheung
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
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16
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Dorrity TJ, Shin H, Wiegand KA, Aruda J, Closser M, Jung E, Gertie JA, Leone A, Polfer R, Culbertson B, Yu L, Wu C, Ito T, Huang Y, Steckelberg AL, Wichterle H, Chung H. Long 3'UTRs predispose neurons to inflammation by promoting immunostimulatory double-stranded RNA formation. Sci Immunol 2023; 8:eadg2979. [PMID: 37862432 PMCID: PMC11056275 DOI: 10.1126/sciimmunol.adg2979] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 08/18/2023] [Indexed: 10/22/2023]
Abstract
Loss of RNA homeostasis underlies numerous neurodegenerative and neuroinflammatory diseases. However, the molecular mechanisms that trigger neuroinflammation are poorly understood. Viral double-stranded RNA (dsRNA) triggers innate immune responses when sensed by host pattern recognition receptors (PRRs) present in all cell types. Here, we report that human neurons intrinsically carry exceptionally high levels of immunostimulatory dsRNAs and identify long 3'UTRs as giving rise to neuronal dsRNA structures. We found that the neuron-enriched ELAVL family of genes (ELAVL2, ELAVL3, and ELAVL4) can increase (i) 3'UTR length, (ii) dsRNA load, and (iii) activation of dsRNA-sensing PRRs such as MDA5, PKR, and TLR3. In wild-type neurons, neuronal dsRNAs signaled through PRRs to induce tonic production of the antiviral type I interferon. Depleting ELAVL2 in WT neurons led to global shortening of 3'UTR length, reduced immunostimulatory dsRNA levels, and rendered WT neurons susceptible to herpes simplex virus and Zika virus infection. Neurons deficient in ADAR1, a dsRNA-editing enzyme mutated in the neuroinflammatory disorder Aicardi-Goutières syndrome, exhibited intolerably high levels of dsRNA that triggered PRR-mediated toxic inflammation and neuronal death. Depleting ELAVL2 in ADAR1 knockout neurons led to prolonged neuron survival by reducing immunostimulatory dsRNA levels. In summary, neurons are specialized cells where PRRs constantly sense "self" dsRNAs to preemptively induce protective antiviral immunity, but maintaining RNA homeostasis is paramount to prevent pathological neuroinflammation.
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Affiliation(s)
- Tyler J. Dorrity
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Heegwon Shin
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Kenenni A. Wiegand
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Justin Aruda
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Michael Closser
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neuroscience and Neurology, Columbia University Irving Medical Center, New York, NY, USA
- Center for Motor Neuron Biology and Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Emily Jung
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Jake A. Gertie
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Medical Scientist Training Program, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Amanda Leone
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Rachel Polfer
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Bruce Culbertson
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Medical Scientist Training Program, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Lisa Yu
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Christine Wu
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Takamasa Ito
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Yuefeng Huang
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Anna-Lena Steckelberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Hynek Wichterle
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neuroscience and Neurology, Columbia University Irving Medical Center, New York, NY, USA
- Center for Motor Neuron Biology and Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Hachung Chung
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
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17
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Kaltak M, Corradi Z, Collin RWJ, Swildens J, Cremers FPM. Stargardt disease-associated missense and synonymous ABCA4 variants result in aberrant splicing. Hum Mol Genet 2023; 32:3078-3089. [PMID: 37555651 PMCID: PMC10586196 DOI: 10.1093/hmg/ddad129] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/03/2023] [Accepted: 08/03/2023] [Indexed: 08/10/2023] Open
Abstract
Missense variants in ABCA4 constitute ~50% of causal variants in Stargardt disease (STGD1). Their pathogenicity is attributed to their direct effect on protein function, whilst their potential impact on pre-mRNA splicing disruption remains poorly understood. Interestingly, synonymous ABCA4 variants have previously been classified as 'severe' variants based on in silico analyses. Here, we systemically investigated the role of synonymous and missense variants in ABCA4 splicing by combining computational predictions and experimental assays. To identify variants of interest, we used SpliceAI to ascribe defective splice predictions on a dataset of 5579 biallelic STGD1 probands. We selected those variants with predicted delta scores for acceptor/donor gain > 0.20, and no previous reports on their effect on splicing. Fifteen ABCA4 variants were selected, 4 of which were predicted to create a new splice acceptor site and 11 to create a new splice donor site. In addition, three variants of interest with delta scores < 0.20 were included. The variants were introduced in wild-type midigenes that contained 4-12 kb of ABCA4 genomic sequence, which were subsequently expressed in HEK293T cells. By using RT-PCR and Sanger sequencing, we identified splice aberrations for 16 of 18 analyzed variants. SpliceAI correctly predicted the outcomes for 15 out of 18 variants, illustrating its reliability in predicting the impact of coding ABCA4 variants on splicing. Our findings highlight a causal role for coding ABCA4 variants in splicing aberrations, improving the severity assessment of missense and synonymous ABCA4 variants, and guiding to new treatment strategies for STGD1.
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Affiliation(s)
- Melita Kaltak
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
- R&D Department, ProQR Therapeutics, Leiden, 2333 CK, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Jim Swildens
- R&D Department, ProQR Therapeutics, Leiden, 2333 CK, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
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18
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Zhang Y, Duan Y. Genome-Wide Analysis on Driver and Passenger RNA Editing Sites Suggests an Underestimation of Adaptive Signals in Insects. Genes (Basel) 2023; 14:1951. [PMID: 37895300 PMCID: PMC10606203 DOI: 10.3390/genes14101951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing leads to a similar effect to A-to-G mutations. RNA editing provides a temporo-spatial flexibility for organisms. Nonsynonymous (Nonsyn) RNA editing in insects is over-represented compared with synonymous (Syn) editing, suggesting adaptive signals of positive selection on Nonsyn editing during evolution. We utilized the brain RNA editome of Drosophila melanogaster to systematically study the LD (r2) between editing sites and infer its impact on the adaptive signals of RNA editing. Pairs of editing sites (PESs) were identified from the transcriptome. For CDS PESs of two consecutive editing sites, their occurrence was significantly biased to type-3 PES (Syn-Nonsyn). The haplotype frequency of type-3 PES exhibited a significantly higher abundance of AG than GA, indicating that the rear Nonsyn site is the driver that promotes the editing of the front Syn site (passenger). The exclusion of passenger Syn sites dramatically amplifies the adaptive signal of Nonsyn RNA editing. Our study for the first time quantitatively demonstrates that the linkage between RNA editing events comes from hitchhiking effects and leads to the underestimation of adaptive signals for Nonsyn editing. Our work provides novel insights for studying the evolutionary significance of RNA editing events.
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Affiliation(s)
| | - Yuange Duan
- MOA Key Lab of Pest Monitoring and Green Management, Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
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19
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Lin MH, Chou PC, Lee IC, Yang SF, Yu HS, Yu S. Inherited Reticulate Pigmentary Disorders. Genes (Basel) 2023; 14:1300. [PMID: 37372478 DOI: 10.3390/genes14061300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/12/2023] [Accepted: 06/18/2023] [Indexed: 06/29/2023] Open
Abstract
Reticulate pigmentary disorders (RPDs) are a group of inherited and acquired skin conditions characterized by hyperpigmented and/or hypopigmented macules. Inherited RPDs include dyschromatosis symmetrica hereditaria (DSH), dyschromatosis universalis hereditaria (DUH), reticulate acropigmentation of Kitamura (RAK), Dowling-Degos disease (DDD), dyskeratosis congenita (DKC), Naegeli-Franceschetti-Jadassohn syndrome (NFJS), dermatopathia pigmentosa reticularis (DPR), and X-linked reticulate pigmentary disorder. Although reticulate pattern of pigmentation is a common characteristic of this spectrum of disorders, the distribution of pigmentation varies among these disorders, and there may be clinical manifestations beyond pigmentation. DSH, DUH, and RAK are mostly reported in East Asian ethnicities. DDD is more common in Caucasians, although it is also reported in Asian countries. Other RPDs show no racial predilection. This article reviews the clinical, histological, and genetic variations of inherited RPDs.
