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Yang Y, Okada S, Sakurai M. Adenosine-to-inosine RNA editing in neurological development and disease. RNA Biol 2021; 18:999-1013. [PMID: 33393416 DOI: 10.1080/15476286.2020.1867797] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adenosine-to-inosine (A-to-I) editing is one of the most prevalent post-transcriptional RNA modifications in metazoan. This reaction is catalysed by enzymes called adenosine deaminases acting on RNA (ADARs). RNA editing is involved in the regulation of protein function and gene expression. The numerous A-to-I editing sites have been identified in both coding and non-coding RNA transcripts. These editing sites are also found in various genes expressed in the central nervous system (CNS) and play an important role in neurological development and brain function. Aberrant regulation of RNA editing has been associated with the pathogenesis of neurological and psychiatric disorders, suggesting the physiological significance of RNA editing in the CNS. In this review, we discuss the current knowledge of editing on neurological disease and development.
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Affiliation(s)
- Yuxi Yang
- Research Institute for Biomedical Sciences, Tokyo University of Science, Noda-shi, Chiba, Japan
| | - Shunpei Okada
- Research Institute for Biomedical Sciences, Tokyo University of Science, Noda-shi, Chiba, Japan
| | - Masayuki Sakurai
- Research Institute for Biomedical Sciences, Tokyo University of Science, Noda-shi, Chiba, Japan
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Ohishi K, Maruyama T, Seki F, Takeda M. Marine Morbilliviruses: Diversity and Interaction with Signaling Lymphocyte Activation Molecules. Viruses 2019; 11:E606. [PMID: 31277275 PMCID: PMC6669707 DOI: 10.3390/v11070606] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/27/2019] [Accepted: 06/29/2019] [Indexed: 01/08/2023] Open
Abstract
Epidemiological reports of phocine distemper virus (PDV) and cetacean morbillivirus (CeMV) have accumulated since their discovery nearly 30 years ago. In this review, we focus on the interaction between these marine morbilliviruses and their major cellular receptor, the signaling lymphocyte activation molecule (SLAM). The three-dimensional crystal structure and homology models of SLAMs have demonstrated that 35 residues are important for binding to the morbillivirus hemagglutinin (H) protein and contribute to viral tropism. These 35 residues are essentially conserved among pinnipeds and highly conserved among the Caniformia, suggesting that PDV can infect these animals, but are less conserved among cetaceans. Because CeMV can infect various cetacean species, including toothed and baleen whales, the CeMV-H protein is postulated to have broader specificity to accommodate more divergent SLAM interfaces and may enable the virus to infect seals. In silico analysis of viral H protein and SLAM indicates that each residue of the H protein interacts with multiple residues of SLAM and vice versa. The integration of epidemiological, virological, structural, and computational studies should provide deeper insight into host specificity and switching of marine morbilliviruses.
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Affiliation(s)
- Kazue Ohishi
- Faculty of Engineering, Tokyo Polytechnic University, 1583, Iiyama, Atsugi, Kanagawa 243-0297, Japan.
