1
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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] [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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Wadhwa N, Kapoor S, Kapoor M. Arabidopsis T-DNA mutants affected in TRDMT1/DNMT2 show differential protein synthesis and compromised stress tolerance. FEBS J 2024; 291:92-113. [PMID: 37584564 DOI: 10.1111/febs.16935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 07/18/2023] [Accepted: 08/14/2023] [Indexed: 08/17/2023]
Abstract
TRDMT1/DNMT2 belongs to the conserved family of nucleic acid methyltransferases. Unlike the animal systems, studies on TRDMT1/DNMT2 in land plants have been limited. We show that TRDMT1/DNMT2 is strongly conserved in the green lineage. Studies in mosses have previously shown that TRDMT1/DNMT2 plays a crucial role in modulating molecular networks involved in stress perception and signalling and in transcription/stability of specific tRNAs under stress. To gain deeper insight into its biological roles in a flowering plant, we examined more closely the previously reported Arabidopsis SALK_136635C line deficient in TRDMT1/DNMT2 function [Goll MG et al. (2006) Science 311, 395-398]. RNAs derived from Arabidopsis Dnmt2-deficient plants lacked m5 C38 in tRNAAsp . In this study, by transient expression assays we show that Arabidopsis TRDMT1/DNMT2 is distributed in the nucleus, cytoplasm and RNA-processing bodies, suggesting a role for TRDMT1/DNMT2 in RNA metabolic processes possibly by shuttling between cellular compartments. Bright-field and high-resolution SEM and qPCR analysis reveal roles of TRDMT1/DNMT2 in proper growth and developmental progression. Quantitative proteome analysis by LC-MS/MS coupled with qPCR shows AtTRDMT1/AtDNMT2 function to be crucial for protein synthesis and cellular homeostasis via housekeeping roles and proteins with poly-Asp stretches and RNA pol II activity on selected genes are affected in attrdmt1/atdnmt2. This shift in metabolic pathways primes the mutant plants to become increasingly sensitive to oxidative and osmotic stress. Taken together, our study sheds light on the mechanistic role of TRDMT1/DNMT2 in a flowering plant.
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Affiliation(s)
- Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Sanjay Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
- Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Meenu Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
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3
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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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Wang Z, Xu X, Li X, Fang J, Huang Z, Zhang M, Liu J, Qiu X. Investigations of Single-Subunit tRNA Methyltransferases from Yeast. J Fungi (Basel) 2023; 9:1030. [PMID: 37888286 PMCID: PMC10608323 DOI: 10.3390/jof9101030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/28/2023] Open
Abstract
tRNA methylations, including base modification and 2'-O-methylation of ribose moiety, play critical roles in the structural stabilization of tRNAs and the fidelity and efficiency of protein translation. These modifications are catalyzed by tRNA methyltransferases (TRMs). Some of the TRMs from yeast can fully function only by a single subunit. In this study, after performing the primary bioinformatic analyses, the progress of the studies of yeast single-subunit TRMs, as well as the studies of their homologues from yeast and other types of eukaryotes and the corresponding TRMs from other types of organisms was systematically reviewed, which will facilitate the understanding of the evolutionary origin of functional diversity of eukaryotic single-subunit TRM.
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Affiliation(s)
- Zhongyuan Wang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xiangbin Xu
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xinhai Li
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Jiaqi Fang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Zhenkuai Huang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Mengli Zhang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Jiameng Liu
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xiaoting Qiu
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
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5
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Wadhwa N, Singh D, Yadav R, Kapoor S, Kapoor M. Role of TRDMT1/DNMT2 in stress adaptation and its influence on transcriptome and proteome dynamics under osmotic stress in Physcomitrium patens. PHYSIOLOGIA PLANTARUM 2023; 175:e14014. [PMID: 37882266 DOI: 10.1111/ppl.14014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/07/2023] [Accepted: 08/21/2023] [Indexed: 10/27/2023]
Abstract
Early land plants such as the moss Physcomitrium patens lack several morphological traits that offer protection to tracheophytes from environmental stresses. These plants instead have evolved several physiological and biochemical mechanisms that facilitate them to adapt to terrestrial stresses such as drought. We have previously shown that loss-of-function mutants of tRNA (cytosine(38)-C(5))-methyltransferase TRDMT1/DNMT2 in P. patens are highly sensitive to oxidative and osmotic stress. To gain insight into the role of PpTRDMT1/PpDNMT2 in modulating genetic networks under osmotic stress, genome-wide transcriptome and proteome studies were undertaken in wild-type and ppdnmt2 plants. Transcriptome analysis revealed 375 genes to be differentially expressed in the ppdnmt2 under stress compared to the WT. Most of these genes are affiliated with carbohydrate metabolic pathways, photosynthesis, cell wall biogenesis, pathways related to isotropic and polarised cell growth and transcription factors among others. Histochemical staining showed elevated levels of reactive oxygen species in ppdnmt2 while transmission electron microscopy revealed no distinct defects in the ultrastructure of chloroplasts. Immunoprecipitation using PpDNMT2-specific antibody coupled with mass spectrometry revealed core proteins of the glycolytic pathway, antioxidant enzymes, proteins of amino acid biosynthetic pathways and photosynthesis-related proteins among others to co-purify with PpTRDMT1/PpDNMT2 under osmotic stress. Yeast two-hybrid assays, protein deletion and α-galactosidase assays showed the cytosol glycolytic protein glyceraldehyde 3-phosphate dehydrogenase to bind to the catalytic motifs in PpTRDMT1/PpDNMT2. Results presented in this study allow us to better understand genetic networks linking enzymes of energy metabolism, epigenetic processes and RNA pol II-mediated transcription during osmotic stress tolerance in P. patens.
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Affiliation(s)
- Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Darshika Singh
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Radha Yadav
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
| | - Sanjay Kapoor
- Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, Delhi, India
| | - Meenu Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, Delhi, India
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6
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Abstract
The study of eukaryotic tRNA processing has given rise to an explosion of new information and insights in the last several years. We now have unprecedented knowledge of each step in the tRNA processing pathway, revealing unexpected twists in biochemical pathways, multiple new connections with regulatory pathways, and numerous biological effects of defects in processing steps that have profound consequences throughout eukaryotes, leading to growth phenotypes in the yeast Saccharomyces cerevisiae and to neurological and other disorders in humans. This review highlights seminal new results within the pathways that comprise the life of a tRNA, from its birth after transcription until its death by decay. We focus on new findings and revelations in each step of the pathway including the end-processing and splicing steps, many of the numerous modifications throughout the main body and anticodon loop of tRNA that are so crucial for tRNA function, the intricate tRNA trafficking pathways, and the quality control decay pathways, as well as the biogenesis and biology of tRNA-derived fragments. We also describe the many interactions of these pathways with signaling and other pathways in the cell.
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Affiliation(s)
- Eric M Phizicky
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, Ohio State University, Columbus, Ohio 43235, USA
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7
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Zimmermann R, Schwickert M, Meidner JL, Nidoieva Z, Helm M, Schirmeister T. An Optimized Microscale Thermophoresis Method for High-Throughput Screening of DNA Methyltransferase 2 Ligands. ACS Pharmacol Transl Sci 2022; 5:1079-1085. [PMID: 36407957 PMCID: PMC9667538 DOI: 10.1021/acsptsci.2c00175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Indexed: 11/28/2022]
Abstract
Developing methyltransferase inhibitors is challenging, since most of the currently used assays are time-consuming and cost-intensive. Therefore, efficient, fast, and reliable methods for screenings and affinity determinations are of utmost importance. Starting from a literature-known fluorescent S-adenosylhomocysteine derivative, 5-FAM-triazolyl-adenosyl-Dab, developed for a fluorescence polarization assay to investigate the histone methyltransferase mixed-lineage leukemia 1, we herein describe the applicability of this compound as a fluorescent tracer for the investigation of DNA-methyltransferase 2 (DNMT2), a human RNA methyltransferase. Based on these findings, we established a microscale thermophoresis (MST) assay for DNMT2. This displacement assay can circumvent various problems inherent to this method. Furthermore, we optimized a screening method via MST which even indicates if the detected binding is competitive and gives the opportunity to estimate the potency of a ligand, both of which are not possible with a direct binding assay.
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Affiliation(s)
| | | | | | - Zarina Nidoieva
- Institute
of Pharmaceutical and Biomedical
Sciences, Johannes Gutenberg University
Mainz Staudinger Weg 5, D-55128 Mainz, Germany
| | - Mark Helm
- Institute
of Pharmaceutical and Biomedical
Sciences, Johannes Gutenberg University
Mainz Staudinger Weg 5, D-55128 Mainz, Germany
| | - Tanja Schirmeister
- Institute
of Pharmaceutical and Biomedical
Sciences, Johannes Gutenberg University
Mainz Staudinger Weg 5, D-55128 Mainz, Germany
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8
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Bessler L, Kaur N, Vogt LM, Flemmich L, Siebenaller C, Winz ML, Tuorto F, Micura R, Ehrenhofer-Murray AE, Helm M. Functional integration of a semi-synthetic azido-queuosine derivative into translation and a tRNA modification circuit. Nucleic Acids Res 2022; 50:10785-10800. [PMID: 36169220 PMCID: PMC9561289 DOI: 10.1093/nar/gkac822] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/09/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022] Open
Abstract
Substitution of the queuine nucleobase precursor preQ1 by an azide-containing derivative (azido-propyl-preQ1) led to incorporation of this clickable chemical entity into tRNA via transglycosylation in vitro as well as in vivo in Escherichia coli, Schizosaccharomyces pombe and human cells. The resulting semi-synthetic RNA modification, here termed Q-L1, was present in tRNAs on actively translating ribosomes, indicating functional integration into aminoacylation and recruitment to the ribosome. The azide moiety of Q-L1 facilitates analytics via click conjugation of a fluorescent dye, or of biotin for affinity purification. Combining the latter with RNAseq showed that TGT maintained its native tRNA substrate specificity in S. pombe cells. The semi-synthetic tRNA modification Q-L1 was also functional in tRNA maturation, in effectively replacing the natural queuosine in its stimulation of further modification of tRNAAsp with 5-methylcytosine at position 38 by the tRNA methyltransferase Dnmt2 in S. pombe. This is the first demonstrated in vivo integration of a synthetic moiety into an RNA modification circuit, where one RNA modification stimulates another. In summary, the scarcity of queuosinylation sites in cellular RNA, makes our synthetic q/Q system a ‘minimally invasive’ system for placement of a non-natural, clickable nucleobase within the total cellular RNA.
