Cell cycle regulation of nuclear factor p32 DNA-binding activity by novel phase-specific inhibitors

J Biol Chem. 1996 Apr 19;271(16):9215-22. doi: 10.1074/jbc.271.16.9215.

Abstract

The nuclear factor p92, originally discovered by its interaction with the human papillomavirus type 18 enhancer, is a cellular protein whose activity is restricted to S phase in human primary fibroblasts. The human papillomavirus type 18 p92 binding sequence confers enhancer activity on a heterologous promoter, suggesting that p92 acts as a transcription factor. We have identified a class of nuclear inhibitory proteins, I-92s, which noncovalently associate with p92 but not with other transcription factors such as AP1, E2F, or NF-kappaB. Different I-92s occur in G1, G2, and G0, while no I-92 is detectable in S phase. Phase-specific inhibitors, therefore, are responsible for the cell cycle dependence of p92 activity and provide a novel mechanism linking transcription factor regulation with the cell cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Cell Cycle*
  • Cell Nucleus / metabolism*
  • Cells, Cultured
  • DNA-Binding Proteins / metabolism*
  • Enhancer Elements, Genetic
  • Fibroblasts
  • Flow Cytometry
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / metabolism*
  • Oligodeoxyribonucleotides
  • Papillomaviridae / genetics
  • Promoter Regions, Genetic
  • Recombinant Proteins / metabolism
  • S Phase
  • Simian virus 40 / genetics
  • Transcription Factors / metabolism*
  • Transfection

Substances

  • DNA-Binding Proteins
  • Nuclear Proteins
  • Oligodeoxyribonucleotides
  • Recombinant Proteins
  • Transcription Factors