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Li H, Liu H, Zhu D, Dou C, Gang B, Zhang M, Wan Z. Biological function molecular pathways and druggability of DNMT2/TRDMT1. Pharmacol Res 2024; 205:107222. [PMID: 38782147 DOI: 10.1016/j.phrs.2024.107222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024]
Abstract
5-methylcytosine (m5C) is among the most common epigenetic modification in DNA and RNA molecules, and plays an important role in the animal development and disease pathogenesis. Interestingly, unlike other m5C DNA methyltransferases (DNMTs), DNMT2/TRDMT1 has the double-substrate specificity and adopts a DNMT-similar catalytic mechanism to methylate RNA. Moreover, it is widely involved in a variety of physiological regulatory processes, such as the gene expression, precise protein synthesis, immune response, and disease occurrence. Thus, comprehending the epigenetic mechanism and function of DNMT2/TRDMT1 will probably provide new strategies to treat some refractory diseases. Here, we discuss recent studies on the spatiotemporal expression pattern and post-translational modifications of DNMT2/TRDMT1, and summarize the research advances in substrate characteristics, catalytic recognition mechanism, DNMT2/TRDMT1-related genes or proteins, pharmacological application, and inhibitor development. This review will shed light on the pharmacological design by targeting DNMT2/TRDMT1 to treat parasitic, viral and oncologic diseases.
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Affiliation(s)
- Huari Li
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China; College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei Province 430070, PR China.
| | - Huiru Liu
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China
| | - Daiyun Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei Province 430070, PR China; State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Chengli Dou
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China
| | - Baocai Gang
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China
| | - Mengjie Zhang
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China
| | - Ziyu Wan
- Department of Biochemistry and Molecular Biology, College of Laboratory Medicine, Anhui Province Key Laboratory of Cancer Translational Medicine, and The First Affiliated Hospital of Bengbu Medical University, Bengbu Medical University, No.2600 Donghai Avenue, Bengbu, Anhui Province 233030, PR China
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2
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Watson KJ, Bromley RE, Sparklin BC, Gasser MT, Bhattacharya T, Lebov JF, Tyson T, Dai N, Teigen LE, Graf KT, Foster JM, Michalski M, Bruno VM, Lindsey AR, Corrêa IR, Hardy RW, Newton IL, Dunning Hotopp JC. Common analysis of direct RNA sequencinG CUrrently leads to misidentification of m 5C at GCU motifs. Life Sci Alliance 2024; 7:e202302201. [PMID: 38030223 PMCID: PMC10687253 DOI: 10.26508/lsa.202302201] [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: 06/06/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023] Open
Abstract
RNA modifications, such as methylation, can be detected with Oxford Nanopore Technologies direct RNA sequencing. One commonly used tool for detecting 5-methylcytosine (m5C) modifications is Tombo, which uses an "Alternative Model" to detect putative modifications from a single sample. We examined direct RNA sequencing data from diverse taxa including viruses, bacteria, fungi, and animals. The algorithm consistently identified a m5C at the central position of a GCU motif. However, it also identified a m5C in the same motif in fully unmodified in vitro transcribed RNA, suggesting that this is a frequent false prediction. In the absence of further validation, several published predictions of m5C in a GCU context should be reconsidered, including those from human coronavirus and human cerebral organoid samples.
