CBX3 regulates efficient RNA processing genome-wide

Genome Res. 2012 Aug;22(8):1426-36. doi: 10.1101/gr.124818.111. Epub 2012 Jun 8.


CBX5, CBX1, and CBX3 (HP1α, β, and γ, respectively) play an evolutionarily conserved role in the formation and maintenance of heterochromatin. In addition, CBX5, CBX1, and CBX3 may also participate in transcriptional regulation of genes. Recently, CBX3 binding to the bodies of a subset of genes has been observed in human and murine cells. However, the generality of this phenomenon and the role CBX3 may play in this context are unknown. Genome-wide localization analysis reveals CBX3 binding at genic regions, which strongly correlates with gene activity across multiple cell types. Depletion of CBX3 resulted in down-regulation of a subset of target genes. Loss of CBX3 binding leads to a more dramatic accumulation of unspliced nascent transcripts. In addition, we observed defective recruitment of splicing factors, including SNRNP70, to CBX3 target genes. Collectively, our data suggest a role for CBX3 in aiding in efficient cotranscriptional RNA processing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Binding Sites
  • Chromatin Immunoprecipitation
  • Chromobox Protein Homolog 5
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Exons
  • Gene Expression Regulation
  • Genome, Human*
  • HCT116 Cells
  • Heterochromatin / genetics
  • Heterochromatin / metabolism*
  • Humans
  • K562 Cells
  • Protein Binding
  • RNA Processing, Post-Transcriptional*
  • Ribonucleoprotein, U1 Small Nuclear / genetics
  • Ribonucleoprotein, U1 Small Nuclear / metabolism
  • Transcription, Genetic
  • Transcriptional Activation


  • CBX1 protein, human
  • CBX3 protein, human
  • CBX5 protein, human
  • Chromosomal Proteins, Non-Histone
  • Heterochromatin
  • Ribonucleoprotein, U1 Small Nuclear
  • SNRNP70 protein, human
  • Chromobox Protein Homolog 5

Associated data

  • GEO/GSE28115