Transcription factors AP-3 and AP-2 interact with the SV40 enhancer in a mutually exclusive manner

EMBO J. 1989 May;8(5):1455-60.


The 'core' sequence is critical for efficient transcriptional activity of the SV40 enhancer. Moreover, the core was shown to be involved in a signal transduction pathway elicited by treatment of cells with phorbol ester tumor promoters. We report here the identification and characterization of activator protein-3 (AP-3), which recognizes the core element. AP-3 was purified to near homogeneity and identified as a 48K polypeptide. The purified protein is an efficient transcriptional activator in vitro. In addition, we show that AP-3 and a second factor that recognizes the SV40 enhancer, AP-2, interact in a mutually exclusive manner. These studies should facilitate understanding of the mechanism by which the SV40 enhancer achieves its characteristic broad cell-type specificity.

Publication types

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

MeSH terms

  • Base Sequence
  • Binding Sites
  • DNA / genetics
  • DNA / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Enhancer Elements, Genetic*
  • HeLa Cells / metabolism
  • Humans
  • Simian virus 40 / genetics*
  • Transcription Factor AP-2
  • Transcription Factors / genetics
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*


  • DNA-Binding Proteins
  • Transcription Factor AP-2
  • Transcription Factors
  • enhancer-binding protein AP-3
  • DNA