1
|
Smirnoff N, Wheeler GL. The ascorbate biosynthesis pathway in plants is known, but there is a way to go with understanding control and functions. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2604-2630. [PMID: 38300237 PMCID: PMC11066809 DOI: 10.1093/jxb/erad505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/29/2024] [Indexed: 02/02/2024]
Abstract
Ascorbate (vitamin C) is one of the most abundant primary metabolites in plants. Its complex chemistry enables it to function as an antioxidant, as a free radical scavenger, and as a reductant for iron and copper. Ascorbate biosynthesis occurs via the mannose/l-galactose pathway in green plants, and the evidence for this pathway being the major route is reviewed. Ascorbate accumulation is leaves is responsive to light, reflecting various roles in photoprotection. GDP-l-galactose phosphorylase (GGP) is the first dedicated step in the pathway and is important in controlling ascorbate synthesis. Its expression is determined by a combination of transcription and translation. Translation is controlled by an upstream open reading frame (uORF) which blocks translation of the main GGP-coding sequence, possibly in an ascorbate-dependent manner. GGP associates with a PAS-LOV protein, inhibiting its activity, and dissociation is induced by blue light. While low ascorbate mutants are susceptible to oxidative stress, they grow nearly normally. In contrast, mutants lacking ascorbate do not grow unless rescued by supplementation. Further research should investigate possible basal functions of ascorbate in severely deficient plants involving prevention of iron overoxidation in 2-oxoglutarate-dependent dioxygenases and iron mobilization during seed development and germination.
Collapse
Affiliation(s)
- Nicholas Smirnoff
- Biosciences, Faculty of Health and Life Sciences, Exeter EX4 4QD, UK
| | | |
Collapse
|
2
|
Zhang L, Mu Y, Li T, Hu J, Lin H, Zhang L. Molecular basis of an atypical dsDNA 5mC/6mA bifunctional dioxygenase CcTet from Coprinopsis cinerea in catalyzing dsDNA 5mC demethylation. Nucleic Acids Res 2024; 52:3886-3895. [PMID: 38324471 PMCID: PMC11040006 DOI: 10.1093/nar/gkae066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/22/2023] [Accepted: 01/24/2024] [Indexed: 02/09/2024] Open
Abstract
The eukaryotic epigenetic modifications 5-methyldeoxycytosine (5mC) and N6-methyldeoxyadenine (6mA) have indispensable regulatory roles in gene expression and embryonic development. We recently identified an atypical bifunctional dioxygenase CcTet from Coprinopsis cinerea that works on both 5mC and 6mA demethylation. The nonconserved residues Gly331 and Asp337 of CcTet facilitate 6mA accommodation, while D337F unexpectedly abolishes 5mC oxidation activity without interfering 6mA demethylation, indicating a prominent distinct but unclear 5mC oxidation mechanism to the conventional Tet enzymes. Here, we assessed the molecular mechanism of CcTet in catalyzing 5mC oxidation by representing the crystal structure of CcTet-5mC-dsDNA complex. We identified the distinct mechanism by which CcTet recognizes 5mC-dsDNA compared to 6mA-dsDNA substrate. Moreover, Asp337 was found to have a central role in compensating for the loss of a critical 5mC-stablizing H-bond observed in conventional Tet enzymes, and stabilizes 5mC and subsequent intermediates through an H-bond with the N4 atom of the substrates. These findings improve our understanding of Tet enzyme functions in the dsDNA 5mC and 6mA demethylation pathways, and provide useful information for future discovery of small molecular probes targeting Tet enzymes in DNA active demethylation processes.
