Single Molecule Studies of Physiologically Relevant Telomeric Tails Reveal POT1 Mechanism for Promoting G-quadruplex Unfolding

• DOI: 10.1074/jbc.m110.205641
• Publication Date: 2010-12-24T04:00:39Z
• Authors: Hong Wang; Gerald J. Nora; Harshad Ghodke; Patricia L. Opresko
• Keywords: G-quadruplex

Human telomeres are composed of duplex TTAGGG repeats and a 3′ single-stranded DNA tail. The telomeric is protected regulated by the shelterin proteins, including protection 1 (POT1) protein that binds DNA. tail can fold into G-quadruplex (G4) Both POT1 G4 play important roles in regulating telomere length homeostasis. To date, most studies have focused on individual quadruplexes formed four repeats. Telomeric tails human cells average six times as many repeats, no structural examined binding competition with folding. Using single molecule atomic force microscopy imaging, we observed majority 16 two even though were possible. result physiological rarely form maximum potential number units provides basis for coexistence same molecule, which directly captured images. We further significantly more effective disrupting quadruplex long than an antisense oligonucleotide, indicating novel activity beyond simply preventing