1
|
Roučová K, Vopálenský V, Mašek T, Del Llano E, Provazník J, Landry JJM, Azevedo N, Ehler E, Beneš V, Pospíšek M. Loss of ADAR1 protein induces changes in small RNA landscape in hepatocytes. RNA (NEW YORK, N.Y.) 2024; 30:1164-1183. [PMID: 38844344 PMCID: PMC11331409 DOI: 10.1261/rna.080097.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 08/18/2024]
Abstract
In recent years, numerous evidence has been accumulated about the extent of A-to-I editing in human RNAs and the key role ADAR1 plays in the cellular editing machinery. It has been shown that A-to-I editing occurrence and frequency are tissue-specific and essential for some tissue development, such as the liver. To study the effect of ADAR1 function in hepatocytes, we have created Huh7.5 ADAR1 KO cell lines. Upon IFN treatment, the Huh7.5 ADAR1 KO cells show rapid arrest of growth and translation, from which they do not recover. We analyzed translatome changes by using a method based on sequencing of separate polysome profile RNA fractions. We found significant changes in the transcriptome and translatome of the Huh7.5 ADAR1 KO cells. The most prominent changes include negatively affected transcription by RNA polymerase III and the deregulation of snoRNA and Y RNA levels. Furthermore, we observed that ADAR1 KO polysomes are enriched in mRNAs coding for proteins pivotal in a wide range of biological processes such as RNA localization and RNA processing, whereas the unbound fraction is enriched mainly in mRNAs coding for ribosomal proteins and translational factors. This indicates that ADAR1 plays a more relevant role in small RNA metabolism and ribosome biogenesis.
Collapse
Affiliation(s)
- Kristina Roučová
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Václav Vopálenský
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Tomáš Mašek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Edgar Del Llano
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
- Laboratory of Biochemistry and Molecular Biology of Germ Cells, Institute of Animal Physiology and Genetics, CAS, 277 21 Liběchov, Czech Republic
| | | | | | | | - Edvard Ehler
- Department of Biology and Environmental Studies, Faculty of Education, Charles University, 116 39 Prague, Czech Republic
| | | | - Martin Pospíšek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| |
Collapse
|
2
|
Wulff TF, Hahnke K, Lécrivain AL, Schmidt K, Ahmed-Begrich R, Finstermeier K, Charpentier E. Dynamics of diversified A-to-I editing in Streptococcus pyogenes is governed by changes in mRNA stability. Nucleic Acids Res 2024:gkae629. [PMID: 39087550 DOI: 10.1093/nar/gkae629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 07/01/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing plays an important role in the post-transcriptional regulation of eukaryotic cell physiology. However, our understanding of the occurrence, function and regulation of A-to-I editing in bacteria remains limited. Bacterial mRNA editing is catalysed by the deaminase TadA, which was originally described to modify a single tRNA in Escherichia coli. Intriguingly, several bacterial species appear to perform A-to-I editing on more than one tRNA. Here, we provide evidence that in the human pathogen Streptococcus pyogenes, tRNA editing has expanded to an additional tRNA substrate. Using RNA sequencing, we identified more than 27 editing sites in the transcriptome of S. pyogenes SF370 and demonstrate that the adaptation of S. pyogenes TadA to a second tRNA substrate has also diversified the sequence context and recoding scope of mRNA editing. Based on the observation that editing is dynamically regulated in response to several infection-relevant stimuli, such as oxidative stress, we further investigated the underlying determinants of editing dynamics and identified mRNA stability as a key modulator of A-to-I editing. Overall, our findings reveal the presence and diversification of A-to-I editing in S. pyogenes and provide novel insights into the plasticity of the editome and its regulation in bacteria.
Collapse
Affiliation(s)
- Thomas F Wulff
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | - Karin Hahnke
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | | | - Katja Schmidt
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
| | | | | | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, 10117 Berlin, Germany
- Institute for Biology, Humboldt University Berlin, 10115 Berlin, Germany
| |
Collapse
|
3
|
Tao WB, Xiong J, Yuan BF. Site-specific quantification of Adenosine-to-Inosine RNA editing by Endonuclease-Mediated qPCR. Bioorg Med Chem 2024; 110:117837. [PMID: 39013280 DOI: 10.1016/j.bmc.2024.117837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
RNA molecules contain diverse modified nucleobases that play pivotal roles in numerous biological processes. Adenosine-to-inosine (A-to-I) RNA editing, one of the most prevalent RNA modifications in mammalian cells, is linked to a multitude of human diseases. To unveil the functions of A-to-I RNA editing, accurate quantification of inosine at specific sites is essential. In this study, we developed an endonuclease-mediated cleavage and real-time fluorescence quantitative PCR method for A-to-I RNA editing (EM-qPCR) to quantitatively analyze A-to-I RNA editing at a single site. By employing this method, we successfully quantified the levels of A-to-I RNA editing on various transfer RNA (tRNA) molecules at position 34 (I34) in mammalian cells with precision. Subsequently, this method was applied to tissues from sleep-deprived mice, revealing a notable alteration in the levels of I34 between sleep-deprived and control mice. The proposed method sets a precedent for the quantitative analysis of A-to-I RNA editing at specific sites, facilitating a deeper understanding of the biological implications of A-to-I RNA editing.
Collapse
Affiliation(s)
- Wan-Bing Tao
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China
| | - Jun Xiong
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China; Department of Occupational and Environmental Health, School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, PR China
| | - Bi-Feng Yuan
- College of Chemistry and Molecular Sciences, Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, PR China; Department of Occupational and Environmental Health, School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, PR China; Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430072, PR China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan 430071, PR China.
| |
Collapse
|
4
|
Bortoletto E, Rosani U. Bioinformatics for Inosine: Tools and Approaches to Trace This Elusive RNA Modification. Genes (Basel) 2024; 15:996. [PMID: 39202357 PMCID: PMC11353476 DOI: 10.3390/genes15080996] [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: 07/01/2024] [Revised: 07/23/2024] [Accepted: 07/25/2024] [Indexed: 09/03/2024] Open
Abstract
Inosine is a nucleotide resulting from the deamination of adenosine in RNA. This chemical modification process, known as RNA editing, is typically mediated by a family of double-stranded RNA binding proteins named Adenosine Deaminase Acting on dsRNA (ADAR). While the presence of ADAR orthologs has been traced throughout the evolution of metazoans, the existence and extension of RNA editing have been characterized in a more limited number of animals so far. Undoubtedly, ADAR-mediated RNA editing plays a vital role in physiology, organismal development and disease, making the understanding of the evolutionary conservation of this phenomenon pivotal to a deep characterization of relevant biological processes. However, the lack of direct high-throughput methods to reveal RNA modifications at single nucleotide resolution limited an extended investigation of RNA editing. Nowadays, these methods have been developed, and appropriate bioinformatic pipelines are required to fully exploit this data, which can complement existing approaches to detect ADAR editing. Here, we review the current literature on the "bioinformatics for inosine" subject and we discuss future research avenues in the field.
Collapse
Affiliation(s)
| | - Umberto Rosani
- Department of Biology, University of Padova, 35131 Padova, Italy;
| |
Collapse
|
5
|
Reautschnig P, Fruhner C, Wahn N, Wiegand CP, Kragness S, Yung JF, Hofacker DT, Fisk J, Eidelman M, Waffenschmidt N, Feige M, Pfeiffer LS, Schulz AE, Füll Y, Levanon EY, Mandel G, Stafforst T. Precise in vivo RNA base editing with a wobble-enhanced circular CLUSTER guide RNA. Nat Biotechnol 2024:10.1038/s41587-024-02313-0. [PMID: 38997581 DOI: 10.1038/s41587-024-02313-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 05/17/2024] [Indexed: 07/14/2024]
Abstract
Recruiting the endogenous editing enzyme adenosine deaminase acting on RNA (ADAR) with tailored guide RNAs for adenosine-to-inosine (A-to-I) RNA base editing is promising for safely manipulating genetic information at the RNA level. However, the precision and efficiency of editing are often compromised by bystander off-target editing. Here, we find that in 5'-UAN triplets, which dominate bystander editing, G•U wobble base pairs effectively mitigate off-target events while maintaining high on-target efficiency. This strategy is universally applicable to existing A-to-I RNA base-editing systems and complements other suppression methods such as G•A mismatches and uridine (U) depletion. Combining wobble base pairing with a circularized format of the CLUSTER approach achieves highly precise and efficient editing (up to 87%) of a disease-relevant mutation in the Mecp2 transcript in cell culture. Virus-mediated delivery of the guide RNA alone realizes functional MeCP2 protein restoration in the central nervous system of a murine Rett syndrome model with editing yields of up to 19% and excellent bystander control in vivo.
Collapse
Affiliation(s)
- Philipp Reautschnig
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Carolin Fruhner
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Nicolai Wahn
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Charlotte P Wiegand
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Sabrina Kragness
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - John F Yung
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Daniel T Hofacker
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Jenna Fisk
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Michelle Eidelman
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Nils Waffenschmidt
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Maximilian Feige
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Laura S Pfeiffer
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Annika E Schulz
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Yvonne Füll
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany
| | - Erez Y Levanon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Gail Mandel
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Thorsten Stafforst
- Interfaculty Institute of Biochemistry, Faculty of Science, University of Tübingen, Tübingen, Germany.
- Gene and RNA Therapy Center (GRTC), Faculty of Medicine, University of Tübingen, Tübingen, Germany.
- iFIT Cluster of Excellence (EXC2180) Image-Guided and Functionally Instructed Tumor Therapies, University of Tübingen, Tübingen, Germany.
| |
Collapse
|
6
|
Schiksnis EC, Nicastro IA, Pasquinelli AE. Full-length direct RNA sequencing reveals extensive remodeling of RNA expression, processing and modification in aging Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599640. [PMID: 38948813 PMCID: PMC11213008 DOI: 10.1101/2024.06.18.599640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Organismal aging is marked by decline in cellular function and anatomy, ultimately resulting in death. To inform our understanding of the mechanisms underlying this degeneration, we performed standard RNA sequencing and Nanopore direct RNA sequencing over an adult time course in Caenorhabditis elegans. Long reads allowed for identification of hundreds of novel isoforms and age-associated differential isoform accumulation, resulting from alternative splicing and terminal exon choice. Genome-wide analysis reveals a decline in RNA processing fidelity and a rise in inosine and pseudouridine editing events in transcripts from older animals. In this first map of pseudouridine modifications for C. elegans, we find that they largely reside in coding sequences and that the number of genes with this modification increases with age. Collectively, this analysis discovers transcriptomic signatures associated with age and is a valuable resource to understand the many processes that dictate altered gene expression patterns and post-transcriptional regulation in aging.