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Affiliation(s)
- Min-Huei Lin
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Pei-Chen Chou
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - I-Chen Lee
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Syuan-Fei Yang
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Hsin-Su Yu
- Department of Dermatology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Sebastian Yu
- Department of Dermatology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Dermatology, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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20
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Booth BJ, Nourreddine S, Katrekar D, Savva Y, Bose D, Long TJ, Huss DJ, Mali P. RNA editing: Expanding the potential of RNA therapeutics. Mol Ther 2023; 31:1533-1549. [PMID: 36620962 PMCID: PMC9824937 DOI: 10.1016/j.ymthe.2023.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/06/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
RNA therapeutics have had a tremendous impact on medicine, recently exemplified by the rapid development and deployment of mRNA vaccines to combat the COVID-19 pandemic. In addition, RNA-targeting drugs have been developed for diseases with significant unmet medical needs through selective mRNA knockdown or modulation of pre-mRNA splicing. Recently, RNA editing, particularly antisense RNA-guided adenosine deaminase acting on RNA (ADAR)-based programmable A-to-I editing, has emerged as a powerful tool to manipulate RNA to enable correction of disease-causing mutations and modulate gene expression and protein function. Beyond correcting pathogenic mutations, the technology is particularly well suited for therapeutic applications that require a transient pharmacodynamic effect, such as the treatment of acute pain, obesity, viral infection, and inflammation, where it would be undesirable to introduce permanent alterations to the genome. Furthermore, transient modulation of protein function, such as altering the active sites of enzymes or the interface of protein-protein interactions, opens the door to therapeutic avenues ranging from regenerative medicine to oncology. These emerging RNA-editing-based toolsets are poised to broadly impact biotechnology and therapeutic applications. Here, we review the emerging field of therapeutic RNA editing, highlight recent laboratory advancements, and discuss the key challenges on the path to clinical development.
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Affiliation(s)
| | - Sami Nourreddine
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | | | | | | | | | | | - Prashant Mali
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
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21
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Lu D, Lu J, Liu Q, Zhang Q. Emerging role of the RNA-editing enzyme ADAR1 in stem cell fate and function. Biomark Res 2023; 11:61. [PMID: 37280687 DOI: 10.1186/s40364-023-00503-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 05/13/2023] [Indexed: 06/08/2023] Open
Abstract
Stem cells are critical for organism development and the maintenance of tissue homeostasis. Recent studies focusing on RNA editing have indicated how this mark controls stem cell fate and function in both normal and malignant states. RNA editing is mainly mediated by adenosine deaminase acting on RNA 1 (ADAR1). The RNA editing enzyme ADAR1 converts adenosine in a double-stranded RNA (dsRNA) substrate into inosine. ADAR1 is a multifunctional protein that regulate physiological processes including embryonic development, cell differentiation, and immune regulation, and even apply to the development of gene editing technologies. In this review, we summarize the structure and function of ADAR1 with a focus on how it can mediate distinct functions in stem cell self-renewal and differentiation. Targeting ADAR1 has emerged as a potential novel therapeutic strategy in both normal and dysregulated stem cell contexts.
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Affiliation(s)
- Di Lu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Jianxi Lu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Qiuli Liu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
| | - Qi Zhang
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
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22
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Vallecillo-Viejo IC, Voss G, Albertin CB, Liscovitch-Brauer N, Eisenberg E, Rosenthal JJC. Squid express conserved ADAR orthologs that possess novel features. Front Genome Ed 2023; 5:1181713. [PMID: 37342458 PMCID: PMC10278661 DOI: 10.3389/fgeed.2023.1181713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/15/2023] [Indexed: 06/23/2023] Open
Abstract
The coleoid cephalopods display unusually extensive mRNA recoding by adenosine deamination, yet the underlying mechanisms are not well understood. Because the adenosine deaminases that act on RNA (ADAR) enzymes catalyze this form of RNA editing, the structure and function of the cephalopod orthologs may provide clues. Recent genome sequencing projects have provided blueprints for the full complement of coleoid cephalopod ADARs. Previous results from our laboratory have shown that squid express an ADAR2 homolog, with two splice variants named sqADAR2a and sqADAR2b and that these messages are extensively edited. Based on octopus and squid genomes, transcriptomes, and cDNA cloning, we discovered that two additional ADAR homologs are expressed in coleoids. The first is orthologous to vertebrate ADAR1. Unlike other ADAR1s, however, it contains a novel N-terminal domain of 641 aa that is predicted to be disordered, contains 67 phosphorylation motifs, and has an amino acid composition that is unusually high in serines and basic amino acids. mRNAs encoding sqADAR1 are themselves extensively edited. A third ADAR-like enzyme, sqADAR/D-like, which is not orthologous to any of the vertebrate isoforms, is also present. Messages encoding sqADAR/D-like are not edited. Studies using recombinant sqADARs suggest that only sqADAR1 and sqADAR2 are active adenosine deaminases, both on perfect duplex dsRNA and on a squid potassium channel mRNA substrate known to be edited in vivo. sqADAR/D-like shows no activity on these substrates. Overall, these results reveal some unique features in sqADARs that may contribute to the high-level RNA recoding observed in cephalopods.
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Affiliation(s)
| | - Gjendine Voss
- The Eugene Bell Center, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Caroline B. Albertin
- The Eugene Bell Center, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Noa Liscovitch-Brauer
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
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23
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Palmieri M, Pozzer D, Landsberger N. Advanced genetic therapies for the treatment of Rett syndrome: state of the art and future perspectives. Front Neurosci 2023; 17:1172805. [PMID: 37304036 PMCID: PMC10248472 DOI: 10.3389/fnins.2023.1172805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Loss and gain of functions mutations in the X-linked MECP2 (methyl-CpG-binding protein 2) gene are responsible for a set of generally severe neurological disorders that can affect both genders. In particular, Mecp2 deficiency is mainly associated with Rett syndrome (RTT) in girls, while duplication of the MECP2 gene leads, mainly in boys, to the MECP2 duplication syndrome (MDS). No cure is currently available for MECP2 related disorders. However, several studies have reported that by re-expressing the wild-type gene is possible to restore defective phenotypes of Mecp2 null animals. This proof of principle endorsed many laboratories to search for novel therapeutic strategies to cure RTT. Besides pharmacological approaches aimed at modulating MeCP2-downstream pathways, genetic targeting of MECP2 or its transcript have been largely proposed. Remarkably, two studies focused on augmentative gene therapy were recently approved for clinical trials. Both use molecular strategies to well-control gene dosage. Notably, the recent development of genome editing technologies has opened an alternative way to specifically target MECP2 without altering its physiological levels. Other attractive approaches exclusively applicable for nonsense mutations are the translational read-through (TR) and t-RNA suppressor therapy. Reactivation of the MECP2 locus on the silent X chromosome represents another valid choice for the disease. In this article, we intend to review the most recent genetic interventions for the treatment of RTT, describing the current state of the art, and the related advantages and concerns. We will also discuss the possible application of other advanced therapies, based on molecular delivery through nanoparticles, already proposed for other neurological disorders but still not tested in RTT.