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Affiliation(s)
- Larissa Bessler
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Navpreet Kaur
- Institute of Biology, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Lea-Marie Vogt
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Laurin Flemmich
- Department of Organic Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | - Carmen Siebenaller
- Department of Chemistry - Biochemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Marie-Luise Winz
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Francesca Tuorto
- Division of Biochemistry, Mannheim Institute for Innate Immunoscience (MI3), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Ronald Micura
- Department of Organic Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | | | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
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Stein A, Platzbecker U, Cross M. How Azanucleosides Affect Myeloid Cell Fate. Cells 2022; 11:cells11162589. [PMID: 36010665 PMCID: PMC9406747 DOI: 10.3390/cells11162589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 11/16/2022] Open
Abstract
The azanucleosides decitabine and azacytidine are used widely in the treatment of myeloid neoplasia and increasingly in the context of combination therapies. Although they were long regarded as being largely interchangeable in their function as hypomethylating agents, the azanucleosides actually have different mechanisms of action; decitabine interferes primarily with the methylation of DNA and azacytidine with that of RNA. Here, we examine the role of DNA methylation in the lineage commitment of stem cells during normal hematopoiesis and consider how mutations in epigenetic regulators such as DNMT3A and TET2 can lead to clonal expansion and subsequent neoplastic progression. We also consider why the efficacy of azanucleoside treatment is not limited to neoplasias carrying mutations in epigenetic regulators. Finally, we summarise recent data describing a role for azacytidine-sensitive RNA methylation in lineage commitment and in the cellular response to stress. By summarising and interpreting evidence for azanucleoside involvement in a range of cellular processes, our review is intended to illustrate the need to consider multiple modes of action in the design and stratification of future combination therapies.
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10
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Queuosine salvage in fission yeast by Qng1-mediated hydrolysis to queuine. Biochem Biophys Res Commun 2022; 624:146-150. [DOI: 10.1016/j.bbrc.2022.07.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 07/27/2022] [Indexed: 11/02/2022]
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11
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Chen M, Zhou L, Li S, Wei H, Chen J, Yang P, Peng H. Toxoplasma gondii DNA methyltransferases regulate parasitic energy metabolism. Acta Trop 2022; 229:106329. [PMID: 35122712 DOI: 10.1016/j.actatropica.2022.106329] [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: 10/19/2021] [Revised: 01/10/2022] [Accepted: 01/23/2022] [Indexed: 11/29/2022]
Abstract
The intracellular protozoan Toxoplasma gondii results in serious diseases such as encephalitis, and retinochoroiditis in immunocompromised patients. The interconversion between tachyzoites and bradyzoites under the host's immune pressure results in the interchange of acute infection and chronic infection. We previously reported two functional DNA methyltransferases (DNMT) in Toxoplasma gondii named TgDNMTa and TgDNMTb. In this research, proteomics analysis for T. gondii tachyzoites of ME49 WT, dnmta knockout (ME49-∆Tgdnmta), and dnmtb knockout (ME49-∆Tgdnmtb) strains, revealed 362 significantly regulated proteins for ME49-∆Tgdnmta, and 219 for ME49-∆Tgdnmtb, compared with the proteins of ME49 WT. TgDNMTa down regulated three glycolytic enzymes, one gluconeogenic enzyme and four pyruvate metabolic enzymes. Furthermore, TgDNMTb up regulated two proteins in the tricarboxylic acid (TCA) cycle. Glucose metabolic flux detection showed that TgDNMTa inhibited the glycolysis pathway, while TgDNMTb promoted the tricarboxylic acid (TCA) cycle so as to promote parasite's proliferation. These findings demonstrated that the functions of Toxoplasma gondii DNA methyltransferases extended beyond DNA methylation to the regulation of parasitic energy metabolism.
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Affiliation(s)
- Min Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Shengmin Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Hiaxia Wei
- Department of Pathogenic Biology, Guangzhou Medical University, Guangzhou 511436, China
| | - Jiating Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Pei Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China.
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12
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Motorin Y, Helm M. RNA nucleotide methylation: 2021 update. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1691. [PMID: 34913259 DOI: 10.1002/wrna.1691] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 12/14/2022]
Abstract
Among RNA modifications, transfer of methylgroups from the typical cofactor S-adenosyl-l-methionine by methyltransferases (MTases) to RNA is by far the most common reaction. Since our last review about a decade ago, the field has witnessed the re-emergence of mRNA methylation as an important mechanism in gene regulation. Attention has then spread to many other RNA species; all being included into the newly coined concept of the "epitranscriptome." The focus moved from prokaryotes and single cell eukaryotes as model organisms to higher eukaryotes, in particular to mammals. The perception of the field has dramatically changed over the past decade. A previous lack of phenotypes in knockouts in single cell organisms has been replaced by the apparition of MTases in numerous disease models and clinical investigations. Major driving forces of the field include methylation mapping techniques, as well as the characterization of the various MTases, termed "writers." The latter term has spilled over from DNA modification in the neighboring epigenetics field, along with the designations "readers," applied to mediators of biological effects upon specific binding to a methylated RNA. Furthermore "eraser" enzymes effect the newly discovered oxidative removal of methylgroups. A sense of reversibility and dynamics has replaced the older perception of RNA modification as a concrete-cast, irreversible part of RNA maturation. A related concept concerns incompletely methylated residues, which, through permutation of each site, lead to inhomogeneous populations of numerous modivariants. This review recapitulates the major developments of the past decade outlined above, and attempts a prediction of upcoming trends. This article is categorized under: RNA Processing > RNA Editing and Modification.
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Affiliation(s)
- Yuri Motorin
- Université de Lorraine, CNRS, INSERM, UMS2008/US40 IBSLor, EpiRNA-Seq Core Facility, Nancy, France.,Université de Lorraine, CNRS, UMR7365 IMoPA, Nancy, France
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität, Mainz, Germany
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13
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Huang ZX, Li J, Xiong QP, Li H, Wang ED, Liu RJ. Position 34 of tRNA is a discriminative element for m5C38 modification by human DNMT2. Nucleic Acids Res 2021; 49:13045-13061. [PMID: 34871455 PMCID: PMC8682788 DOI: 10.1093/nar/gkab1148] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/05/2021] [Accepted: 11/03/2021] [Indexed: 12/05/2022] Open
Abstract
Dnmt2, a member of the DNA methyltransferase superfamily, catalyzes the formation of 5-methylcytosine at position 38 in the anticodon loop of tRNAs. Dnmt2 regulates many cellular biological processes, especially the production of tRNA-derived fragments and intergenerational transmission of paternal metabolic disorders to offspring. Moreover, Dnmt2 is closely related to human cancers. The tRNA substrates of mammalian Dnmt2s are mainly detected using bisulfite sequencing; however, we lack supporting biochemical data concerning their substrate specificity or recognition mechanism. Here, we deciphered the tRNA substrates of human DNMT2 (hDNMT2) as tRNAAsp(GUC), tRNAGly(GCC) and tRNAVal(AAC). Intriguingly, for tRNAAsp(GUC) and tRNAGly(GCC), G34 is the discriminator element; whereas for tRNAVal(AAC), the inosine modification at position 34 (I34), which is formed by the ADAT2/3 complex, is the prerequisite for hDNMT2 recognition. We showed that the C32U33(G/I)34N35 (C/U)36A37C38 motif in the anticodon loop, U11:A24 in the D stem, and the correct size of the variable loop are required for Dnmt2 recognition of substrate tRNAs. Furthermore, mammalian Dnmt2s possess a conserved tRNA recognition mechanism.
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MESH Headings
- 5-Methylcytosine/metabolism
- Adenosine Deaminase/genetics
- Adenosine Deaminase/metabolism
- Animals
- Anticodon/genetics
- Anticodon/metabolism
- Base Sequence
- DNA (Cytosine-5-)-Methyltransferases/chemistry
- DNA (Cytosine-5-)-Methyltransferases/genetics
- DNA (Cytosine-5-)-Methyltransferases/metabolism
- HEK293 Cells
- HeLa Cells
- Humans
- Inosine/metabolism
- Mice
- Models, Molecular
- NIH 3T3 Cells
- Nucleic Acid Conformation
- Protein Binding
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- RNA, Transfer, Asp/chemistry
- RNA, Transfer, Asp/genetics
- RNA, Transfer, Asp/metabolism
- RNA, Transfer, Gly/chemistry
- RNA, Transfer, Gly/genetics
- RNA, Transfer, Gly/metabolism
- RNA, Transfer, Val/chemistry
- RNA, Transfer, Val/genetics
- RNA, Transfer, Val/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Substrate Specificity
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Affiliation(s)
- Zhi-Xuan Huang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Jing Li
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Qing-Ping Xiong
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hao Li
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - En-Duo Wang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
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14
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Li H, Zhu D, Wu J, Ma Y, Cai C, Chen Y, Qin M, Dai H. New substrates and determinants for tRNA recognition of RNA methyltransferase DNMT2/TRDMT1. RNA Biol 2021; 18:2531-2545. [PMID: 34110975 PMCID: PMC8632113 DOI: 10.1080/15476286.2021.1930756] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/16/2021] [Accepted: 05/12/2021] [Indexed: 02/07/2023] Open
Abstract
Methylation is a common post-transcriptional modification of tRNAs, particularly in the anticodon loop region. The cytosine 38 (C38) in tRNAs, such as tRNAAsp-GUC, tRNAGly-GCC, tRNAVal-AAC, and tRNAGlu-CUC, can be methylated by human DNMT2/TRDMT1 and some homologs found in bacteria, plants, and animals. However, the substrate properties and recognition mechanism of DNMT2/TRDMT1 remain to be explored. Here, taking into consideration common features of the four known substrate tRNAs, we investigated methylation activities of DNMT2/TRDMT1 on the tRNAGly-GCC truncation and point mutants, and conformational changes of mutants. The results demonstrated that human DNMT2/TRDMT1 preferred substrate tRNAGly-GCC in vitro. L-shaped conformation of classical tRNA could be favourable for DNMT2/TRDMT1 activity. The complete sequence and structure of tRNA were dispensable for DNMT2/TRDMT1 activity, whereas T-arm was indispensable to this activity. G19, U20, and A21 in D-loop were identified as the important bases for DNMT2/TRDMT1 activity, while G53, C56, A58, and C61 in T-loop were found as the critical bases. The conserved CUXXCAC sequence in the anticodon loop was confirmed to be the most critical determinant, and it could stabilize C38-flipping to promote C38 methylation. Based on these tRNA properties, new substrates, tRNAVal-CAC and tRNAGln-CUG, were discovered in vitro. Moreover, a single nucleotide substitute, U32C, could convert non-substrate tRNAAla-AGC into a substrate for DNMT2/TRDMT1. Altogether, our findings imply that DNMT2/TRDMT1 relies on a delicate network involving both the primary sequence and tertiary structure of tRNA for substrate recognition.
