RNA polymerase II- and AGO4-associated protein acts in RNA-directed DNA methylation

• Published in: Nature (London) 2010-05, Vol.465 (7294), p.106-109
• Main Authors: Gao, Zhihuan, Liu, Hai-Liang, Daxinger, Lucia, Pontes, Olga, He, Xinjian, Qian, Weiqiang, Lin, Huixin, Xie, Mingtang, Lorkovic, Zdravko J, Zhang, Shoudong, Miki, Daisuke, Zhan, Xiangqiang, Pontier, Dominique, Lagrange, Thierry, Jin, Hailing, Matzke, Antonius J.M
• Format: Article
• Language: English
• Subjects: 631/208/2491; 631/337/176/1988; 631/449; Arabidopsis; Arabidopsis - metabolism; Arabidopsis Proteins; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Argonaute Proteins; Biochemistry; Biochemistry, Molecular Biology; Biodiversity; Bioinformatics; Cell Nucleus; Cell Nucleus - metabolism; Cellular Biology; Computer Science; Deoxyribonucleic acid; DNA; DNA Methylation; DNA-Binding Proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Gene Expression Regulation, Plant; Gene mutations; Gene Silencing; Gene Silencing - physiology; Genetic aspects; Genetics; Genomics; Humanities and Social Sciences; letter; Life Sciences; Methylation; Methyltransferases; Methyltransferases - metabolism; Molecular biology; Molecular Networks; multidisciplinary; Mutation; Physiological aspects; Plant breeding; Plants genetics; Polymerase chain reaction; Populations and Evolution; Proteins; Quantitative Methods; RNA Polymerase II; RNA Polymerase II - metabolism; RNA, Plant; RNA, Plant - metabolism; Science; Science (multidisciplinary); Structural Biology; Systematics, Phylogenetics and taxonomy; Vegetal Biology
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature09025

DNA methylation is an important epigenetic mark in many eukaryotes1, 2, 3, 4, 5. In plants, 24-nucleotide small interfering RNAs (siRNAs) bound to the effector protein, Argonaute 4 (AGO4), can direct de novo DNA methylation by the methyltransferase DRM2 (refs 2, 4–6). Here we report a new regulator of RNA-directed DNA methylation (RdDM) in Arabidopsis: RDM1. Loss-of-function mutations in the RDM1 gene impair the accumulation of 24-nucleotide siRNAs, reduce DNA methylation, and release transcriptional gene silencing at RdDM target loci. RDM1 encodes a small protein that seems to bind single-stranded methyl DNA, and associates and co-localizes with RNA polymerase II (Pol II, also known as NRPB), AGO4 and DRM2 in the nucleus. Our results indicate that RDM1 is a component of the RdDM effector complex and may have a role in linking siRNA production with pre-existing or de novo cytosine methylation. Our results also indicate that, although RDM1 and Pol V (also known as NRPE) may function together at some RdDM target sites in the peri-nucleolar siRNA processing centre, Pol II rather than Pol V is associated with the RdDM effector complex at target sites in the nucleoplasm.