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DTF1 is a core component of RNA-directed DNA methylation and may assist in the recruitment of Pol IV.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2013 May 14; Vol. 110 (20), pp. 8290-5. Date of Electronic Publication: 2013 May 01. - Publication Year :
- 2013
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Abstract
- DNA methylation is an important epigenetic mark in many eukaryotic organisms. De novo DNA methylation in plants can be achieved by the RNA-directed DNA methylation (RdDM) pathway, where the plant-specific DNA-dependent RNA polymerase IV (Pol IV) transcribes target sequences to initiate 24-nt siRNA production and action. The putative DNA binding protein DTF1/SHH1 of Arabidopsis has been shown to associate with Pol IV and is required for 24-nt siRNA accumulation and transcriptional silencing at several RdDM target loci. However, the extent and mechanism of DTF1 function in RdDM is unclear. We show here that DTF1 is necessary for the accumulation of the majority of Pol IV-dependent 24-nt siRNAs. It is also required for a large proportion of Pol IV-dependent de novo DNA methylation. Interestingly, there is a group of RdDM target loci where 24-nt siRNA accumulation but not DNA methylation is dependent on DTF1. DTF1 interacts directly with the chromatin remodeling protein CLASSY 1 (CLSY1), and both DTF1 and CLSY1 are associated in vivo with Pol IV but not Pol V, which functions downstream in the RdDM effector complex. DTF1 and DTF2 (a DTF1-like protein) contain a SAWADEE domain, which was found to bind specifically to histone H3 containing H3K9 methylation. Taken together, our results show that DTF1 is a core component of the RdDM pathway, and suggest that DTF1 interacts with CLSY1 to assist in the recruitment of Pol IV to RdDM target loci where H3K9 methylation may be an important feature. Our results also suggest the involvement of DTF1 in an important negative feedback mechanism for DNA methylation at some RdDM target loci.
- Subjects :
- Arabidopsis metabolism
Arabidopsis Proteins genetics
Cloning, Molecular
DNA-Binding Proteins metabolism
Gene Silencing
Histones metabolism
Homeodomain Proteins genetics
Mutation
RNA, Plant metabolism
RNA, Small Interfering metabolism
Transcription, Genetic
Two-Hybrid System Techniques
Arabidopsis genetics
Arabidopsis Proteins metabolism
DNA Methylation
DNA Polymerase beta metabolism
Homeodomain Proteins metabolism
RNA-Directed DNA Polymerase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 110
- Issue :
- 20
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 23637343
- Full Text :
- https://doi.org/10.1073/pnas.1300585110