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Affiliation(s)
- Huari Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Daiyun Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jian Wu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yunfei Ma
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chao Cai
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yong Chen
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Mian Qin
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Hanchuan Dai
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
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15
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Kubiak-Szymendera M, Pryszcz LP, Białas W, Celińska E. Epigenetic Response of Yarrowia lipolytica to Stress: Tracking Methylation Level and Search for Methylation Patterns via Whole-Genome Sequencing. Microorganisms 2021; 9:microorganisms9091798. [PMID: 34576693 PMCID: PMC8471669 DOI: 10.3390/microorganisms9091798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 01/02/2023] Open
Abstract
DNA methylation is a common, but not universal, epigenetic modification that plays an important role in multiple cellular processes. While definitely settled for numerous plant, mammalian, and bacterial species, the genome methylation in different fungal species, including widely studied and industrially-relevant yeast species, Yarrowia lipolytica, is still a matter of debate. In this paper, we report a differential DNA methylation level in the genome of Y. lipolytica subjected to sequential subculturing and to heat stress conditions. To this end, we adopted repeated batch bioreactor cultivations of Y. lipolytica subjected to thermal stress in specific time intervals. To analyze the variation in DNA methylation between stressed and control cultures, we (a) quantified the global DNA methylation status using an immuno-assay, and (b) studied DNA methylation patterns through whole-genome sequencing. Primarily, we demonstrated that 5 mC modification can be detected using a commercial immuno-assay, and that the modifications are present in Y. lipolytica’s genome at ~0.5% 5 mC frequency. On the other hand, we did not observe any changes in the epigenetic response of Y. lipolytica to heat shock (HS) treatment. Interestingly, we identified a general phenomenon of decreased 5 mC level in Y. lipolytica’s genome in the stationary phase of growth, when compared to a late-exponential epigenome. While this study provides an insight into the subculturing stress response and adaptation to the stress at epigenetic level by Y. lipolytica, it also leaves an open question of inability to detect any genomic DNA methylation level (either in CpG context or context-less) through whole-genome sequencing. The results of ONT sequencing, suggesting that 5 mC modification is either rare or non-existent in Y. lipolytica genome, are contradicted with the results of the immunoassay.
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Affiliation(s)
- Monika Kubiak-Szymendera
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, 460-637 Poznań, Poland; (M.K.-S.); (W.B.)
| | - Leszek P. Pryszcz
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08003 Barcelona, Spain;
| | - Wojciech Białas
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, 460-637 Poznań, Poland; (M.K.-S.); (W.B.)
| | - Ewelina Celińska
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, 460-637 Poznań, Poland; (M.K.-S.); (W.B.)
- Correspondence:
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16
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Gao Y, Fang J. RNA 5-methylcytosine modification and its emerging role as an epitranscriptomic mark. RNA Biol 2021; 18:117-127. [PMID: 34288807 DOI: 10.1080/15476286.2021.1950993] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
5-methylcytosine (m5C) is identified as an abundant and conserved modification in various RNAs, including tRNAs, mRNAs, rRNAs, and other non-coding RNAs. The application of high-throughput sequencing and mass spectrometry allowed for the detection of m5C at a single-nucleotide resolution and at a global abundance separately; this contributes to a better understanding of m5C modification and its biological functions. m5C modification plays critical roles in diverse aspects of RNA processing, including tRNA stability, rRNA assembly, and mRNA translation. Notably, altered m5C modifications and mutated RNA m5C methyltransferases are associated with diverse pathological processes, such as nervous system disorders and cancers. This review may provide new sights of molecular mechanism and functional importance of m5C modification.
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Affiliation(s)
- Yaqi Gao
- State Key Laboratory for Oncogenes and Related Genes, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jingyuan Fang
- State Key Laboratory for Oncogenes and Related Genes, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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17
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Zhu X, Wang X, Yan W, Yang H, Xiang Y, Lv F, Shi Y, Li HY, Lan L. Ubiquitination-mediated degradation of TRDMT1 regulates homologous recombination and therapeutic response. NAR Cancer 2021; 3:zcab010. [PMID: 33778494 PMCID: PMC7984809 DOI: 10.1093/narcan/zcab010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/08/2021] [Accepted: 02/24/2021] [Indexed: 12/25/2022] Open
Abstract
The RNA methyltransferase TRDMT1 has recently emerged as a key regulator of homologous recombination (HR) in the transcribed regions of the genome, but how it is regulated and its relevance in cancer remain unknown. Here, we identified that TRDMT1 is poly-ubiquitinated at K251 by the E3 ligase TRIM28, removing TRDMT1 from DNA damage sites and allowing completion of HR. Interestingly, K251 is adjacent to G155 in the 3D structure, and the G155V mutation leads to hyper ubiquitination of TRDMT1, reduced TRDMT1 levels and impaired HR. Accordingly, a TRDMT1 G155V mutation in an ovarian cancer super responder to platinum treatment. Cells expressing TRDMT1-G155V are sensitive to cisplatin in vitro and in vivo. In contrast, high expression of TRDMT1 in patients with ovarian cancer correlates with platinum resistance. A potent TRDMT1 inhibitor resensitizes TRDMT1-high tumor cells to cisplatin. These results suggest that TRDMT1 is a promising therapeutic target to sensitize ovarian tumors to platinum therapy.
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Affiliation(s)
- Xiaolan Zhu
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Xiangyu Wang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Wei Yan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Haibo Yang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yufei Xiang
- Department of Cell Biology, University of Pittsburgh, 3501 fifth Ave., Pittsburgh, PA 15260, USA
| | - Fengping Lv
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Yi Shi
- Department of Cell Biology, University of Pittsburgh, 3501 fifth Ave., Pittsburgh, PA 15260, USA
| | - Hong-yu Li
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
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18
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Schaefer MR. The Regulation of RNA Modification Systems: The Next Frontier in Epitranscriptomics? Genes (Basel) 2021; 12:genes12030345. [PMID: 33652758 PMCID: PMC7996938 DOI: 10.3390/genes12030345] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 12/12/2022] Open
Abstract
RNA modifications, long considered to be molecular curiosities embellishing just abundant and non-coding RNAs, have now moved into the focus of both academic and applied research. Dedicated research efforts (epitranscriptomics) aim at deciphering the underlying principles by determining RNA modification landscapes and investigating the molecular mechanisms that establish, interpret and modulate the information potential of RNA beyond the combination of four canonical nucleotides. This has resulted in mapping various epitranscriptomes at high resolution and in cataloguing the effects caused by aberrant RNA modification circuitry. While the scope of the obtained insights has been complex and exciting, most of current epitranscriptomics appears to be stuck in the process of producing data, with very few efforts to disentangle cause from consequence when studying a specific RNA modification system. This article discusses various knowledge gaps in this field with the aim to raise one specific question: how are the enzymes regulated that dynamically install and modify RNA modifications? Furthermore, various technologies will be highlighted whose development and use might allow identifying specific and context-dependent regulators of epitranscriptomic mechanisms. Given the complexity of individual epitranscriptomes, determining their regulatory principles will become crucially important, especially when aiming at modifying specific aspects of an epitranscriptome both for experimental and, potentially, therapeutic purposes.
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Affiliation(s)
- Matthias R Schaefer
- Centre for Anatomy & Cell Biology, Division of Cell-and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, Haus C, 1st Floor, 1090 Vienna, Austria
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19
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Nai YS, Huang YC, Yen MR, Chen PY. Diversity of Fungal DNA Methyltransferases and Their Association With DNA Methylation Patterns. Front Microbiol 2021; 11:616922. [PMID: 33552027 PMCID: PMC7862722 DOI: 10.3389/fmicb.2020.616922] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/28/2020] [Indexed: 11/24/2022] Open
Abstract
DNA methyltransferases (DNMTs) are a group of proteins that catalyze DNA methylation by transferring a methyl group to DNA. The genetic variation in DNMTs results in differential DNA methylation patterns associated with various biological processes. In fungal species, DNMTs and their DNA methylation profiles were found to be very diverse and have gained many research interests. We reviewed fungal DNMTs in terms of their biological functions, protein domain structures, and their associated epigenetic regulations compared to those known in plant and animal systems. In addition, we summarized recent reports on potential RNA-directed DNA methylation (RdDM) related to DNMT5 in fungi. We surveyed up to 40 fungal species with published genome-wide DNA methylation profiles (methylomes) and presented the associations between the specific patterns of fungal DNA methylation and their DNMTs based on a phylogenetic tree of protein domain structures. For example, the main DNMTs in Basidiomycota, DNMT1 with RFD domain + DNMT5, contributing to CG methylation preference, were distinct from RID + Dim-2 in Ascomycota, resulting in a non-CG methylation preference. Lastly, we revealed that the dynamic methylation involved in fungal life stage changes was particularly low in mycelium and DNA methylation was preferentially located in transposable elements (TEs). This review comprehensively discussed fungal DNMTs and methylomes and their connection with fungal development and taxonomy to present the diverse usages of DNA methylation in fungal genomes.