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Affiliation(s)
- Kaylee J Watson
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robin E Bromley
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Benjamin C Sparklin
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark T Gasser
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Tamanash Bhattacharya
- https://ror.org/01kg8sb98 Department of Biology, Indiana University, Bloomington, IN, USA
| | - Jarrett F Lebov
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Tyonna Tyson
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nan Dai
- https://ror.org/04ywg3445 New England Biolabs, Ipswich, MA, USA
| | - Laura E Teigen
- https://ror.org/05w22af52 Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - Karen T Graf
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jeremy M Foster
- https://ror.org/04ywg3445 New England Biolabs, Ipswich, MA, USA
| | - Michelle Michalski
- https://ror.org/05w22af52 Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - Vincent M Bruno
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- https://ror.org/04rq5mt64 Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amelia Ri Lindsey
- https://ror.org/01kg8sb98 Department of Biology, Indiana University, Bloomington, IN, USA
| | - Ivan R Corrêa
- https://ror.org/04ywg3445 New England Biolabs, Ipswich, MA, USA
| | - Richard W Hardy
- https://ror.org/01kg8sb98 Department of Biology, Indiana University, Bloomington, IN, USA
| | - Irene Lg Newton
- https://ror.org/01kg8sb98 Department of Biology, Indiana University, Bloomington, IN, USA
| | - Julie C Dunning Hotopp
- https://ror.org/04rq5mt64 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- https://ror.org/04rq5mt64 Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
- https://ror.org/04rq5mt64 Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
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3
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De Fabrizio V, Trotta V, Pariti L, Radice RP, Martelli G. Preliminary characterization of biomolecular processes related to plasticity in Acyrthosiphonpisum. Heliyon 2024; 10:e23650. [PMID: 38187294 PMCID: PMC10770479 DOI: 10.1016/j.heliyon.2023.e23650] [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: 05/09/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
Global warming strongly impacts many organisms' development, distribution and population structure. This problem has attracted the attention of many scientists to understand and study its actual effects, especially on insects influenced by environmental temperatures. Aphids are a model for studies of the genetics and physiology of stress. Aphids are characterized by parthenogenetic reproduction, which limits the effects of recombination on evolutionary processes, and have shown resistance to various biotic and abiotic stresses. This study was based on the hypothesis that aphids have optimized, over time, genetic mechanisms capable to give them plasticity through genome modifications mediated by transposition. To understand and evaluate the effects of heat stress, the expression levels of transposases and methylases were analyzed in mothers and daughters. Our results show that after four days from the thermal shock, methylation decreases in both mothers and daughters, while transposition significantly increases in daughters, thus generating gene variability, essential for adaptation.
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Affiliation(s)
- Vincenzo De Fabrizio
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Vincenzo Trotta
- School of Agricultural Forestry, Food and Environmental Sciences (SAFE), University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Luigi Pariti
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Rosa Paola Radice
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
- Bioinnova srls, Via ponte nove luci, 22, 85100, Potenza, Italy
| | - Giuseppe Martelli
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
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Li H, Zhu D, Yang Y, Ma Y, Chen Y, Xue P, Chen J, Qin M, Xu D, Cai C, Cheng H. Restricted tRNA methylation by intermolecular disulfide bonds in DNMT2/TRDMT1. Int J Biol Macromol 2023; 251:126310. [PMID: 37579906 DOI: 10.1016/j.ijbiomac.2023.126310] [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: 02/23/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/16/2023]
Abstract
Reportedly, DNMT2/TRDMT1 mainly methylates tRNAs at C38 and prevents them from the cleavage under stress. It also plays an essential role in the survival and physiological homeostasis of organisms. Nevertheless, DNMT2/TRDMT1 exhibits much weaker tRNA methylation activity in vitro than other tRNA methyltransferases, TrmD and Trm5. Here, we explored the restricted tRNA methylation mechanism by DNMT2/TRDMT1. In the current study, the optimized buffer C at 37 °C was the best condition for DNMT2/TRDMT1 activation. Of note, Dithiothreitol (DTT) was an indispensable component for this enzyme catalysis. Moreover, reductants took similar effects on the conformation change and oligomeric formation of DNMT2/TRDMT1. Ultimately, LC-MS/MS result revealed that C292-C292 and C292-C287 were predominant intermolecular disulfide bonds in recombinant DNMT2/TRDMT1. Notably, DNMT2/TRDMT1 existed primarily as dimers via intermolecular disulfide bonds C79-C24, C292-C292, and C222-C24 in HEK293T cells. GSSG stress enhanced tRNA methylation level in the early stage of stress, whereas the DNMT2/TRDMT1 activity might be unfavorable along with this enzyme accumulation in the nucleus. Excitingly, GSH stress downregulated the DNMT2/TRDMT1 expression and promoted tRNA methylation in cells, probably through breaking intermolecular disulfide bonds in this enzyme. Thus, our findings demonstrated restricted tRNA methylation by disulfide bonds in DNMT2/TRDMT1, and will provide important implications for redox stress related-diseases.