| | - Tadashi Maruyama
- School of Marine Biosciences, Kitasato University, 1-15-1, Kitazato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Fumio Seki
- Department of Virology III, National Institute of Infectious Diseases, 4-7-1, Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Makoto Takeda
- Department of Virology III, National Institute of Infectious Diseases, 4-7-1, Gakuen, Musashimurayama, Tokyo 208-0011, Japan
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Di Guardo G, Mazzariol S. Cetacean Morbillivirus-Associated Pathology: Knowns and Unknowns. Front Microbiol 2016; 7:112. [PMID: 26903991 PMCID: PMC4744835 DOI: 10.3389/fmicb.2016.00112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 01/22/2016] [Indexed: 11/13/2022] Open
Abstract
The present minireview deals with the pathology of Cetacean Morbillivirus (CeMV) infection in free-ranging cetaceans. In this respect, while "classical" CeMV-associated lesions were observed in the lung, brain, and lymphoid tissues from striped dolphins (Stenella coeruleoalba) and pilot whales (Globicephala melas) which were victims of the 1990-1992 and 2006-2008 epidemics in the Western Mediterranean, an apparent reduction in CeMV neurovirulence, along with a different viral antigen's tissue and cell distribution, were found during the 2010-2011 and the 2013 outbreaks in the same area. Of remarkable concern are also the documented CeMV ability to induce maternally acquired infections in wild cetaceans, coupled with the progressively expanding geographic and host range of the virus in both Hemispheres, as well as in conjunction with the intriguing forms of "brain-only" morbilliviral infection increasingly reported in Mediterranean-striped dolphins. Future research in this area should address the virus-host interaction dynamics, with particular emphasis on the cell receptors specifying viral tissue tropism in relation to the different cetacean species and to their susceptibility to infection, as well as to the CeMV strains circulating worldwide.
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Affiliation(s)
| | - Sandro Mazzariol
- Department of Comparative Biomedicine and Food Hygiene, University of Padova Padova, Italy
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4
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Oldstone MBA. The Anatomy of a Career in Science. DNA Cell Biol 2016; 35:109-17. [PMID: 26836569 DOI: 10.1089/dna.2016.3232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michael B A Oldstone
- Viral-Immunobiology Laboratory, The Scripps Research Institute , La Jolla, California
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5
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George CX, John L, Samuel CE. An RNA editor, adenosine deaminase acting on double-stranded RNA (ADAR1). J Interferon Cytokine Res 2015; 34:437-46. [PMID: 24905200 DOI: 10.1089/jir.2014.0001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Adenosine deaminase acting on RNA1 (ADAR1) catalyzes the C6 deamination of adenosine (A) to produce inosine (I) in regions of RNA with double-stranded (ds) character. This process is known as A-to-I RNA editing. Alternative promoters drive the expression of the Adar1 gene and alternative splicing gives rise to transcripts that encode 2 ADAR1 protein size isoforms. ADAR1 p150 is an interferon (IFN)-inducible dsRNA adenosine deaminase found in the cytoplasm and nucleus, whereas ADAR1 p110 is constitutively expressed and nuclear in localization. Dependent on the duplex structure of the dsRNA substrate, deamination of adenosine by ADAR can be either highly site-selective or nonspecific. A-to-I editing can alter the stability of RNA structures and the coding of RNA as I is read as G instead of A by ribosomes during mRNA translation and by polymerases during RNA replication. A-to-I editing is of broad physiologic significance. Both the production and the action of IFNs, and hence the subsequent interaction of viruses with their hosts, are among the processes affected by A-to-I editing.
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Affiliation(s)
- Cyril X George
- Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California
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6
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Richetta C, Grégoire IP, Verlhac P, Azocar O, Baguet J, Flacher M, Tangy F, Rabourdin-Combe C, Faure M. Sustained autophagy contributes to measles virus infectivity. PLoS Pathog 2013; 9:e1003599. [PMID: 24086130 PMCID: PMC3784470 DOI: 10.1371/journal.ppat.1003599] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 07/17/2013] [Indexed: 01/06/2023] Open
Abstract