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Affiliation(s)
- Yu-Shin Nai
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan.,Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chun Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.,Bioinformatics Program, Taiwan International Graduate Program, National Taiwan University, Taipei, Taiwan.,Bioinformatics Program, Institute of Information Science, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
| | - Ming-Ren Yen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Pao-Yang Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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20
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Singh D, Yadav R, Kaushik S, Wadhwa N, Kapoor S, Kapoor M. Transcriptome Analysis of ppdnmt2 and Identification of Superoxide Dismutase as a Novel Interactor of DNMT2 in the Moss Physcomitrella patens. FRONTIERS IN PLANT SCIENCE 2020; 11:1185. [PMID: 32849734 PMCID: PMC7419982 DOI: 10.3389/fpls.2020.01185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/21/2020] [Indexed: 05/07/2023]
Abstract
DNMT2 is a DNA/tRNA cytosine methyltransferase that is highly conserved in structure and function in eukaryotes. In plants however, limited information is available on the function of this methyltransferase. We have previously reported that in the moss Physcomitrella patens, DNMT2 plays a crucial role in stress recovery and tRNAAsp transcription/stability under salt stress. To further investigate the role of PpDNMT2 at genome level, in this study we have performed RNA sequencing of ppdnmt2. Transcriptome analysis reveals a number of genes and pathways to function differentially and suggests a close link between PpDNMT2 function and osmotic and ionic stress tolerance. We propose PpDNMT2 to play a pivotal role in regulating salt tolerance by affecting molecular networks involved in stress perception and signal transduction that underlie maintenance of ion homeostasis in cells. We also examined interactome of PpDNMT2 using affinity purification (AP) coupled to mass spectrometry (AP-MS). Quantitative proteomic analysis reveals several chloroplast proteins involved in light reactions and carbon assimilation and proteins involved in stress response and some not implicated in stress to co-immunoprecipitate with PpDNMT2. Comparison between transcriptome and interactome datasets has revealed novel association between PpDNMT2 activity and the antioxidant enzyme Superoxide dismutase (SOD), protein turnover mediated by the Ubiquitin-proteasome system and epigenetic gene regulation. PpDNMT2 possibly exists in complex with CuZn-SODs in vivo and the two proteins also directly interact in the yeast nucleus as observed by yeast two-hybrid assay. Taken together, the work presented in this study sheds light on diverse roles of PpDNMT2 in maintaining molecular and physiological homeostasis in P. patens. This is a first report describing transcriptome and interactome of DNMT2 in any land plant.
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Affiliation(s)
- Darshika Singh
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Radha Yadav
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Shubham Kaushik
- Vproteomics, Valerian Chem Private Limited Green Park Mains, New Delhi, India
| | - Nikita Wadhwa
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Sanjay Kapoor
- Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Meenu Kapoor
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
- *Correspondence: Meenu Kapoor,
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21
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Müller M, Legrand C, Tuorto F, Kelly VP, Atlasi Y, Lyko F, Ehrenhofer-Murray AE. Queuine links translational control in eukaryotes to a micronutrient from bacteria. Nucleic Acids Res 2019; 47:3711-3727. [PMID: 30715423 PMCID: PMC6468285 DOI: 10.1093/nar/gkz063] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/11/2019] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
In eukaryotes, the wobble position of tRNA with a GUN anticodon is modified to the 7-deaza-guanosine derivative queuosine (Q34), but the original source of Q is bacterial, since Q is synthesized by eubacteria and salvaged by eukaryotes for incorporation into tRNA. Q34 modification stimulates Dnmt2/Pmt1-dependent C38 methylation (m5C38) in the tRNAAsp anticodon loop in Schizosaccharomyces pombe. Here, we show by ribosome profiling in S. pombe that Q modification enhances the translational speed of the C-ending codons for aspartate (GAC) and histidine (CAC) and reduces that of U-ending codons for asparagine (AAU) and tyrosine (UAU), thus equilibrating the genome-wide translation of synonymous Q codons. Furthermore, Q prevents translation errors by suppressing second-position misreading of the glycine codon GGC, but not of wobble misreading. The absence of Q causes reduced translation of mRNAs involved in mitochondrial functions, and accordingly, lack of Q modification causes a mitochondrial defect in S. pombe. We also show that Q-dependent stimulation of Dnmt2 is conserved in mice. Our findings reveal a direct mechanism for the regulation of translational speed and fidelity in eukaryotes by a nutrient originating from bacteria.
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Affiliation(s)
- Martin Müller
- Institut für Biologie, Molekulare Zellbiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Carine Legrand
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Francesca Tuorto
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Vincent P Kelly
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Trinity College Dublin, Dublin, Ireland
| | - Yaser Atlasi
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Ann E Ehrenhofer-Murray
- Institut für Biologie, Molekulare Zellbiologie, Humboldt-Universität zu Berlin, Berlin, Germany
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22
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Mosca P, Leheup B, Dreumont N. Nutrigenomics and RNA methylation: Role of micronutrients. Biochimie 2019; 164:53-59. [DOI: 10.1016/j.biochi.2019.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/06/2019] [Indexed: 12/24/2022]
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23
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Genenncher B, Durdevic Z, Hanna K, Zinkl D, Mobin MB, Senturk N, Da Silva B, Legrand C, Carré C, Lyko F, Schaefer M. Mutations in Cytosine-5 tRNA Methyltransferases Impact Mobile Element Expression and Genome Stability at Specific DNA Repeats. Cell Rep 2019; 22:1861-1874. [PMID: 29444437 DOI: 10.1016/j.celrep.2018.01.061] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/18/2017] [Accepted: 01/19/2018] [Indexed: 12/22/2022] Open
Abstract
The maintenance of eukaryotic genome stability is ensured by the interplay of transcriptional as well as post-transcriptional mechanisms that control recombination of repeat regions and the expression and mobility of transposable elements. We report here that mutations in two (cytosine-5) RNA methyltransferases, Dnmt2 and NSun2, impact the accumulation of mobile element-derived sequences and DNA repeat integrity in Drosophila. Loss of Dnmt2 function caused moderate effects under standard conditions, while heat shock exacerbated these effects. In contrast, NSun2 function affected mobile element expression and genome integrity in a heat shock-independent fashion. Reduced tRNA stability in both RCMT mutants indicated that tRNA-dependent processes affected mobile element expression and DNA repeat stability. Importantly, further experiments indicated that complex formation with RNA could also contribute to the impact of RCMT function on gene expression control. These results thus uncover a link between tRNA modification enzymes, the expression of repeat DNA, and genomic integrity.
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Affiliation(s)
- Bianca Genenncher
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Zeljko Durdevic
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany; Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Katharina Hanna
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Daniela Zinkl
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Mehrpouya Balaghy Mobin
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany; Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Nevcin Senturk
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany; Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 581, 69120 Heidelberg, Germany
| | - Bruno Da Silva
- Drosophila Genetics and Epigenetics Lab, Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris Seine (IBPS), 9, Quai St Bernard, Boîte courrier 24, 75252 Paris Cedex 05, France
| | - Carine Legrand
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Clément Carré
- Drosophila Genetics and Epigenetics Lab, Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris Seine (IBPS), 9, Quai St Bernard, Boîte courrier 24, 75252 Paris Cedex 05, France
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Matthias Schaefer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria.
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24
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Müller M, Samel-Pommerencke A, Legrand C, Tuorto F, Lyko F, Ehrenhofer-Murray AE. Division of labour: tRNA methylation by the NSun2 tRNA methyltransferases Trm4a and Trm4b in fission yeast. RNA Biol 2019; 16:249-256. [PMID: 30646830 PMCID: PMC6380293 DOI: 10.1080/15476286.2019.1568819] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Enzymes of the cytosine-5 RNA methyltransferase Trm4/NSun2 family methylate tRNAs at C48 and C49 in multiple tRNAs, as well as C34 and C40 in selected tRNAs. In contrast to most other organisms, fission yeast Schizosaccharomyces pombe carries two Trm4/NSun2 homologs, Trm4a (SPAC17D4.04) and Trm4b (SPAC23C4.17). Here, we have employed tRNA methylome analysis to determine the dependence of cytosine-5 methylation (m5C) tRNA methylation in vivo on the two enzymes. Remarkably, Trm4a is responsible for all C48 methylation, which lies in the tRNA variable loop, as well as for C34 in tRNALeuCAA and tRNAProCGG, which are at the anticodon wobble position. Conversely, Trm4b methylates C49 and C50, which both lie in the TΨC-stem. Thus, S. pombe show an unusual separation of activities of the NSun2/Trm4 enzymes that are united in a single enzyme in other eukaryotes like humans, mice and Saccharomyces cerevisiae. Furthermore, in vitro activity assays showed that Trm4a displays intron-dependent methylation of C34, whereas Trm4b activity is independent of the intron. The absence of Trm4a, but not Trm4b, causes a mild resistance of S. pombe to calcium chloride.
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Affiliation(s)
- Martin Müller
- a Institut für Biologie, Molekulare Zellbiologie , Humboldt-Universität zu Berlin , Berlin , Germany
| | - Anke Samel-Pommerencke
- a Institut für Biologie, Molekulare Zellbiologie , Humboldt-Universität zu Berlin , Berlin , Germany
| | - Carine Legrand
- b Division of Epigenetics, DKFZ-ZMBH Alliance , German Cancer Research Center , Heidelberg , Germany
| | - Francesca Tuorto
- b Division of Epigenetics, DKFZ-ZMBH Alliance , German Cancer Research Center , Heidelberg , Germany
| | - Frank Lyko
- b Division of Epigenetics, DKFZ-ZMBH Alliance , German Cancer Research Center , Heidelberg , Germany
| | - Ann E Ehrenhofer-Murray
- a Institut für Biologie, Molekulare Zellbiologie , Humboldt-Universität zu Berlin , Berlin , Germany
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25
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García-Vílchez R, Sevilla A, Blanco S. Post-transcriptional regulation by cytosine-5 methylation of RNA. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1862:240-252. [PMID: 30593929 DOI: 10.1016/j.bbagrm.2018.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/04/2018] [Accepted: 12/07/2018] [Indexed: 02/02/2023]
Abstract
The recent advent of high-throughput sequencing technologies coupled with RNA modifications detection methods has allowed the detection of RNA modifications at single nucleotide resolution giving a more comprehensive landscape of post-transcriptional gene regulation pathways. In this review, we focus on the occurrence of 5-methylcytosine (m5C) in the transcriptome. We summarise the main findings of the molecular role in post-transcriptional regulation that governs m5C deposition in RNAs. Functionally, m5C deposition can regulate several cellular and physiological processes including development, differentiation and survival to stress stimuli. Despite many aspects concerning m5C deposition in RNA, such as position or sequence context and the fact that many readers and erasers still remain elusive, the overall recent findings indicate that RNA cytosine methylation is a powerful mechanism to post-transcriptionally regulate physiological processes. In addition, mutations in RNA cytosine-5 methyltransferases are associated to pathological processes ranging from neurological syndromes to cancer.