Collapse
Affiliation(s)
- Erin C Schiksnis
- Molecular Biology Department, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0349, USA
| | - Ian A Nicastro
- Molecular Biology Department, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0349, USA
| | - Amy E Pasquinelli
- Molecular Biology Department, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0349, USA
| |
Collapse
|
7
|
Ravn Berg S, Dikic A, Sharma A, Hagen L, Vågbø CB, Zatula A, Misund K, Waage A, Slupphaug G. Progression of monoclonal gammopathy of undetermined significance to multiple myeloma is associated with enhanced translational quality control and overall loss of surface antigens. J Transl Med 2024; 22:548. [PMID: 38849800 PMCID: PMC11162064 DOI: 10.1186/s12967-024-05345-x] [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: 03/22/2024] [Accepted: 05/23/2024] [Indexed: 06/09/2024] Open
Abstract
BACKGROUND Despite significant advancements in treatment strategies, multiple myeloma remains incurable. Additionally, there is a distinct lack of reliable biomarkers that can guide initial treatment decisions and help determine suitable replacement or adjuvant therapies when relapse ensues due to acquired drug resistance. METHODS To define specific proteins and pathways involved in the progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM), we have applied super-SILAC quantitative proteomic analysis to CD138 + plasma cells from 9 individuals with MGUS and 37 with MM. RESULTS Unsupervised hierarchical clustering defined three groups: MGUS, MM, and MM with an MGUS-like proteome profile (ML) that may represent a group that has recently transformed to MM. Statistical analysis identified 866 differentially expressed proteins between MM and MGUS, and 189 between MM and ML, 177 of which were common between MGUS and ML. Progression from MGUS to MM is accompanied by upregulated EIF2 signaling, DNA repair, and proteins involved in translational quality control, whereas integrin- and actin cytoskeletal signaling and cell surface markers are downregulated. CONCLUSION Compared to the premalignant plasma cells in MGUS, malignant MM cells apparently have mobilized several pathways that collectively contribute to ensure translational fidelity and to avoid proteotoxic stress, especially in the ER. The overall reduced expression of immunoglobulins and surface antigens contribute to this and may additionally mediate evasion from recognition by the immune apparatus. Our analyses identified a range of novel biomarkers with potential prognostic and therapeutic value, which will undergo further evaluation to determine their clinical significance.
Collapse
Affiliation(s)
- Sigrid Ravn Berg
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
| | - Aida Dikic
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
| | - Animesh Sharma
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
- PROMEC Core Facility for Proteomics and Modomics, Norwegian University of Science and Technology, NTNU, and the Central Norway Regional Health Authority Norway, N-7491, Trondheim, Norway
| | - Lars Hagen
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
- PROMEC Core Facility for Proteomics and Modomics, Norwegian University of Science and Technology, NTNU, and the Central Norway Regional Health Authority Norway, N-7491, Trondheim, Norway
| | - Cathrine Broberg Vågbø
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
- PROMEC Core Facility for Proteomics and Modomics, Norwegian University of Science and Technology, NTNU, and the Central Norway Regional Health Authority Norway, N-7491, Trondheim, Norway
| | - Alexey Zatula
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway
| | - Kristine Misund
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Department of Medical Genetics, St Olavs hospital, N-7491, Trondheim, Norway
| | - Anders Waage
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway
- Department of Hematology, and Biobank1, St Olavs hospital, N-7491, Trondheim, Norway
| | - Geir Slupphaug
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, N-7491, Trondheim, Norway.
- Clinic of Laboratory Medicine, St. Olavs hospital, N-7491, Trondheim, Norway.
- PROMEC Core Facility for Proteomics and Modomics, Norwegian University of Science and Technology, NTNU, and the Central Norway Regional Health Authority Norway, N-7491, Trondheim, Norway.
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Margvelani G, Welden JR, Maquera AA, Van Eyk JE, Murray C, Miranda Sardon SC, Stamm S. Influence of FTDP-17 mutants on circular tau RNAs. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167036. [PMID: 38286213 DOI: 10.1016/j.bbadis.2024.167036] [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: 09/20/2023] [Revised: 12/21/2023] [Accepted: 01/21/2024] [Indexed: 01/31/2024]
Abstract
At least 53 mutations in the microtubule associated protein tau gene (MAPT) have been identified that cause frontotemporal dementia. 47 of these mutations are localized between exons 7 and 13. They could thus affect the formation of circular RNAs (circRNAs) from the MAPT gene that occurs through backsplicing from exon 12 to either exon 10 or exon 7. We analyzed representative mutants and found that five FTDP-17 mutations increase the formation of 12➔7 circRNA and three different mutations increase the amount of 12➔10 circRNA. CircRNAs are translated after undergoing adenosine to inosine RNA editing, catalyzed by ADAR enzymes. We found that the interferon induced ADAR1-p150 isoform has the strongest effect on circTau RNA translation. ADAR1-p150 activity had a stronger effect on circTau RNA expression and strongly decreased 12➔7 circRNA, but unexpectedly increased 12➔10 circRNA. In both cases, ADAR-activity strongly promoted translation of circTau RNAs. Unexpectedly, we found that the 12➔7 circTau protein interacts with eukaryotic initiation factor 4B (eIF4B), which is reduced by four FTDP-17 mutations located in the second microtubule domain. These are the first studies of the effect of human mutations on circular RNA formation and translation. They show that point mutations influence circRNA expression levels, likely through changes in pre-mRNA structures. The effect of the mutations is surpassed by editing of the circular RNAs, leading to their translation. Thus, circular RNAs and their editing status should be considered when analyzing FTDP-17 mutations.
Collapse
Affiliation(s)
- Giorgi Margvelani
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Justin R Welden
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Andrea Arizaca Maquera
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | | | | | - Sandra C Miranda Sardon
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
| |
Collapse
|
10
|
Spaggiari L, Pedretti N, Ricchi F, Pinetti D, Campisciano G, De Seta F, Comar M, Kenno S, Ardizzoni A, Pericolini E. An Untargeted Metabolomic Analysis of Lacticaseibacillus ( L.) rhamnosus, Lactobacillus ( L.) acidophilus, Lactiplantibacillus ( L.) plantarum and Limosilactobacillus ( L.) reuteri Reveals an Upregulated Production of Inosine from L. rhamnosus. Microorganisms 2024; 12:662. [PMID: 38674606 PMCID: PMC11051988 DOI: 10.3390/microorganisms12040662] [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: 02/18/2024] [Revised: 03/19/2024] [Accepted: 03/23/2024] [Indexed: 04/28/2024] Open
Abstract
Lactic acid bacteria are considered an inexhaustible source of bioactive compounds; indeed, products from their metabolism are known to have immunomodulatory and anti-inflammatory activity. Recently, we demonstrated that Cell-Free Supernatants (CFS) obtained from Lactobacillus (L.) acidophilus, Lactiplantibacillus (L.) plantarum, Lacticaseibacillus (L.) rhamnosus, and Limosilactobacillus (L.) reuteri can impair Candida pathogenic potential in an in vitro model of epithelial vaginal infection. This effect could be ascribed to a direct effect of living lactic acid bacteria on Candida virulence and to the production of metabolites that are able to impair fungal virulence. In the present work, stemming from these data, we deepened our knowledge of CFS from these four lactic acid bacteria by performing a metabolomic analysis to better characterize their composition. By using an untargeted metabolomic approach, we detected consistent differences in the metabolites produced by these four different lactic acid bacteria. Interestingly, L. rhamnosus and L. acidophilus showed the most peculiar metabolic profiles. Specifically, after a hierarchical clustering analysis, L. rhamnosus and L. acidophilus showed specific areas of significantly overexpressed metabolites that strongly differed from the same areas in other lactic acid bacteria. From the overexpressed compounds in these areas, inosine from L. rhamnosus returned with the best identification profile. This molecule has been described as having antioxidant, anti-inflammatory, anti-infective, and neuroprotective properties. The biological significance of its overproduction by L. rhamnosus might be important in its probiotic and/or postbiotic activity.
Collapse
Affiliation(s)
- Luca Spaggiari
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125 Modena, Italy; (L.S.); (F.R.)
| | - Natalia Pedretti
- Department of Surgical, Medical, Dental and Morphological Sciences with Interest in Transplant, Oncological and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (N.P.); (S.K.); (A.A.)
| | - Francesco Ricchi
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125 Modena, Italy; (L.S.); (F.R.)
| | - Diego Pinetti
- Centro Interdipartimentale Grandi Strumenti, University of Modena and Reggio Emilia, 41125 Modena, Italy;
| | - Giuseppina Campisciano
- Institute for Maternal and Child Health-IRCCS, Burlo Garofolo, 34137 Trieste, Italy; (G.C.); (M.C.)
| | - Francesco De Seta
- Department of Obstetrics and Gynecology, IRCCS San Raffaele Scientific Institute, University Vita and Salute, 20132 Milan, Italy;
| | - Manola Comar
- Institute for Maternal and Child Health-IRCCS, Burlo Garofolo, 34137 Trieste, Italy; (G.C.); (M.C.)