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Affiliation(s)
- Michela Palmieri
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Diego Pozzer
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Nicoletta Landsberger
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Faculty of Medicine and Surgery, University of Milan, Milan, Italy
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24
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Bellingrath JS, McClements ME, Fischer MD, MacLaren RE. Programmable RNA editing with endogenous ADAR enzymes - a feasible option for the treatment of inherited retinal disease? Front Mol Neurosci 2023; 16:1092913. [PMID: 37293541 PMCID: PMC10244592 DOI: 10.3389/fnmol.2023.1092913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 04/27/2023] [Indexed: 06/10/2023] Open
Abstract
RNA editing holds great promise for the therapeutic correction of pathogenic, single nucleotide variants (SNV) in the human transcriptome since it does not risk creating permanent off-targets edits in the genome and has the potential for innovative delivery options. Adenine deaminases acting on RNA (ADAR) enzymes catalyse the most widespread form of posttranscriptional RNA editing in humans and their ability to hydrolytically deaminate adenosine to inosine in double stranded RNA (dsRNA) has been harnessed to change pathogenic single nucleotide variants (SNVs) in the human genome on a transcriptional level. Until now, the most promising target editing rates have been achieved by exogenous delivery of the catalytically active ADAR deaminase domain (ADARDD) fused to an RNA binding protein. While it has been shown that endogenous ADARs can be recruited to a defined target site with the sole help of an ADAR-recruiting guide RNA, thus freeing up packaging space, decreasing the chance of an immune response against a foreign protein, and decreasing transcriptome-wide off-target effects, this approach has been limited by a low editing efficiency. Through the recent development of novel circular ADAR-recruiting guide RNAs as well as the optimisation of ADAR-recruiting antisense oligonucleotides, RNA editing with endogenous ADAR is now showing promising target editing efficiency in vitro and in vivo. A target editing efficiency comparable to RNA editing with exogenous ADAR was shown both in wild-type and disease mouse models as well as in wild-type non-human primates (NHP) immediately following and up to 6 weeks after application. With these encouraging results, RNA editing with endogenous ADAR has the potential to present an attractive option for the treatment of inherited retinal diseases (IRDs), a field where gene replacement therapy has been established as safe and efficacious, but where an unmet need still exists for genes that exceed the packaging capacity of an adeno associated virus (AAV) or are expressed in more than one retinal isoform. This review aims to give an overview of the recent developments in the field of RNA editing with endogenous ADAR and assess its applicability for the field of treatment of IRD.
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Affiliation(s)
- Julia-Sophia Bellingrath
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - M. Dominik Fischer
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
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25
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Binothman N, Aljadani M, Alghanem B, Refai MY, Rashid M, Al Tuwaijri A, Alsubhi NH, Alrefaei GI, Khan MY, Sonbul SN, Aljoud F, Alhayyani S, Abdulal RH, Ganash M, Hashem AM. Identification of novel interacts partners of ADAR1 enzyme mediating the oncogenic process in aggressive breast cancer. Sci Rep 2023; 13:8341. [PMID: 37221310 DOI: 10.1038/s41598-023-35517-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/19/2023] [Indexed: 05/25/2023] Open
Abstract
Triple-negative breast cancer (TNBC) subtype is characterized by aggressive clinical behavior and poor prognosis patient outcomes. Here, we show that ADAR1 is more abundantly expressed in infiltrating breast cancer (BC) tumors than in benign tumors. Further, ADAR1 protein expression is higher in aggressive BC cells (MDA-MB-231). Moreover, we identify a novel interacting partners proteins list with ADAR1 in MDA-MB-231, using immunoprecipitation assay and mass spectrometry. Using iLoop, a protein-protein interaction prediction server based on structural features, five proteins with high iloop scores were discovered: Histone H2A.V, Kynureninase (KYNU), 40S ribosomal protein SA, Complement C4-A, and Nebulin (ranged between 0.6 and 0.8). In silico analysis showed that invasive ductal carcinomas had the highest level of KYNU gene expression than the other classifications (p < 0.0001). Moreover, KYNU mRNA expression was shown to be considerably higher in TNBC patients (p < 0.0001) and associated with poor patient outcomes with a high-risk value. Importantly, we found an interaction between ADAR1 and KYNU in the more aggressive BC cells. Altogether, these results propose a new ADAR-KYNU interaction as potential therapeutic targeted therapy in aggressive BC.
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Affiliation(s)
- Najat Binothman
- Department of Chemistry, College of Sciences and Arts, King Abdulaziz University, Rabigh, Saudi Arabia.
- Vaccine and Immunotherapy Unit, King Fahad Medical Research Center, King Abdulaziz University Saudi Arabia, Jeddah, Saudi Arabia.
| | - Majidah Aljadani
- Department of Chemistry, College of Sciences and Arts, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Bandar Alghanem
- Medical Research Core Facility and Platforms (MRCFP), King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences (KSAU-HS), King Abdulaziz Medical City (KAMC), National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Mohammed Y Refai
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Mamoon Rashid
- Department of AI and Bioinformatics, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), King Abdulaziz Medical City, Ministry of National Guard Health Affairs, P.O. Box 22490, Riyadh, 11426, Saudi Arabia
| | - Abeer Al Tuwaijri
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), Ministry of National Guard Health Affairs (MNGH), Riyadh, Saudi Arabia
- Clinical Laboratory Sciences Department, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Nouf H Alsubhi
- Biological Sciences Department, College of Science & Arts, King Abdulaziz University, Rabigh, 21911, Saudi Arabia
| | - Ghadeer I Alrefaei
- Department of Biology, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Muhammad Yasir Khan
- Vaccine and Immunotherapy Unit, King Fahad Medical Research Center, King Abdulaziz University Saudi Arabia, Jeddah, Saudi Arabia
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Sultan N Sonbul
- Biochemistry Department, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Fadwa Aljoud
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
- Regenerative Medicine Unit, King Fahd Medical Research Centre, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Sultan Alhayyani
- Department of Chemistry, College of Sciences and Arts, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Rwaa H Abdulal
- Vaccine and Immunotherapy Unit, King Fahad Medical Research Center, King Abdulaziz University Saudi Arabia, Jeddah, Saudi Arabia
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Magdah Ganash
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Anwar M Hashem
- Vaccine and Immunotherapy Unit, King Fahad Medical Research Center, King Abdulaziz University Saudi Arabia, Jeddah, Saudi Arabia
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, King AbdulAziz University, Jeddah, Saudi Arabia
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26
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Pomaville MM, He C. Advances in targeting RNA modifications for anticancer therapy. Trends Cancer 2023:S2405-8033(23)00059-6. [PMID: 37147166 DOI: 10.1016/j.trecan.2023.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 05/07/2023]
Abstract
Numerous strategies are employed by cancer cells to control gene expression and facilitate tumorigenesis. In the study of epitranscriptomics, a diverse set of modifications to RNA represent a new player of gene regulation in disease and in development. N6-methyladenosine (m6A) is the most common modification on mammalian messenger RNA and tends to be aberrantly placed in cancer. Recognized by a series of reader proteins that dictate the fate of the RNA, m6A-modified RNA could promote tumorigenesis by driving protumor gene expression signatures and altering the immunologic response to tumors. Preclinical evidence suggests m6A writer, reader, and eraser proteins are attractive therapeutic targets. First-in-human studies are currently testing small molecule inhibition against the methyltransferase-like 3 (METTL3)/methyltransferase-like 14 (METTL14) methyltransferase complex. Additional modifications to RNA are adopted by cancers to drive tumor development and are under investigation.
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Affiliation(s)
- Monica M Pomaville
- Department of Pediatrics, University of Chicago Comer Children's Hospital, Chicago, IL, USA; Howard Hughes Medical Institute, University of Chicago, Chicago, IL, USA.
| | - Chuan He
- Howard Hughes Medical Institute, University of Chicago, Chicago, IL, USA; Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
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27
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Jiang K, Koob J, Chen XD, Krajeski RN, Zhang Y, Volf V, Zhou W, Sgrizzi SR, Villiger L, Gootenberg JS, Chen F, Abudayyeh OO. Programmable eukaryotic protein synthesis with RNA sensors by harnessing ADAR. Nat Biotechnol 2023; 41:698-707. [PMID: 36302988 DOI: 10.1038/s41587-022-01534-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/28/2022] [Indexed: 11/09/2022]
Abstract
Programmable approaches to sense and respond to the presence of specific RNAs in biological systems have broad applications in research, diagnostics, and therapeutics. Here we engineer a programmable RNA-sensing technology, reprogrammable ADAR sensors (RADARS), which harnesses RNA editing by adenosine deaminases acting on RNA (ADAR) to gate translation of a cargo protein by the presence of endogenous RNA transcripts. Introduction of a stop codon in a guide upstream of the cargo makes translation contingent on binding of an endogenous transcript to the guide, leading to ADAR editing of the stop codon and allowing translational readthrough. Through systematic sensor engineering, we achieve 277 fold improvement in sensor activation and engineer RADARS with diverse cargo proteins, including luciferases, fluorescent proteins, recombinases, and caspases, enabling detection sensitivity on endogenous transcripts expressed at levels as low as 13 transcripts per million. We show that RADARS are functional as either expressed DNA or synthetic mRNA and with either exogenous or endogenous ADAR. We apply RADARS in multiple contexts, including tracking transcriptional states, RNA-sensing-induced cell death, cell-type identification, and control of synthetic mRNA translation.
