The methyl-CpG-binding protein MBD7 facilitates active DNA demethylation to limit DNA hyper-methylation and transcriptional gene silencing

Mol Cell. 2015 Mar 19;57(6):971-983. doi: 10.1016/j.molcel.2015.01.009. Epub 2015 Feb 12.


DNA methylation is a conserved epigenetic mark that plays important roles in plant and vertebrate development, genome stability, and gene regulation. Canonical Methyl-CpG-binding domain (MBD) proteins are important interpreters of DNA methylation that recognize methylated CG sites and recruit chromatin remodelers, histone deacetylases, and histone methyltransferases to repress transcription. Here, we show that Arabidopsis MBD7 and Increased DNA Methylation 3 (IDM3) are anti-silencing factors that prevent gene repression and DNA hypermethylation. MBD7 preferentially binds to highly methylated, CG-dense regions and physically associates with other anti-silencing factors, including the histone acetyltransferase IDM1 and the alpha-crystallin domain proteins IDM2 and IDM3. IDM1 and IDM2 were previously shown to facilitate active DNA demethylation by the 5-methylcytosine DNA glycosylase/lyase ROS1. Thus, MBD7 tethers the IDM proteins to methylated DNA, which enables the function of DNA demethylases that in turn limit DNA methylation and prevent transcriptional gene silencing.

Publication types

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

MeSH terms

  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Binding Sites
  • DNA Methylation*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Plant
  • Gene Silencing*
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Plants, Genetically Modified


  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • IDM2 protein, Arabidopsis
  • Nuclear Proteins
  • ROS1 protein, Arabidopsis
  • MBD7 protein, Arabidopsis
  • Histone Acetyltransferases
  • IDM1 protein, Arabidopsis

Associated data

  • GEO/GSE58787
  • GEO/GSE58789
  • GEO/GSE59712