Identification of a single-stranded DNA-binding protein that interacts with an S1 nuclease-sensitive region in the platelet-derived growth factor A-chain gene promoter.
We previously observed that transcription of the platelet-derived growth factor (PDGF) A-chain gene is enhanced in cells stimulated by PDGF through a serum response element (SRE) in its 5'-flanking sequence. We now show that the region of the SRE is sensitive to S1 nuclease in vitro. We also identify a single-stranded DNA-binding protein in HeLa cell nuclear extracts that binds to the noncoding strand of the PDGF A-chain SRE but not to its double-stranded counterpart or to the single-stranded coding sequence. Competition assays using oligonucleotides with sequence-specific mutations that diminished or eliminated detectable complex formation were used to establish the specificity of this protein/DNA interaction. Remarkably, the sequence-specific single-stranded binding protein binds to this region only when it is highly supercoiled. The data suggest that the single-stranded DNA-binding protein specifically interacts with a highly supercoiled region of the PDGF A-chain promoter and that this interaction may have a role in the transcriptional regulation of this gene.
Wang
Z Y
ZY
Department of Medicine, Jewish Hospital of St. Louis, Missouri.
Lin
X H
XH
Nobuyoshi
M
M
Deuel
T F
TF
D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002467:Cell Nucleus / Q000378:metabolism; D002846:Chromatography, Affinity; D004277:DNA, Single-Stranded / Q000378:metabolism*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
D004277:DNA, Single-Stranded; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D010982:Platelet-Derived Growth Factor; D015719:Single-Strand Specific DNA and RNA Endonucleases