动植物DNA主动去甲基化途径及其调控机制研究进展  

Progress on the Active DNA Demethylation Pathways and Their Regulation Mechanisms in Animals and Plants

作　　者：刘春雨 王宇[1] 解莉楠[1] LIU Chun-yu;WANG Yu;XIE Li-nan(Key Laboratory of Saline-alkali Vegetation Ecology Restoration,Ministry of Education,College of Life Science,Northeast Forestry University,Harbin 150040,Heilongjiang,China)

机构地区：[1]东北林业大学生命科学学院东北盐碱植被恢复与重建教育部重点实验室,中国黑龙江哈尔滨150040

出　　处：《生命科学研究》2020年第5期415-424,共10页Life Science Research

基　　金：国家自然科学基金资助项目(31871220);中央高校基本科研业务费专项资金项目(2572017DA06)。

摘　　要：甲基化是DNA的一种化学修饰,能够在不改变DNA序列的前提下改变遗传表现,是一种相对稳定且可遗传的表观遗传标记。在生物体内DNA甲基化和去甲基化的动态平衡控制着基因表达的强度。植物和动物细胞中均存在DNA主动去甲基化现象,植物中ROS1/DME切除甲基化的胞嘧啶后由碱基切除修复机制完成DNA主动去甲基化;动物中则是TET1蛋白先将5-甲基胞嘧啶(5-methylcytosine,5mC)氧化为5-羟甲基胞嘧啶(5-hydroxymethylcytosine,5hmC)、5-甲酰基胞嘧啶(5-formylcytosine,5fC)和5-羧基胞嘧啶(5-carboxycytosine,5caC),然后通过胸腺嘧啶DNA糖基化酶(thymine DNA glycosylase,TDG)切除5fC和5caC,最后经过碱基切除修复得到未修饰的胞嘧啶。本文主要对动植物中DNA主动去甲基化途径及其调控机制的最新研究进展进行综述及比较分析,为相关领域的进一步深入研究提供理论支持。Methylation is a chemical modification of DNA that can change genetic performance without changing the DNA sequence.It is a relatively stable and heritable epigenetic marker.The dynamic balance of DNA methylation and demethylation controls gene expression in organisms.Active demethylation of DNA has been found in both plant and animal cells.In plants,ROS1/DME enzymes cut methylated cytosines and complete active demethylation through the base excision repair mechanism.In animals,5-methylcytosines(5mCs)are first oxidized by TET1 protein to produce 5-hydroxymethylcytosine(5hmC),5-formylcytosine(5fC),and 5-carboxycytosine(5caC),then 5fC and 5caC are cut by thymine DNA glycosylase(TDG),and finally unmodified cytosines are obtained after base excision repair.Herein,the latest research progress on active DNA demethylation pathways and their regulatory mechanisms in plants and animals is reviewed,in hope of providing theoretical support for further research.

关 键 词：DNA甲基化 DNA去甲基化 ROS1蛋白 TET蛋白 碱基切除修复(BER) 

分 类 号：Q75[生物学—分子生物学]