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Affiliation(s)
| | - Ana Sevilla
- Physiology, Cellular Biology and Immunology Department - Biology Faculty. University of Barcelona, Avda. Diagonal 643, 08028 Barcelona. Spain
| | - Sandra Blanco
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain; Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), University of Salamanca, 37007 Salamanca, Spain..
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26
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Oberbauer V, Schaefer MR. tRNA-Derived Small RNAs: Biogenesis, Modification, Function and Potential Impact on Human Disease Development. Genes (Basel) 2018; 9:genes9120607. [PMID: 30563140 PMCID: PMC6315542 DOI: 10.3390/genes9120607] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/27/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022] Open
Abstract
Transfer RNAs (tRNAs) are abundant small non-coding RNAs that are crucially important for decoding genetic information. Besides fulfilling canonical roles as adaptor molecules during protein synthesis, tRNAs are also the source of a heterogeneous class of small RNAs, tRNA-derived small RNAs (tsRNAs). Occurrence and the relatively high abundance of tsRNAs has been noted in many high-throughput sequencing data sets, leading to largely correlative assumptions about their potential as biologically active entities. tRNAs are also the most modified RNAs in any cell type. Mutations in tRNA biogenesis factors including tRNA modification enzymes correlate with a variety of human disease syndromes. However, whether it is the lack of tRNAs or the activity of functionally relevant tsRNAs that are causative for human disease development remains to be elucidated. Here, we review the current knowledge in regard to tsRNAs biogenesis, including the impact of RNA modifications on tRNA stability and discuss the existing experimental evidence in support for the seemingly large functional spectrum being proposed for tsRNAs. We also argue that improved methodology allowing exact quantification and specific manipulation of tsRNAs will be necessary before developing these small RNAs into diagnostic biomarkers and when aiming to harness them for therapeutic purposes.
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Affiliation(s)
- Vera Oberbauer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria.
| | - Matthias R Schaefer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria.
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27
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Romano G, Veneziano D, Nigita G, Nana-Sinkam SP. RNA Methylation in ncRNA: Classes, Detection, and Molecular Associations. Front Genet 2018; 9:243. [PMID: 30050561 PMCID: PMC6052889 DOI: 10.3389/fgene.2018.00243] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/20/2018] [Indexed: 11/25/2022] Open
Abstract
Nearly all classes of coding and non-coding RNA undergo post-transcriptional modification, as more than 150 distinct modification types have been reported. Since RNA modifications were first described over 50 years ago, our understanding of their functional relevance in cellular control mechanisms and phenotypes has truly progressed only in the last 15 years due to advancements in detection and experimental techniques. Specifically, the phenomenon of RNA methylation in the context of ncRNA has emerged as a novel process in the arena of epitranscriptomics. Methylated ncRNA molecules may indeed contribute to a potentially vast functional panorama, from regulation of post-transcriptional gene expression to adaptive cellular responses. Recent discoveries have uncovered novel dynamic mechanisms and new layers of complexity, paving the way to a greater understanding of the role of such phenomena within the broader molecular cellular context of human disease.
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Affiliation(s)
- Giulia Romano
- Internal Medicine "Division of Pulmonary and Critical Care Medicine", Virginia Commonwealth University Health System, Richmond, VA, United States
| | - Dario Veneziano
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, OH, United States
| | - Giovanni Nigita
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, OH, United States
| | - Serge P Nana-Sinkam
- Internal Medicine "Division of Pulmonary and Critical Care Medicine", Virginia Commonwealth University Health System, Richmond, VA, United States
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28
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Lewinska A, Adamczyk-Grochala J, Kwasniewicz E, Wnuk M. Downregulation of methyltransferase Dnmt2 results in condition-dependent telomere shortening and senescence or apoptosis in mouse fibroblasts. J Cell Physiol 2017; 232:3714-3726. [PMID: 28177119 DOI: 10.1002/jcp.25848] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 01/05/2023]
Abstract
Dnmt2 is a highly conserved methyltransferase of uncertain biological function(s). As Dnmt2 was considered as a driver of fruit fly longevity and a modulator of stress response, we decided to evaluate the role of Dnmt2 during stress-induced premature senescence in NIH3T3 mouse fibroblasts. Stable knockdown of Dnmt2 resulted in hydrogen peroxide-mediated sensitivity and apoptosis, whereas in the control conditions, senescence was induced. Cellular senescence was accompanied by elevated levels of p53 and p21, decreased telomere length and telomerase activity, increased production of reactive oxygen species and protein carbonylation, and DNA damage. Dnmt2 silencing also promoted global DNA and RNA hypermethylation, and upregulation of methyltransferases, namely Dnmt1, Dnmt3a, and Dnmt3b. Taken together, we show for the first time that Dnmt2 may promote lifespan in the control conditions and survival during stress conditions in mouse fibroblasts.
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Affiliation(s)
- Anna Lewinska
- Laboratory of Cell Biology, University of Rzeszow, Kolbuszowa, Poland
| | | | - Ewa Kwasniewicz
- Laboratory of Cell Biology, University of Rzeszow, Kolbuszowa, Poland
| | - Maciej Wnuk
- Department of Genetics, University of Rzeszow, Kolbuszowa, Poland
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29
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Govindaraju G, Jabeena CA, Sethumadhavan DV, Rajaram N, Rajavelu A. DNA methyltransferase homologue TRDMT1 in Plasmodium falciparum specifically methylates endogenous aspartic acid tRNA. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:1047-1057. [PMID: 28847733 DOI: 10.1016/j.bbagrm.2017.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/17/2017] [Accepted: 08/21/2017] [Indexed: 11/28/2022]
Abstract
In eukaryotes, cytosine methylation regulates diverse biological processes such as gene expression, development and maintenance of genomic integrity. However, cytosine methylation and its functions in pathogenic apicomplexan protozoans remain enigmatic. To address this, here we investigated the presence of cytosine methylation in the nucleic acids of the protozoan Plasmodium falciparum. Interestingly, P. falciparum has TRDMT1, a conserved homologue of DNA methyltransferase DNMT2. However, we found that TRDMT1 did not methylate DNA, in vitro. We demonstrate that TRDMT1 methylates cytosine in the endogenous aspartic acid tRNA of P. falciparum. Through RNA bisulfite sequencing, we mapped the position of 5-methyl cytosine in aspartic acid tRNA and found methylation only at C38 position. P. falciparum proteome has significantly higher aspartic acid content and a higher proportion of proteins with poly aspartic acid repeats than other apicomplexan pathogenic protozoans. Proteins with such repeats are functionally important, with significant roles in host-pathogen interactions. Therefore, TRDMT1 mediated C38 methylation of aspartic acid tRNA might play a critical role by translational regulation of important proteins and modulate the pathogenicity of the malarial parasite.
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Affiliation(s)
- Gayathri Govindaraju
- Department of Tropical Disease Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram, Kerala 695 014, India
| | - C A Jabeena
- Department of Tropical Disease Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram, Kerala 695 014, India
| | | | - Nivethika Rajaram
- Department of Tropical Disease Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram, Kerala 695 014, India
| | - Arumugam Rajavelu
- Department of Tropical Disease Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram, Kerala 695 014, India.
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30
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David R, Burgess A, Parker B, Li J, Pulsford K, Sibbritt T, Preiss T, Searle IR. Transcriptome-Wide Mapping of RNA 5-Methylcytosine in Arabidopsis mRNAs and Noncoding RNAs. THE PLANT CELL 2017; 29:445-460. [PMID: 28062751 PMCID: PMC5385953 DOI: 10.1105/tpc.16.00751] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/08/2016] [Accepted: 01/02/2017] [Indexed: 05/20/2023]
Abstract
Posttranscriptional methylation of RNA cytosine residues to 5-methylcytosine (m5C) is an important modification with diverse roles, such as regulating stress responses, stem cell proliferation, and RNA metabolism. Here, we used RNA bisulfite sequencing for transcriptome-wide quantitative mapping of m5C in the model plant Arabidopsis thaliana We discovered more than a thousand m5C sites in Arabidopsis mRNAs, long noncoding RNAs, and other noncoding RNAs across three tissue types (siliques, seedling shoots, and roots) and validated a number of these sites. Quantitative differences in methylated sites between these three tissues suggest tissue-specific regulation of m5C. Perturbing the RNA m5C methyltransferase TRM4B resulted in the loss of m5C sites on mRNAs and noncoding RNAs and reduced the stability of tRNAAsp(GTC) We also demonstrate the importance of m5C in plant development, as trm4b mutants have shorter primary roots than the wild type due to reduced cell division in the root apical meristem. In addition, trm4b mutants show increased sensitivity to oxidative stress. Finally, we provide insights into the targeting mechanism of TRM4B by demonstrating that a 50-nucleotide sequence flanking m5C C3349 in MAIGO5 mRNA is sufficient to confer methylation of a transgene reporter in Nicotiana benthamiana.
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Affiliation(s)
- Rakesh David
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Alice Burgess
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Brian Parker
- Department of Biology, New York University, New York, New York 1003-6688
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jun Li
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Kalinya Pulsford
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Tennille Sibbritt
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia
| | - Iain Robert Searle
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
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31
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David R, Burgess A, Parker B, Li J, Pulsford K, Sibbritt T, Preiss T, Searle IR. Transcriptome-Wide Mapping of RNA 5-Methylcytosine in Arabidopsis mRNAs and Noncoding RNAs. THE PLANT CELL 2017. [PMID: 28062751 DOI: 10.6084/m9.figshare.3408193.v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Posttranscriptional methylation of RNA cytosine residues to 5-methylcytosine (m5C) is an important modification with diverse roles, such as regulating stress responses, stem cell proliferation, and RNA metabolism. Here, we used RNA bisulfite sequencing for transcriptome-wide quantitative mapping of m5C in the model plant Arabidopsis thaliana We discovered more than a thousand m5C sites in Arabidopsis mRNAs, long noncoding RNAs, and other noncoding RNAs across three tissue types (siliques, seedling shoots, and roots) and validated a number of these sites. Quantitative differences in methylated sites between these three tissues suggest tissue-specific regulation of m5C. Perturbing the RNA m5C methyltransferase TRM4B resulted in the loss of m5C sites on mRNAs and noncoding RNAs and reduced the stability of tRNAAsp(GTC) We also demonstrate the importance of m5C in plant development, as trm4b mutants have shorter primary roots than the wild type due to reduced cell division in the root apical meristem. In addition, trm4b mutants show increased sensitivity to oxidative stress. Finally, we provide insights into the targeting mechanism of TRM4B by demonstrating that a 50-nucleotide sequence flanking m5C C3349 in MAIGO5 mRNA is sufficient to confer methylation of a transgene reporter in Nicotiana benthamiana.
