Binding of single-stranded oligonucleotides to a non-B-form DNA structure results in loss of promoter activity of the platelet-derived growth factor A-chain gene.
Levels of expression of the platelet-derived growth factor (PDGF) A-chain gene differ significantly in normal and transformed cells. We have identified an S1 nuclease-sensitive site in a GC box located at -55 to -72 in the PDGF A-chain promoter region. We now demonstrate that a 24-base, G-rich complementary oligonucleotide anneals specifically to the C-rich strand of the GC box and protects the GC box from nicking by S1 nuclease whereas the C-rich complementary oligonucleotide and its double-stranded counterpart do not. In transient transfection assays, expression of the PDGF A-chain gene is sharply reduced by deletions within the GC box or if the 24-base G-rich complementary oligonucleotide is preincubated with the promoter construct prior to transfection. The data suggest that the GC box of the PDGF A-chain gene may promote a non-B-form DNA structure, which is recognized by S1 nuclease and which anneals to a short complementary G-rich oligonucleotide. The data also suggest that this non-B-form DNA is important for efficient transcription of PDGF A-chain gene.
Wang
Z Y
ZY
Department of Medicine, Washington University Medical Center, St. Louis, Missouri.
Lin
X H
XH
Nobyuoshi
M
M
Qui
Q Q
QQ
Deuel
T F
TF
D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000378:metabolism*; D010957:Plasmids; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D014162:Transfection
D009841:Oligonucleotides; D010982:Platelet-Derived Growth Factor; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase