A DNA ligase required for active DNA demethylation anti genomic imprinting in Arabidopsis  

作　　者：Yan Li Cheng-Guo Duan Xiaohong Zhu Weiqiang Qian Jian-Kang Zhu 

机构地区：[1]Shanghai Center for Plant Stress Biology, Shanghai Institutes for Bio- logical Sciences, Chinese Academy of Sciences, Shanghai 200032, China [2]State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Science, Peking University, Beo'ing 100871, China [3]Department of Horticulture and Landscape Archi-tecture, Purdue University, West Lafayette, IN 47906, USA

出　　处：《Cell Research》2015年第6期757-760,共4页细胞研究（英文版）

摘　　要：Dear Editor, Active DNA demethylation plays crucial roles in the regulation of gene expression and gene imprinting. In plants, active DNA demethylation is initiated by the ROS1/DME family of 5-methylcytosine-specific DNA glycosylases via a base excision repair mechanism [ 1, 2]. ROS1 and DME are bifunctional DNA glycosylases that excise the 5-methylcytosine base and then cleave the DNA backbone at the abasic site, resulting in a gap with a 3＇ phosphate or 3＇ dRP （3＇ a, D-unsaturated aldehyde） terminus. The DNA phosphatase ZDP and the apurinic/ apyrimidinic endonuclease APE1L process the 3＇ phos- phate and 3＇ dRP termini, respectively, to generate a 3＇ OH group so that downstream polymerases and ligases can fill in the gap with an unmethylated cytosine [3, 4].

关 键 词：DNA连接酶 基因组印记 去甲基化 拟南芥 活性 

分 类 号：Q78[生物学—分子生物学] S826.822[农业科学—畜牧学]