title: A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice.
abstract: DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counteract transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.
authors: Department of Plant Pathology, Ohio State University, Columbus, OH 43210, USA.
authors: Honggui
authors: H
authors: La
authors: Bo
authors: B
authors: Ding
authors: Gyan P
authors: GP
authors: Mishra
authors: Bo
authors: B
authors: Zhou
authors: Hongmei
authors: H
authors: Yang
authors: Maria del Rosario
authors: Mdel R
authors: Bellizzi
authors: Songbiao
authors: S
authors: Chen
authors: Blake C
authors: BC
authors: Meyers
authors: Zhaohua
authors: Z
authors: Peng
authors: Jian-Kang
authors: JK
authors: Zhu
authors: Guo-Liang
authors: GL
authors: Wang
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism; D045647:DNA Glycosylases / Q000378:metabolism*; D019175:DNA Methylation; D018744:DNA, Plant / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D055786:Gene Knockout Techniques; D008190:Lyases / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics*; D030821:Plants, Genetically Modified; D018626:Retroelements / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D018626:Retroelements; D044503:5-Methylcytosine; C093335:5-methylcytosine-DNA glycosylase; D045647:DNA Glycosylases; D008190:Lyases