The dynamic character of the G-quadruplex element in the c-MYC promoter and modification by TMPyP4.
The nuclease hypersensitivity element III1 (NHE III1) upstream of the P1 and P2 promoters of c-MYC controls 80-90% of the transcriptional activity of this gene. The purine-rich strand in this region can form a G-quadruplex structure that is a critical part of the silencer element for this promoter. We have demonstrated that this G-quadruplex structure can form a mixture of four biologically relevant parallel-loop isomers, which upon interaction with the cationic porphyrin TMPyP4 are converted to mixed parallel/antiparallel G-quadruplex structures.
Seenisamy
Jeyaprakashnarayanan
J
College of Pharmacy, The University of Arizona, 1703 East Mabel, Tucson, Arizona 85721, USA.
Rezler
Evonne M
EM
Powell
Tiffanie J
TJ
Tye
Denise
D
Gokhale
Vijay
V
Joshi
Chandana Sharma
CS
Siddiqui-Jain
Adam
A
Hurley
Laurence H
LH
D004247:DNA / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D016259:Genes, myc / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D009690:Nucleic Acid Conformation / Q000187:drug effects; D011166:Porphyrins / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics*; D037941:Silencer Elements, Transcriptional / Q000187:drug effects* / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*
D011166:Porphyrins; C021096:tetra(4-N-methylpyridyl)porphine; D004247:DNA