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Affiliation(s)
- Rakesh David
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Alice Burgess
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Brian Parker
- Department of Biology, New York University, New York, New York 1003-6688
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jun Li
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Kalinya Pulsford
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
| | - Tennille Sibbritt
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia
| | - Iain Robert Searle
- School of Biological Sciences, The University of Adelaide, The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Adelaide, South Australia 5005, Australia
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32
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Cross-Talk between Dnmt2-Dependent tRNA Methylation and Queuosine Modification. Biomolecules 2017; 7:biom7010014. [PMID: 28208632 PMCID: PMC5372726 DOI: 10.3390/biom7010014] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 12/22/2022] Open
Abstract
Enzymes of the Dnmt2 family of methyltransferases have yielded a number of unexpected discoveries. The first surprise came more than ten years ago when it was realized that, rather than being DNA methyltransferases, Dnmt2 enzymes actually are transfer RNA (tRNA) methyltransferases for cytosine-5 methylation, foremost C38 (m5C38) of tRNAAsp. The second unanticipated finding was our recent discovery of a nutritional regulation of Dnmt2 in the fission yeast Schizosaccharomyces pombe. Significantly, the presence of the nucleotide queuosine in tRNAAsp strongly stimulates Dnmt2 activity both in vivo and in vitro in S. pombe. Queuine, the respective base, is a hypermodified guanine analog that is synthesized from guanosine-5’-triphosphate (GTP) by bacteria. Interestingly, most eukaryotes have queuosine in their tRNA. However, they cannot synthesize it themselves, but rather salvage it from food or from gut microbes. The queuine obtained from these sources comes from the breakdown of tRNAs, where the queuine ultimately was synthesized by bacteria. Queuine thus has been termed a micronutrient. This review summarizes the current knowledge of Dnmt2 methylation and queuosine modification with respect to translation as well as the organismal consequences of the absence of these modifications. Models for the functional cooperation between these modifications and its wider implications are discussed.
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33
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Kaiser S, Jurkowski TP, Kellner S, Schneider D, Jeltsch A, Helm M. The RNA methyltransferase Dnmt2 methylates DNA in the structural context of a tRNA. RNA Biol 2016; 14:1241-1251. [PMID: 27819523 PMCID: PMC5699543 DOI: 10.1080/15476286.2016.1236170] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The amino acid sequence of Dnmt2 is very similar to the catalytic domains of bacterial and eukaryotic DNA-(cytosine 5)-methyltransferases, but it efficiently catalyzes tRNA methylation, while its DNA methyltransferase activity is the subject of controversial reports with rates varying between zero and very weak. By using composite nucleic acid molecules as substrates, we surprisingly found that DNA fragments, when presented as covalent DNA-RNA hybrids in the structural context of a tRNA, can be more efficiently methylated than the corresponding natural tRNA substrate. Furthermore, by stepwise development of tRNAAsp, we showed that this natural Dnmt2 substrate could be engineered to employ RNAs that act like guide RNAs in vitro. The 5’-half of tRNAAsp was able to efficiently guide methylation toward a single stranded tRNA fragment as would result from tRNA cleavage by tRNA specific nucleases. In a more artificial setting, a composite system of guide RNAs could ultimately be engineered to enable the enzyme to perform cytidine methylation on single stranded DNA in vitro.
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Affiliation(s)
- Steffen Kaiser
- a Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Mainz , Germany
| | - Tomasz P Jurkowski
- b Institute of Biochemistry, Faculty of Chemistry, University Stuttgart , Stuttgart , Germany
| | - Stefanie Kellner
- a Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Mainz , Germany
| | - Dirk Schneider
- a Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Mainz , Germany
| | - Albert Jeltsch
- b Institute of Biochemistry, Faculty of Chemistry, University Stuttgart , Stuttgart , Germany
| | - Mark Helm
- a Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Mainz , Germany
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34
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Jeltsch A, Ehrenhofer-Murray A, Jurkowski TP, Lyko F, Reuter G, Ankri S, Nellen W, Schaefer M, Helm M. Mechanism and biological role of Dnmt2 in Nucleic Acid Methylation. RNA Biol 2016; 14:1108-1123. [PMID: 27232191 PMCID: PMC5699548 DOI: 10.1080/15476286.2016.1191737] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A group of homologous nucleic acid modification enzymes called Dnmt2, Trdmt1, Pmt1, DnmA, and Ehmet in different model organisms catalyze the transfer of a methyl group from the cofactor S-adenosyl-methionine (SAM) to the carbon-5 of cytosine residues. Originally considered as DNA MTases, these enzymes were shown to be tRNA methyltransferases about a decade ago. Between the presumed involvement in DNA modification-related epigenetics, and the recent foray into the RNA modification field, significant progress has characterized Dnmt2-related research. Here, we review this progress in its diverse facets including molecular evolution, structural biology, biochemistry, chemical biology, cell biology and epigenetics.
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Affiliation(s)
- Albert Jeltsch
- a Institute of Biochemistry , Stuttgart University , Stuttgart , Germany
| | | | - Tomasz P Jurkowski
- a Institute of Biochemistry , Stuttgart University , Stuttgart , Germany
| | - Frank Lyko
- c Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center , Heidelberg , Germany
| | - Gunter Reuter
- d Institute of Biology, Developmental Genetics, Martin Luther University Halle , Halle , Germany
| | - Serge Ankri
- e Department of Molecular Microbiology , The Bruce Rappaport Faculty of Medicine , Technion , Haifa , Israel
| | - Wolfgang Nellen
- f Abteilung für Genetik, Universität Kassel , Kassel , Germany
| | - Matthias Schaefer
- g Medical University of Vienna, Center for Anatomy & Cell Biology , Vienna , Austria
| | - Mark Helm
- h Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz , Mainz , Germany
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35
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Arya D, Kapoor S, Kapoor M. Physcomitrella patens DNA methyltransferase 2is required for recovery from salt and osmotic stress. FEBS J 2016; 283:556-70. [DOI: 10.1111/febs.13611] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/06/2015] [Accepted: 11/25/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Deepshikha Arya
- University School of Biotechnology; Guru Gobind Singh Indraprastha University; New Delhi India
| | - Sanjay Kapoor
- Department of Plant Molecular Biology; Interdisciplinary Centre for Plant Genomics; University of Delhi; India
| | - Meenu Kapoor
- University School of Biotechnology; Guru Gobind Singh Indraprastha University; New Delhi India
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36
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Abstract
tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed.
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Affiliation(s)
- William E Swinehart
- a Center for RNA Biology and Department of Chemistry and Biochemistry ; Ohio State University ; Columbus , OH USA
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37
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Gaston KW, Limbach PA. The identification and characterization of non-coding and coding RNAs and their modified nucleosides by mass spectrometry. RNA Biol 2015; 11:1568-85. [PMID: 25616408 PMCID: PMC4615682 DOI: 10.4161/15476286.2014.992280] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The analysis of ribonucleic acids (RNA) by mass spectrometry has been a valuable analytical approach for more than 25 years. In fact, mass spectrometry has become a method of choice for the analysis of modified nucleosides from RNA isolated out of biological samples. This review summarizes recent progress that has been made in both nucleoside and oligonucleotide mass spectral analysis. Applications of mass spectrometry in the identification, characterization and quantification of modified nucleosides are discussed. At the oligonucleotide level, advances in modern mass spectrometry approaches combined with the standard RNA modification mapping protocol enable the characterization of RNAs of varying lengths ranging from low molecular weight short interfering RNAs (siRNAs) to the extremely large 23 S rRNAs. New variations and improvements to this protocol are reviewed, including top-down strategies, as these developments now enable qualitative and quantitative measurements of RNA modification patterns in a variety of biological systems.
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Affiliation(s)
- Kirk W Gaston
- a Rieveschl Laboratories for Mass Spectrometry; Department of Chemistry ; University of Cincinnati ; Cincinnati , OH USA
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38
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Müller M, Hartmann M, Schuster I, Bender S, Thüring KL, Helm M, Katze JR, Nellen W, Lyko F, Ehrenhofer-Murray AE. Dynamic modulation of Dnmt2-dependent tRNA methylation by the micronutrient queuine. Nucleic Acids Res 2015; 43:10952-62. [PMID: 26424849 PMCID: PMC4678861 DOI: 10.1093/nar/gkv980] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/17/2015] [Indexed: 01/13/2023] Open
Abstract
Dnmt2 enzymes are cytosine-5 methyltransferases that methylate C38 of several tRNAs. We report here that the activities of two Dnmt2 homologs, Pmt1 from Schizosaccharomyces pombe and DnmA from Dictyostelium discoideum, are strongly stimulated by prior queuosine (Q) modification of the substrate tRNA. In vivo tRNA methylation levels were stimulated by growth of cells in queuine-containing medium; in vitro Pmt1 activity was enhanced on Q-containing RNA; and queuine-stimulated in vivo methylation was abrogated by the absence of the enzyme that inserts queuine into tRNA, eukaryotic tRNA-guanine transglycosylase. Global analysis of tRNA methylation in S. pombe showed a striking selectivity of Pmt1 for tRNA(Asp) methylation, which distinguishes Pmt1 from other Dnmt2 homologs. The present analysis also revealed a novel Pmt1- and Q-independent tRNA methylation site in S. pombe, C34 of tRNA(Pro). Notably, queuine is a micronutrient that is scavenged by higher eukaryotes from the diet and gut microflora. This work therefore reveals an unanticipated route by which the environment can modulate tRNA modification in an organism.
