Telobox motifs recruit CLF/SWN-PRC2 for H3K27me3 deposition via TRB factors in Arabidopsis

Nat Genet. 2018 May;50(5):638-644. doi: 10.1038/s41588-018-0109-9. Epub 2018 Apr 26.

Abstract

Polycomb repressive complexes (PRCs) control organismic development in higher eukaryotes through epigenetic gene repression1-4. PRC proteins do not contain DNA-binding domains, thus prompting questions regarding how PRCs find their target loci 5 . Here we present genome-wide evidence of PRC2 recruitment by telomere-repeat-binding factors (TRBs) through telobox-related motifs in Arabidopsis. A triple trb1-2, trb2-1, and trb3-2 (trb1/2/3) mutant with a developmental phenotype and a transcriptome strikingly similar to those of strong PRC2 mutants showed redistribution of trimethyl histone H3 Lys27 (H3K27me3) marks and lower H3K27me3 levels, which were correlated with derepression of TRB1-target genes. TRB1-3 physically interacted with the PRC2 proteins CLF and SWN. A SEP3 reporter gene with a telobox mutation showed ectopic expression, which was correlated with H3K27me3 depletion, whereas tethering TRB1 to the mutated cis element partially restored repression. We propose that telobox-related motifs recruit PRC2 through the interaction between TRBs and CLF/SWN, a mechanism essential for H3K27me3 deposition at a subset of target genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics*
  • Gene Expression Regulation, Plant / genetics
  • Genes, Plant / genetics
  • Histones / genetics*
  • Homeodomain Proteins / genetics*
  • Phenotype
  • Polycomb Repressive Complex 2
  • Polycomb-Group Proteins / genetics
  • Repressor Proteins / genetics*
  • Telomere-Binding Proteins / genetics
  • Transcription Factors / genetics*

Substances

  • Arabidopsis Proteins
  • CURLY LEAF protein, Arabidopsis
  • Histones
  • Homeodomain Proteins
  • PRC2 protein, Arabidopsis
  • Polycomb-Group Proteins
  • Repressor Proteins
  • SWINGER protein, Arabidopsis
  • Telomere-Binding Proteins
  • Transcription Factors
  • Polycomb Repressive Complex 2