- Department of Medical Sciences, University of Trieste, 34129 Trieste, Italy
| | - Samyr Kenno
- Department of Surgical, Medical, Dental and Morphological Sciences with Interest in Transplant, Oncological and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (N.P.); (S.K.); (A.A.)
| | - Andrea Ardizzoni
- Department of Surgical, Medical, Dental and Morphological Sciences with Interest in Transplant, Oncological and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (N.P.); (S.K.); (A.A.)
| | - Eva Pericolini
- Department of Surgical, Medical, Dental and Morphological Sciences with Interest in Transplant, Oncological and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (N.P.); (S.K.); (A.A.)
| |
Collapse
|
11
|
Szabo B, Mandl TC, Woldrich B, Diensthuber G, Martin D, Jantsch MF, Licht K. RNA Pol II-dependent transcription efficiency fine-tunes A-to-I editing levels. Genome Res 2024; 34:231-242. [PMID: 38471738 PMCID: PMC10984384 DOI: 10.1101/gr.277686.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024]
Abstract
A-to-I RNA editing is a widespread epitranscriptomic phenomenon leading to the conversion of adenosines to inosines, which are primarily interpreted as guanosines by cellular machines. Consequently, A-to-I editing can alter splicing or lead to recoding of transcripts. As misregulation of editing can cause a variety of human diseases, A-to-I editing requires tight regulation of the extent of deamination, particularly in protein-coding regions. The bulk of A-to-I editing occurs cotranscriptionally. Thus, we studied A-to-I editing regulation in the context of transcription and pre-mRNA processing. We show that stimulation of transcription impacts editing levels. Activation of the transcription factor MYC leads to an up-regulation of A-to-I editing, particularly in transcripts that are suppressed upon MYC activation. Moreover, low pre-mRNA synthesis rates and low pre-mRNA expression levels support high levels of editing. We also show that editing levels greatly differ between nascent pre-mRNA and mRNA in a cellular system, as well as in mouse tissues. Editing levels can increase or decrease from pre-mRNA to mRNA and can vary across editing targets and across tissues, showing that pre-mRNA processing is an important layer of editing regulation. Several lines of evidence suggest that the differences emerge during pre-mRNA splicing. Moreover, actinomycin D treatment of primary neuronal cells and editing level analysis suggests that regulation of editing levels also depends on transcription.
Collapse
Affiliation(s)
- Brigitta Szabo
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Therese C Mandl
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Bernhard Woldrich
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Gregor Diensthuber
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - David Martin
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael F Jantsch
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Konstantin Licht
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| |
Collapse
|
12
|
Schneider N, Steinberg R, Ben-David A, Valensi J, David-Kadoch G, Rosenwasser Z, Banin E, Levanon EY, Sharon D, Ben-Aroya S. A pipeline for identifying guide RNA sequences that promote RNA editing of nonsense mutations that cause inherited retinal diseases. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102130. [PMID: 38375504 PMCID: PMC10875612 DOI: 10.1016/j.omtn.2024.102130] [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] [Received: 03/01/2023] [Accepted: 01/24/2024] [Indexed: 02/21/2024]
Abstract
Adenosine deaminases acting on RNA (ADARs) are endogenous enzymes catalyzing the deamination of adenosines to inosines, which are then read as guanosines during translation. This ability to recode makes ADAR an attractive therapeutic tool to edit genetic mutations and reprogram genetic information at the mRNA level. Using the endogenous ADARs and guiding them to a selected target has promising therapeutic potential. Indeed, different studies have reported several site-directed RNA-editing approaches for making targeted base changes in RNA molecules. The basic strategy has been to use guide RNAs (gRNAs) that hybridize and form a double-stranded RNA (dsRNA) structure with the desired RNA target because of ADAR activity in regions of dsRNA formation. Here we report on a novel pipeline for identifying disease-causing variants as candidates for RNA editing, using a yeast-based screening system to select efficient gRNAs for editing of nonsense mutations, and test them in a human cell line reporter system. We have used this pipeline to modify the sequence of transcripts carrying nonsense mutations that cause inherited retinal diseases in the FAM161A, KIZ, TRPM1, and USH2A genes. Our approach can serve as a basis for gene therapy intervention in knockin mouse models and ultimately in human patients.
Collapse
Affiliation(s)
- Nina Schneider
- Division of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Ricky Steinberg
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| | - Amit Ben-David
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| | - Johanna Valensi
- Division of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Galit David-Kadoch
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| | - Zohar Rosenwasser
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| | - Eyal Banin
- Division of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Erez Y. Levanon
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| | - Dror Sharon
- Division of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Shay Ben-Aroya
- The Nano Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 206, Room B-840, Ramat Gan 52900, Israel
| |
Collapse
|
13
|
Zheng YY, Reddy K, Vangaveti S, Sheng J. Inosine-Induced Base Pairing Diversity during Reverse Transcription. ACS Chem Biol 2024; 19:348-356. [PMID: 38252964 PMCID: PMC10877575 DOI: 10.1021/acschembio.3c00555] [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: 09/08/2023] [Revised: 11/27/2023] [Accepted: 01/10/2024] [Indexed: 01/24/2024]
Abstract
A-to-I editing catalyzed by adenosine deaminase acting on RNAs impacts numerous physiological and biochemical processes that are essential for cellular functions and is a big contributor to the infectivity of certain RNA viruses. The outcome of this deamination leads to changes in the eukaryotic transcriptome functionally resembling A-G transitions since inosine preferentially pairs with cytosine. Moreover, hyper-editing or multiple A to G transitions in clusters were detected in measles virus. Inosine modifications either directly on viral RNA or on cellular RNA can have antiviral or pro-viral repercussions. While many of the significant roles of inosine in cellular RNAs are well understood, the effects of hyper-editing of A to I on viral polymerase activity during RNA replication remain elusive. Moreover, biological strategies such as molecular cloning and RNA-seq for transcriptomic interrogation rely on RT-polymerase chain reaction with little to no emphasis placed on the first step, reverse transcription, which may reshape the sequencing results when hypermodification is present. In this study, we systematically explore the influence of inosine modification, varying the number and position of inosines, on decoding outcomes using three different reverse transcriptases (RTs) followed by standard Sanger sequencing. We find that inosine alone or in clusters can differentially affect the RT activity. To gain structural insights into the accommodation of inosine in the polymerase site of HIV-1 reverse transcriptase (HIV-1-RT) and how this structural context affects the base pairing rules for inosine, we performed molecular dynamics simulations of the HIV-1-RT. The simulations highlight the importance of the protein-nucleotide interaction as a critical factor in deciphering the base pairing behavior of inosine clusters. This effort sets the groundwork for decrypting the physiological significance of inosine and linking the fidelity of reverse transcriptase and the possible diverse transcription outcomes of cellular RNAs and/or viral RNAs where hyper-edited inosines are present in the transcripts.
Collapse
Affiliation(s)
- Ya Ying Zheng
- Department
of Chemistry, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
- The
RNA Institute, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
| | - Kaalak Reddy
- The
RNA Institute, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
| | - Sweta Vangaveti
- The
RNA Institute, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
| | - Jia Sheng
- Department
of Chemistry, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
- The
RNA Institute, University at Albany, State
University of New York, 1400 Washington Avenue, Albany, New York 12222, United States
| |
Collapse
|
14
|
Li J, Li C, Xu W. Liver cancer-specific mutations in functional domains of ADAR2 lead to the elevation of coding and non-coding RNA editing in multiple tumor-related genes. Mol Genet Genomics 2024; 299:1. [PMID: 38170228 DOI: 10.1007/s00438-023-02091-5] [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] [Received: 08/24/2023] [Accepted: 10/17/2023] [Indexed: 01/05/2024]
Abstract
Mutation is the major cause of phenotypic innovations. Apart from DNA mutations, the alteration on RNA such as the ADAR-mediated A-to-I RNA editing could also shape the phenotype. These two layers of variations have not been systematically combined to study their collective roles in cancers. We collected the high-quality transcriptomes of ten hepatocellular carcinoma (HCC) and the matched control samples. We systematically identified HCC-specific mutations in the exonic regions and profiled the A-to-I RNA editome in each sample. All ten HCC samples had mutations in the CDS of ADAR2 gene (dsRNA-binding domain or catalytic domain). The consequence of these mutations converged to the elevation of ADAR2 efficiency as reflected by the global increase of RNA editing levels in HCC. The up-regulated editing sites (UES) were enriched in the CDS and UTR of oncogenes and tumor suppressor genes (TSG), indicating the possible roles of these target genes in HCC oncogenesis. We present the mutation-ADAR2-UES-oncogene/TSG-HCC axis that explains how mutations at different layers would finally lead to abnormal phenotype. In the light of central dogma, our work provides novel insights into how to fully take advantage of the transcriptome data to decipher the consequence of mutations.
Collapse
Affiliation(s)
- Jian Li
- Department of Molecular Imaging and Nuclear Medicine, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China
| | - Chaowei Li
- Department of PET/CT, The Second Clinical Medical College of Qingdao University (Qingdao Center Hospital), Qingdao, 266042, China
| | - Wengui Xu
- Department of Molecular Imaging and Nuclear Medicine, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China.
| |
Collapse
|
15
|
Mulroney TE, Pöyry T, Yam-Puc JC, Rust M, Harvey RF, Kalmar L, Horner E, Booth L, Ferreira AP, Stoneley M, Sawarkar R, Mentzer AJ, Lilley KS, Smales CM, von der Haar T, Turtle L, Dunachie S, Klenerman P, Thaventhiran JED, Willis AE. N 1-methylpseudouridylation of mRNA causes +1 ribosomal frameshifting. Nature 2024; 625:189-194. [PMID: 38057663 PMCID: PMC10764286 DOI: 10.1038/s41586-023-06800-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 10/31/2023] [Indexed: 12/08/2023]
Abstract
In vitro-transcribed (IVT) mRNAs are modalities that can combat human disease, exemplified by their use as vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). IVT mRNAs are transfected into target cells, where they are translated into recombinant protein, and the biological activity or immunogenicity of the encoded protein exerts an intended therapeutic effect1,2. Modified ribonucleotides are commonly incorporated into therapeutic IVT mRNAs to decrease their innate immunogenicity3-5, but their effects on mRNA translation fidelity have not been fully explored. Here we demonstrate that incorporation of N1-methylpseudouridine into mRNA results in +1 ribosomal frameshifting in vitro and that cellular immunity in mice and humans to +1 frameshifted products from BNT162b2 vaccine mRNA translation occurs after vaccination. The +1 ribosome frameshifting observed is probably a consequence of N1-methylpseudouridine-induced ribosome stalling during IVT mRNA translation, with frameshifting occurring at ribosome slippery sequences. However, we demonstrate that synonymous targeting of such slippery sequences provides an effective strategy to reduce the production of frameshifted products. Overall, these data increase our understanding of how modified ribonucleotides affect the fidelity of mRNA translation, and although there are no adverse outcomes reported from mistranslation of mRNA-based SARS-CoV-2 vaccines in humans, these data highlight potential off-target effects for future mRNA-based therapeutics and demonstrate the requirement for sequence optimization.