Collapse
Affiliation(s)
- Lin Zhang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Systems Medicine for Cancer, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yajuan Mu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Systems Medicine for Cancer, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Tingting Li
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Systems Medicine for Cancer, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingyan Hu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Systems Medicine for Cancer, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Houwen Lin
- Research Centre for Marine Drugs, State Key Laboratory of Oncogene and Related Genes, Department of Pharmacy, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Institute of Marine Biomedicine, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Liang Zhang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Systems Medicine for Cancer, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| |
Collapse
|
3
|
Meng WY, Wang ZX, Zhang Y, Hou Y, Xue JH. Epigenetic marks or not? The discovery of novel DNA modifications in eukaryotes. J Biol Chem 2024; 300:106791. [PMID: 38403247 PMCID: PMC11065753 DOI: 10.1016/j.jbc.2024.106791] [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: 10/29/2023] [Revised: 01/24/2024] [Accepted: 02/04/2024] [Indexed: 02/27/2024] Open
Abstract
DNA modifications add another layer of complexity to the eukaryotic genome to regulate gene expression, playing critical roles as epigenetic marks. In eukaryotes, the study of DNA epigenetic modifications has been confined to 5mC and its derivatives for decades. However, rapid developing approaches have witnessed the expansion of DNA modification reservoirs during the past several years, including the identification of 6mA, 5gmC, 4mC, and 4acC in diverse organisms. However, whether these DNA modifications function as epigenetic marks requires careful consideration. In this review, we try to present a panorama of all the DNA epigenetic modifications in eukaryotes, emphasizing recent breakthroughs in the identification of novel DNA modifications. The characterization of their roles in transcriptional regulation as potential epigenetic marks is summarized. More importantly, the pathways for generating or eliminating these DNA modifications, as well as the proteins involved are comprehensively dissected. Furthermore, we briefly discuss the potential challenges and perspectives, which should be taken into account while investigating novel DNA modifications.
Collapse
Affiliation(s)
- Wei-Ying Meng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital affiliated to Tongji University, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zi-Xin Wang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital affiliated to Tongji University, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yunfang Zhang
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yujun Hou
- Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
| | - Jian-Huang Xue
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Tongji Hospital affiliated to Tongji University, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
| |
Collapse
|
4
|
Liu X, He W, Hu L. Exploring transient global transcriptional changes induced by ascorbic acid revealed via atKAS-seq profiling. Funct Integr Genomics 2024; 24:66. [PMID: 38526630 DOI: 10.1007/s10142-024-01349-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 03/27/2024]
Abstract
Transcription initiates the formation of single-stranded DNA (ssDNA) regions within the genome, delineating transcription bubbles, a highly dynamic genomic process. Kethoxal-assisted single-stranded DNA sequencing (KAS-seq) utilizing N3-kethoxal has emerged as a potent tool for mapping specific guanine positions in ssDNA on a genome-wide scale. However, the original KAS-seq method required the costly Accel-NGS Methyl-seq DNA library kit. This study introduces an optimized iteration of the KAS-seq technique, referred to as adapter-tagged KAS-seq (atKAS-seq), incorporating an adapter tagging strategy. This modification involves integrating sequencing adapters via complementary strand synthesis using random N9 tagging. Additionally, by harnessing the potential of ascorbic acid (ASC), recognized for inducing global epigenetic changes, we employed the atKAS-seq methodology to elucidate critical pathways influenced by short-term, high-dose ASC treatment. Our findings underscore that atKAS-seq enables rapid and precise analyses of transcription dynamics and enhancer activities concurrently. This method offers a streamlined, cost-efficient, and low-input approach, affirming its utility in probing intricate genomic regulatory mechanisms.
Collapse
Affiliation(s)
- Xiangyue Liu
- Cancer Institute, Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-Laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Weizhi He
- Cancer Institute, Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-Laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Lulu Hu
- Cancer Institute, Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-Laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai, 200032, China.
