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RNA ‐directed DNA methylation requires stepwise binding of silencing factors to long non‐coding RNA
Author(s) -
Böhmdorfer Gudrun,
Rowley M. Jordan,
Kuciński Jan,
Zhu Yongyou,
Amies Ivan,
Wierzbicki Andrzej T.
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12563
Subject(s) - biology , rna directed dna methylation , chromatin , dna methylation , rna , microbiology and biotechnology , transcription (linguistics) , rna induced transcriptional silencing , non coding rna , genetics , dna , gene expression , gene , linguistics , philosophy
Summary Ribonucleic acid‐mediated transcriptional gene silencing (known as RNA ‐directed DNA methylation, or Rd DM , in A rabidopsis thaliana ) is important for influencing gene expression and the inhibition of transposons by the deposition of repressive chromatin marks such as histone modifications and DNA methylation. A key event in de novo methylation of DNA by Rd DM is the production of long non‐coding RNA (lnc RNA ) by RNA polymerase V (Pol V). Little is known about the events that connect P ol V transcription to the establishment of repressive chromatin modifications. Using RNA immunoprecipitation, we elucidated the order of events downstream of lnc RNA production and discovered interdependency between lnc RNA ‐associated proteins. We found that the effector protein ARGONAUTE 4 ( AGO 4) binds lnc RNA independent of the RNA ‐binding protein INVOLVED IN DE NOVO 2 ( IDN 2). In contrast, IDN 2 binds lnc RNA in an AGO 4‐dependent manner. We further found that the de novo DNA methyltransferase DOMAINS REARRANGED METHYLTRANSFERASE 2 ( DRM 2) also associates with lnc RNA produced by Pol V and that this event depends on AGO 4 and IDN 2. We propose a model where the silencing proteins AGO 4, IDN 2 and DRM 2 bind to lnc RNA in a stepwise manner, resulting in DNA methylation of Rd DM target loci.