Regulation of Active DNA Demethylation through RAR-Mediated Recruitment of a TET/TDG Complex

Cell Rep. 2017 May 23;19(8):1685-1697. doi: 10.1016/j.celrep.2017.05.007.

Abstract

Retinoic acid (RA) plays important roles in development, growth, and homeostasis through regulation of the nuclear receptors for RA (RARs). Herein, we identify Hypermethylated in Cancer 1 (Hic1) as an RA-inducible gene. HIC1 encodes a tumor suppressor, which is often silenced by promoter hypermethylation in cancer. Treatment of cells with an RAR agonist causes a rapid recruitment of an RAR/RXR complex consisting of TDG, the lysine acetyltransferase CBP, and TET 1/2 to the Hic1 promoter. Complex binding coincides with a transient accumulation of 5fC/5caC and concomitant upregulation of Hic1 expression, both of which are TDG dependent. Furthermore, conditional deletion of Tdg in vivo is associated with Hic1 silencing and DNA hypermethylation of the Hic1 promoter. These findings suggest that the catalytic and scaffolding activities of TDG are essential for RA-dependent gene expression and provide important insights into the mechanisms underlying targeting of TET-TDG complexes.

Keywords: DNA methylation; Hypermethylated in Cancer 1; active demethylation; retinoic acid; thymine DNA glycosylase.

MeSH terms

  • Animals
  • DNA Demethylation* / drug effects
  • DNA-Binding Proteins / metabolism*
  • Dioxygenases
  • Gene Deletion
  • Gene Silencing / drug effects
  • Kruppel-Like Transcription Factors
  • Membrane Proteins / metabolism
  • Mice, Transgenic
  • Phosphoproteins / metabolism
  • Proto-Oncogene Proteins / metabolism*
  • Receptors, Retinoic Acid / metabolism*
  • Thymine DNA Glycosylase / metabolism*
  • Tretinoin / pharmacology

Substances

  • DNA-Binding Proteins
  • Hic1 protein, mouse
  • Kruppel-Like Transcription Factors
  • Membrane Proteins
  • Pag1 protein, mouse
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Receptors, Retinoic Acid
  • TET1 protein, mouse
  • retinoic acid receptor beta
  • Tretinoin
  • Dioxygenases
  • Tet2 protein, mouse
  • Thymine DNA Glycosylase