| |
Collapse
|
5
|
Wu P, Li B, Liu Y, Bian Z, Xiong J, Wang Y, Zhu B. Multiple Physiological and Biochemical Functions of Ascorbic Acid in Plant Growth, Development, and Abiotic Stress Response. Int J Mol Sci 2024; 25:1832. [PMID: 38339111 PMCID: PMC10855474 DOI: 10.3390/ijms25031832] [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: 12/04/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/12/2024] Open
Abstract
Ascorbic acid (AsA) is an important nutrient for human health and disease cures, and it is also a crucial indicator for the quality of fruit and vegetables. As a reductant, AsA plays a pivotal role in maintaining the intracellular redox balance throughout all the stages of plant growth and development, fruit ripening, and abiotic stress responses. In recent years, the de novo synthesis and regulation at the transcriptional level and post-transcriptional level of AsA in plants have been studied relatively thoroughly. However, a comprehensive and systematic summary about AsA-involved biochemical pathways, as well as AsA's physiological functions in plants, is still lacking. In this review, we summarize and discuss the multiple physiological and biochemical functions of AsA in plants, including its involvement as a cofactor, substrate, antioxidant, and pro-oxidant. This review will help to facilitate a better understanding of the multiple functions of AsA in plant cells, as well as provide information on how to utilize AsA more efficiently by using modern molecular biology methods.
Collapse
Affiliation(s)
- Peiwen Wu
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| | - Bowen Li
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| | - Ye Liu
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| | - Zheng Bian
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| | - Jiaxin Xiong
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| | - Yunxiang Wang
- Institute of Agri-Food Processing and Nutrition, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
| | - Benzhong Zhu
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; (P.W.); (B.L.); (Y.L.); (Z.B.); (J.X.)
| |
Collapse
|
6
|
He W, Yin X, Xu C, Liu X, Huang Y, Yang C, Xu Y, Hu L. Ascorbic Acid Reprograms Epigenome and Epitranscriptome by Reducing Fe(III) in the Catalytic Cycle of Dioxygenases. ACS Chem Biol 2024; 19:129-140. [PMID: 38100359 DOI: 10.1021/acschembio.3c00567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Ascorbic acid (ASC) has been reported to stimulate DNA iterative oxidase ten-eleven translocation (TET) enzymes, Jumonji C-domain-containing histone demethylases, and potentially RNA m6A demethylases FTO and ALKBH5 as a cofactor. Although ascorbic acid has been widely investigated in reprogramming DNA and histone methylation status in vitro, in cultured cells and mouse models, its specific role in the catalytic cycle of dioxygenases remains enigmatic. Here, we systematically investigated the stimulation of ASC toward TET2, ALKBH3, histone demethylases, and FTO. We find that ASC reprograms epitranscriptome by erasing the hypermethylated m6A sites in mRNA. Biochemistry and electron spin resonance assays demonstrate that ASC enters the active pocket of dioxygenases and reduces Fe(III), either incorporated upon protein synthesis or generated upon rebounding the hydroxyl radical during oxidation, into Fe(II). Finally, we propose a remedied model for the catalytic cycle of dioxygenases by adding in the essential cofactor, ASC, which refreshes and regenerates inactive dioxygenase through recycling Fe(III) into Fe(II) in a dynamic "hit-and-run" manner.
Collapse
Affiliation(s)
- Weizhi He
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiaotong Yin
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Chu Xu
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiangyue Liu
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yue Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Caiguang Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yanhui Xu
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Lulu Hu
- Cancer Institute, Fudan university Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Shanghai Medical College of Fudan University, Shanghai 200032, China
| |
Collapse
|
7
|
Treadway CJ, Boyer JA, Yang S, Yang H, Liu M, Li Z, Cheng M, Marzluff WF, Ye D, Xiong Y, Baldwin AS, Zhang Q, Brown NG. Using NMR to Monitor TET-Dependent Methylcytosine Dioxygenase Activity and Regulation. ACS Chem Biol 2024; 19:15-21. [PMID: 38193366 PMCID: PMC11075173 DOI: 10.1021/acschembio.3c00619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The active removal of DNA methylation marks is governed by the ten-eleven translocation (TET) family of enzymes (TET1-3), which iteratively oxidize 5-methycytosine (5mC) into 5-hydroxymethycytosine (5hmC), and then 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). TET proteins are frequently mutated in myeloid malignancies or inactivated in solid tumors. These methylcytosine dioxygenases are α-ketoglutarate (αKG)-dependent and are, therefore, sensitive to metabolic homeostasis. For example, TET2 is activated by vitamin C (VC) and inhibited by specific oncometabolites. However, understanding the regulation of the TET2 enzyme by different metabolites and its activity remains challenging because of limitations in the methods used to simultaneously monitor TET2 substrates, products, and cofactors during catalysis. Here, we measure TET2-dependent activity in real time using NMR. Additionally, we demonstrate that in vitro activity of TET2 is highly dependent on the presence of VC in our system and is potently inhibited by an intermediate metabolite of the TCA cycle, oxaloacetate (OAA). Despite these opposing effects on TET2 activity, the binding sites of VC and OAA on TET2 are shared with αKG. Overall, our work suggests that NMR can be effectively used to monitor TET2 catalysis and illustrates how TET activity is regulated by metabolic and cellular conditions at each oxidation step.