Collapse
Affiliation(s)
| | - Tuija Pöyry
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | | | - Maria Rust
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | | | - Lajos Kalmar
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Emily Horner
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Lucy Booth
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | | | - Mark Stoneley
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | | | | | - Kathryn S Lilley
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - C Mark Smales
- School of Biosciences, Division of Natural Sciences, University of Kent, Canterbury, UK
- National Institute for Bioprocessing Research and Training, University College Dublin, Foster Avenue, Mount Merrion, Dublin, Ireland
| | - Tobias von der Haar
- School of Biosciences, Division of Natural Sciences, University of Kent, Canterbury, UK
| | - Lance Turtle
- NIHR Health Protection Research Unit for Emerging and Zoonotic Infections, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Susanna Dunachie
- NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- NDM Centre for Global Health Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Paul Klenerman
- NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Translational Gastroenterology Unit, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK.
| |
Collapse
|
16
|
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
The 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.
Collapse
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
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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: 13] [Impact Index Per Article: 13.0] [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.
Collapse
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.
| |
Collapse
|
19
|
Sun H, Li K, Liu C, Yi C. Regulation and functions of non-m 6A mRNA modifications. Nat Rev Mol Cell Biol 2023; 24:714-731. [PMID: 37369853 DOI: 10.1038/s41580-023-00622-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2023] [Indexed: 06/29/2023]
Abstract
Nucleobase modifications are prevalent in eukaryotic mRNA and their discovery has resulted in the emergence of epitranscriptomics as a research field. The most abundant internal (non-cap) mRNA modification is N6-methyladenosine (m6A), the study of which has revolutionized our understanding of post-transcriptional gene regulation. In addition, numerous other mRNA modifications are gaining great attention because of their major roles in RNA metabolism, immunity, development and disease. In this Review, we focus on the regulation and function of non-m6A modifications in eukaryotic mRNA, including pseudouridine (Ψ), N6,2'-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), inosine, 5-methylcytidine (m5C), N4-acetylcytidine (ac4C), 2'-O-methylated nucleotide (Nm) and internal N7-methylguanosine (m7G). We highlight their regulation, distribution, stoichiometry and known roles in mRNA metabolism, such as mRNA stability, translation, splicing and export. We also discuss their biological consequences in physiological and pathological processes. In addition, we cover research techniques to further study the non-m6A mRNA modifications and discuss their potential future applications.
Collapse
Affiliation(s)
- Hanxiao Sun
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Kai Li
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Cong Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
- Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
| |
Collapse
|
20
|
Margvelani G, Welden JR, Maquera AA, Van Eyk JE, Murray C, Miranda Sardon SC, Stamm S. Influence of FTDP-17 mutants on circular Tau RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.08.556913. [PMID: 37786725 PMCID: PMC10541600 DOI: 10.1101/2023.09.08.556913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
At least 53 mutations in the microtubule associated protein tau gene (MAPT) have been identified that cause frontotemporal dementia. 47 of these mutations are localized between exons 7 and 13. They could thus affect the formation of circular RNAs (circRNAs) from the MAPT gene that occur through backsplicing from exon 12 to either exon 10 or exon 7. We analyzed representative mutants and found that five FTDP-17 mutations increase the formation of 12➔7 circRNA and three different mutations increase the amount of 12➔10 circRNA. CircRNAs are translated after undergoing adenosine to inosine RNA editing, catalyzed by ADAR enzymes. We found that the interferon induced ADAR1-p150 isoform has the strongest effect on circTau RNA translation. ADAR1-p150 activity had a stronger effect on circTau RNA expression and strongly decreased 12➔7 circRNA, but unexpectedly increased 12➔10 circRNA. In both cases, ADAR-activity strongly promoted translation of circTau RNAs. Unexpectedly, we found that the 12➔7 circTau protein interacts with eukaryotic initiation factor 4B (eIF4B), which is reduced by four FTDP-17 mutations located in the second microtubule domain. These are the first studies of the effect of human mutations on circular RNA formation and translation. They show that point mutations influence circRNA expression levels, likely through changes in the secondary pre-mRNA structures. The effect of the mutations is surpassed by editing of the circular RNAs, leading to their translation. Thus, circular RNAs and their editing status should be considered when analyzing FTDP-17 mutations. Highlights 47/53 known FTDP-17 mutations are located in regions that could influence generation of circular RNAs from the MAPT geneCircular Tau RNAs are translated after adenosine to inosine RNA editing, most effectively caused by ADAR1-p150FTDP-17 mutations influence both circTau RNA and circTau protein expression levelsCircTau protein expression levels do not correlate with circTau RNA expression levelsCircTau proteins bind to eukaryotic initiation factor 4B, which is antagonized by FTDP-17 mutations in exon 10. Graphic Abstract
Collapse
|
21
|
Datta R, Adamska JZ, Bhate A, Li JB. A-to-I RNA editing by ADAR and its therapeutic applications: From viral infections to cancer immunotherapy. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 15:e1817. [PMID: 37718249 PMCID: PMC10947335 DOI: 10.1002/wrna.1817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
ADAR deaminases catalyze adenosine-to-inosine (A-to-I) editing on double-stranded RNA (dsRNA) substrates that regulate an umbrella of biological processes. One of the two catalytically active ADAR enzymes, ADAR1, plays a major role in innate immune responses by suppression of RNA sensing pathways which are orchestrated through the ADAR1-dsRNA-MDA5 axis. Unedited immunogenic dsRNA substrates are potent ligands for the cellular sensor MDA5. Upon activation, MDA5 leads to the induction of interferons and expression of hundreds of interferon-stimulated genes with potent antiviral activity. In this way, ADAR1 acts as a gatekeeper of the RNA sensing pathway by striking a fine balance between innate antiviral responses and prevention of autoimmunity. Reduced editing of immunogenic dsRNA by ADAR1 is strongly linked to the development of common autoimmune and inflammatory diseases. In viral infections, ADAR1 exhibits both antiviral and proviral effects. This is modulated by both editing-dependent and editing-independent functions, such as PKR antagonism. Several A-to-I RNA editing events have been identified in viruses, including in the insidious viral pathogen, SARS-CoV-2 which regulates viral fitness and infectivity, and could play a role in shaping viral evolution. Furthermore, ADAR1 is an attractive target for immuno-oncology therapy. Overexpression of ADAR1 and increased dsRNA editing have been observed in several human cancers. Silencing ADAR1, especially in cancers that are refractory to immune checkpoint inhibitors, is a promising therapeutic strategy for cancer immunotherapy in conjunction with epigenetic therapy. The mechanistic understanding of dsRNA editing by ADAR1 and dsRNA sensing by MDA5 and PKR holds great potential for therapeutic applications. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Disease.
Collapse
Affiliation(s)
- Rohini Datta
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Julia Z Adamska
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Amruta Bhate
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
22
|
Redhead C, Taye N, Hubmacher D. En route towards a personalized medicine approach: Innovative therapeutic modalities for connective tissue disorders. Matrix Biol 2023; 122:46-54. [PMID: 37657665 PMCID: PMC10529529 DOI: 10.1016/j.matbio.2023.08.005] [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: 06/28/2023] [Revised: 08/25/2023] [Accepted: 08/27/2023] [Indexed: 09/03/2023]
Abstract
Connective tissue disorders can be caused by pathogenic variants (mutations) in genes encoding extracellular matrix (ECM) proteins. Such disorders typically manifest during development or postnatal growth and result in significant morbidity and mortality. The development of curative treatments for connective tissue disorders is hampered in part by the inability of many mature connective tissues to efficiently regenerate. To be most effective, therapeutic strategies designed to preserve or restore tissue function will likely need to be initiated during phases of significant endogenous connective tissue remodeling and organ sculpting postnatally and directly target the underlying ECM protein mutations. With recent advances in whole exome sequencing, in-vitro and in-vivo disease modeling, and the development of mutation-specific molecular therapeutic modalities, it is now feasible to directly correct disease-causing mutations underlying connective tissue disorders and ameliorate their pathogenic consequences. These technological advances may lead to potentially curative personalized medicine approaches for connective tissue disorders that have previously been considered incurable. In this review, we highlight innovative therapeutic modalities including gene replacement, exon skipping, DNA/mRNA editing, and pharmacological approaches that were used to preserve or restore tissue function in the context of connective tissue disorders. Inherent to a successful application of these approaches is the need to deepen the understanding of mechanisms that regulate ECM formation and homeostasis, and to decipher how individual mutations in ECM proteins compromise ECM and connective tissue development and function.
Collapse
Affiliation(s)
- Charlene Redhead
- Orthopedic Research Laboratories, Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Nandaraj Taye
- Orthopedic Research Laboratories, Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dirk Hubmacher
- Orthopedic Research Laboratories, Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| |
Collapse
|
23
|
Liang Z, Goradia A, Walkley CR, Heraud-Farlow JE. Generation of a new Adar1p150 -/- mouse demonstrates isoform-specific roles in embryonic development and adult homeostasis. RNA (NEW YORK, N.Y.) 2023; 29:1325-1338. [PMID: 37290963 PMCID: PMC10573302 DOI: 10.1261/rna.079509.122] [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: 11/07/2022] [Accepted: 05/09/2023] [Indexed: 06/10/2023]
Abstract
The RNA editing enzyme adenosine deaminase acting on RNA 1 (ADAR1) is an essential regulator of the innate immune response to both cellular and viral double-stranded RNA (dsRNA). Adenosine-to-inosine (A-to-I) editing by ADAR1 modifies the sequence and structure of endogenous dsRNA and masks it from the cytoplasmic dsRNA sensor melanoma differentiation-associated protein 5 (MDA5), preventing innate immune activation. Loss-of-function mutations in ADAR are associated with rare autoinflammatory disorders including Aicardi-Goutières syndrome (AGS), defined by a constitutive systemic up-regulation of type I interferon (IFN). The murine Adar gene encodes two protein isoforms with distinct functions: ADAR1p110 is constitutively expressed and localizes to the nucleus, whereas ADAR1p150 is primarily cytoplasmic and is inducible by IFN. Recent studies have demonstrated the critical requirement for ADAR1p150 to suppress innate immune activation by self dsRNAs. However, detailed in vivo characterization of the role of ADAR1p150 during development and in adult mice is lacking. We identified a new ADAR1p150-specific knockout mouse mutant based on a single nucleotide deletion that resulted in the loss of the ADAR1p150 protein without affecting ADAR1p110 expression. The Adar1p150 -/- died embryonically at E11.5-E12.5 accompanied by cell death in the fetal liver and an activated IFN response. Somatic loss of ADAR1p150 in adults was lethal and caused rapid hematopoietic failure, demonstrating an ongoing requirement for ADAR1p150 in vivo. The generation and characterization of this mouse model demonstrates the essential role of ADAR1p150 in vivo and provides a new tool for dissecting the functional differences between ADAR1 isoforms and their physiological contributions.
