Nuclear factor I and mammary gland factor (STAT5) play a critical role in regulating rat whey acidic protein gene expression in transgenic mice

Mol Cell Biol. 1995 Apr;15(4):2063-70. doi: 10.1128/MCB.15.4.2063.

Abstract

The rat whey acidic protein (WAP) gene contains a mammary gland-specific and hormonally regulated DNase I-hypersensitive site 830 to 720 bp 5' to the site of transcription initiation. We have reported previously that nuclear factor I (NFI) binding at a palindromic site and binding at a half-site are the major DNA-protein interactions detected within this tissue-specific nuclease-hypersensitive region. We now show that point mutations introduced into these NFI-binding sites dramatically affect WAP gene expression in transgenic mice. Transgene expression was totally abrogated when the palindromic NFI site or both binding sites were mutated, suggesting that NFI is a key regulator of WAP gene expression. In addition, a recognition site for mammary gland factor (STAT5), which mediates prolactin induction of milk protein gene expression, was also identified immediately proximal to the NFI-binding sites. Mutation of this site reduced transgene expression by approximately 90% per gene copy, but did not alter tissue specificity. These results suggest that regulation of WAP gene expression is determined by the cooperative interactions among several enhancers that constitute a composite response element.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites / genetics
  • CCAAT-Enhancer-Binding Proteins*
  • DNA Mutational Analysis
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation*
  • Lactation / genetics*
  • Mammary Glands, Animal / physiology
  • Mice
  • Mice, Transgenic
  • Milk Proteins / biosynthesis*
  • Milk Proteins / genetics
  • Molecular Sequence Data
  • NFI Transcription Factors
  • Nuclear Proteins
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Rats
  • STAT5 Transcription Factor
  • Trans-Activators / metabolism*
  • Transcription Factors*
  • Y-Box-Binding Protein 1

Substances

  • CCAAT-Enhancer-Binding Proteins
  • DNA-Binding Proteins
  • Milk Proteins
  • NFI Transcription Factors
  • Nuclear Proteins
  • STAT5 Transcription Factor
  • Stat5a protein, mouse
  • Trans-Activators
  • Transcription Factors
  • Y-Box-Binding Protein 1
  • YBX1 protein, human
  • whey acidic proteins