Collapse
Affiliation(s)
- Colton J. Treadway
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Joshua A Boyer
- Department. of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Shiyue Yang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Hui Yang
- Molecular & Cell Biology Lab, Institutes of Biomedical Sciences, Shanghai College of Medicine, Fudan University, Shanghai 200032, China
- Present address: Department of Neurosurgery, Huashan Hospital, Institute for Translational Brain Research, Shanghai College of Medicine, Fudan University, Shanghai, 200032, China
| | - Mengxi Liu
- Molecular & Cell Biology Lab, Institutes of Biomedical Sciences, Shanghai College of Medicine, Fudan University, Shanghai 200032, China
- Present address: Plexium, Inc., San Diego, CA 92121, United States
| | - Zhijun Li
- Department. of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Meng Cheng
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - William F. Marzluff
- Department. of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Dan Ye
- Molecular & Cell Biology Lab, Institutes of Biomedical Sciences, Shanghai College of Medicine, Fudan University, Shanghai 200032, China
| | - Yue Xiong
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Present address: Cullgen, Inc., 12730 High Bluff Drive, San Diego, CA, 92130, United States
| | - Albert S. Baldwin
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Qi Zhang
- Department. of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Nicholas G. Brown
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| |
Collapse
|
8
|
Ushimaru R, Abe I. Unusual Dioxygen-Dependent Reactions Catalyzed by Nonheme Iron Enzymes in Natural Product Biosynthesis. ACS Catal 2022. [DOI: 10.1021/acscatal.2c05247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Richiro Ushimaru
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- ACT-X, Japan Science and Technology Agency (JST), Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
9
|
A fungal dioxygenase CcTet serves as a eukaryotic 6mA demethylase on duplex DNA. Nat Chem Biol 2022; 18:733-741. [PMID: 35654845 DOI: 10.1038/s41589-022-01041-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 03/31/2022] [Indexed: 12/24/2022]
Abstract
N6-methyladenosine (6mA) is a DNA modification that has recently been found to play regulatory roles during mammalian early embryo development and mitochondrial transcription. We found that a dioxygenase CcTet from the fungus Coprinopsis cinerea is also a dsDNA 6mA demethylase. It oxidizes 6mA to the intermediate N6-hydroxymethyladenosine (6hmA) with robust activity of 6mA-containing duplex DNA (dsDNA) as well as isolated genomics DNA. Structural characterization revealed that CcTet utilizes three flexible loop regions and two key residues-D337 and G331-in the active pocket to preferentially recognize substrates on dsDNA. A CcTet D337F mutant protein retained the catalytic activity on 6mA but lost activity on 5-methylcytosine. Our findings uncovered a 6mA demethylase that works on dsDNA, suggesting potential 6mA demethylation in fungi and elucidating 6mA recognition and the catalytic mechanism of CcTet. The CcTet D337F mutant protein also provides a chemical biology tool for future functional manipulation of DNA 6mA in vivo.
Collapse
|
10
|
Structure and Function of TET Enzymes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:239-267. [DOI: 10.1007/978-3-031-11454-0_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|