Poly(dA:dT), a ubiquitous promoter element that stimulates transcription via its intrinsic DNA structure

EMBO J. 1995 Jun 1;14(11):2570-9.

Abstract

Many yeast promoters contain homopolymeric dA:dT sequences that affect nucleosome formation in vitro and are required for wild-type levels of transcription in vivo. Here, we show that poly(dA:dT) is a novel promoter element whose function depends on its intrinsic structure, not its interaction with sequence-specific, DNA-binding proteins. First, poly(dA:dT) stimulates Gcn4-activated transcription in a manner that is length dependent and inversely related to intracellular Gcn4 levels. Second, Datin, the only known poly(dA:dT)-binding protein, behaves as a repressor through poly(dA:dT) sequences. Third, poly(dG:dC), a structurally dissimilar homopolymer that also affects nucleosomes, has transcriptional properties virtually identical to those of poly(dA:dT). Three probes of chromatin structure including HinfI endonuclease cleavage in vivo indicate that poly(dA:dT) increases accessibility of the Gcn4 binding site and adjacent sequences in physiological chromatin. These observations suggest that, by virtue of its intrinsic structure, poly(dA:dT) locally affects nucleosomes and increases the accessibility of transcription factors bound to nearby sequences.

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, Fungal / chemistry
  • DNA, Fungal / genetics
  • DNA-Binding Proteins / metabolism
  • Dopamine Plasma Membrane Transport Proteins
  • Fungal Proteins / metabolism
  • Membrane Glycoproteins*
  • Membrane Transport Proteins*
  • Molecular Sequence Data
  • Molecular Structure
  • Nerve Tissue Proteins*
  • Nucleosomes / metabolism
  • Poly dA-dT / chemistry
  • Poly dA-dT / genetics*
  • Poly dA-dT / metabolism
  • Polydeoxyribonucleotides / chemistry
  • Polydeoxyribonucleotides / genetics
  • Polydeoxyribonucleotides / metabolism
  • Promoter Regions, Genetic*
  • Protein Kinases / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Transcription, Genetic

Substances

  • DAT1 protein, S cerevisiae
  • DNA, Fungal
  • DNA-Binding Proteins
  • Dopamine Plasma Membrane Transport Proteins
  • Fungal Proteins
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • Nucleosomes
  • Polydeoxyribonucleotides
  • Saccharomyces cerevisiae Proteins
  • Poly dA-dT
  • poly(dC-dG)
  • Protein Kinases