Collapse
Affiliation(s)
- Zhen Liang
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Ankita Goradia
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Carl R Walkley
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Jacki E Heraud-Farlow
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| |
Collapse
|
24
|
Schroader JH, Handley MT, Reddy K. Inosine triphosphate pyrophosphatase: A guardian of the cellular nucleotide pool and potential mediator of RNA function. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1790. [PMID: 37092460 DOI: 10.1002/wrna.1790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 03/20/2023] [Indexed: 04/25/2023]
Abstract
Inosine triphosphate pyrophosphatase (ITPase), encoded by the ITPA gene in humans, is an important enzyme that preserves the integrity of cellular nucleotide pools by hydrolyzing the noncanonical purine nucleotides (deoxy)inosine and (deoxy)xanthosine triphosphate into monophosphates and pyrophosphate. Variants in the ITPA gene can cause partial or complete ITPase deficiency. Partial ITPase deficiency is benign but clinically relevant as it is linked to altered drug responses. Complete ITPase deficiency causes a severe multisystem disorder characterized by seizures and encephalopathy that is frequently associated with fatal infantile dilated cardiomyopathy. In the absence of ITPase activity, its substrate noncanonical nucleotides have the potential to accumulate and become aberrantly incorporated into DNA and RNA. Hence, the pathophysiology of ITPase deficiency could arise from metabolic imbalance, altered DNA or RNA regulation, or from a combination of these factors. Here, we review the known functions of ITPase and highlight recent work aimed at determining the molecular basis for ITPA-associated pathogenesis which provides evidence for RNA dysfunction. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
Collapse
Affiliation(s)
- Jacob H Schroader
- The RNA Institute, University at Albany, State University of New York, Albany, New York, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Mark T Handley
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Kaalak Reddy
- The RNA Institute, University at Albany, State University of New York, Albany, New York, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| |
Collapse
|
25
|
Patrasso EA, Raikundalia S, Arango D. Regulation of the epigenome through RNA modifications. Chromosoma 2023; 132:231-246. [PMID: 37138119 PMCID: PMC10524150 DOI: 10.1007/s00412-023-00794-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 05/05/2023]
Abstract
Chemical modifications of nucleotides expand the complexity and functional properties of genomes and transcriptomes. A handful of modifications in DNA bases are part of the epigenome, wherein DNA methylation regulates chromatin structure, transcription, and co-transcriptional RNA processing. In contrast, more than 150 chemical modifications of RNA constitute the epitranscriptome. Ribonucleoside modifications comprise a diverse repertoire of chemical groups, including methylation, acetylation, deamination, isomerization, and oxidation. Such RNA modifications regulate all steps of RNA metabolism, including folding, processing, stability, transport, translation, and RNA's intermolecular interactions. Initially thought to influence all aspects of the post-transcriptional regulation of gene expression exclusively, recent findings uncovered a crosstalk between the epitranscriptome and the epigenome. In other words, RNA modifications feedback to the epigenome to transcriptionally regulate gene expression. The epitranscriptome achieves this feat by directly or indirectly affecting chromatin structure and nuclear organization. This review highlights how chemical modifications in chromatin-associated RNAs (caRNAs) and messenger RNAs (mRNAs) encoding factors involved in transcription, chromatin structure, histone modifications, and nuclear organization affect gene expression transcriptionally.
Collapse
Affiliation(s)
- Emmely A Patrasso
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Medical and Pharmaceutical Biotechnology Program, IMC University of Applied Sciences, Krems, Austria
| | - Sweta Raikundalia
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Daniel Arango
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, USA.
| |
Collapse
|
26
|
Wang F, Cao H, Xia Q, Liu Z, Wang M, Gao F, Xu D, Deng B, Diao Y, Kapranov P. Lessons from discovery of true ADAR RNA editing sites in a human cell line. BMC Biol 2023; 21:160. [PMID: 37468903 PMCID: PMC10357658 DOI: 10.1186/s12915-023-01651-w] [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: 01/23/2023] [Accepted: 06/20/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Conversion or editing of adenosine (A) into inosine (I) catalyzed by specialized cellular enzymes represents one of the most common post-transcriptional RNA modifications with emerging connection to disease. A-to-I conversions can happen at specific sites and lead to increase in proteome diversity and changes in RNA stability, splicing, and regulation. Such sites can be detected as adenine-to-guanine sequence changes by next-generation RNA sequencing which resulted in millions reported sites from multiple genome-wide surveys. Nonetheless, the lack of extensive independent validation in such endeavors, which is critical considering the relatively high error rate of next-generation sequencing, leads to lingering questions about the validity of the current compendiums of the editing sites and conclusions based on them. RESULTS Strikingly, we found that the current analytical methods suffer from very high false positive rates and that a significant fraction of sites in the public databases cannot be validated. In this work, we present potential solutions to these problems and provide a comprehensive and extensively validated list of A-to-I editing sites in a human cancer cell line. Our findings demonstrate that most of true A-to-I editing sites in a human cancer cell line are located in the non-coding transcripts, the so-called RNA 'dark matter'. On the other hand, many ADAR editing events occurring in exons of human protein-coding mRNAs, including those that can recode the transcriptome, represent false positives and need to be interpreted with caution. Nonetheless, yet undiscovered authentic ADAR sites that increase the diversity of human proteome exist and warrant further identification. CONCLUSIONS Accurate identification of human ADAR sites remains a challenging problem, particularly for the sites in exons of protein-coding mRNAs. As a result, genome-wide surveys of ADAR editome must still be accompanied by extensive Sanger validation efforts. However, given the vast number of unknown human ADAR sites, there is a need for further developments of the analytical techniques, potentially those that are based on deep learning solutions, in order to provide a quick and reliable identification of the editome in any sample.
Collapse
Affiliation(s)
- Fang Wang
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Huifen Cao
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China.
| | - Qiu Xia
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Ziheng Liu
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Ming Wang
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Fan Gao
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Dongyang Xu
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Bolin Deng
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Yong Diao
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China
| | - Philipp Kapranov
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, Xiamen, 361021, China.
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
| |
Collapse
|
27
|
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: 31] [Impact Index Per Article: 31.0] [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.
Collapse
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.
| |
Collapse
|
28
|
Jones JD, Franco MK, Smith TJ, Snyder LR, Anders AG, Ruotolo BT, Kennedy RT, Koutmou KS. Methylated guanosine and uridine modifications in S. cerevisiae mRNAs modulate translation elongation. RSC Chem Biol 2023; 4:363-378. [PMID: 37181630 PMCID: PMC10170649 DOI: 10.1039/d2cb00229a] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/15/2023] [Indexed: 02/22/2023] Open
Abstract
Chemical modifications to protein encoding messenger RNAs (mRNAs) influence their localization, translation, and stability within cells. Over 15 different types of mRNA modifications have been observed by sequencing and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) approaches. While LC-MS/MS is arguably the most essential tool available for studying analogous protein post-translational modifications, the high-throughput discovery and quantitative characterization of mRNA modifications by LC-MS/MS has been hampered by the difficulty of obtaining sufficient quantities of pure mRNA and limited sensitivities for modified nucleosides. We have overcome these challenges by improving the mRNA purification and LC-MS/MS pipelines. The methodologies we developed result in no detectable non-coding RNA modifications signals in our purified mRNA samples, quantify 50 ribonucleosides in a single analysis, and provide the lowest limit of detection reported for ribonucleoside modification LC-MS/MS analyses. These advancements enabled the detection and quantification of 13 S. cerevisiae mRNA ribonucleoside modifications and reveal the presence of four new S. cerevisiae mRNA modifications at low to moderate levels (1-methyguanosine, N2-methylguanosine, N2,N2-dimethylguanosine, and 5-methyluridine). We identified four enzymes that incorporate these modifications into S. cerevisiae mRNAs (Trm10, Trm11, Trm1, and Trm2, respectively), though our results suggest that guanosine and uridine nucleobases are also non-enzymatically methylated at low levels. Regardless of whether they are incorporated in a programmed manner or as the result of RNA damage, we reasoned that the ribosome will encounter the modifications that we detect in cells. To evaluate this possibility, we used a reconstituted translation system to investigate the consequences of modifications on translation elongation. Our findings demonstrate that the introduction of 1-methyguanosine, N2-methylguanosine and 5-methyluridine into mRNA codons impedes amino acid addition in a position dependent manner. This work expands the repertoire of nucleoside modifications that the ribosome must decode in S. cerevisiae. Additionally, it highlights the challenge of predicting the effect of discrete modified mRNA sites on translation de novo because individual modifications influence translation differently depending on mRNA sequence context.
