title: The splicing factor SR45 affects the RNA-directed DNA methylation pathway in Arabidopsis.
abstract: Cytosine DNA methylation is an epigenetic mark frequently associated with silencing of genes and transposons. In Arabidopsis, the establishment of cytosine DNA methylation is performed by DOMAINS REARRANGED METHYLTRANSFERASE 2 (DRM2). DRM2 is guided to target sequences by small interfering RNAs (siRNAs) in a pathway termed RNA-directed DNA methylation (RdDM). We performed a screen for mutants that affect the establishment of DNA methylation by investigating genes that contain predicted RNA-interacting domains. After transforming FWA into 429 T-DNA insertion lines, we assayed for mutants that exhibited a late-flowering phenotype due to hypomethylated, thus ectopically expressed, copies of FWA. A T-DNA insertion line within the coding region of the spliceosome gene SR45 (sr45-1) flowered late after FWA transformation. Additionally, sr45-1 mutants display defects in the maintenance of DNA methylation. DNA methylation establishment and maintenance defects present in sr45-1 mutants are enhanced in dcl3-1 mutant background, suggesting a synergistic cooperation between SR45 and DICER-LIKE3 (DCL3) in the RdDM pathway.
authors.affiliation: Department of Molecular, Cell and Developmental Biology, Campus Universidad Autonoma de Madrid, Madrid, Spain.
authors.forename: Israel
authors.initials: I
authors.lastname: Ausin
authors.forename: Maxim V C
authors.initials: MV
authors.lastname: Greenberg
authors.forename: Carey Fei
authors.initials: CF
authors.lastname: Li
authors.forename: Steven E
authors.initials: SE
authors.lastname: Jacobsen
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D019175:DNA Methylation; D009154:Mutation; D012326:RNA Splicing; D018749:RNA, Plant / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D043244:Ribonuclease III / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D018749:RNA, Plant; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C483303:SR45 protein, Arabidopsis; C519654:DCL3 protein, Arabidopsis; D043244:Ribonuclease III