The zinc finger and C-terminal domains of MTA proteins are required for FOG-2-mediated transcriptional repression via the NuRD complex

J Mol Cell Cardiol. 2008 Feb;44(2):352-60. doi: 10.1016/j.yjmcc.2007.10.023. Epub 2007 Nov 12.

Abstract

FOG-2 is a transcriptional co-regulator that is required for cardiac morphogenesis as mice deficient in this factor die during mid-gestation of cardiac malformations. FOG-2 interacts with GATA4 to attenuate GATA4-dependent gene expression. The first 12 amino acids of FOG-2 (the FOG Repression Motif) are necessary to mediate this repression. To determine the mechanism by which the FOG Repression Motif functions, we identified 7 polypeptides from rat cardiac nuclear extracts that co-purified with a GST-FOG-2 fusion protein. All proteins identified are members of the NuRD nucleosome remodeling complex. Using in vitro binding and co-immunoprecipitation assays, we demonstrate that Metastasis-Associated proteins (MTA)-1, 2 and 3 and Retinoblastoma binding proteins RbAp46 and RbAp48 interact with FOG-2, but not with a mutant form of FOG-2 that is unable to repress transcription. Furthermore, we define a novel domain located in the C-terminal portion of MTA-1 that mediates the FOG-2/MTA-1 interaction. We also demonstrate that knockdown of MTA protein expression dramatically impairs the ability of FOG-2 to repress GATA4 activity. Finally, we show that the zinc finger domain of MTA-1 is required for FOG-2-mediated transcriptional repression and that this domain interacts with RbAp46 and RbAp48 subunits of the NuRD complex. Together, these results demonstrate the importance of FOG-2/MTA/RbAp interactions for FOG-2-mediated transcriptional repression and further define the molecular interactions between the FOG Repression Motif and the NuRD complex.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Chromatography, Affinity
  • DNA-Binding Proteins / metabolism*
  • Histone Deacetylases / metabolism*
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex
  • Mice
  • NIH 3T3 Cells
  • Neoplasm Proteins / chemistry
  • Neoplasm Proteins / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Subunits / metabolism
  • Protein Transport
  • Rats
  • Repressor Proteins / chemistry*
  • Repressor Proteins / metabolism*
  • Retinoblastoma Protein / metabolism
  • Trans-Activators
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism
  • Transcription, Genetic*
  • Zinc Fingers*

Substances

  • DNA-Binding Proteins
  • Mta1 protein, mouse
  • Mta3 protein, mouse
  • Neoplasm Proteins
  • Protein Subunits
  • Repressor Proteins
  • Retinoblastoma Protein
  • Trans-Activators
  • Transcription Factors
  • Histone Deacetylases
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex