Aninda Sundar Dey, Chayan Bhattacharya, Y. Guan, B. Jha, Mridul Mukherji
{"title":"TET2 5-甲基胞嘧啶二氧合酶引发DNA中非CpG位点的去甲基化","authors":"Aninda Sundar Dey, Chayan Bhattacharya, Y. Guan, B. Jha, Mridul Mukherji","doi":"10.3390/dna1010004","DOIUrl":null,"url":null,"abstract":"In the mammalian genome, cytosine methylation predominantly occurs at CpG sites. In addition, a number of recent studies have uncovered extensive C5 cytosine methylation (5mC) at non-CpG (5mCpH, where H = A/C/T) sites. Little is known about the enzyme responsible for active demethylation of 5mCpH sites. Using a very sensitive and quantitative LC–MS/MS method, we demonstrate that the human TET2, an iron (II)- and 2OG-dependent dioxygenase, which is a frequently mutated gene in several myeloid malignancies, as well as in a number of other types of cancers, can oxidize 5mCpH sites in double-stranded DNA in vitro. Similar to oxidation of 5mCpG, oxidation of 5mC at CpH sites produces 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC) bases in DNA. After 5mCpG, which is the most preferred substrate, TET2 prefers 5mCpC as a substrate, followed by 5mCpA and then 5mCpT. Since the TDG/BER pathway and deformylation or decarboxylation of 5fC or 5caC, respectively, can convert 5fCpH and 5caCpH to an unmodified cytosine base in DNA, our results suggest a novel demethylation pathway of 5mCpH sites initiated by TET2 dioxygenase.","PeriodicalId":77708,"journal":{"name":"DNA (Mary Ann Liebert, Inc.)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Demethylation of Non-CpG Sites in DNA Is Initiated by TET2 5-Methylcytosine Dioxygenase\",\"authors\":\"Aninda Sundar Dey, Chayan Bhattacharya, Y. Guan, B. Jha, Mridul Mukherji\",\"doi\":\"10.3390/dna1010004\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In the mammalian genome, cytosine methylation predominantly occurs at CpG sites. In addition, a number of recent studies have uncovered extensive C5 cytosine methylation (5mC) at non-CpG (5mCpH, where H = A/C/T) sites. Little is known about the enzyme responsible for active demethylation of 5mCpH sites. Using a very sensitive and quantitative LC–MS/MS method, we demonstrate that the human TET2, an iron (II)- and 2OG-dependent dioxygenase, which is a frequently mutated gene in several myeloid malignancies, as well as in a number of other types of cancers, can oxidize 5mCpH sites in double-stranded DNA in vitro. Similar to oxidation of 5mCpG, oxidation of 5mC at CpH sites produces 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC) bases in DNA. After 5mCpG, which is the most preferred substrate, TET2 prefers 5mCpC as a substrate, followed by 5mCpA and then 5mCpT. Since the TDG/BER pathway and deformylation or decarboxylation of 5fC or 5caC, respectively, can convert 5fCpH and 5caCpH to an unmodified cytosine base in DNA, our results suggest a novel demethylation pathway of 5mCpH sites initiated by TET2 dioxygenase.\",\"PeriodicalId\":77708,\"journal\":{\"name\":\"DNA (Mary Ann Liebert, Inc.)\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-09-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"DNA (Mary Ann Liebert, Inc.)\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3390/dna1010004\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"DNA (Mary Ann Liebert, Inc.)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/dna1010004","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Demethylation of Non-CpG Sites in DNA Is Initiated by TET2 5-Methylcytosine Dioxygenase
In the mammalian genome, cytosine methylation predominantly occurs at CpG sites. In addition, a number of recent studies have uncovered extensive C5 cytosine methylation (5mC) at non-CpG (5mCpH, where H = A/C/T) sites. Little is known about the enzyme responsible for active demethylation of 5mCpH sites. Using a very sensitive and quantitative LC–MS/MS method, we demonstrate that the human TET2, an iron (II)- and 2OG-dependent dioxygenase, which is a frequently mutated gene in several myeloid malignancies, as well as in a number of other types of cancers, can oxidize 5mCpH sites in double-stranded DNA in vitro. Similar to oxidation of 5mCpG, oxidation of 5mC at CpH sites produces 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC) bases in DNA. After 5mCpG, which is the most preferred substrate, TET2 prefers 5mCpC as a substrate, followed by 5mCpA and then 5mCpT. Since the TDG/BER pathway and deformylation or decarboxylation of 5fC or 5caC, respectively, can convert 5fCpH and 5caCpH to an unmodified cytosine base in DNA, our results suggest a novel demethylation pathway of 5mCpH sites initiated by TET2 dioxygenase.