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Affiliation(s)
- Kaiyi Jiang
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jeremy Koob
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Xi Dawn Chen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
- Systems, Synthetic, and Quantitative Biology Program, Harvard Medical School, Boston, MA, USA
| | - Rohan N Krajeski
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yifan Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Verena Volf
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Wenyuan Zhou
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Samantha R Sgrizzi
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lukas Villiger
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jonathan S Gootenberg
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Fei Chen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA.
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Omar O Abudayyeh
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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28
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Gatsiou A, Tual-Chalot S, Napoli M, Ortega-Gomez A, Regen T, Badolia R, Cesarini V, Garcia-Gonzalez C, Chevre R, Ciliberti G, Silvestre-Roig C, Martini M, Hoffmann J, Hamouche R, Visker JR, Diakos N, Wietelmann A, Silvestris DA, Georgiopoulos G, Moshfegh A, Schneider A, Chen W, Guenther S, Backs J, Kwak S, Selzman CH, Stamatelopoulos K, Rose-John S, Trautwein C, Spyridopoulos I, Braun T, Waisman A, Gallo A, Drakos SG, Dimmeler S, Sperandio M, Soehnlein O, Stellos K. The RNA editor ADAR2 promotes immune cell trafficking by enhancing endothelial responses to interleukin-6 during sterile inflammation. Immunity 2023; 56:979-997.e11. [PMID: 37100060 DOI: 10.1016/j.immuni.2023.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 01/02/2023] [Accepted: 03/30/2023] [Indexed: 04/28/2023]
Abstract
Immune cell trafficking constitutes a fundamental component of immunological response to tissue injury, but the contribution of intrinsic RNA nucleotide modifications to this response remains elusive. We report that RNA editor ADAR2 exerts a tissue- and stress-specific regulation of endothelial responses to interleukin-6 (IL-6), which tightly controls leukocyte trafficking in IL-6-inflamed and ischemic tissues. Genetic ablation of ADAR2 from vascular endothelial cells diminished myeloid cell rolling and adhesion on vascular walls and reduced immune cell infiltration within ischemic tissues. ADAR2 was required in the endothelium for the expression of the IL-6 receptor subunit, IL-6 signal transducer (IL6ST; gp130), and subsequently, for IL-6 trans-signaling responses. ADAR2-induced adenosine-to-inosine RNA editing suppressed the Drosha-dependent primary microRNA processing, thereby overwriting the default endothelial transcriptional program to safeguard gp130 expression. This work demonstrates a role for ADAR2 epitranscriptional activity as a checkpoint in IL-6 trans-signaling and immune cell trafficking to sites of tissue injury.
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Affiliation(s)
- Aikaterini Gatsiou
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; RNA Metabolism and Vascular Inflammation Laboratory, Institute of Cardiovascular Regeneration and Department of Cardiology, JW Goethe University Frankfurt, Frankfurt am Main, Germany.
| | - Simon Tual-Chalot
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Matteo Napoli
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Center for Experimental Medicine Biomedical Center (BMC), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Almudena Ortega-Gomez
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany
| | - Tommy Regen
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Rachit Badolia
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Valeriana Cesarini
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Raphael Chevre
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany
| | - Giorgia Ciliberti
- Department of Cardiovascular Research, European Center for Angioscience (ECAS), Heidelberg University, Mannheim, Germany
| | - Carlos Silvestre-Roig
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany
| | - Maurizio Martini
- Fondazione Policlinico Universitario "A. Gemelli," IRCCS, UOC Anatomia Patologica, Rome, Italy; Istituto di Anatomia Patologica, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Jedrzej Hoffmann
- Department of Cardiology, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Rana Hamouche
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Joseph R Visker
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nikolaos Diakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Astrid Wietelmann
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Domenico Alessandro Silvestris
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Georgios Georgiopoulos
- Department of Clinical Therapeutics, Alexandra Hospital, National and Kapodistrian University of Athens Medical School, Athens, Greece; Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ali Moshfegh
- Kancera AB, Stockholm, Sweden; Department of Oncology and Pathology at Karolinska Institutet, Stockholm, Sweden
| | - Andre Schneider
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China; Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Stefan Guenther
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Johannes Backs
- Institute of Experimental Cardiology, University Hospital Heidelberg, Heidelberg, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Heidelberg/Mannheim Partner Site, Heidelberg and Mannheim, Germany
| | - Shin Kwak
- Department of Molecular Neuropathogenesis, Tokyo Medical University, Tokyo, Japan
| | - Craig H Selzman
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA; Division of Cardiothoracic Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Kimon Stamatelopoulos
- Department of Clinical Therapeutics, Alexandra Hospital, National and Kapodistrian University of Athens Medical School, Athens, Greece; Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Stefan Rose-John
- Institute of Biochemistry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Christian Trautwein
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Ioakim Spyridopoulos
- Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Department of Cardiology, Freeman Hospital, Newcastle upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Thomas Braun
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Angela Gallo
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Stavros G Drakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA; Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Stefanie Dimmeler
- Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt, Frankfurt am Main, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Frankfurt Partner Site, Germany
| | - Markus Sperandio
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Center for Experimental Medicine Biomedical Center (BMC), Ludwig-Maximilians-Universität München, Munich, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Munich Heart Alliance Partner Site, Munich, Germany
| | - Oliver Soehnlein
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Munich Heart Alliance Partner Site, Munich, Germany; Department of Physiology and Pharmacology (FyFa), Karolinska Institutet, Stockholm, Sweden
| | - Konstantinos Stellos
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; RNA Metabolism and Vascular Inflammation Laboratory, Institute of Cardiovascular Regeneration and Department of Cardiology, JW Goethe University Frankfurt, Frankfurt am Main, Germany; Department of Cardiovascular Research, European Center for Angioscience (ECAS), Heidelberg University, Mannheim, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Heidelberg/Mannheim Partner Site, Heidelberg and Mannheim, Germany; Cardio-Pulmonary Institute (CPI), Frankfurt am Main, Germany.
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29
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Lewis Z. Expanding the proteome: A-to-I RNA editing provides an adaptive advantage. Proc Natl Acad Sci U S A 2023; 120:e2303563120. [PMID: 37036963 PMCID: PMC10120046 DOI: 10.1073/pnas.2303563120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023] Open
Affiliation(s)
- Zachary A. Lewis
- Department of Microbiology, University of Georgia, Athens, GA30602
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30
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Chen L, Ou L, Jing X, Kong Y, Xie B, Zhang N, Shi H, Qin H, Li X, Hao P. DeepEdit: single-molecule detection and phasing of A-to-I RNA editing events using nanopore direct RNA sequencing. Genome Biol 2023; 24:75. [PMID: 37069604 PMCID: PMC10108526 DOI: 10.1186/s13059-023-02921-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/28/2023] [Indexed: 04/19/2023] Open
Abstract
Single-molecule detection and phasing of A-to-I RNA editing events remain an unresolved problem. Long-read and PCR-free nanopore native RNA sequencing offers a great opportunity for direct RNA editing detection. Here, we develop a neural network model, DeepEdit, that not only recognizes A-to-I editing events in single reads of Oxford Nanopore direct RNA sequencing, but also resolves the phasing of RNA editing events on transcripts. We illustrate the robustness of DeepEdit by applying it to Schizosaccharomyces pombe and Homo sapiens transcriptome data. We anticipate DeepEdit to be a powerful tool for the study of RNA editing from a new perspective.
