title: Parallel action of AtDRB2 and RdDM in the control of transposable element expression.
abstract: BACKGROUND
  In plants and animals, a large number of double-stranded RNA binding proteins (DRBs) have been shown to act as non-catalytic cofactors of DICERs and to participate in the biogenesis of small RNAs involved in RNA silencing. We have previously shown that the loss of Arabidopsis thaliana's DRB2 protein results in a significant increase in the population of RNA polymerase IV (p4) dependent siRNAs, which are involved in the RNA-directed DNA methylation (RdDM) process.
  
  
  RESULTS
  Surprisingly, despite this observation, we show in this work that DRB2 is part of a high molecular weight complex that does not involve RdDM actors but several chromatin regulator proteins, such as MSI4, PRMT4B and HDA19. We show that DRB2 can bind transposable element (TE) transcripts in vivo but that drb2 mutants do not have a significant variation in TE DNA methylation.
  
  
  CONCLUSIONS
  We propose that DRB2 is part of a repressive epigenetic regulator complex involved in a negative feedback loop, adjusting epigenetic state to transcription level at TE loci, in parallel of the RdDM pathway. Loss of DRB2 would mainly result in an increased production of TE transcripts, readily converted in p4-siRNAs by the RdDM machinery.
authors: Marion
authors: M
authors: Clavel
authors: Thierry
authors: T
authors: Pélissier
authors: Julie
authors: J
authors: Descombin
authors: Viviane
authors: V
authors: Jean
authors: Claire
authors: C
authors: Picart
authors: Cyril
authors: C
authors: Charbonel
authors: Julio
authors: J
authors: Saez-Vásquez
authors: Cécile
authors: C
authors: Bousquet-Antonelli
authors: Jean-Marc
authors: JM
authors: Deragon
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D013058:Mass Spectrometry; D008954:Models, Biological; D008970:Molecular Weight; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D004251:DNA Transposable Elements; C561224:DRB2 protein, Arabidopsis; D012333:RNA, Messenger; D018749:RNA, Plant; D016601:RNA-Binding Proteins