The interplay between autophagy and intracellular pathogens is intricate as autophagy is an essential cellular response to fight against infections, whereas numerous microbes have developed strategies to escape this process or even exploit it to their own benefit. The fine tuned timing and/or selective molecular pathways involved in the induction of autophagy upon infections could be the cornerstone allowing cells to either control intracellular pathogens, or be invaded by them. We report here that measles virus infection induces successive autophagy signallings in permissive cells, via distinct and uncoupled molecular pathways. Immediately upon infection, attenuated measles virus induces a first transient wave of autophagy, via a pathway involving its cellular receptor CD46 and the scaffold protein GOPC. Soon after infection, a new autophagy signalling is initiated which requires viral replication and the expression of the non-structural measles virus protein C. Strikingly, this second autophagy signalling can be sustained overtime within infected cells, independently of the expression of C, but via a third autophagy input resulting from cell-cell fusion and the formation of syncytia. Whereas this sustained autophagy signalling leads to the autophagy degradation of cellular contents, viral proteins escape from degradation. Furthermore, this autophagy flux is ultimately exploited by measles virus to limit the death of infected cells and to improve viral particle formation. Whereas CD150 dependent virulent strains of measles virus are unable to induce the early CD46/GOPC dependent autophagy wave, they induce and exploit the late and sustained autophagy. Overall, our work describes distinct molecular pathways for an induction of self-beneficial sustained autophagy by measles virus. Autophagy is an evolutionarily conserved lysosomal dependent degradative pathway for recycling of long-lived proteins and damaged organelles. Autophagy is also an essential cellular response to fight infection by destroying infectious pathogens trapped within autophagosomes and plays a key role in the induction of both innate and adaptive immune responses. Numerous viruses have evolved strategies to counteract autophagy in order to escape from degradation or/and to inhibit immune signals. The kinetic and molecular pathways involved in the induction of autophagy upon infections might determine if cells would be able to control pathogens or would be invaded by them. We showed that measles virus (MeV) infection induces successive autophagy signallings in cells via distinct molecular pathways. A first autophagy wave is induced by the engagement of the MeV cellular receptor CD46 and the scaffold protein GOPC. A second wave is initiated after viral replication by the expression of the non-structural MeV protein C and is sustained overtime within infected cells thanks to the formation of syncytia. This sustained autophagy is exploited by MeV to limit the death of infected cells and to improve viral particle formation. We describe new molecular pathways by which MeV hijacks autophagy to promote its infectivity.
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Affiliation(s)
- Clémence Richetta
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Isabel P. Grégoire
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Pauline Verlhac
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Olga Azocar
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Joël Baguet
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Monique Flacher
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Frédéric Tangy
- Unité de Génomique Virale et Vaccination, Institut Pasteur, CNRS URA-3015, Paris, France
| | - Chantal Rabourdin-Combe
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
| | - Mathias Faure
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France
- Inserm, U1111, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France
- CNRS, UMR5308, Lyon, France
- * E-mail:
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7
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Hardie DR, Albertyn C, Heckmann JM, Smuts HEM. Molecular characterisation of virus in the brains of patients with measles inclusion body encephalitis (MIBE). Virol J 2013; 10:283. [PMID: 24025157 PMCID: PMC3847183 DOI: 10.1186/1743-422x-10-283] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 09/09/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND During 2009/10 a major measles epidemic caused by genotype B3 occurred in South Africa. Measles inclusion body encephalitis (MIBE) was diagnosed in a number of highly immuno-compromised HIV patients. The diagnosis was based on typical clinical and MRI findings and positive measles virus PCR in brain or CSF.To characterize the brain virus, nucleoprotein, matrix, fusion and haemagglutinin genes from 4 cases was compared with virus from acutely infected patients. METHODS cDNA was synthesized using random primers and viral genes were amplified by nested RT-PCR. PCR products were sequenced in the forward and reverse direction and a contig of each gene was created. Sequences were aligned with reference sequences from GenBank and other local sequences. RESULTS Brain virus was very similar to the South African epidemic virus. Features characteristic of persistent measles virus in the brain were absent. Mutation frequency in brain virus was similar to epidemic virus and had the same substitution preference (U to C and C to U). The virus of 2 patients had the same L454W mutation in the fusion protein. CONCLUSION The brain virus was very similar to the epidemic strain. The relatively few mutations probably reflect the short time from infection to brain disease in these highly immuno-compromised patients.
