title: Epigenetic role for the conserved Fe-S cluster biogenesis protein AtDRE2 in Arabidopsis thaliana.
abstract: On fertilization in Arabidopsis thaliana, one maternal gamete, the central cell, forms a placenta-like tissue, the endosperm. The DNA glycosylase DEMETER (DME) excises 5-methylcytosine via the base excision repair pathway in the central cell before fertilization, creating patterns of asymmetric DNA methylation and maternal gene expression across DNA replications in the endosperm lineage (EDL). Active DNA demethylation in the central cell is essential for transcriptional activity in the EDL of a set of genes, including FLOWERING WAGENINGEN (FWA). A DME-binding motif for iron-sulfur (Fe-S) cluster cofactors is indispensable for its catalytic activity. We used an FWA-GFP reporter to find mutants defective in maternal activation of FWA-GFP in the EDL, and isolated an allele of the yeast Dre2/human antiapoptotic factor CIAPIN1 homolog, encoding an enzyme previously implicated in the cytosolic Fe-S biogenesis pathway (CIA), which we named atdre2-2. We found that AtDRE2 acts in the central cell to regulate genes maternally activated in the EDL by DME. Furthermore, the FWA-GFP expression defect in atdre2-2 was partially suppressed genetically by a mutation in the maintenance DNA methyltransferase MET1; the DNA methylation levels at four DME targets increased in atdre2-2 seeds relative to WT. Although atdre2-2 shares zygotic seed defects with CIA mutants, it also uniquely manifests dme phenotypic hallmarks. These results demonstrate a previously unidentified epigenetic function of AtDRE2 that may be separate from the CIA pathway.
authors.affiliation: Plant Reproductive Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan; Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 526-0829, Japan; Kihara Institute for Biological Research, Yokohama City University, Yokohama 244-0813, Japan; and diana@yokohama-cu.ac.jp tkinoshi@yokohama-cu.ac.jp.
authors.forename: Diana Mihaela
authors.initials: DM
authors.lastname: Buzas
authors.affiliation: Plant Reproductive Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan; Department of Plant Biology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Plant Reproductive Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan; Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 526-0829, Japan; Kihara Institute for Biological Research, Yokohama City University, Yokohama 244-0813, Japan; and diana@yokohama-cu.ac.jp tkinoshi@yokohama-cu.ac.jp.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D019175:DNA Methylation / Q000235:genetics; D056625:Endosperm / Q000378:metabolism; D044127:Epigenesis, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D055993:Germ Cells, Plant / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012098:Reproduction
chemical_list: D029681:Arabidopsis Proteins; C000597089:DRE2 protein, Arabidopsis; D007506:Iron-Sulfur Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins