The promoter-specific transcription factor Sp1 binds to upstream sequences in the SV40 early promoter

Cell. 1983 Nov;35(1):79-87. doi: 10.1016/0092-8674(83)90210-6.


Fractionation of HeLa cell extracts reveals the presence of a promoter-specific transcription factor, Sp 1, which activates a class of promoters that includes the SV40 early promoter but not several others that have been tested. We analyzed SV40 early-promoter deletion mutants and determined that transcriptional activation by Sp 1 requires sequences within tandem 21 bp repeats located 70-110 bp upstream of the transcription initiation sites. In a DNAase footprinting assay, Sp 1 protected sequences in this same 21 bp repeat region, thus indicating the presence of a specific site for Sp 1 binding. During purification of Sp 1, there was a correlation between transcription-stimulatory activity and promoter-binding activity. These results suggest that direct binding of Sp 1 to sequences in the upstream promoter element is the mechanism by which this factor activates transcription by RNA polymerase II at the SV40 early promoter.

Publication types

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

MeSH terms

  • Binding Sites
  • DNA, Viral / metabolism*
  • Genes, Viral*
  • HeLa Cells
  • Humans
  • Mutation
  • Operon*
  • Repetitive Sequences, Nucleic Acid
  • Simian virus 40 / genetics*
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*
  • Transcription, Genetic


  • DNA, Viral
  • Transcription Factors

Associated data

  • GENBANK/J02400
  • GENBANK/J02402
  • GENBANK/J02403
  • GENBANK/J02406
  • GENBANK/J02407
  • GENBANK/J02408
  • GENBANK/J02409
  • GENBANK/J02410
  • GENBANK/V01380