A DNA 3' phosphatase functions in active DNA demethylation in Arabidopsis.
DNA methylation is an important epigenetic mark established by the combined actions of methylation and demethylation reactions. Plants use a base excision repair pathway for active DNA demethylation. After 5-methylcytosine removal, the Arabidopsis DNA glycosylase/lyase ROS1 incises the DNA backbone and part of the product has a single-nucleotide gap flanked by 3'- and 5'-phosphate termini. Here we show that the DNA phosphatase ZDP removes the blocking 3' phosphate, allowing subsequent DNA polymerization and ligation steps needed to complete the repair reactions. ZDP and ROS1 interact in vitro and colocalize in vivo in nucleoplasmic foci. Extracts from zdp mutant plants are unable to complete DNA demethylation in vitro, and the mutations cause DNA hypermethylation and transcriptional silencing of a reporter gene. Genome-wide methylation analysis in zdp mutant plants identified hundreds of hypermethylated endogenous loci. Our results show that ZDP functions downstream of ROS1 in one branch of the active DNA demethylation pathway.
Department of Genetics, University of Córdoba, 14071 Córdoba, Spain.
María Isabel
MI
Martínez-Macías
Weiqiang
W
Qian
Daisuke
D
Miki
Olga
O
Pontes
Yunhua
Y
Liu
Kai
K
Tang
Renyi
R
Liu
Teresa
T
Morales-Ruiz
Rafael R
RR
Ariza
Teresa
T
Roldán-Arjona
Jian-Kang
JK
Zhu
D044503:5-Methylcytosine / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D053837:DNA Cleavage; D019175:DNA Methylation; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017930:Genes, Reporter; D056426:Genetic Loci; D018745:Genome, Plant; D007700:Kinetics; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D009708:Nucleotidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000378:metabolism; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C471271:ROS1 protein, Arabidopsis; C533007:ROS3 protein, Arabidopsis; D044503:5-Methylcytosine; D008156:Luciferases; D009708:Nucleotidases; C039170:deoxynucleotide 3'-phosphatase