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Affiliation(s)
- Diana R Hardie
- Division of Medical Virology, Department of Clinical Laboratory Sciences, University of Cape Town and National Health Laboratory Service, Cape Town, South Africa
| | - Christine Albertyn
- Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Jeannine M Heckmann
- Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Heidi EM Smuts
- Division of Medical Virology, Department of Clinical Laboratory Sciences, University of Cape Town and National Health Laboratory Service, Cape Town, South Africa
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8
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Experimental measles encephalitis in Lewis rats: dissemination of infected neuronal cell subtypes. J Neurovirol 2013; 19:461-70. [DOI: 10.1007/s13365-013-0199-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 08/05/2013] [Accepted: 08/09/2013] [Indexed: 12/11/2022]
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9
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Stress granule formation induced by measles virus is protein kinase PKR dependent and impaired by RNA adenosine deaminase ADAR1. J Virol 2012; 87:756-66. [PMID: 23115276 DOI: 10.1128/jvi.02270-12] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
ADAR1, an interferon (IFN)-inducible double-stranded (ds) RNA-specific adenosine deaminase, downregulates host innate responses, including activation of the dsRNA-dependent protein kinase (PKR) and induction of IFN-β mRNA. Conversely, PKR amplifies IFN-β induction by measles virus (MV) and inhibits virus protein synthesis. Formation of stress granules (SGs), cytoplasmic aggregates of stalled translation complexes and RNA-binding proteins, is a host response to virus infection mediated by translation initiation factor eIF2α phosphorylation. We examined the roles of PKR and ADAR1 in SG formation using HeLa cells stably deficient in either PKR (PKR(kd)) or ADAR1 (ADAR1(kd)) compared to control (CON(kd)) cells. Infection with either wild-type (WT) MV or an isogenic mutant lacking C protein expression (C(ko)) comparably induced formation of SG in ADAR1(kd) cells, whereas only the C(ko) mutant was an efficient inducer in control cells. Both ADAR1 and PKR colocalized with SG following infection. MV-induced; SG formation was PKR dependent but impaired by ADAR1. Complementation of ADAR1(kd) cells by expression of either p150 WT isoform or the p150 Zα (Y177A) Z-DNA-binding mutant of ADAR1 restored suppression of host responses, including SG formation and PKR activation. In contrast, neither the p110 WT isoform nor the p150 catalytic (H910A, E912A) mutant of ADAR1 complemented the ADAR1(kd) phenotype. These results further establish ADAR1 as a suppressor of host innate responses, including activation of PKR and the subsequent SG response.
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10
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Noyce RS, Richardson CD. Nectin 4 is the epithelial cell receptor for measles virus. Trends Microbiol 2012; 20:429-39. [PMID: 22721863 DOI: 10.1016/j.tim.2012.05.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/14/2012] [Accepted: 05/23/2012] [Indexed: 01/06/2023]
Abstract
Measles virus (MV) causes acute respiratory disease, infects lymphocytes and multiple organs, and produces immune suppression leading to secondary infections. In rare instances it can also cause persistent infections in the brain and central nervous system. Vaccine and laboratory-adapted strains of MV use CD46 as a receptor, whereas wild-type strains of MV (wtMV) cannot. Both vaccine and wtMV strains infect lymphocytes, monocytes, and dendritic cells (DCs) using the signaling lymphocyte activation molecule (CD150/SLAM). In addition, MV can infect the airway epithelial cells of the host. Nectin 4 (PVRL4) was recently identified as the epithelial cell receptor for MV. Coupled with recent observations made in MV-infected macaques, this discovery has led to a new paradigm for how the virus accesses the respiratory tract and exits the host. Nectin 4 is also a tumor cell marker which is highly expressed on the apical surface of many adenocarcinoma cell lines, making it a potential target for MV oncolytic therapy.