Collapse
Affiliation(s)
- Joshua D Jones
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Monika K Franco
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
| | - Tyler J Smith
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Laura R Snyder
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Anna G Anders
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
| | - Kristin S Koutmou
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
| |
Collapse
|
29
|
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
| |
Collapse
|
30
|
Nakahama T, Kawahara Y. The RNA-editing enzyme ADAR1: a regulatory hub that tunes multiple dsRNA-sensing pathways. Int Immunol 2023; 35:123-133. [PMID: 36469491 DOI: 10.1093/intimm/dxac056] [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: 10/06/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that catalyzes adenosine-to-inosine conversions in double-stranded RNAs (dsRNAs). In mammals, ADAR1 is composed of two isoforms: a nuclear short p110 isoform and a cytoplasmic long p150 isoform. Whereas both isoforms contain right-handed dsRNA-binding and deaminase domains, ADAR1 p150 harbors a Zα domain that binds to left-handed dsRNAs, termed Z-RNAs. Myeloma differentiation-associated gene 5 (MDA5) sensing of endogenous dsRNAs as non-self leads to the induction of type I interferon (IFN)-stimulated genes, but recent studies revealed that ADAR1 p150-mediated RNA editing, but not ADAR1 p110, prevents this MDA5-mediated sensing. ADAR1 p150-specific RNA-editing sites are present and at least a Zα domain-Z-RNA interaction is required for this specificity. Mutations in the ADAR1 gene cause Aicardi-Goutières syndrome (AGS), an infant encephalopathy with type I IFN overproduction. Insertion of a point mutation in the Zα domain of the Adar1 gene induces AGS-like encephalopathy in mice, which is rescued by concurrent deletion of MDA5. This finding indicates that impaired ADAR1 p150-mediated RNA-editing is a mechanism underlying AGS caused by an ADAR1 mutation. ADAR1 p150 also prevents ZBP1 sensing of endogenous Z-RNA, which leads to programmed cell death, via the Zα domain and its RNA-editing activity. Furthermore, ADAR1 prevents protein kinase R (PKR) sensing of endogenous right-handed dsRNAs, which leads to translational shutdown and growth arrest. Thus, ADAR1 acts as a regulatory hub that blocks sensing of endogenous dsRNAs as non-self by multiple sensor proteins, both in RNA editing-dependent and -independent manners, and is a potential therapeutic target for diseases, especially cancer.
Collapse
Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
31
|
Autocatalytic base editing for RNA-responsive translational control. Nat Commun 2023; 14:1339. [PMID: 36906659 PMCID: PMC10008589 DOI: 10.1038/s41467-023-36851-z] [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: 07/01/2022] [Accepted: 02/20/2023] [Indexed: 03/13/2023] Open
Abstract
Genetic circuits that control transgene expression in response to pre-defined transcriptional cues would enable the development of smart therapeutics. To this end, here we engineer programmable single-transcript RNA sensors in which adenosine deaminases acting on RNA (ADARs) autocatalytically convert target hybridization into a translational output. Dubbed DART VADAR (Detection and Amplification of RNA Triggers via ADAR), our system amplifies the signal from editing by endogenous ADAR through a positive feedback loop. Amplification is mediated by the expression of a hyperactive, minimal ADAR variant and its recruitment to the edit site via an orthogonal RNA targeting mechanism. This topology confers high dynamic range, low background, minimal off-target effects, and a small genetic footprint. We leverage DART VADAR to detect single nucleotide polymorphisms and modulate translation in response to endogenous transcript levels in mammalian cells.
Collapse
|
32
|
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.
Collapse
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
| |
Collapse
|
33
|
The Repertoire of RNA Modifications Orchestrates a Plethora of Cellular Responses. Int J Mol Sci 2023; 24:ijms24032387. [PMID: 36768716 PMCID: PMC9916637 DOI: 10.3390/ijms24032387] [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: 12/31/2022] [Revised: 01/21/2023] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
Although a plethora of DNA modifications have been extensively investigated in the last decade, recent breakthroughs in molecular biology, including high throughput sequencing techniques, have enabled the identification of post-transcriptional marks that decorate RNAs; hence, epitranscriptomics has arisen. This recent scientific field aims to decode the regulatory layer of the transcriptome and set the ground for the detection of modifications in ribose nucleotides. Until now, more than 170 RNA modifications have been reported in diverse types of RNA that contribute to various biological processes, such as RNA biogenesis, stability, and transcriptional and translational accuracy. However, dysfunctions in the RNA-modifying enzymes that regulate their dynamic level can lead to human diseases and cancer. The present review aims to highlight the epitranscriptomic landscape in human RNAs and match the catalytic proteins with the deposition or deletion of a specific mark. In the current review, the most abundant RNA modifications, such as N6-methyladenosine (m6A), N5-methylcytosine (m5C), pseudouridine (Ψ) and inosine (I), are thoroughly described, their functional and regulatory roles are discussed and their contributions to cellular homeostasis are stated. Ultimately, the involvement of the RNA modifications and their writers, erasers, and readers in human diseases and cancer is also discussed.
Collapse
|
34
|
Ding JH, Chen MY, Xie NB, Xie C, Xiong N, He JG, Wang J, Guo C, Feng YQ, Yuan BF. Quantitative and site-specific detection of inosine modification in RNA by acrylonitrile labeling-mediated elongation stalling. Biosens Bioelectron 2023; 219:114821. [PMID: 36279821 DOI: 10.1016/j.bios.2022.114821] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/04/2022] [Accepted: 10/14/2022] [Indexed: 11/19/2022]
Abstract
RNA molecules contain diverse modifications that play crucial roles in a wide variety of biological processes. Inosine is one of the most prevalent modifications in RNA and dysregulation of inosine is correlated with many human diseases. Herein, we established an acrylonitrile labeling-mediated elongation stalling (ALES) method for quantitative and site-specific detection of inosine in RNA from biological samples. In ALES method, inosine is selectively cyanoethylated with acrylonitrile to form N1-cyanoethylinosine (ce1I) through a Michael addition reaction. The N1-cyanoethyl group of ce1I compromises the hydrogen bond between ce1I and other nucleobases, leading to the stalling of reverse transcription at original inosine site. This specific property of stalling at inosine site could be evaluated by subsequent real-time quantitative PCR (qPCR). With the proposed ALES method, we found the significantly increased level of inosine at position Chr1:63117284 of Ino80dos RNA of multiple tissues from sleep-deprived mice compared to the control mice. This is the first report on the investigation of inosine modification in sleep-deprived mice, which may open up new direction for deciphering insomnia from RNA modifications. In addition, we found the decreased level of inosine at GluA2 Q/R site (Chr4:157336723) in glioma tissues, indicating the decreased level of inosine at GluA2 Q/R site may serve as potential indicator for the diagnosis of glioma. Taken together, the proposed ALES method is capable of quantitative and site-specific detection of inosine in RNA, which provides a valuable tool to uncover the functions of inosine in human diseases.
Collapse
Affiliation(s)
- Jiang-Hui Ding
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China
| | - Meng-Yuan Chen
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China
| | - Neng-Bin Xie
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China; Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan, 430071, China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, 430071, China
| | - Conghua Xie
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, 430071, China
| | - Nanxiang Xiong
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, 430071, China
| | - Jin-Gang He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jie Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Cheng Guo
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, China
| | - Yu-Qi Feng
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China
| | - Bi-Feng Yuan
- School of Public Health, College of Chemistry and Molecular Sciences, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430072, China; Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan, 430071, China; Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, 430071, China.
| |
Collapse
|
35
|
Liu Y. Attenuation and Degeneration of SARS-CoV-2 Despite Adaptive Evolution. Cureus 2023; 15:e33316. [PMID: 36741655 PMCID: PMC9894646 DOI: 10.7759/cureus.33316] [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: 11/17/2022] [Accepted: 01/02/2023] [Indexed: 01/04/2023] Open
Abstract
The evolution of severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) has followed similar trends as other RNA viruses, such as human immunodeficiency virus type 1 and the influenza A virus. Rapid initial diversification was followed by strong competition and a rapid succession of dominant variants. Host-initiated RNA editing has been the primary mechanism for introducing mutations. A significant number of mutations detrimental to viral replication have been quickly purged. Fixed mutations are mostly diversifying mutations selected for host adaptation and immune evasion, with the latter accounting for the majority of the mutations. However, immune evasion often comes at the cost of functionality, and thus, optimal functionality is still far from being accomplished. Instead, selection for antibody-escaping variants and accumulation of near-neutral mutations have led to suboptimal codon usage and reduced replicative capacity, as demonstrated in non-respiratory cell lines. Beneficial adaptation of the virus includes reduced infectivity in lung tissues and increased tropism for the upper airway, resulting in shorter incubation periods, milder diseases, and more efficient transmission between people.
Collapse
Affiliation(s)
- Yingguang Liu
- Molecular and Cellular Sciences, Liberty University College of Osteopathic Medicine, Lynchburg, USA
| |
Collapse
|
36
|
Welden JR, Margvelani G, Arizaca Maquera KA, Gudlavalleti B, Miranda Sardón S, Campos A, Robil N, Lee D, Hernandez A, Wang WX, Di J, de la Grange P, Nelson P, Stamm S. RNA editing of microtubule-associated protein tau circular RNAs promotes their translation and tau tangle formation. Nucleic Acids Res 2022; 50:12979-12996. [PMID: 36533443 PMCID: PMC9825173 DOI: 10.1093/nar/gkac1129] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 10/06/2022] [Accepted: 11/09/2022] [Indexed: 12/23/2022] Open
Abstract
Aggregation of the microtubule-associated protein tau characterizes tauopathies, including Alzheimer's disease and frontotemporal lobar degeneration (FTLD-Tau). Gene expression regulation of tau is complex and incompletely understood. Here we report that the human tau gene (MAPT) generates two circular RNAs (circRNAs) through backsplicing of exon 12 to either exon 7 (12→7 circRNA) or exon 10 (12→10 circRNA). Both circRNAs lack stop codons. The 12→7 circRNA contains one start codon and is translated in a rolling circle, generating a protein consisting of multimers of the microtubule-binding repeats R1-R4. For the 12→10 circRNA, a start codon can be introduced by two FTLD-Tau mutations, generating a protein consisting of multimers of the microtubule-binding repeats R2-R4, suggesting that mutations causing FTLD may act in part through tau circRNAs. Adenosine to inosine RNA editing dramatically increases translation of circRNAs and, in the 12→10 circRNA, RNA editing generates a translational start codon by changing AUA to AUI. Circular tau proteins self-aggregate and promote aggregation of linear tau proteins. Our data indicate that adenosine to inosine RNA editing initiates translation of human circular tau RNAs, which may contribute to tauopathies.