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Affiliation(s)
- Longxian Chen
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Liang Ou
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Xinyun Jing
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yimeng Kong
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bingran Xie
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Niubing Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Han Shi
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hang Qin
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xuan Li
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Pei Hao
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
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31
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Bhokisham N, Laudermilch E, Traeger LL, Bonilla TD, Ruiz-Estevez M, Becker JR. CRISPR-Cas System: The Current and Emerging Translational Landscape. Cells 2023; 12:cells12081103. [PMID: 37190012 DOI: 10.3390/cells12081103] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/17/2023] Open
Abstract
CRISPR-Cas technology has rapidly changed life science research and human medicine. The ability to add, remove, or edit human DNA sequences has transformative potential for treating congenital and acquired human diseases. The timely maturation of the cell and gene therapy ecosystem and its seamless integration with CRISPR-Cas technologies has enabled the development of therapies that could potentially cure not only monogenic diseases such as sickle cell anemia and muscular dystrophy, but also complex heterogenous diseases such as cancer and diabetes. Here, we review the current landscape of clinical trials involving the use of various CRISPR-Cas systems as therapeutics for human diseases, discuss challenges, and explore new CRISPR-Cas-based tools such as base editing, prime editing, CRISPR-based transcriptional regulation, CRISPR-based epigenome editing, and RNA editing, each promising new functionality and broadening therapeutic potential. Finally, we discuss how the CRISPR-Cas system is being used to understand the biology of human diseases through the generation of large animal disease models used for preclinical testing of emerging therapeutics.
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Affiliation(s)
| | - Ethan Laudermilch
- Corporate Research Material Labs, 3M Center, 3M Company, Maplewood, MN 55144, USA
| | - Lindsay L Traeger
- Corporate Research Material Labs, 3M Center, 3M Company, Maplewood, MN 55144, USA
| | - Tonya D Bonilla
- Corporate Research Material Labs, 3M Center, 3M Company, Maplewood, MN 55144, USA
| | | | - Jordan R Becker
- Corporate Research Material Labs, 3M Center, 3M Company, Maplewood, MN 55144, USA
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Evidence Supporting That C-to-U RNA Editing Is the Major Force That Drives SARS-CoV-2 Evolution. J Mol Evol 2023; 91:214-224. [PMID: 36799984 PMCID: PMC9936484 DOI: 10.1007/s00239-023-10097-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/03/2023] [Indexed: 02/18/2023]
Abstract
Mutations of DNA organisms are introduced by replication errors. However, SARS-CoV-2, as an RNA virus, is additionally subjected to rampant RNA editing by hosts. Both resources contributed to SARS-CoV-2 mutation and evolution, but the relative prevalence of the two origins is unknown. We performed comparative genomic analyses at intra-species (world-wide SARS-CoV-2 strains) and inter-species (SARS-CoV-2 and RaTG13 divergence) levels. We made prior predictions of the proportion of each mutation type (nucleotide substitution) under different scenarios and compared the observed versus the expected. C-to-T alteration, representing C-to-U editing, is far more abundant that all other mutation types. Derived allele frequency (DAF) as well as novel mutation rate of C-to-T are the highest in SARS-CoV-2 population, and C-T substitution dominates the divergence sites between SARS-CoV-2 and RaTG13. This is compelling evidence suggesting that C-to-U RNA editing is the major source of SARS-CoV-2 mutation. While replication errors serve as a baseline of novel mutation rate, the C-to-U editing has elevated the mutation rate for orders of magnitudes and accelerates the evolution of the virus.
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Rosenthal JJC, Eisenberg E. Extensive Recoding of the Neural Proteome in Cephalopods by RNA Editing. Annu Rev Anim Biosci 2023; 11:57-75. [PMID: 36790891 DOI: 10.1146/annurev-animal-060322-114534] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The coleoid cephalopods have the largest brains, and display the most complex behaviors, of all invertebrates. The molecular and cellular mechanisms that underlie these remarkable advancements remain largely unexplored. Early molecular cloning studies of squid ion channel transcripts uncovered an unusually large number of A→I RNA editing sites that recoded codons. Further cloning of other neural transcripts showed a similar pattern. The advent of deep-sequencing technologies and the associated bioinformatics allowed the mapping of RNA editing events across the entire neural transcriptomes of various cephalopods. The results were remarkable: They contained orders of magnitude more recoding editing sites than any other taxon. Although RNA editing sites are abundant in most multicellular metazoans, they rarely recode. In cephalopods, the majority of neural transcripts are recoded. Recent studies have focused on whether these events are adaptive, as well as other noncanonical aspects of cephalopod RNA editing.
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Affiliation(s)
- Joshua J C Rosenthal
- The Eugene Bell Center, The Marine Biological Laboratory, Woods Hole, Massachusetts, USA;
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
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Li F, Deng J, He Q, Zhong Y. ZBP1 and heatstroke. Front Immunol 2023; 14:1091766. [PMID: 36845119 PMCID: PMC9950778 DOI: 10.3389/fimmu.2023.1091766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/19/2023] [Indexed: 02/12/2023] Open
Abstract
Heatstroke, which is associated with circulatory failure and multiple organ dysfunction, is a heat stress-induced life-threatening condition characterized by a raised core body temperature and central nervous system dysfunction. As global warming continues to worsen, heatstroke is expected to become the leading cause of death globally. Despite the severity of this condition, the detailed mechanisms that underlie the pathogenesis of heatstroke still remain largely unknown. Z-DNA-binding protein 1 (ZBP1), also referred to as DNA-dependent activator of IFN-regulatory factors (DAI) and DLM-1, was initially identified as a tumor-associated and interferon (IFN)-inducible protein, but has recently been reported to be a Z-nucleic acid sensor that regulates cell death and inflammation; however, its biological function is not yet fully understood. In the present study, a brief review of the main regulators is presented, in which the Z-nucleic acid sensor ZBP1 was identified to be a significant factor in regulating the pathological characteristics of heatstroke through ZBP1-dependent signaling. Thus, the lethal mechanism of heatstroke is revealed, in addition to a second function of ZBP1 other than as a nucleic acid sensor.
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Affiliation(s)
- Fanglin Li
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China,Department of Critical Care Medicine and Hematology, The 3rd Xiangya Hospital, Central South University, Changsha, China
| | - Jiayi Deng
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Qiuli He
- Department of Nephrology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China,*Correspondence: Qiuli He, ; Yanjun Zhong,
| | - Yanjun Zhong
- Critical Care Medicine, The Second Xiangya Hospital, Central South University, Changsha, China,*Correspondence: Qiuli He, ; Yanjun Zhong,
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35
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A-to-I editing prevents self-RNA sensing. Nat Rev Mol Cell Biol 2023; 24:85. [PMID: 36076034 DOI: 10.1038/s41580-022-00540-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2022] [Indexed: 01/28/2023]
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Hwang H, Chang HR, Baek D. Determinants of Functional MicroRNA Targeting. Mol Cells 2023; 46:21-32. [PMID: 36697234 PMCID: PMC9880601 DOI: 10.14348/molcells.2023.2157] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 01/27/2023] Open
Abstract
MicroRNAs (miRNAs) play cardinal roles in regulating biological pathways and processes, resulting in significant physiological effects. To understand the complex regulatory network of miRNAs, previous studies have utilized massivescale datasets of miRNA targeting and attempted to computationally predict the functional targets of miRNAs. Many miRNA target prediction tools have been developed and are widely used by scientists from various fields of biology and medicine. Most of these tools consider seed pairing between miRNAs and their mRNA targets and additionally consider other determinants to improve prediction accuracy. However, these tools exhibit limited prediction accuracy and high false positive rates. The utilization of additional determinants, such as RNA modifications and RNA-binding protein binding sites, may further improve miRNA target prediction. In this review, we discuss the determinants of functional miRNA targeting that are currently used in miRNA target prediction and the potentially predictive but unappreciated determinants that may improve prediction accuracy.
