The Binding Sites for the Chromatin Insulator Protein CTCF Map to DNA Methylation-Free Domains Genome-Wide (original) (raw)

  1. Rituparna Mukhopadhyay1,5,
  2. WenQiang Yu1,5,
  3. Joanne Whitehead1,5,
  4. JunWang Xu1,
  5. Magda Lezcano1,
  6. Svetlana Pack2,
  7. Chandrasekhar Kanduri1,
  8. Meena Kanduri1,
  9. Vasudeva Ginjala1,
  10. Alexander Vostrov3,
  11. Wolfgang Quitschke3,
  12. Igor Chernukhin4,
  13. Elena Klenova4,
  14. Victor Lobanenkov2, and
  15. Rolf Ohlsson1,6
  16. 1 Department of Development & Genetics, Evolution Biology Centre, Uppsala University, Norbyvägen 18A, S-752 36 Uppsala, Sweden
  17. 2 Molecular Pathology Section, Laboratory of Immunopathology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
  18. 3 Department of Psychiatry and Behavioral Science, State University of New York at Stony Brook, Stony Brook, New York 11794-8101, USA
  19. 4 Department of Biological Sciences, Central Campus, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom

Abstract

All known vertebrate chromatin insulators interact with the highly conserved, multivalent 11-zinc finger nuclear factor CTCF to demarcate expression domains by blocking enhancer or silencer signals in a position-dependent manner. Recent observations document that the properties of CTCF include reading and propagating the epigenetic state of the differentially methylated_H19_ imprinting control region. To assess whether these findings may reflect a universal role for CTCF targets, we identified more than 200 new CTCF target sites by generating DNA microarrays of clones derived from chromatin-immunopurified (ChIP) DNA followed by ChIP-on-chip hybridization analysis. Target sites include not only known loci involved in multiple cellular functions, such as metabolism, neurogenesis, growth, apoptosis, and signalling, but potentially also heterochromatic sequences. Using a novel insulator trapping assay, we also show that the majority of these targets manifest insulator functions with a continuous distribution of stringency. As these targets are generally DNA methylation-free as determined by antibodies against 5-methylcytidine and a methyl-binding protein (MBD2), a CTCF-based network correlates with genome-wide epigenetic states.

Footnotes