Collapse
Affiliation(s)
| | - Giorgi Margvelani
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | | | - Bhavani Gudlavalleti
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Sandra C Miranda Sardón
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Alexandre Rosa Campos
- Sanford Burnham Prebys Medical Discovery Institute Proteomics Core, La Jolla, CA, USA
| | | | - Daniel C Lee
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA,Alzheimer's Disease Research Center Neuroscience, University of Kentucky, Lexington, KY, USA
| | | | - Wang-Xia Wang
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA,Alzheimer's Disease Research Center and Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY, USA
| | - Jing Di
- Alzheimer's Disease Research Center and Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA,Alzheimer's Disease Research Center and Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY, USA
| | | |
Collapse
|
37
|
L’ARNm et ses modifications chez les eucaryotes*. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2022. [DOI: 10.1016/j.banm.2022.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
38
|
Hertler J, Slama K, Schober B, Özrendeci Z, Marchand V, Motorin Y, Helm M. Synthesis of point-modified mRNA. Nucleic Acids Res 2022; 50:e115. [PMID: 36062567 PMCID: PMC9723659 DOI: 10.1093/nar/gkac719] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 07/20/2022] [Accepted: 08/15/2022] [Indexed: 12/24/2022] Open
Abstract
Synthetic mRNA has recently moved into the focus of therapeutic and vaccination efforts. Incorporation of modified nucleotides during in vitro transcription can improve translation and attenuate immunogenicity, but is limited to triphosphate nucleotides which are accepted by RNA polymerases, and their incorporation is either random or complete. In contrast, site-specific modification, herein termed 'point modification' in analogy to point mutations, holds significant technical challenge. We developed fundamental techniques for isolation of long, translatable and internally point-modified mRNAs. Enabling concepts include three-way-one-pot splint ligations, and isolation of mRNA by real-time elution from agarose gels. The use of blue light permitted visualization of mRNA in pre-stained gels without the photochemical damage associated with the use of hard UV-radiation. This allowed visualization of the mRNA through its migration in the agarose gel, which in turn, was a prerequisite for its recovery by electroelution into precast troughs. Co-eluting agarose particles were quantified and found to not be detrimental to mRNA translation in vitro. Translation of EGFP-coding mRNA into functional protein was quantified by incorporation of 35S-labelled methionine and by in-gel EGFP fluorescence. This enabled the functional analysis of point modifications, specifically of ribose methylations in the middle of a 1371 nt long mRNA.
Collapse
Affiliation(s)
- Jasmin Hertler
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Staudinger Weg 5, D-55128 Mainz, Germany
| | - Kaouthar Slama
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Staudinger Weg 5, D-55128 Mainz, Germany
| | - Benedikt Schober
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Staudinger Weg 5, D-55128 Mainz, Germany
| | - Zeynep Özrendeci
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Staudinger Weg 5, D-55128 Mainz, Germany
| | - Virginie Marchand
- IMoPA UMR7365 CNRS-UL, BioPole Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Yuri Motorin
- IMoPA UMR7365 CNRS-UL, BioPole Université de Lorraine, Vandœuvre-lès-Nancy, France
- Epitranscriptomics and RNA Sequencing (EpiRNA-Seq) Core Facility, UMS2008 IBSLor (CNRS-UL)/US40 (INSERM), Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Staudinger Weg 5, D-55128 Mainz, Germany
| |
Collapse
|
39
|
Li M, Yan C, Jiao Y, Xu Y, Bai C, Miao R, Jiang J, Liu J. Site-directed RNA editing by harnessing ADARs: advances and challenges. Funct Integr Genomics 2022; 22:1089-1103. [DOI: 10.1007/s10142-022-00910-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 11/04/2022]
|
40
|
Ramasamy S, Sahayasheela VJ, Sharma S, Yu Z, Hidaka T, Cai L, Thangavel V, Sugiyama H, Pandian GN. Chemical Probe-Based Nanopore Sequencing to Selectively Assess the RNA Modifications. ACS Chem Biol 2022; 17:2704-2709. [PMID: 36190780 DOI: 10.1021/acschembio.2c00221] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nanopore direct RNA sequencing (dRNA-Seq) reads reveal RNA modifications through consistent error profiles specific to a modified nucleobase. However, a null data set is required to identify actual RNA modification-associated errors for distinguishing it from confounding highly intrinsic sequencing errors. Here, we reveal that inosine creates a signature mismatch error in dRNA-Seq reads and obviates the need for a null data set by harnessing the selective reactivity of acrylonitrile for validating the presence of actual inosine modifications. Selective reactivity of acrylonitrile toward inosine altered multiple dRNA-Seq parameters like signal intensity and trace value. We also deduced the stoichiometry of inosine modification through deviation in signal intensity and trace value using this chemical biology approach. Furthermore, we devised Nano ICE-Seq, a protocol to overcome the low coverage issue associated with direct RNA sequencing. Taken together, our chemical probe-based approach may facilitate the knockout-free detection of disease-associated RNA modifications in clinical scenarios.
Collapse
Affiliation(s)
- Soundhar Ramasamy
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| | - Vinodh J Sahayasheela
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo Ku, Kyoto 606-8502, Japan
| | - Surbhi Sharma
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| | - Zutao Yu
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| | - Takuya Hidaka
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| | - Li Cai
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08855, United States of America
| | - Vaijayanthi Thangavel
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| | - Hiroshi Sugiyama
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan.,Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo Ku, Kyoto 606-8502, Japan
| | - Ganesh N Pandian
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo Ku, Kyoto 606-8501, Japan
| |
Collapse
|
41
|
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.
Collapse
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
| |
Collapse
|
42
|
Schroader JH, Jones LA, Meng R, Shorrock HK, Richardson J, Shaughnessy S, Lin Q, Begley T, Berglund J, Fuchs G, Handley M, Reddy K. Disease-associated inosine misincorporation into RNA hinders translation. Nucleic Acids Res 2022; 50:9306-9318. [PMID: 35979951 PMCID: PMC9458462 DOI: 10.1093/nar/gkac709] [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: 04/02/2022] [Revised: 07/08/2022] [Accepted: 08/06/2022] [Indexed: 12/24/2022] Open
Abstract
Failure to prevent accumulation of the non-canonical nucleotide inosine triphosphate (ITP) by inosine triphosphate pyrophosphatase (ITPase) during nucleotide synthesis results in misincorporation of inosine into RNA and can cause severe and fatal developmental anomalies in humans. While the biochemical activity of ITPase is well understood, the pathogenic basis of ITPase deficiency and the molecular and cellular consequences of ITP misincorporation into RNA remain cryptic. Here, we demonstrate that excess ITP in the nucleotide pool during in vitro transcription results in T7 polymerase-mediated inosine misincorporation in luciferase RNA. In vitro translation of inosine-containing luciferase RNA reduces resulting luciferase activity, which is only partly explained by reduced abundance of the luciferase protein produced. Using Oxford Nanopore Direct RNA sequencing, we reveal inosine misincorporation to be stochastic but biased largely towards misincorporation in place of guanosine, with evidence for misincorporation also in place of cytidine, adenosine and uridine. Inosine misincorporation into RNA is also detected in Itpa-null mouse embryonic heart tissue as an increase in relative variants compared with the wild type using Illumina RNA sequencing. By generating CRISPR/Cas9 rat H9c2 Itpa-null cardiomyoblast cells, we validate a translation defect in cells that accumulate inosine within endogenous RNA. Furthermore, we observe hindered cellular translation of transfected luciferase RNA containing misincorporated inosine in both wild-type and Itpa-null cells. We therefore conclude that inosine misincorporation into RNA perturbs translation, thus providing mechanistic insight linking ITPase deficiency, inosine accumulation and pathogenesis.
Collapse
Affiliation(s)
| | | | - Ryan Meng
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Hannah K Shorrock
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Jared I Richardson
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA,Department of Biochemistry and Molecular Biology, Center for NeuroGenetics, University of Florida, Gainesville, FL 32611, USA
| | - Sharon M Shaughnessy
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Qishan Lin
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA,RNA Epitranscriptomics & Proteomics Resource, University at Albany, Albany, NY 12222, USA
| | - Thomas J Begley
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA,Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA,RNA Epitranscriptomics & Proteomics Resource, University at Albany, Albany, NY 12222, USA
| | - J Andrew Berglund
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA,Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA,Department of Biochemistry and Molecular Biology, Center for NeuroGenetics, University of Florida, Gainesville, FL 32611, USA
| | - Gabriele Fuchs
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA,Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Mark T Handley
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Kaalak Reddy
- *To whom correspondence should be addressed. Tel: +1 518 442 1464;
| |
Collapse
|
43
|
Sinnamon JR, Jacobson ME, Yung JF, Fisk JR, Jeng S, McWeeney SK, Parmelee LK, Chan CN, Yee SP, Mandel G. Targeted RNA editing in brainstem alleviates respiratory dysfunction in a mouse model of Rett syndrome. Proc Natl Acad Sci U S A 2022; 119:e2206053119. [PMID: 35939700 PMCID: PMC9388114 DOI: 10.1073/pnas.2206053119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/27/2022] [Indexed: 12/26/2022] Open
Abstract
Rett syndrome is a neurological disease due to loss-of-function mutations in the transcription factor, Methyl CpG binding protein 2 (MECP2). Because overexpression of endogenous MECP2 also causes disease, we have exploited a targeted RNA-editing approach to repair patient mutations where levels of MECP2 protein will never exceed endogenous levels. Here, we have constructed adeno-associated viruses coexpressing a bioengineered wild-type ADAR2 catalytic domain (Editasewt) and either Mecp2-targeting or nontargeting gfp RNA guides. The viruses are introduced systemically into male mice containing a guanosine to adenosine mutation that eliminates MeCP2 protein and causes classic Rett syndrome in humans. We find that in the mutant mice injected with the Mecp2-targeting virus, the brainstem exhibits the highest RNA-editing frequency compared to other brain regions. The efficiency is sufficient to rescue MeCP2 expression and function in the brainstem of mice expressing the Mecp2-targeting virus. Correspondingly, we find that abnormal Rett-like respiratory patterns are alleviated, and survival is prolonged, compared to mice injected with the control gfp guide virus. The levels of RNA editing among most brain regions corresponds to the distribution of guide RNA rather than Editasewt. Our results provide evidence that a targeted RNA-editing approach can alleviate a hallmark symptom in a mouse model of human disease.