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Affiliation(s)
- Hyeonseo Hwang
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Hee Ryung Chang
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Daehyun Baek
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
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37
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Gan WL, Ng L, Ng BYL, Chen L. Recent Advances in Adenosine-to-Inosine RNA Editing in Cancer. Cancer Treat Res 2023; 190:143-179. [PMID: 38113001 DOI: 10.1007/978-3-031-45654-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
RNA epigenetics, or epitranscriptome, is a growing group of RNA modifications historically classified into two categories: RNA editing and RNA modification. RNA editing is usually understood as post-transcriptional RNA processing (except capping, splicing and polyadenylation) that changes the RNA nucleotide sequence encoded by the genome. This processing can be achieved through the insertion or deletion of nucleotides or deamination of nucleobases, generating either standard nucleotides such as uridine (U) or the rare nucleotide inosine (I). Adenosine-to-inosine (A-to-I) RNA editing is the most prevalent type of RNA modification in mammals and is catalyzed by adenosine deaminase acting on the RNA (ADAR) family of enzymes that recognize double-stranded RNAs (dsRNAs). Inosine mimics guanosine (G) in base pairing with cytidine (C), thereby A-to-I RNA editing alters dsRNA secondary structure. Inosine is also recognized as guanosine by the splicing and translation machineries, resulting in mRNA alternative splicing and protein recoding. Therefore, A-to-I RNA editing is an important mechanism that causes and regulates "RNA mutations" in both normal physiology and diseases including cancer. In this chapter, we reviewed current paradigms and developments in the field of A-to-I RNA editing in the context of cancer.
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Affiliation(s)
- Wei Liang Gan
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Larry Ng
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Bryan Y L Ng
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Leilei Chen
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore.
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117594, Singapore.
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore.
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Liao W, Nie W, Ahmad I, Chen G, Zhu B. The occurrence, characteristics, and adaptation of A-to-I RNA editing in bacteria: A review. Front Microbiol 2023; 14:1143929. [PMID: 36960293 PMCID: PMC10027721 DOI: 10.3389/fmicb.2023.1143929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/15/2023] [Indexed: 03/09/2023] Open
Abstract
A-to-I RNA editing is a very important post-transcriptional modification or co-transcriptional modification that creates isoforms and increases the diversity of proteins. In this process, adenosine (A) in RNA molecules is hydrolyzed and deaminated into inosine (I). It is well known that ADAR (adenosine deaminase acting on RNA)-dependent A-to-I mRNA editing is widespread in animals. Next, the discovery of A-to-I mRNA editing was mediated by TadA (tRNA-specific adenosine deaminase) in Escherichia coli which is ADAR-independent event. Previously, the editing event S128P on the flagellar structural protein FliC enhanced the bacterial tolerance to oxidative stress in Xoc. In addition, the editing events T408A on the enterobactin iron receptor protein XfeA act as switches by controlling the uptake of Fe3+ in response to the concentration of iron in the environment. Even though bacteria have fewer editing events, the great majority of those that are currently preserved have adaptive benefits. Interestingly, it was found that a TadA-independent A-to-I RNA editing event T408A occurred on xfeA, indicating that there may be other new enzymes that perform a function like TadA. Here, we review recent advances in the characteristics, functions, and adaptations of editing in bacteria.
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Affiliation(s)
- Weixue Liao
- Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Shanghai Cooperative Innovation Center for Modern Seed Industry, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Wenhan Nie
- Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Shanghai Cooperative Innovation Center for Modern Seed Industry, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Wenhan Nie,
| | - Iftikhar Ahmad
- Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Shanghai Cooperative Innovation Center for Modern Seed Industry, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari, Pakistan
| | - Gongyou Chen
- Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Shanghai Cooperative Innovation Center for Modern Seed Industry, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Bo Zhu
- Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Shanghai Cooperative Innovation Center for Modern Seed Industry, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Bo Zhu,
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Zhang K, Wang S, Chen T, Tu Z, Huang X, Zang G, Wu C, Fan X, Liu J, Tian Y, Cheng Y, Lu N, Zhang G. ADAR1p110 promotes Enterovirus D68 replication through its deaminase domain and inhibition of PKR pathway. Virol J 2022; 19:222. [PMID: 36550502 PMCID: PMC9773460 DOI: 10.1186/s12985-022-01952-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Severe respiratory and neurological diseases caused by human enterovirus D68 (EV-D68) pose a serious threat to public health, and there are currently no effective drugs and vaccines. Adenosine deaminase acting on RNA1 (ADAR1) has diverse biological functions in various viral infections, but its role in EV-D68 infections remains undetermined. METHODS Rhabdomyosarcoma (RD) and human embryonic kidney 293 T (293 T) cells, and HeLa cells were used to evaluate the expression level of ADAR1 upon EV-D68 (Fermon strain) and human parainfluenza virus type 3 (HPIV3; NIH47885) infection, respectively. Knockdown through silencing RNA (siRNA) and overexpression of either ADAR1p110 or ADAR1p150 in cells were used to determine the function of the two proteins after viral infection. ADAR1p110 double-stranded RNA binding domains (dsRBDs) deletion mutation was generated using a seamless clone kit. The expression of ADAR1, EV-D68 VP1, and HPIV3 hemagglutinin-neuraminidase (HN) proteins was identified using western blotting. The median tissue culture infectious dose (TCID50) was applied to detect viral titers. The transcription level of EV-D68 mRNA was analyzed using reverse transcription-quantitative PCR (RT-qPCR) and the viral 5'-untranslated region (5'-UTR)-mediated translation was analyzed using a dual luciferase reporter system. CONCLUSION We found that the transcription and expression of ADAR1 was inhibited upon EV-D68 infection. RNA interference of endogenous ADAR1 decreased VP1 protein expression and viral titers, while overexpression of ADAR1p110, but not ADAR1p150, facilitated viral replication. Immunofluorescence assays showed that ADAR1p110 migrated from the nucleus to the cytoplasm after EV-D68 infection. Further, ADAR1p110 lost its pro-viral ability after mutations of the active sites in the deaminase domain, and 5'-UTR sequencing of the viral genome revealed that ADAR1p110 likely plays a role in EV-D68 RNA editing. In addition, after ADAR1 knockdown, the levels of both phosphorylated double-stranded RNA dependent protein kinase (p-PKR) and phosphorylated eukaryotic initiation factor 2α (p-eIF2α) increased. Attenuated translation activity of the viral genome 5'-UTR was also observed in the dual-luciferase reporter assay. Lastly, the deletion of ADAR1p110 dsRBDs increased the level of p-PKR, which correlated with a decreased VP1 expression, indicating that the promotion of EV-D68 replication by ADAR1p110 is also related to the inhibition of PKR activation by its dsRBDs. Our study illustrates that ADAR1p110 is a novel pro-viral factor of EV-D68 replication and provides a theoretical basis for EV-D68 antiviral research.
