Related Experiment Video
Updated: Aug 7, 2026
Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome
Published on: September 13, 2024
DNA sequence-specific polyamides alleviate transcription inhibition associated with long GAA.TTC repeats in
Ryan Burnett1, Christian Melander, James W Puckett
1Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Abstract:
The DNA abnormality found in 98% of Friedreich's ataxia (FRDA) patients is the unstable hyperexpansion of a GAA.TTC triplet repeat in the first intron of the frataxin gene. Expanded GAA.TTC repeats result in decreased transcription and reduced levels of frataxin protein in affected individuals. Beta-alanine-linked pyrrole-imidazole polyamides bind GAA.TTC tracts with high affinity and disrupt the intramolecular DNA.DNA-associated region of the sticky-DNA conformation formed by long GAA.TTC repeats. Fluorescent polyamide-Bodipy conjugates localize in the nucleus of a lymphoid cell line derived from a FRDA patient. The synthetic ligands increase transcription of the frataxin gene in cell culture, resulting in increased levels of frataxin protein. DNA microarray analyses indicate that a limited number of genes are significantly affected in FRDA cells. Polyamides may increase transcription by altering the DNA conformation of genes harboring long GAA.TTC repeats or by chromatin opening.