Collapse
Affiliation(s)
- John R. Sinnamon
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | | | - John F. Yung
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Jenna R. Fisk
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Sophia Jeng
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239
| | - Shannon K. McWeeney
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239
- Division of Bioinformatics and Computational Biology, Oregon Health and Science University, Portland, OR 97239
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health and Science University, Portland, OR 97239
- Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, OR 97239
| | - Lindsay K. Parmelee
- Integrated Pathology Core, Oregon National Primate Research Center, Beaverton, OR 97006
| | - Chi Ngai Chan
- Integrated Pathology Core, Oregon National Primate Research Center, Beaverton, OR 97006
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030
| | - Gail Mandel
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| |
Collapse
|
44
|
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: 34] [Impact Index Per Article: 17.0] [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.
Collapse
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.
| |
Collapse
|
45
|
Jain M, Weber A, Maly K, Manjaly G, Deek J, Tsvyetkova O, Stulić M, Toca‐Herrera JL, Jantsch MF. A-to-I RNA editing of Filamin A regulates cellular adhesion, migration and mechanical properties. FEBS J 2022; 289:4580-4601. [PMID: 35124883 PMCID: PMC9546289 DOI: 10.1111/febs.16391] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 12/23/2021] [Accepted: 02/04/2022] [Indexed: 02/06/2023]
Abstract
A-to-I RNA editing by ADARs is an abundant epitranscriptomic RNA-modification in metazoa. In mammals, Flna pre-mRNA harbours a single conserved A-to-I RNA editing site that introduces a Q-to-R amino acid change in Ig repeat 22 of the encoded protein. Previously, we showed that FLNA editing regulates smooth muscle contraction in the cardiovascular system and affects cardiac health. The present study investigates how ADAR2-mediated A-to-I RNA editing of Flna affects actin crosslinking, cell mechanics, cellular adhesion and cell migration. Cellular assays and AFM measurements demonstrate that the edited version of FLNA increases cellular stiffness and adhesion but impairs cell migration in both, mouse fibroblasts and human tumour cells. In vitro, edited FLNA leads to increased actin crosslinking, forming actin gels of higher stress resistance. Our study shows that Flna RNA editing is a novel regulator of cytoskeletal organisation, affecting the mechanical property and mechanotransduction of cells.
Collapse
Affiliation(s)
- Mamta Jain
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Andreas Weber
- Department of NanobiotechnologyInstitute for BiophysicsUniversity of Natural Resources and Life Sciences Vienna (BOKU)Austria
| | - Kathrin Maly
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Greeshma Manjaly
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Joanna Deek
- Department of Physics, Cellular Biophysics E27Technical University of MunichGarchingGermany
| | - Olena Tsvyetkova
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Maja Stulić
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - José L. Toca‐Herrera
- Department of NanobiotechnologyInstitute for BiophysicsUniversity of Natural Resources and Life Sciences Vienna (BOKU)Austria
| | - Michael F. Jantsch
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| |
Collapse
|
46
|
Chen JJ, You XJ, Li L, Xie NB, Ding JH, Yuan BF, Feng YQ. Single-Base Resolution Detection of Adenosine-to-Inosine RNA Editing by Endonuclease-Mediated Sequencing. Anal Chem 2022; 94:8740-8747. [PMID: 35678728 DOI: 10.1021/acs.analchem.2c01226] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RNA molecules contain diverse modifications that play crucial roles in a wide variety of biological processes. Adenosine-to-inosine (A-to-Ino) RNA editing is one of the most prevalent modifications among all types of RNA. Abnormal A-to-InoRNA editing has been demonstrated to be associated with many human diseases. Identification of A-to-Ino editing sites is indispensable to deciphering their biological roles. Herein, by employing the unique property of human endonuclease V (hEndoV), we proposed a hEndoV-mediated sequencing (hEndoV-seq) method for the single-base resolution detection of A-to-InoRNA editing sites. In this approach, the terminal 3'OH of RNA is first blocked by 3'-deoxyadenosine (3'-deoxy-A). Specific cleavage of Ino sites by hEndoV protein produces new terminal 3'OH, which can be identified by sequencing analysis, and therefore offers the site-specific detection of Ino in RNA. The principle of hEndoV-seq is straightforward and the analytical procedure is simple. No chemical reaction is involved in the sequencing library preparation. The whole procedure in hEndoV-seq is carried out under mild conditions and RNA is not prone to degradation. Taken together, the proposed hEndoV-seq method is capable of site-specific identification of A-to-Ino editing in RNA, which provides a valuable tool for elucidating the functions of A-to-Ino editing in RNA.
Collapse
Affiliation(s)
- Juan-Juan Chen
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Xue-Jiao You
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China.,School of Public Health, Wuhan University, Wuhan 430071, China
| | - Lin Li
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Neng-Bin Xie
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Jiang-Hui Ding
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Bi-Feng Yuan
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China.,School of Public Health, Wuhan University, Wuhan 430071, China.,Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan 430071, China
| | - Yu-Qi Feng
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China.,School of Public Health, Wuhan University, Wuhan 430071, China.,Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan 430071, China
| |
Collapse
|
47
|
Feng YJ, You XJ, Ding JH, Zhang YF, Yuan BF, Feng YQ. Identification of Inosine and 2'- O-Methylinosine Modifications in Yeast Messenger RNA by Liquid Chromatography-Tandem Mass Spectrometry Analysis. Anal Chem 2022; 94:4747-4755. [PMID: 35266699 DOI: 10.1021/acs.analchem.1c05292] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The discovery of reversible modifications in messenger RNA (mRNA) opens new research directions in RNA modification-mediated epigenetic regulation. Yeast is an extensively used model organism in molecular biology. Systematic investigation and profiling of modifications in yeast mRNA would promote our understanding of the physiological regulation mechanisms in yeast. However, due to the high abundance of ribosomal RNA (rRNA) and transfer RNA (tRNA) in total RNA, isolation of low abundance of mRNA frequently suffers from the contamination of rRNA and tRNA, which will lead to the false-positive determination and inaccurate quantification of modifications in mRNA. Therefore, obtaining high-purity mRNA is critical for precise determination and accurate quantification of modifications in mRNA, especially for studies that focus on discovering new ones. Herein, we proposed a successive orthogonal isolation method by combining polyT-based purification and agarose gel electrophoresis purification for extracting high-purity mRNA. With the extracted high-purity yeast mRNA, we systemically explored the modifications in yeast mRNA by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis. The results showed that in addition to the previously reported eight kinds of modifications, two novel modifications of inosine (Ino) and 2'-O-methylinosine (Im) were identified to be prevalent in yeast mRNA. It is worth noting that Im was reported for the first time, to the best of our knowledge, to exist in living organisms in the three domains of life. Moreover, we observed that the levels of 10 kinds of modifications including Ino and Im in yeast mRNA exhibited dynamic change at different growth stages of yeast cells. Furthermore, Im in mRNA showed a significant decrease while in response to H2O2 treatment. These results indicated that the two newly identified modifications in yeast mRNA were involved in yeast cell growth and response to environmental stress. Taken together, we reported two new modifications of Ino and Im in yeast mRNA, which expends the diversity of RNA modifications in yeast and also suggests new regulators for modulating yeast physiological functions.
Collapse
Affiliation(s)
- Ya-Jing Feng
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Xue-Jiao You
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Jiang-Hui Ding
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Yu-Fan Zhang
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Bi-Feng Yuan
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China.,School of Public Health, Wuhan University, Wuhan 430071, China
| | - Yu-Qi Feng
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University, Wuhan 430072, China.,School of Public Health, Wuhan University, Wuhan 430071, China
| |
Collapse
|
48
|
Dutta N, Deb I, Sarzynska J, Lahiri A. Inosine and its methyl derivatives: Occurrence, biogenesis, and function in RNA. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 169-170:21-52. [PMID: 35065168 DOI: 10.1016/j.pbiomolbio.2022.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 12/11/2021] [Accepted: 01/11/2022] [Indexed: 05/21/2023]
Abstract
Inosine is one of the most common post-transcriptional modifications. Since its discovery, it has been noted for its ability to contribute to non-Watson-Crick interactions within RNA. Rapidly accumulating evidence points to the widespread generation of inosine through hydrolytic deamination of adenosine to inosine by different classes of adenosine deaminases. Three naturally occurring methyl derivatives of inosine, i.e., 1-methylinosine, 2'-O-methylinosine and 1,2'-O-dimethylinosine are currently reported in RNA modification databases. These modifications are expected to lead to changes in the structure, folding, dynamics, stability and functions of RNA. The importance of the modifications is indicated by the strong conservation of the modifying enzymes across organisms. The structure, binding and catalytic mechanism of the adenosine deaminases have been well-studied, but the underlying mechanism of the catalytic reaction is not very clear yet. Here we extensively review the existing data on the occurrence, biogenesis and functions of inosine and its methyl derivatives in RNA. We also included the structural and thermodynamic aspects of these modifications in our review to provide a detailed and integrated discussion on the consequences of A-to-I editing in RNA and the contribution of different structural and thermodynamic studies in understanding its role in RNA. We also highlight the importance of further studies for a better understanding of the mechanisms of the different classes of deamination reactions. Further investigation of the structural and thermodynamic consequences and functions of these modifications in RNA should provide more useful information about their role in different diseases.
Collapse
Affiliation(s)
- Nivedita Dutta
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata, 700009, West Bengal, India
| | - Indrajit Deb
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata, 700009, West Bengal, India
| | - Joanna Sarzynska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Ansuman Lahiri
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata, 700009, West Bengal, India.
| |
Collapse
|
49
|
Chemical modifications to mRNA nucleobases impact translation elongation and termination. Biophys Chem 2022; 285:106780. [DOI: 10.1016/j.bpc.2022.106780] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/03/2022] [Accepted: 02/13/2022] [Indexed: 12/15/2022]
|
50
|
You XJ, Li L, Ji TT, Xie NB, Yuan BF, Feng YQ. 6-Thioguanine incorporates into RNA and induces adenosine-to-inosine editing in acute lymphoblastic leukemia cells. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.01.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|