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Affiliation(s)
- Martin Müller
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Mark Hartmann
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | | | - Sebastian Bender
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Kathrin L Thüring
- Institut für Pharmakologie und Biochemie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Mark Helm
- Institut für Pharmakologie und Biochemie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Jon R Katze
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Wolfgang Nellen
- Abteilung für Genetik, Universität Kassel, 34132 Kassel, Germany
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
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39
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Haag S, Warda AS, Kretschmer J, Günnigmann MA, Höbartner C, Bohnsack MT. NSUN6 is a human RNA methyltransferase that catalyzes formation of m5C72 in specific tRNAs. RNA (NEW YORK, N.Y.) 2015; 21:1532-43. [PMID: 26160102 PMCID: PMC4536315 DOI: 10.1261/rna.051524.115] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 06/01/2015] [Indexed: 05/04/2023]
Abstract
Many cellular RNAs require modification of specific residues for their biogenesis, structure, and function. 5-methylcytosine (m(5)C) is a common chemical modification in DNA and RNA but in contrast to the DNA modifying enzymes, only little is known about the methyltransferases that establish m(5)C modifications in RNA. The putative RNA methyltransferase NSUN6 belongs to the family of Nol1/Nop2/SUN domain (NSUN) proteins, but so far its cellular function has remained unknown. To reveal the target spectrum of human NSUN6, we applied UV crosslinking and analysis of cDNA (CRAC) as well as chemical crosslinking with 5-azacytidine. We found that human NSUN6 is associated with tRNAs and acts as a tRNA methyltransferase. Furthermore, we uncovered tRNA(Cys) and tRNA(Thr) as RNA substrates of NSUN6 and identified the cytosine C72 at the 3' end of the tRNA acceptor stem as the target nucleoside. Interestingly, target recognition in vitro depends on the presence of the 3'-CCA tail. Together with the finding that NSUN6 localizes to the cytoplasm and largely colocalizes with marker proteins for the Golgi apparatus and pericentriolar matrix, our data suggest that NSUN6 modifies tRNAs in a late step in their biogenesis.
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Affiliation(s)
- Sara Haag
- Centre for Biochemistry and Molecular Cell Biology, Georg-August-University, 37073 Göttingen, Germany
| | - Ahmed S Warda
- Centre for Biochemistry and Molecular Cell Biology, Georg-August-University, 37073 Göttingen, Germany
| | - Jens Kretschmer
- Centre for Biochemistry and Molecular Cell Biology, Georg-August-University, 37073 Göttingen, Germany
| | - Manuel A Günnigmann
- Centre for Biochemistry and Molecular Cell Biology, Georg-August-University, 37073 Göttingen, Germany
| | - Claudia Höbartner
- Institute for Organic and Biomolecular Chemistry, Georg-August-University, 37077 Göttingen, Germany
| | - Markus T Bohnsack
- Centre for Biochemistry and Molecular Cell Biology, Georg-August-University, 37073 Göttingen, Germany Göttingen Centre for Molecular Biosciences, Georg-August-University, 37073 Göttingen, Germany
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40
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Tuorto F, Herbst F, Alerasool N, Bender S, Popp O, Federico G, Reitter S, Liebers R, Stoecklin G, Gröne HJ, Dittmar G, Glimm H, Lyko F. The tRNA methyltransferase Dnmt2 is required for accurate polypeptide synthesis during haematopoiesis. EMBO J 2015; 34:2350-62. [PMID: 26271101 PMCID: PMC4570521 DOI: 10.15252/embj.201591382] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 07/16/2015] [Indexed: 12/17/2022] Open
Abstract
The Dnmt2 enzyme utilizes the catalytic mechanism of eukaryotic DNA methyltransferases to methylate several tRNAs at cytosine 38. Dnmt2 mutant mice, flies, and plants were reported to be viable and fertile, and the biological function of Dnmt2 has remained elusive. Here, we show that endochondral ossification is delayed in newborn Dnmt2-deficient mice, which is accompanied by a reduction of the haematopoietic stem and progenitor cell population and a cell-autonomous defect in their differentiation. RNA bisulfite sequencing revealed that Dnmt2 methylates C38 of tRNA AspGTC, GlyGCC, and ValAAC, thus preventing tRNA fragmentation. Proteomic analyses from primary bone marrow cells uncovered systematic differences in protein expression that are due to specific codon mistranslation by tRNAs lacking Dnmt2-dependent methylation. Our observations demonstrate that Dnmt2 plays an important role in haematopoiesis and define a novel function of C38 tRNA methylation in the discrimination of near-cognate codons, thereby ensuring accurate polypeptide synthesis.
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Affiliation(s)
- Francesca Tuorto
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Friederike Herbst
- Department of Translational Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nader Alerasool
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Sebastian Bender
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Oliver Popp
- Mass Spectrometry Core Unit, MDC, Berlin, Germany
| | - Giuseppina Federico
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
| | - Sonja Reitter
- Helmholtz Junior Research Group Posttranscriptional Control of Gene Expression, German Cancer Research Center (DKFZ) and Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Reinhard Liebers
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Georg Stoecklin
- Helmholtz Junior Research Group Posttranscriptional Control of Gene Expression, German Cancer Research Center (DKFZ) and Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Hermann-Josef Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
| | | | - Hanno Glimm
- Department of Translational Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
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41
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The Spontaneous Mutation Rate in the Fission Yeast Schizosaccharomyces pombe. Genetics 2015; 201:737-44. [PMID: 26265703 DOI: 10.1534/genetics.115.177329] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/30/2015] [Indexed: 02/07/2023] Open
Abstract
The rate at which new mutations arise in the genome is a key factor in the evolution and adaptation of species. Here we describe the rate and spectrum of spontaneous mutations for the fission yeast Schizosaccharomyces pombe, a key model organism with many similarities to higher eukaryotes. We undertook an ∼1700-generation mutation accumulation (MA) experiment with a haploid S. pombe, generating 422 single-base substitutions and 119 insertion-deletion mutations (indels) across the 96 replicates. This equates to a base-substitution mutation rate of 2.00 × 10(-10) mutations per site per generation, similar to that reported for the distantly related budding yeast Saccharomyces cerevisiae. However, these two yeast species differ dramatically in their spectrum of base substitutions, the types of indels (S. pombe is more prone to insertions), and the pattern of selection required to counteract a strong AT-biased mutation rate. Overall, our results indicate that GC-biased gene conversion does not play a major role in shaping the nucleotide composition of the S. pombe genome and suggest that the mechanisms of DNA maintenance may have diverged significantly between fission and budding yeasts. Unexpectedly, CpG sites appear to be excessively liable to mutation in both species despite the likely absence of DNA methylation.
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42
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Shanmugam R, Fierer J, Kaiser S, Helm M, Jurkowski TP, Jeltsch A. Cytosine methylation of tRNA-Asp by DNMT2 has a role in translation of proteins containing poly-Asp sequences. Cell Discov 2015; 1:15010. [PMID: 27462411 PMCID: PMC4860778 DOI: 10.1038/celldisc.2015.10] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/26/2015] [Indexed: 01/09/2023] Open
Abstract
The Dnmt2 RNA methyltransferase catalyses the methylation of C38 in the anticodon loop of tRNA-Asp, but the molecular role of this methylation is unknown. Here, we report that mouse aspartyl-tRNA synthetase shows a four to fivefold preference for C38-methylated tRNA-Asp. Consistently, a 30% reduced charging level of tRNA-Asp was observed in Dnmt2 knockout (KO) murine embryonic fibroblast cells. Gene expression analysis with fluorescent reporter proteins fused to an N-terminal poly-Asp sequence showed that protein synthesis of poly-Asp-tagged reporter proteins was reduced in Dnmt2 KO cells as well. The same effect was observed with endogenous proteins containing poly-Asp sequences, indicating that Dnmt2-mediated C38 methylation of tRNA-Asp regulates the translation of proteins containing poly-Asp sequences. Gene ontology searches for proteins containing poly-Asp sequences in the human proteome showed that a significant number of these proteins have roles in transcriptional regulation and gene expression. Hence, the Dnmt2-mediated methylation of tRNA-Asp exhibits a post-transcriptional regulatory role by controlling the synthesis of a group of target proteins containing poly-Asp sequences.
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Affiliation(s)
- Raghuvaran Shanmugam
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
| | - Jacob Fierer
- MoLife Program, School of Engineering and Science, Jacobs University Bremen , Bremen, Germany
| | - Steffen Kaiser
- Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany
| | - Tomasz P Jurkowski
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
| | - Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
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43
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Khoddami V, Yerra A, Cairns BR. Experimental Approaches for Target Profiling of RNA Cytosine Methyltransferases. Methods Enzymol 2015; 560:273-96. [PMID: 26253975 DOI: 10.1016/bs.mie.2015.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
RNA cytosine methyltransferases (m(5)C-RMTs) constitute an important class of RNA-modifying enzymes, methylating specific cytosines within particular RNA targets in both coding and noncoding RNAs. Almost all organisms express at least one m(5)C-RMT, and vertebrates often express different types or variants of m(5)C-RMTs in different cell types. Deletion or mutation of particular m(5)C-RMTs is connected to severe pathological manifestations ranging from developmental defects to infertility and mental retardation. Some m(5)C-RMTs show spatiotemporal patterns of expression and activity requiring careful experimental design for their analysis in order to capture their context-dependent targets. An essential step for understanding the functions of both the enzymes and the modified cytosines is defining the one-to-one connection between particular m(5)C-RMTs and their target cytosines. Recent technological and methodological advances have provided researchers with new tools to comprehensively explore RNA cytosine methylation and methyltransferases. Here, we describe three complementary approaches applicable for both discovery and validation of candidate target sites of specific m(5)C-RMTs.
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Affiliation(s)
- Vahid Khoddami
- HHMI, Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, USA; Current address: Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Archana Yerra
- HHMI, Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Bradley R Cairns
- HHMI, Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, USA.
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44
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Abstract
Cells have developed molecular machineries, which can chemically modify DNA and RNA nucleosides. One particular and chemically simple modification, (cytosine-5) methylation (m(5)C), has been detected both in RNA and DNA suggesting universal use of m(5)C for the function of these nucleotide polymers. m(5)C can be reproducibly mapped to abundant noncoding RNAs (transfer RNA, tRNA and ribosomal RNA, rRNA), and recently, also nonabundant RNAs (including mRNAs) have been reported to carry this modification. Quantification of m(5)C content in total RNA preparations indicates that a limited number of RNAs carry this modification and suggests specific functions for (cytosine-5) RNA methylation. What exactly is the biological function of m(5)C in RNA? Before attempting to address this question, m(5)C needs to be mapped specifically and reproducibly, preferably on a transcriptome-wide scale. To facilitate the detection of m(5)C in its sequence context, RNA bisulfite sequencing (RNA-BisSeq) has been developed. This method relies on the efficient chemical deamination of nonmethylated cytosine, which can be read out as single nucleotide polymorphism (nonmethylated cytosine as thymine vs. methylated cytosine as cytosine), when differentially comparing cDNA libraries to reference sequences after DNA sequencing. Here, the basic protocol of RNA-BisSeq, its current applications and limitations are described.