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Affiliation(s)
- Kehan Zhang
- grid.203458.80000 0000 8653 0555Pathogen Biology and Immunology Laboratory and Laboratory of Tissue and Cell Biology, Experimental Teaching and Management Center, Chongqing Medical University, Chongqing, China ,grid.203458.80000 0000 8653 0555Department of the First Clinical Medicine, Chongqing Medical University, Chongqing, China
| | - Siyuan Wang
- grid.203458.80000 0000 8653 0555Department of the First Clinical Medicine, Chongqing Medical University, Chongqing, China
| | - Tingting Chen
- grid.203458.80000 0000 8653 0555Pathogen Biology and Immunology Laboratory and Laboratory of Tissue and Cell Biology, Experimental Teaching and Management Center, Chongqing Medical University, Chongqing, China
| | - Zeng Tu
- grid.203458.80000 0000 8653 0555Department of Pathogen Biology, Basic Medical School, Chongqing Medical University, Chongqing, China
| | - Xia Huang
- grid.203458.80000 0000 8653 0555Department of the First Clinical Medicine, Chongqing Medical University, Chongqing, China
| | - Guangchao Zang
- grid.203458.80000 0000 8653 0555Pathogen Biology and Immunology Laboratory and Laboratory of Tissue and Cell Biology, Experimental Teaching and Management Center, Chongqing Medical University, Chongqing, China
| | - Chun Wu
- Chongqing Better Biotechnology LLC, Chongqing, China
| | - Xinyue Fan
- grid.203458.80000 0000 8653 0555Department of the First Clinical Medicine, Chongqing Medical University, Chongqing, China
| | - Jia Liu
- grid.203458.80000 0000 8653 0555Pathogen Biology and Immunology Laboratory and Laboratory of Tissue and Cell Biology, Experimental Teaching and Management Center, Chongqing Medical University, Chongqing, China
| | - Yunbo Tian
- Quality Management Section, Chongqing Blood Center, Chongqing, China
| | - Yong Cheng
- Monitoring On Terrestrial Wildlife-Borne Infectious Diseases, Jinggangshan National Nature Reserve of Jiangxi Province, Ji’an, Jiangxi China
| | - Nan Lu
- grid.203458.80000 0000 8653 0555Department of Pathogen Biology, Basic Medical School, Chongqing Medical University, Chongqing, China
| | - Guangyuan Zhang
- grid.203458.80000 0000 8653 0555Pathogen Biology and Immunology Laboratory and Laboratory of Tissue and Cell Biology, Experimental Teaching and Management Center, Chongqing Medical University, Chongqing, China
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Hajji K, Sedmík J, Cherian A, Amoruso D, Keegan LP, O'Connell MA. ADAR2 enzymes: efficient site-specific RNA editors with gene therapy aspirations. RNA (NEW YORK, N.Y.) 2022; 28:1281-1297. [PMID: 35863867 PMCID: PMC9479739 DOI: 10.1261/rna.079266.122] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The adenosine deaminase acting on RNA (ADAR) enzymes are essential for neuronal function and innate immune control. ADAR1 RNA editing prevents aberrant activation of antiviral dsRNA sensors through editing of long, double-stranded RNAs (dsRNAs). In this review, we focus on the ADAR2 proteins involved in the efficient, highly site-specific RNA editing to recode open reading frames first discovered in the GRIA2 transcript encoding the key GLUA2 subunit of AMPA receptors; ADAR1 proteins also edit many of these sites. We summarize the history of ADAR2 protein research and give an up-to-date review of ADAR2 structural studies, human ADARBI (ADAR2) mutants causing severe infant seizures, and mouse disease models. Structural studies on ADARs and their RNA substrates facilitate current efforts to develop ADAR RNA editing gene therapy to edit disease-causing single nucleotide polymorphisms (SNPs). Artificial ADAR guide RNAs are being developed to retarget ADAR RNA editing to new target transcripts in order to correct SNP mutations in them at the RNA level. Site-specific RNA editing has been expanded to recode hundreds of sites in CNS transcripts in Drosophila and cephalopods. In Drosophila and C. elegans, ADAR RNA editing also suppresses responses to self dsRNA.
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Affiliation(s)
- Khadija Hajji
- CEITEC Masaryk University, Brno 62500, Czech Republic
| | - Jiří Sedmík
- CEITEC Masaryk University, Brno 62500, Czech Republic
| | - Anna Cherian
- CEITEC Masaryk University, Brno 62500, Czech Republic
| | | | - Liam P Keegan
- CEITEC Masaryk University, Brno 62500, Czech Republic
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Xiang Y, Katrekar D, Mali P. Methods for recruiting endogenous and exogenous ADAR enzymes for site-specific RNA editing. Methods 2022; 205:158-166. [PMID: 35779766 DOI: 10.1016/j.ymeth.2022.06.011] [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: 02/04/2022] [Revised: 06/08/2022] [Accepted: 06/27/2022] [Indexed: 12/01/2022] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) can be repurposed to achieve site-specific A-to-I RNA editing by recruiting them to a target of interest via an ADAR-recruiting guide RNA (adRNA). In this chapter, we present details towards experimental methods to enable this via two orthogonal strategies: one, via recruitment of endogenous ADARs (i.e. ADARs already natively expressed in cells); and two, via recruitment of exogenous ADARs (i.e. ADARs delivered into cells). Towards the former, we describe the use of circular adRNAs to recruit endogenous ADARs to a desired mRNA target. This results in robust, persistent and highly transcript specific editing both in vitro and in vivo. Towards the latter, we describe the use of a split-ADAR2 system, which allows for overexpression of ADAR2 variants that can be utilized to edit adenosines with high specificity, including at challenging to edit adenosines in non-preferred motifs such as those flanked by a 5' guanosine. We anticipate the described methods should facilitate RNA editing applications across research and biotechnology settings.
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Affiliation(s)
- Yichen Xiang
- Department of Bioengineering, University of California San Diego, USA
| | | | - Prashant Mali
- Department of Bioengineering, University of California San Diego, USA.
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42
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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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Gumpper RH, Fay JF, Roth BL. Molecular insights into the regulation of constitutive activity by RNA editing of 5HT 2C serotonin receptors. Cell Rep 2022; 40:111211. [PMID: 35977511 PMCID: PMC9422347 DOI: 10.1016/j.celrep.2022.111211] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/01/2022] [Accepted: 07/21/2022] [Indexed: 11/25/2022] Open
Abstract
RNA editing is a process by which post-transcriptional changes of mRNA nucleotides alter protein function through modification of the amino acid content. The 5HT2C serotonin receptor, which undergoes 32 distinct RNA-editing events leading to 24 protein isoforms, is a notable example of this process. These 5HT2C isoforms display differences in constitutive activity, agonist/inverse agonist potencies, and efficacies. To elucidate the molecular mechanisms responsible for these effects of RNA editing, we present four active-state 5HT2C-transducer-coupled structures of three representative isoforms (INI, VGV, and VSV) with the selective drug lorcaserin (Belviq) and the classic psychedelic psilocin. We also provide a comprehensive analysis of agonist activation and constitutive activity across all 24 protein isoforms. Collectively, these findings reveal a unique hydrogen-bonding network located on intracellular loop 2 that is subject to RNA editing, which differentially affects GPCR constitutive and agonist signaling activities. It is established that the 5HT2C receptor undergoes RNA editing leading to 24 isoforms. Several isoforms exhibit changes in basal activity and are linked to pathologies. Gumpper et al. have done a systematic structure-function characterization of all the isoforms revealing the underlying mechanisms that govern basal activity of the 5HT2C receptor.
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Affiliation(s)
- Ryan H Gumpper
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| | - Jonathan F Fay
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
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Neuronal role of taxi is imperative for flight in Drosophila melanogaster. Gene X 2022; 833:146593. [PMID: 35597528 DOI: 10.1016/j.gene.2022.146593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/10/2022] [Accepted: 05/16/2022] [Indexed: 11/20/2022] Open
Abstract
Extensive studies in Drosophila have led to the elucidation of the roles of many molecular players involved in the sensorimotor coordination of flight. However, the identification and characterisation of new players can add novel perspectives to the process. In this paper, we show that the extant mutant, jumper, is a hypermorphic allele of the taxi/delilah gene, which encodes a transcription factor. The defective flight of jumper flies results from the insertion of an I-element in the 5'-UTR of taxi gene, leading to an over-expression of the taxi. We also show that the molecular lesion responsible for the taxi1 allele results from a 25 bp deletion leading to a shift in the reading frame at the C-terminus of the taxi coding sequence. Thus, the last 20 residues are replaced by 32 disparate residues in taxi1. Both taxi1, a hypomorphic allele, and the CRISPR-Cas9 knock-out (taxiKO) null allele, show a defective flight phenotype. Electrophysiological studies show taxi hypermorphs, hypomorphs, and knock out flies show abnormal neuronal firing. We further show that neuronal-specific knock-down or over-expression of taxi cause a defect in the brain's inputs to the flight muscles, leading to reduced flight ability. Through transcriptomic analysis of the taxiKO fly head, we have identified several putative targets of Taxi that may play important roles in flight. In conclusion, from molecularly characterising jumper to establishing Taxi's role during Drosophila flight, our work shows that the forward genetics approach still can lead to the identification of novel molecular players required for neuronal transmission.
