Analysis of hepatocyte nuclear factor-3 beta protein domains required for transcriptional activation and nuclear targeting

Nucleic Acids Res. 1995 Apr 11;23(7):1184-91. doi: 10.1093/nar/23.7.1184.


Three distinct hepatocyte nuclear factor 3 (HNF-3) proteins (alpha, beta and gamma) regulate transcription of the transthyretin (TTR) and numerous other liver-specific genes. The HNF-3 proteins bind DNA via a homologous winged helix motif common to a number of developmental regulatory proteins including the Drosophila homeotic fork head (fkh) protein. The mammalian HNF-3/fkh family consists of at least thirty distinct members and is expressed in a variety of different cellular lineages. In addition to the winged helix motif, several HNF-3/fkh family members also share homology within transcriptional activation region II and III sequences. In the present study we further define the sequence boundaries of the HNF-3 beta N-terminal transcriptional activation domain to extend from amino acids 14 to 93 and include conserved region IV and V sequences. We also demonstrate that activity of the HNF-3 N-terminal domain was diminished by mutations which altered a putative alpha-helical structure located between amino acid residues 14 and 19. However, transcriptional activity was not affected by mutations which eliminated two conserved casein kinase I sites or increased the number of acidic amino acid residues in the N-terminal domain. Furthermore, we determined that the nuclear localization signal overlaps with the winged helix DNA-binding motif. These results suggest that conserved sequences within the winged helix motif of the HNF-3/fkh family may be involved not only in DNA recognition, but also in nuclear targeting.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites / genetics
  • Casein Kinases
  • Cell Nucleus / metabolism
  • Conserved Sequence
  • DNA / genetics
  • DNA / metabolism
  • DNA Primers / genetics
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Hepatocyte Nuclear Factor 3-beta
  • Humans
  • Molecular Sequence Data
  • Mutagenesis
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Proline / genetics
  • Protein Kinases
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Transcription Factors*
  • Transcriptional Activation*
  • beta-Galactosidase / metabolism


  • DNA Primers
  • DNA-Binding Proteins
  • FOXA2 protein, human
  • Nuclear Proteins
  • Transcription Factors
  • Hepatocyte Nuclear Factor 3-beta
  • DNA
  • Proline
  • Protein Kinases
  • Casein Kinases
  • beta-Galactosidase