HIC1 interacts with a specific subunit of SWI/SNF complexes, ARID1A/BAF250A

Biochem Biophys Res Commun. 2009 Aug 7;385(4):586-90. doi: 10.1016/j.bbrc.2009.05.115. Epub 2009 May 30.

Abstract

HIC1, a tumor suppressor gene epigenetically silenced in many human cancers encodes a transcriptional repressor involved in regulatory loops modulating p53-dependent and E2F1-dependent cell survival and stress responses. HIC1 is also implicated in growth control since it recruits BRG1, one of the two alternative ATPases (BRM or BRG1) of SWI/SNF chromatin-remodeling complexes to repress transcription of E2F1 in quiescent fibroblasts. Here, through yeast two-hybrid screening, we identify ARID1A/BAF250A, as a new HIC1 partner. ARID1A/BAF250A is one of the two mutually exclusive ARID1-containing subunits of SWI/SNF complexes which define subsets of complexes endowed with anti-proliferative properties. Co-immunoprecipitation assays in WI38 fibroblasts and in BRG1-/- SW13 cells showed that endogenous HIC1 and ARID1A proteins interact in a BRG1-dependent manner. Furthermore, we demonstrate that HIC1 does not interact with BRM. Finally, sequential chromatin immunoprecipitation (ChIP-reChIP) experiments demonstrated that HIC1 represses E2F1 through the recruitment of anti-proliferative SWI/SNF complexes containing ARID1A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Chromatin Immunoprecipitation
  • DNA-Binding Proteins
  • Down-Regulation
  • E2F1 Transcription Factor / genetics*
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism*
  • Two-Hybrid System Techniques

Substances

  • ARID1A protein, human
  • DNA-Binding Proteins
  • E2F1 Transcription Factor
  • E2F1 protein, human
  • HIC1 protein, human
  • Kruppel-Like Transcription Factors
  • Nuclear Proteins
  • Protein Subunits
  • Transcription Factors
  • Tumor Suppressor Proteins