Small RNAs prevent transcription-coupled loss of histone H3 lysine 9 methylation in Arabidopsis thaliana

In eukaryotes, histone H3 lysine 9 methylation (H3K9me) mediates silencing of invasive sequences to prevent deleterious consequences including the expression of aberrant gene products and mobilization of transposons. In Arabidopsis thaliana, H3K9me maintained by SUVH histone methyltransferases (MTas...

Full description

Saved in:
Bibliographic Details
Published in:PLoS genetics 2011-10, Vol.7 (10), p.e1002350-e1002350
Main Authors: Enke, Raymond A, Dong, Zhicheng, Bender, Judith
Format: Article
Language:English
Subjects:
Acquisitions & mergers
Arabidopsis - enzymology
Arabidopsis - genetics
Arabidopsis Proteins - genetics
Arabidopsis Proteins - metabolism
Arabidopsis thaliana
Biology
Cell Cycle Proteins - genetics
Cell Cycle Proteins - metabolism
Chromatin Assembly and Disassembly - genetics
Cytosine - metabolism
Deoxyribonucleic acid
DNA
DNA Methylation
DNA Transposable Elements - genetics
DNA-Cytosine Methylases - genetics
DNA-Cytosine Methylases - metabolism
Experiments
Gene Expression Regulation, Plant
Genes
Genetic transcription
Genetics
Genomes
Histone-Lysine N-Methyltransferase - genetics
Histone-Lysine N-Methyltransferase - metabolism
Histones - genetics
Histones - metabolism
Lysine
Lysine - genetics
Methylation
Methyltransferases - genetics
Methyltransferases - metabolism
Molecular weight
Mutation
Physiological aspects
Protein Interaction Domains and Motifs - genetics
Proteins
Ribonuclease III - genetics
Ribonuclease III - metabolism
RNA, Plant - genetics
RNA, Small Interfering - genetics
RNA, Small Interfering - metabolism
Transcription, Genetic
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In eukaryotes, histone H3 lysine 9 methylation (H3K9me) mediates silencing of invasive sequences to prevent deleterious consequences including the expression of aberrant gene products and mobilization of transposons. In Arabidopsis thaliana, H3K9me maintained by SUVH histone methyltransferases (MTases) is associated with cytosine methylation (5meC) maintained by the CMT3 cytosine MTase. The SUVHs contain a 5meC binding domain and CMT3 contains an H3K9me binding domain, suggesting that the SUVH/CMT3 pathway involves an amplification loop between H3K9me and 5meC. However, at loci subject to read-through transcription, the stability of the H3K9me/5meC loop requires a mechanism to counteract transcription-coupled loss of H3K9me. Here we use the duplicated PAI genes, which stably maintain SUVH-dependent H3K9me and CMT3-dependent 5meC despite read-through transcription, to show that when PAI sRNAs are depleted by dicer ribonuclease mutations, PAI H3K9me and 5meC levels are reduced and remaining PAI 5meC is destabilized upon inbreeding. The dicer mutations confer weaker reductions in PAI 5meC levels but similar or stronger reductions in PAI H3K9me levels compared to a cmt3 mutation. This comparison indicates a connection between sRNAs and maintenance of H3K9me independent of CMT3 function. The dicer mutations reduce PAI H3K9me and 5meC levels through a distinct mechanism from the known role of dicer-dependent sRNAs in guiding the DRM2 cytosine MTase because the PAI genes maintain H3K9me and 5meC at levels similar to wild type in a drm2 mutant. Our results support a new role for sRNAs in plants to prevent transcription-coupled loss of H3K9me.
ISSN:1553-7404
1553-7390
1553-7404
DOI:10.1371/journal.pgen.1002350