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Affiliation(s)
- Huari Li
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China.
| | - Daiyun Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yapeng Yang
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yunfei Ma
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yong Chen
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Pingfang Xue
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Juan Chen
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Mian Qin
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Dandan Xu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Chao Cai
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Hongjing Cheng
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
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Sergeeva A, Davydova K, Perenkov A, Vedunova M. Mechanisms of human DNA methylation, alteration of methylation patterns in physiological processes and oncology. Gene 2023:147487. [PMID: 37211289 DOI: 10.1016/j.gene.2023.147487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/05/2023] [Accepted: 05/11/2023] [Indexed: 05/23/2023]
Abstract
DNA methylation is one of the epigenetic modifications of the genome, the essence of which is the attachment of a methyl group to nitrogenous bases. In the eukaryote genome, cytosine is methylated in the vast majority of cases. About 98% of cytosines are methylated as part of CpG dinucleotides. They, in turn, form CpG islands, which are clusters of these dinucleotides. Islands located in the regulatory elements of genes are in particular interest. They are assumed to play an important role in the regulation of gene expression in humans. Besides that, cytosine methylation serves the functions of genomic imprinting, transposon suppression, epigenetic memory maintenance, X- chromosome inactivation, and embryonic development. Of particular interest are the enzymatic processes of methylation and demethylation. The methylation process always depends on the work of enzymatic complexes and is very precisely regulated. The methylation process largely depends on the functioning of three groups of enzymes: writers, readers and erasers. Writers include proteins of the DNMT family, readers are proteins containing the MBD, BTB/POZ or SET- and RING-associated domains and erasers are proteins of the TET family. Whereas demethylation can be performed not only by enzymatic complexes, but also passively during DNA replication. Hence, the maintenance of DNA methylation is important. Changes in methylation patterns are observed during embryonic development, aging, and cancers. In both aging and cancer, massive hypomethylation of the genome with local hypermethylation is observed. In this review, we will review the current understanding of the mechanisms of DNA methylation and demethylation in humans, the structure and distribution of CpG islands, the role of methylation in the regulation of gene expression, embryogenesis, aging, and cancer development.
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Affiliation(s)
- A Sergeeva
- Institute of Biology and Biomedicine, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
| | - K Davydova
- Institute of Biology and Biomedicine, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
| | - A Perenkov
- Institute of Biology and Biomedicine, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
| | - M Vedunova
- Institute of Biology and Biomedicine, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
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6
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Watson KJ, Bromley RE, Sparklin BC, Gasser MT, Bhattacharya T, Lebov JF, Tyson T, Teigen LE, Graf KT, Michalski M, Bruno VM, Lindsey ARI, Hardy RW, Newton ILG, Hotopp JCD. Common Analysis of Direct RNA SequencinG CUrrently Leads to Misidentification of 5-Methylcytosine Modifications at GCU Motifs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539298. [PMID: 37205495 PMCID: PMC10187288 DOI: 10.1101/2023.05.03.539298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
RNA modifications, such as méthylation, can be detected with Oxford Nanopore Technologies direct RNA sequencing. One commonly used tool for detecting 5-methylcytosine (m5C) modifications is Tombo, which uses an "Alternative Model" to detect putative modifications from a single sample. We examined direct RNA sequencing data from diverse taxa including virus, bacteria, fungi, and animals. The algorithm consistently identified a 5-methylcytosine at the central position of a GCU motif. However, it also identified a 5-methylcytosine in the same motif in fully unmodified in vitro transcribed RNA, suggesting that this a frequent false prediction. In the absence of further validation, several published predictions of 5-methylcytosine in human coronavirus and human cerebral organoid RNA in a GCU context should be reconsidered.
