In vitro squelching of activated transcription by serum response factor: Evidence for a common coactivator used by muliple transcriptional activators

Ron Prywes, Hua Zhu

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Low amounts of serum response factor (SRF) activate transcription in vitro from a fos promoter construct containing an SRF binding site. Using this human HeLa cell-derived in vitro transcription system, we have found that high amounts of SRF inhibited, or 'squelched', transcription from this construct. Transcription from several other promoters activated by different gene-specific factors, including CREB and the acidic activator VP16, was also inhibited by high amounts of SRF. Basal transcription, from TATA-only promoters, however, was not inhibited. These results suggest that SRF binds to a common factor(s) (termed coactivator) required for activated transcription by a diverse group of transcriptional activators. Inhibition of transcription by SRF could be blocked by a double stranded oligonucleotide containing an SRF binding site. Mutations in SRF which abolished its DNA binding activity also reduced its ability to inhibit transcription. In addition, a C-terminal truncation of SRF which reduced its ability to activate transcription also reduced SRF's ability to inhibit transcription. These results suggest that activation and inhibition of transcription may be mediated by SRF binding to the same factor and that SRF can only bind to this factor when SRF is bound to plasmid DNA.

Original languageEnglish (US)
Pages (from-to)513-520
Number of pages8
JournalNucleic acids research
Volume20
Issue number3
DOIs
StatePublished - Feb 11 1992
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Genetics

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