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del Valle-Morales D, Le P, Saviana M, Romano G, Nigita G, Nana-Sinkam P, Acunzo M. The Epitranscriptome in miRNAs: Crosstalk, Detection, and Function in Cancer. Genes (Basel) 2022; 13:genes13071289. [PMID: 35886072 PMCID: PMC9316458 DOI: 10.3390/genes13071289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/09/2022] [Accepted: 07/19/2022] [Indexed: 02/06/2023] Open
Abstract
The epitranscriptome encompasses all post-transcriptional modifications that occur on RNAs. These modifications can alter the function and regulation of their RNA targets, which, if dysregulated, result in various diseases and cancers. As with other RNAs, miRNAs are highly modified by epitranscriptomic modifications such as m6A methylation, 2′-O-methylation, m5C methylation, m7G methylation, polyuridine, and A-to-I editing. miRNAs are a class of small non-coding RNAs that regulates gene expression at the post-transcriptional level. miRNAs have gathered high clinical interest due to their role in disease, development, and cancer progression. Epitranscriptomic modifications alter the targeting, regulation, and biogenesis of miRNAs, increasing the complexity of miRNA regulation. In addition, emerging studies have revealed crosstalk between these modifications. In this review, we will summarize the epitranscriptomic modifications—focusing on those relevant to miRNAs—examine the recent crosstalk between these modifications, and give a perspective on how this crosstalk expands the complexity of miRNA biology.
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Affiliation(s)
- Daniel del Valle-Morales
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
| | - Patricia Le
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
| | - Michela Saviana
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
| | - Giulia Romano
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
| | - Giovanni Nigita
- Comprehensive Cancer Center, Department of Cancer Biology and Genetics, The Ohio State University, Columbus, OH 43210, USA;
| | - Patrick Nana-Sinkam
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
| | - Mario Acunzo
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA; (D.d.V.-M.); (P.L.); (M.S.); (G.R.); (P.N.-S.)
- Correspondence:
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Zhai J, Koh JH, Soong TW. RNA editing of ion channels and receptors in physiology and neurological disorders. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac010. [PMID: 38596706 PMCID: PMC11003377 DOI: 10.1093/oons/kvac010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/14/2022] [Accepted: 05/15/2022] [Indexed: 04/11/2024]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing is a post-transcriptional modification that diversifies protein functions by recoding RNA or alters protein quantity by regulating mRNA level. A-to-I editing is catalyzed by adenosine deaminases that act on RNA. Millions of editing sites have been reported, but they are mostly found in non-coding sequences. However, there are also several recoding editing sites in transcripts coding for ion channels or transporters that have been shown to play important roles in physiology and changes in editing level are associated with neurological diseases. These editing sites are not only found to be evolutionary conserved across species, but they are also dynamically regulated spatially, developmentally and by environmental factors. In this review, we discuss the current knowledge of A-to-I RNA editing of ion channels and receptors in the context of their roles in physiology and pathological disease. We also discuss the regulation of editing events and site-directed RNA editing approaches for functional study that offer a therapeutic pathway for clinical applications.
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Affiliation(s)
- Jing Zhai
- Department of Physiology, National University of Singapore, Singapore 117593, Singapore
| | - Joanne Huifen Koh
- Department of Physiology, National University of Singapore, Singapore 117593, Singapore
| | - Tuck Wah Soong
- Department of Physiology, National University of Singapore, Singapore 117593, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore,
Singapore 117456, Singapore
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Katrekar D, Yen J, Xiang Y, Saha A, Meluzzi D, Savva Y, Mali P. Efficient in vitro and in vivo RNA editing via recruitment of endogenous ADARs using circular guide RNAs. Nat Biotechnol 2022; 40:938-945. [PMID: 35145312 PMCID: PMC9232839 DOI: 10.1038/s41587-021-01171-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022]
Abstract
Recruiting endogenous adenosine deaminases using exogenous guide RNAs to edit cellular RNAs is a promising therapeutic strategy, but editing efficiency and durability remain low using current guide RNA designs. In this study, we engineered circular ADAR-recruiting guide RNAs (cadRNAs) to enable more efficient programmable adenosine-to-inosine RNA editing without requiring co-delivery of any exogenous proteins. Using these cadRNAs, we observed robust and durable RNA editing across multiple sites and cell lines, in both untranslated and coding regions of RNAs, and high transcriptome-wide specificity. Additionally, we increased transcript-level specificity for the target adenosine by incorporating interspersed loops in the antisense domains, reducing bystander editing. In vivo delivery of cadRNAs via adeno-associated viruses enabled 53% RNA editing of the mPCSK9 transcript in C57BL/6J mice livers and 12% UAG-to-UGG RNA correction of the amber nonsense mutation in the IDUA-W392X mouse model of mucopolysaccharidosis type I-Hurler syndrome. cadRNAs enable efficient programmable RNA editing in vivo with diverse protein modulation and gene therapeutic applications.
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Affiliation(s)
- Dhruva Katrekar
- Department of Bioengineering, University of California, San Diego, San Diego, CA, USA
| | - James Yen
- Department of Bioengineering, University of California, San Diego, San Diego, CA, USA
| | - Yichen Xiang
- Department of Bioengineering, University of California, San Diego, San Diego, CA, USA
| | - Anushka Saha
- Department of Bioengineering, University of California, San Diego, San Diego, CA, USA
| | - Dario Meluzzi
- Department of Medicine, University of California, San Diego, San Diego, CA, USA
| | | | - Prashant Mali
- Department of Bioengineering, University of California, San Diego, San Diego, CA, USA.
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Interplay between A-to-I Editing and Splicing of RNA: A Potential Point of Application for Cancer Therapy. Int J Mol Sci 2022; 23:ijms23095240. [PMID: 35563631 PMCID: PMC9105294 DOI: 10.3390/ijms23095240] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/17/2022] Open
Abstract
Adenosine-to-inosine RNA editing is a system of post-transcriptional modification widely distributed in metazoans which is catalyzed by ADAR enzymes and occurs mostly in double-stranded RNA (dsRNA) before splicing. This type of RNA editing changes the genetic code, as inosine generally pairs with cytosine in contrast to adenosine, and this expectably modulates RNA splicing. We review the interconnections between RNA editing and splicing in the context of human cancer. The editing of transcripts may have various effects on splicing, and resultant alternatively spliced isoforms may be either tumor-suppressive or oncogenic. Dysregulated RNA splicing in cancer often causes the release of excess amounts of dsRNA into cytosol, where specific dsRNA sensors provoke antiviral-like responses, including type I interferon signaling. These responses may arrest cell division, causing apoptosis and, externally, stimulate antitumor immunity. Thus, small-molecule spliceosome inhibitors have been shown to facilitate the antiviral-like signaling and are considered to be potential cancer therapies. In turn, a cytoplasmic isoform of ADAR can deaminate dsRNA in cytosol, thereby decreasing its levels and diminishing antitumor innate immunity. We propose that complete or partial inhibition of ADAR may enhance the proapoptotic and cytotoxic effects of splicing inhibitors and that it may be considered a promising addition to cancer therapies targeting RNA splicing.
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Jones EL, Mlotkowski AJ, Hebert SP, Schlegel HB, Chow CS. Calculations of p Ka Values for a Series of Naturally Occurring Modified Nucleobases. J Phys Chem A 2022; 126:1518-1529. [PMID: 35201779 DOI: 10.1021/acs.jpca.1c10905] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Modified nucleobases are found in functionally important regions of RNA and are often responsible for essential structural roles. Many of these nucleobase modifications are dynamically regulated in nature, with each modification having a different biological role in RNA. Despite the high abundance of modifications, many of their characteristics are still poorly understood. One important property of a nucleobase is its pKa value, which has been widely studied for unmodified nucleobases, but not for the modified versions. In this study, the pKa values of modified nucleobases were determined by performing ab initio quantum mechanical calculations using a B3LYP density functional with the 6-31+G(d,p) basis set and a combination of implicit-explicit solvation systems. This method, which was previously employed to determine the pKa values of unmodified nucleobases, is applicable to a variety of modified nucleobases. Comparisons of the pKa values of modified nucleobases give insight into their structural and energetic impacts within nucleic acids.
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Affiliation(s)
- Evan L Jones
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Alan J Mlotkowski
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Sebastien P Hebert
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - H Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Christine S Chow
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
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Endogenous ADAR-mediated RNA editing in non-human primates using stereopure chemically modified oligonucleotides. Nat Biotechnol 2022; 40:1093-1102. [DOI: 10.1038/s41587-022-01225-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 01/17/2022] [Indexed: 12/18/2022]
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