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Affiliation(s)
- Ryan S Noyce
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
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11
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Adenosine deaminase acting on RNA 1 (ADAR1) suppresses the induction of interferon by measles virus. J Virol 2012; 86:3787-94. [PMID: 22278222 DOI: 10.1128/jvi.06307-11] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
ADAR1, the interferon (IFN)-inducible adenosine deaminase acting on RNA, catalyzes the C-6 deamination of adenosine (A) to produce inosine (I) in RNA substrates with a double-stranded character. Because double-stranded RNA is a known inducer of IFN, we tested the role of ADAR1 in IFN induction following virus infection. HeLa cells made stably deficient in ADAR1 (ADAR1(kd)) were compared to vector control (CON(kd)) and protein kinase PKR-deficient (PKR(kd)) cells for IFN-β induction following infection with either parental (wild-type [WT]) recombinant Moraten vaccine strain measles virus (MV) or isogenic knockout mutants deficient for either V (V(ko)) or C (C(ko)) protein expression. We observed potent IFN-β transcript induction in ADAR1(kd) cells by all three viruses; in contrast, in ADAR1-sufficient CON(kd) cells, only the C(ko) mutant virus was an effective inducer and the IFN-β RNA induction was amplified by PKR. The enhanced IFN-β transcript-inducing capacity of the WT and V(ko) viruses seen in ADAR1-deficient cells correlated with the enhanced activation of PKR, IFN regulatory factor IRF3, and activator of transcription ATF2, reaching levels similar to those seen in C(ko) virus-infected cells. However, the level of IFN-β protein produced was not proportional to the level of IFN-β RNA but rather correlated inversely with the level of activated PKR. These results suggest that ADAR1 functions as an important suppressor of MV-mediated responses, including the activation of PKR and IRF3 and the induction of IFN-β RNA. Our findings further implicate a balanced interplay between PKR and ADAR1 in modulating IFN-β protein production following virus infection.
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12
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Abstract
Double-stranded RNA (dsRNA) functions both as a substrate of ADARs and also as a molecular trigger of innate immune responses. ADARs, adenosine deaminases that act on RNA, catalyze the deamination of adenosine (A) to produce inosine (I) in dsRNA. ADARs thereby can destablize RNA structures, because the generated I:U mismatch pairs are less stable than A:U base pairs. Additionally, I is read as G instead of A by ribosomes during translation and by viral RNA-dependent RNA polymerases during RNA replication. Members of several virus families have the capacity to produce dsRNA during viral genome transcription and replication. Sequence changes (A-G, and U-C) characteristic of A-I editing can occur during virus growth and persistence. Foreign viral dsRNA also mediates both the induction and the action of interferons. In this chapter our current understanding of the role and significance of ADARs in the context of innate immunity, and as determinants of the outcome of viral infection, will be considered.
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Affiliation(s)
- Charles E Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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13
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Host response to polyomavirus infection is modulated by RNA adenosine deaminase ADAR1 but not by ADAR2. J Virol 2011; 85:8338-47. [PMID: 21632755 DOI: 10.1128/jvi.02666-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) catalyze the C-6 deamination of adenosine (A) to produce inosine (I), which behaves as guanine (G), thereby altering base pairing in RNAs with double-stranded character. Two genes, adar1 and adar2, are known to encode enzymatically active ADARs in mammalian cells. Furthermore, two size forms of ADAR1 are expressed by alternative promoter usage, a short (p110) nuclear form that is constitutively made and a long (p150) form that is interferon inducible and present in both the cytoplasm and nucleus. ADAR2 is also a constitutively expressed nuclear protein. Extensive A-to-G substitution has been described in mouse polyomavirus (PyV) RNA isolated late times after infection, suggesting modification by ADAR. To test the role of ADAR in PyV infection, we used genetically null mouse embryo fibroblast cells deficient in either ADAR1 or ADAR2. The single-cycle yields and growth kinetics of PyV were comparable between adar1(-/-) and adar2(-/-) genetic null fibroblast cells. While large T antigen was expressed to higher levels in adar1(-/-) cells than adar2(-/-) cells, less difference was seen in VP1 protein expression levels between the two knockout MEFs. However, virus-induced cell killing was greatly enhanced in PyV-infected adar1(-/-) cells compared to that of adar2(-/-) cells. Complementation with p110 protected cells from PyV-induced cytotoxicity. UV-irradiated PyV did not display any enhanced cytopathic effect in adar1(-/-) cells. Reovirus and vesicular stomatitis virus single-cycle yields were comparable between adar1(-/-) and adar2(-/-) cells, and neither reovirus nor VSV showed enhanced cytotoxicity in adar1(-/-)-infected cells. These results suggest that ADAR1 plays a virus-selective role in the host response to infection.