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Affiliation(s)
- Kaylee J. Watson
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Robin E. Bromley
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Benjamin C. Sparklin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mark T. Gasser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Jarrett F. Lebov
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Tyonna Tyson
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Laura E. Teigen
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - Karen T. Graf
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Michelle Michalski
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - Vincent M. Bruno
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | | | - Julie C. Dunning Hotopp
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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7
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Schulz NKE, Mohamed FF, Lo LK, Peuß R, de Buhr MF, Kurtz J. Paternal knockdown of tRNA(cytosine-5-)-methyltransferase (Dnmt2) increases offspring susceptibility to infection in red flour beetles. INSECT MOLECULAR BIOLOGY 2022; 31:711-721. [PMID: 35790040 DOI: 10.1111/imb.12798] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Intergenerational effects from fathers to offspring are increasingly reported from diverse organisms, but the underlying mechanisms remain speculative. Paternal trans-generational immune priming (TGIP) was demonstrated in the red flour beetle Tribolium castaneum: non-infectious bacterial exposure of fathers protects their offspring against an infectious challenge for at least two generations. Epigenetic processes, such as cytosine methylation of nucleic acids, have been proposed to enable transfer of information from fathers to offspring. Here we studied a potential role in TGIP of the Dnmt2 gene (renamed as Trdmt1 in humans), which encodes a highly conserved enzyme that methylates different RNAs, including specific cytosines of a set of tRNAs. Dnmt2 has previously been reported to be involved in intergenerational epigenetic inheritance in mice and protection against viruses in fruit flies. We first studied gene expression and found that Dnmt2 is expressed in various life history stages and tissues of T. castaneum, with high expression in the reproductive organs. RNAi-mediated knockdown of Dnmt2 in fathers was systemic, slowed down offspring larval development and increased mortality of the adult offspring upon bacterial infection. However, these effects were independent of bacterial exposure of the fathers. In conclusion, our results point towards a role of Dnmt2 for paternal effects, while elucidation of the mechanisms behind paternal TGIP needs further studies.
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Affiliation(s)
- Nora K E Schulz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Fakry F Mohamed
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
- Institute of Virology Muenster, Center for Molecular Biology of Inflammation (ZMBE), University Hospital Muenster, Muenster, Germany
| | - Lai Ka Lo
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Robert Peuß
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Maike F de Buhr
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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Differential viral RNA methylation contributes to pathogen blocking in Wolbachia-colonized arthropods. PLoS Pathog 2022; 18:e1010393. [PMID: 35294495 PMCID: PMC8959158 DOI: 10.1371/journal.ppat.1010393] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/28/2022] [Accepted: 02/24/2022] [Indexed: 02/06/2023] Open
Abstract
Arthropod endosymbiont Wolbachia pipientis is part of a global biocontrol strategy to reduce the replication of mosquito-borne RNA viruses such as alphaviruses. We previously demonstrated the importance of a host cytosine methyltransferase, DNMT2, in Drosophila and viral RNA as a cellular target during pathogen-blocking. Here we report a role for DNMT2 in Wolbachia-induced alphavirus inhibition in Aedes species. Expression of DNMT2 in mosquito tissues, including the salivary glands, is elevated upon virus infection. Notably, this is suppressed in Wolbachia-colonized animals, coincident with reduced virus replication and decreased infectivity of progeny virus. Ectopic expression of DNMT2 in cultured Aedes cells is proviral, increasing progeny virus infectivity, and this effect of DNMT2 on virus replication and infectivity is dependent on its methyltransferase activity. Finally, examining the effects of Wolbachia on modifications of viral RNA by LC-MS show a decrease in the amount of 5-methylcytosine modification consistent with the down-regulation of DNMT2 in Wolbachia colonized mosquito cells and animals. Collectively, our findings support the conclusion that disruption of 5-methylcytosine modification of viral RNA is a vital mechanism operative in pathogen blocking. These data also emphasize the essential role of epitranscriptomic modifications in regulating fundamental alphavirus replication and transmission processes.
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