Hypermethylated in cancer 1 (HIC1) recruits polycomb repressive complex 2 (PRC2) to a subset of its target genes through interaction with human polycomb-like (hPCL) proteins

J Biol Chem. 2012 Mar 23;287(13):10509-10524. doi: 10.1074/jbc.M111.320234. Epub 2012 Feb 7.

Abstract

HIC1 (hypermethylated in cancer 1) is a tumor suppressor gene epigenetically silenced or deleted in many human cancers. HIC1 is involved in regulatory loops modulating p53- and E2F1-dependent cell survival, growth control, and stress responses. HIC1 is also essential for normal development because Hic1-deficient mice die perinatally and exhibit gross developmental defects throughout the second half of development. HIC1 encodes a transcriptional repressor with five C(2)H(2) zinc fingers mediating sequence-specific DNA binding and two repression domains: an N-terminal BTB/POZ domain and a central region recruiting CtBP and NuRD complexes. By yeast two-hybrid screening, we identified the Polycomb-like protein hPCL3 as a novel co-repressor for HIC1. Using multiple biochemical strategies, we demonstrated that HIC1 interacts with hPCL3 and its paralog PHF1 to form a stable complex with the PRC2 members EZH2, EED, and Suz12. Confirming the implication of HIC1 in Polycomb recruitment, we showed that HIC1 shares some of its target genes with PRC2, including ATOH1. Depletion of HIC1 by siRNA interference leads to a partial displacement of EZH2 from the ATOH1 promoter. Furthermore, in vivo, ATOH1 repression by HIC1 is associated with Polycomb activity during mouse cerebellar development. Thus, our results identify HIC1 as the first transcription factor in mammals able to recruit PRC2 to some target promoters through its interaction with Polycomb-like proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cerebellum / embryology
  • Cerebellum / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Enhancer of Zeste Homolog 2 Protein
  • Female
  • Histone-Lysine N-Methyltransferase / genetics
  • Histone-Lysine N-Methyltransferase / metabolism
  • Humans
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Mice
  • Neoplasm Proteins
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Polycomb Repressive Complex 2
  • Polycomb-Group Proteins
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Zinc Fingers

Substances

  • ATOH1 protein, human
  • Atoh1 protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Carrier Proteins
  • DNA-Binding Proteins
  • EED protein, human
  • Eed protein, mouse
  • HIC1 protein, human
  • Hic1 protein, mouse
  • Kruppel-Like Transcription Factors
  • Neoplasm Proteins
  • Nuclear Proteins
  • PHF19 protein, human
  • Polycomb-Group Proteins
  • Repressor Proteins
  • SUZ12 protein, human
  • Suz12 protein, mouse
  • Transcription Factors
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein
  • Ezh2 protein, mouse
  • Histone-Lysine N-Methyltransferase
  • Polycomb Repressive Complex 2