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14
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Samuel CE. Adenosine deaminases acting on RNA (ADARs) are both antiviral and proviral. Virology 2011; 411:180-93. [PMID: 21211811 DOI: 10.1016/j.virol.2010.12.004] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 12/04/2010] [Indexed: 12/18/2022]
Abstract
A-to-I RNA editing, the deamination of adenosine (A) to inosine (I) that occurs in regions of RNA with double-stranded character, is catalyzed by a family of Adenosine Deaminases Acting on RNA (ADARs). In mammals there are three ADAR genes. Two encode proteins that possess demonstrated deaminase activity: ADAR1, which is interferon-inducible, and ADAR2 which is constitutively expressed. ADAR3, by contrast, has not yet been shown to be an active enzyme. The specificity of the ADAR1 and ADAR2 deaminases ranges from highly site-selective to non-selective, dependent on the duplex structure of the substrate RNA. A-to-I editing is a form of nucleotide substitution editing, because I is decoded as guanosine (G) instead of A by ribosomes during translation and by polymerases during RNA-dependent RNA replication. Additionally, A-to-I editing can alter RNA structure stability as I:U mismatches are less stable than A:U base pairs. Both viral and cellular RNAs are edited by ADARs. A-to-I editing is of broad physiologic significance. Among the outcomes of A-to-I editing are biochemical changes that affect how viruses interact with their hosts, changes that can lead to either enhanced or reduced virus growth and persistence depending upon the specific virus.
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Affiliation(s)
- Charles E Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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15
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Ward SV, George CX, Welch MJ, Liou LY, Hahm B, Lewicki H, de la Torre JC, Samuel CE, Oldstone MB. RNA editing enzyme adenosine deaminase is a restriction factor for controlling measles virus replication that also is required for embryogenesis. Proc Natl Acad Sci U S A 2011; 108:331-6. [PMID: 21173229 PMCID: PMC3017198 DOI: 10.1073/pnas.1017241108] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Measles virus (MV), a member of the family Paramyxoviridae and an exclusively human pathogen, is among the most infectious viruses. A progressive fatal neurodegenerative complication, subacute sclerosing panencephalitis (SSPE), occurs during persistent MV infection of the CNS and is associated with biased hypermutations of the viral genome. The observed hypermutations of A-to-G are consistent with conversions catalyzed by the adenosine deaminase acting on RNA (ADAR1). To evaluate the role of ADAR1 in MV infection, we selectively disrupted expression of the IFN-inducible p150 ADAR1 isoform and found it caused embryonic lethality at embryo day (E) 11-E12. We therefore generated p150-deficient and WT mouse embryo fibroblast (MEF) cells stably expressing the MV receptor signaling lymphocyte activation molecule (SLAM or CD150). The p150(-/-) but not WT MEF cells displayed extensive syncytium formation and cytopathic effect (CPE) following infection with MV, consistent with an anti-MV role of the p150 isoform of ADAR1. MV titers were 3 to 4 log higher in p150(-/-) cells compared with WT cells at 21 h postinfection, and restoration of ADAR1 in p150(-/-) cells prevented MV cytopathology. In contrast to infection with MV, p150 disruption had no effect on vesicular stomatitis virus, reovirus, or lymphocytic choriomeningitis virus replication but protected against CPE resulting from infection with Newcastle disease virus, Sendai virus, canine distemper virus, and influenza A virus. Thus, ADAR1 is a restriction factor in the replication of paramyxoviruses and orthomyxoviruses.
