Functional association between CBP and HNF4 in trans-activation

Biochem Biophys Res Commun. 1997 Dec 29;241(3):664-9. doi: 10.1006/bbrc.1997.7871.

Abstract

CBP functions as a key transcriptional coactivator for a variety of transcription factors. We show here that the hepatocyte nuclear factor 4 (HNF4), a transcription factor in the nuclear receptor superfamily with no defined ligand, is cloned by yeast two-hybrid system using CBP as a bait. GST-pull down assay with nuclear extracts or in vitro translation products revealed that CBP and HNF4 interact with each other at the middle portion (aa 119-375) of HNF4 and two distinct regions (aa 271-451 and 1626-2259) of CBP, respectively, in the ligand-independent manner. Co-transfection experiments indicated that CBP is capable of activating HNF4 site-mediated transcription. These results suggested a functional association between CBP and HNF4 in trans-activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • CREB-Binding Protein
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Hepatocyte Nuclear Factor 4
  • Liver / metabolism
  • Mice
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / physiology*
  • Phosphoproteins / genetics*
  • Phosphoproteins / isolation & purification
  • Phosphoproteins / physiology*
  • Rats
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / isolation & purification
  • Saccharomyces cerevisiae / genetics
  • Trans-Activators*
  • Transcription Factors / genetics*
  • Transcription Factors / isolation & purification
  • Transcription Factors / physiology*
  • Transcription, Genetic
  • Transfection

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • DNA-Binding Proteins
  • Hepatocyte Nuclear Factor 4
  • Nuclear Proteins
  • Phosphoproteins
  • Recombinant Fusion Proteins
  • Tcfl4 protein, mouse
  • Trans-Activators
  • Transcription Factors
  • CREB-Binding Protein
  • Crebbp protein, mouse
  • Crebbp protein, rat