The G-quadruplex ligand telomestatin inhibits POT1 binding to telomeric sequences in vitro and induces GFP-POT1 dissociation from telomeres in human cells.

Telomestatin is a potent G-quadruplex ligand that specifically interacts with the 3' telomeric overhang, leading to its degradation and that induces a delayed senescence and apoptosis of cancer cells. Protection of Telomere 1 (POT1) was recently identified as a specific single-stranded telomere-binding protein involved in telomere capping and T-loop maintenance. We showed here that a telomestatin treatment inhibits POT1 binding to the telomeric overhang in vitro.