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Affiliation(s)
- Simone V. Ward
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Cyril X. George
- Department of Molecular, Cellular, and Developmental Biology and
| | - Megan J. Welch
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Li-Ying Liou
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Bumsuk Hahm
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
- Departments of Surgery and Molecular Microbiology and Immunology, University of Missouri, Columbia, MO 65212
| | - Hanna Lewicki
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Juan C. de la Torre
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Charles E. Samuel
- Department of Molecular, Cellular, and Developmental Biology and
- Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, CA 92106; and
| | - Michael B. Oldstone
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
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George CX, Gan Z, Liu Y, Samuel CE. Adenosine deaminases acting on RNA, RNA editing, and interferon action. J Interferon Cytokine Res 2010; 31:99-117. [PMID: 21182352 DOI: 10.1089/jir.2010.0097] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) catalyze adenosine (A) to inosine (I) editing of RNA that possesses double-stranded (ds) structure. A-to-I RNA editing results in nucleotide substitution, because I is recognized as G instead of A both by ribosomes and by RNA polymerases. A-to-I substitution can also cause dsRNA destabilization, as I:U mismatch base pairs are less stable than A:U base pairs. Three mammalian ADAR genes are known, of which two encode active deaminases (ADAR1 and ADAR2). Alternative promoters together with alternative splicing give rise to two protein size forms of ADAR1: an interferon-inducible ADAR1-p150 deaminase that binds dsRNA and Z-DNA, and a constitutively expressed ADAR1-p110 deaminase. ADAR2, like ADAR1-p110, is constitutively expressed and binds dsRNA. A-to-I editing occurs with both viral and cellular RNAs, and affects a broad range of biological processes. These include virus growth and persistence, apoptosis and embryogenesis, neurotransmitter receptor and ion channel function, pancreatic cell function, and post-transcriptional gene regulation by microRNAs. Biochemical processes that provide a framework for understanding the physiologic changes following ADAR-catalyzed A-to-I ( = G) editing events include mRNA translation by changing codons and hence the amino acid sequence of proteins; pre-mRNA splicing by altering splice site recognition sequences; RNA stability by changing sequences involved in nuclease recognition; genetic stability in the case of RNA virus genomes by changing sequences during viral RNA replication; and RNA-structure-dependent activities such as microRNA production or targeting or protein-RNA interactions.
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Affiliation(s)
- Cyril X George
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA
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George CX, Das S, Samuel CE. Organization of the mouse RNA-specific adenosine deaminase Adar1 gene 5'-region and demonstration of STAT1-independent, STAT2-dependent transcriptional activation by interferon. Virology 2008; 380:338-43. [PMID: 18774582 PMCID: PMC2628478 DOI: 10.1016/j.virol.2008.07.029] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 06/27/2008] [Accepted: 07/25/2008] [Indexed: 12/24/2022]
Abstract
The p150 form of the RNA-specific adenosine deaminase ADAR1 is interferon-inducible and catalyzes A-to-I editing of viral and cellular RNAs. We have characterized mouse genomic clones containing the promoter regions required for Adar1 gene transcription and analyzed interferon induction of the p150 protein using mutant mouse cell lines. Transient transfection analyses using reporter constructs led to the identification of three promoters, one interferon-inducible (P(A)) and two constitutively active (P(B) and P(C)). The TATA-less P(A) promoter, characterized by the presence of a consensus ISRE element and a PKR kinase KCS-like element, directed interferon-inducible reporter expression in rodent and human cells. Interferon induction of p150 was impaired in mouse cells deficient in IFNAR receptor, JAK1 kinase or STAT2 but not STAT1. Whereas Adar1 gene organization involving multiple promoters and alternative exon 1 structures was highly preserved, sequences of the promoters and exon 1 structures were not well conserved between human and mouse.
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Affiliation(s)
- Cyril X. George
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106
| | - Sonali Das
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106
| | - Charles E. Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106
- Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, CA 93106
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