Estrogen-related receptor, hERR1, modulates estrogen receptor-mediated response of human lactoferrin gene promoter

J Biol Chem. 1996 Mar 8;271(10):5795-804. doi: 10.1074/jbc.271.10.5795.


We have shown previously that estrogen-stimulated transcription from the human lactoferrin gene in RL95-2 endometrium carcinoma cells is mediated through an imperfect estrogen response element (ERE) at the 5 -flanking region of the gene. Upstream from the ERE, a DNA sequence (-418 to -378, FP1) was selectively protected from DNase I digestion by nuclear extracts from endometrial and mammary gland cell lines. In this report, using the electrophoresis mobility shift assay, site-directed mutagenesis, and DNA methylation interference analyses, we show that three different nuclear proteins bind to the FP1 region (C1, C2, and C3 sites). The nuclear receptor, COUP-TF, binds to the C2 site. Mutations in the C1 binding region abolish C1 complex formation and reduce estrogen-dependent transcription from the lactoferrin ERE. When the imperfect ERE of the lactoferrin gene is converted to a perfect palindromic structure, the enhancing effect of the C1 binding element for estrogen responsiveness was abolished. We isolated a complementary DNA (cDNA) clone from an RL95-2 expression library that encodes the C1 site-binding protein. The encoded polypeptide maintains 99% amino acid identity with the previously described orphan nuclear receptor hERR1. A 2.2-kilobase mRNA was detected in RL95-2 cells by the newly isolated cDNA but not by the first 180 base pair of the published hERR1 sequence. By Western analysis, a major 42-kDa protein is detected in the RL95-2 nuclear extract with antibody generated against GST-hERR1 fusion protein. Finally, we show that the hERR1 interacts with the human estrogen receptor through protein-protein contacts.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Breast
  • Carcinoma, Endometrioid
  • Cell Line
  • Chloramphenicol O-Acetyltransferase / biosynthesis
  • DNA Primers
  • DNA, Complementary
  • DNA, Neoplasm / metabolism
  • DNA-Binding Proteins / metabolism*
  • ERRalpha Estrogen-Related Receptor
  • Female
  • Gene Expression*
  • Gene Library
  • Glutathione Transferase / biosynthesis
  • Humans
  • Lactoferrin / biosynthesis*
  • Lactoferrin / genetics*
  • Methylation
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Mutagenesis, Site-Directed
  • Nuclear Proteins / metabolism
  • Promoter Regions, Genetic*
  • Receptors, Cytoplasmic and Nuclear / isolation & purification
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Receptors, Estrogen / isolation & purification
  • Receptors, Estrogen / metabolism*
  • Recombinant Proteins / biosynthesis
  • Regulatory Sequences, Nucleic Acid
  • Transcription, Genetic
  • Transfection
  • Tumor Cells, Cultured


  • DNA Primers
  • DNA, Complementary
  • DNA, Neoplasm
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Estrogen
  • Recombinant Proteins
  • Chloramphenicol O-Acetyltransferase
  • Glutathione Transferase
  • Lactoferrin

Associated data

  • GENBANK/L38487