The dynamic character of the G-quadruplex element in the c-MYC promoter and modification by TMPyP4.

Abstract

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.

• Authors: Jeyaprakashnarayanan Seenisamy, Evonne M Rezler, Tiffanie J Powell, Denise Tye, Vijay Gokhale, Chandana Sharma Joshi, Adam Siddiqui-Jain, Laurence H Hurley
• Journal: Journal of the American Chemical Society (J Am Chem Soc) Vol. 126 Issue 28 Pg. 8702-9 (Jul 21 2004) ISSN: 0002-7863 [Print] United States
• PMID: 15250722 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Porphyrins
• tetra(4-N-methylpyridyl)porphine
• DNA

Topics

• DNA (chemistry, drug effects, genetics)
• Genes, myc (drug effects, genetics)
• Humans
• Models, Genetic
• Nucleic Acid Conformation (drug effects)
• Porphyrins (pharmacology)
• Promoter Regions, Genetic (drug effects, genetics)
• Silencer Elements, Transcriptional (drug effects, genetics)
• Transcription, Genetic (genetics)