CTCF tethers an insulator to subnuclear sites, suggesting shared insulator mechanisms across species

Mol Cell. 2004 Jan 30;13(2):291-8. doi: 10.1016/s1097-2765(04)00029-2.

Abstract

Insulators can block an enhancer of one gene from activating a promoter on another nearby gene. Almost all described vertebrate insulators require binding of the regulatory protein CTCF for their activity. We show that CTCF copurifies with the nucleolar protein nucleophosmin and both are present at insulator sites in vivo. Furthermore, exogenous insulator sequences are tethered to the nucleolus in a CTCF-dependent manner. These interactions, quite different from those of the gypsy insulator element in Drosophila, may generate similar loop structures, suggesting a common theme and model for enhancer-blocking insulator action.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • CCCTC-Binding Factor
  • Cell Nucleus / metabolism*
  • Chickens
  • Chromatin / chemistry
  • Chromatin / metabolism
  • DNA, Complementary / metabolism
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • Dimerization
  • HeLa Cells
  • Humans
  • In Situ Hybridization, Fluorescence
  • K562 Cells
  • Mass Spectrometry
  • Models, Biological
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism
  • Nucleophosmin
  • Precipitin Tests
  • Protein Binding
  • Repressor Proteins / metabolism
  • Repressor Proteins / physiology*
  • Silver Staining
  • Species Specificity

Substances

  • CCCTC-Binding Factor
  • CTCF protein, human
  • Chromatin
  • DNA, Complementary
  • DNA-Binding Proteins
  • NPM1 protein, human
  • Nuclear Proteins
  • Repressor Proteins
  • Nucleophosmin