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Affiliation(s)
- Matthias Schaefer
- Vienna Biocenter, Max F. Perutz Laboratories, Department of Biochemistry and Cell Biology, Universität Wien, Vienna, Austria.
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45
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Elhardt W, Shanmugam R, Jurkowski TP, Jeltsch A. Somatic cancer mutations in the DNMT2 tRNA methyltransferase alter its catalytic properties. Biochimie 2015; 112:66-72. [PMID: 25747896 DOI: 10.1016/j.biochi.2015.02.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/24/2015] [Indexed: 12/22/2022]
Abstract
Methylation of tRNA is an important post-transcriptional modification and aberrations in tRNA modification has been implicated in cancer. The DNMT2 protein methylates C38 of tRNA-Asp and it has a role in cellular physiology and stress response and its expression levels are altered in cancer tissues. Here we studied whether DNMT2 somatic mutations found in cancer tissues affect the activity of the enzyme. We have generated 13 DNMT2 variants and purified the corresponding proteins. All proteins were properly folded as determined by circular dichroism spectroscopy. We tested their RNA methylation activity using in vitro generated tRNA-Asp. One of the mutations (E63K) caused a twofold increase in activity, while two of them led to a strong (over fourfold) decrease in activity (G155S and L257V). Two additional mutant proteins were almost inactive (R371H and G155V). The strong effect of some of the somatic cancer mutations on DNMT2 activity suggests that these mutations have a functional role in tumorigenesis.
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Affiliation(s)
- Winfried Elhardt
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany
| | | | - Tomasz P Jurkowski
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany.
| | - Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany.
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46
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Choi Y, Mango SE. Hunting for Darwin's gemmules and Lamarck's fluid: Transgenerational signaling and histone methylation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:1440-53. [DOI: 10.1016/j.bbagrm.2014.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 05/07/2014] [Accepted: 05/13/2014] [Indexed: 01/22/2023]
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47
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Shanmugam R, Aklujkar M, Schäfer M, Reinhardt R, Nickel O, Reuter G, Lovley DR, Ehrenhofer-Murray A, Nellen W, Ankri S, Helm M, Jurkowski TP, Jeltsch A. The Dnmt2 RNA methyltransferase homolog of Geobacter sulfurreducens specifically methylates tRNA-Glu. Nucleic Acids Res 2014; 42:6487-96. [PMID: 24711368 PMCID: PMC4041430 DOI: 10.1093/nar/gku256] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Dnmt2 enzymes are conserved in eukaryotes, where they methylate C38 of tRNA-Asp with high activity. Here, the activity of one of the very few prokaryotic Dnmt2 homologs from Geobacter species (GsDnmt2) was investigated. GsDnmt2 was observed to methylate tRNA-Asp from flies and mice. Unexpectedly, it had only a weak activity toward its matching Geobacter tRNA-Asp, but methylated Geobacter tRNA-Glu with good activity. In agreement with this result, we show that tRNA-Glu is methylated in Geobacter while the methylation is absent in tRNA-Asp. The activities of Dnmt2 enzymes from Homo sapiens, Drosophila melanogaster, Schizosaccharomyces pombe and Dictyostelium discoideum for methylation of the Geobacter tRNA-Asp and tRNA-Glu were determined showing that all these Dnmt2s preferentially methylate tRNA-Asp. Hence, the GsDnmt2 enzyme has a swapped transfer ribonucleic acid (tRNA) specificity. By comparing the different tRNAs, a characteristic sequence pattern was identified in the variable loop of all preferred tRNA substrates. An exchange of two nucleotides in the variable loop of murine tRNA-Asp converted it to the corresponding variable loop of tRNA-Glu and led to a strong reduction of GsDnmt2 activity. Interestingly, the same loss of activity was observed with human DNMT2, indicating that the variable loop functions as a specificity determinant in tRNA recognition of Dnmt2 enzymes.
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Affiliation(s)
| | - Muktak Aklujkar
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA
| | - Matthias Schäfer
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | | | - Olaf Nickel
- Institute of Biology, Developmental Genetics, Martin Luther University Halle, 06120 Halle, Germany
| | - Gunter Reuter
- Institute of Biology, Developmental Genetics, Martin Luther University Halle, 06120 Halle, Germany
| | - Derek R Lovley
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA
| | | | - Wolfgang Nellen
- Department of Genetics, University of Kassel, 34132 Kassel, Germany
| | - Serge Ankri
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Tomasz P Jurkowski
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany
| | - Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany
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48
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Capuano F, Mülleder M, Kok R, Blom HJ, Ralser M. Cytosine DNA methylation is found in Drosophila melanogaster but absent in Saccharomyces cerevisiae, Schizosaccharomyces pombe, and other yeast species. Anal Chem 2014; 86:3697-702. [PMID: 24640988 PMCID: PMC4006885 DOI: 10.1021/ac500447w] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
![]()
The methylation of cytosine to 5-methylcytosine
(5-meC) is an important
epigenetic DNA modification in many bacteria, plants, and mammals,
but its relevance for important model organisms, including Caenorhabditis elegans and Drosophila
melanogaster, is still equivocal. By reporting the
presence of 5-meC in a broad variety of wild, laboratory, and industrial
yeasts, a recent study also challenged the dogma about the absence
of DNA methylation in yeast species. We would like to bring to attention
that the protocol used for gas chromatography/mass spectrometry involved
hydrolysis of the DNA preparations. As this process separates cytosine
and 5-meC from the sugar phosphate backbone, this method is unable
to distinguish DNA- from RNA-derived 5-meC. We employed an alternative
LC–MS/MS protocol where by targeting 5-methyldeoxycytidine
moieties after enzymatic digestion, only 5-meC specifically derived
from DNA is quantified. This technique unambiguously identified cytosine
DNA methylation in Arabidopsis thaliana (14.0% of cytosines methylated), Mus musculus (7.6%), and Escherichia coli (2.3%).
Despite achieving a detection limit at 250 attomoles (corresponding
to <0.00002 methylated cytosines per nonmethylated cytosine), we
could not confirm any cytosine DNA methylation in laboratory and industrial
strains of Saccharomyces cerevisiae, Schizosaccharomyces pombe, Saccharomyces boulardii, Saccharomyces
paradoxus, or Pichia pastoris. The protocol however unequivocally confirmed DNA methylation in
adult Drosophila melanogaster at a
value (0.034%) that is up to 2 orders of magnitude below the detection
limit of bisulphite sequencing. Thus, 5-meC is a rare DNA modification
in drosophila but absent in yeast.
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Affiliation(s)
- Floriana Capuano
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge , 80 Tennis Court Road, Cambridge CB2 1GA, U.K
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49
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The Entamoeba histolytica Dnmt2 homolog (Ehmeth) confers resistance to nitrosative stress. EUKARYOTIC CELL 2014; 13:494-503. [PMID: 24562908 DOI: 10.1128/ec.00031-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nitric oxide (NO) has antimicrobial properties against many pathogens due to its reactivity as an S-nitrosylating agent. It inhibits many of the key enzymes that are involved in the metabolism and virulence of the parasite Entamoeba histolytica through S-nitrosylation of essential cysteine residues. Very little information is available on the mechanism of resistance to NO by pathogens in general and by this parasite in particular. Here, we report that exposure of the parasites to S-nitrosoglutathione (GSNO), an NO donor molecule, strongly reduces their viability and protein synthesis. However, the deleterious effects of NO were significantly reduced in trophozoites overexpressing Ehmeth, the cytosine-5 methyltransferase of the Dnmt2 family. Since these trophozoites also exhibited high levels of tRNA(Asp) methylation, the high levels suggested that Ehmeth-mediated tRNA(Asp) methylation is part of the resistance mechanism to NO. We previously reported that enolase, another glycolytic enzyme, binds to Ehmeth and inhibits its activity. We observed that the amount of Ehmeth-enolase complex was significantly reduced in GSNO-treated E. histolytica, which explains the aforementioned increase of tRNA methylation. Specifically, we demonstrated via site-directed mutagenesis that cysteine residues 228 and 229 of Ehmeth are susceptible to S-nitrosylation and are crucial for Ehmeth binding to enolase and for Ehmeth-mediated resistance to NO. These results indicate that Ehmeth has a central role in the response of the parasite to NO, and they contribute to the growing evidence that NO is a regulator of epigenetic mechanisms.
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Rallis C, López-Maury L, Georgescu T, Pancaldi V, Bähler J. Systematic screen for mutants resistant to TORC1 inhibition in fission yeast reveals genes involved in cellular ageing and growth. Biol Open 2014; 3:161-71. [PMID: 24463365 PMCID: PMC3925319 DOI: 10.1242/bio.20147245] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Target of rapamycin complex 1 (TORC1), which controls growth in response to nutrients, promotes ageing in multiple organisms. The fission yeast Schizosaccharomyces pombe emerges as a valuable genetic model system to study TORC1 function and cellular ageing. Here we exploited the combinatorial action of rapamycin and caffeine, which inhibit fission yeast growth in a TORC1-dependent manner. We screened a deletion library, comprising ∼84% of all non-essential fission yeast genes, for drug-resistant mutants. This screen identified 33 genes encoding functions such as transcription, kinases, mitochondrial respiration, biosynthesis, intra-cellular trafficking, and stress response. Among the corresponding mutants, 5 showed shortened and 21 showed increased maximal chronological lifespans; 15 of the latter mutants showed no further lifespan increase with rapamycin and might thus represent key targets downstream of TORC1. We pursued the long-lived sck2 mutant with additional functional analyses, revealing that the Sck2p kinase functions within the TORC1 network and is required for normal cell growth, global protein translation, and ribosomal S6 protein phosphorylation in a nutrient-dependent manner. Notably, slow cell growth was associated with all long-lived mutants while oxidative-stress resistance was not.
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Affiliation(s)
- Charalampos Rallis
- Department of Genetics, Evolution and Environment, and Institute of Healthy Ageing, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
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