Human telomere RNA: a potential target for ligand recognition.

A recent finding demonstrated that telomere DNA is transcribed into telomeric repeat-containing RNA (referred to as TERRA) in mammalian cells. The existence of TERRA RNA may reveal a new level of regulation and protection of chromosome ends that could promote valuable insight into fundamental biological processes such as cancer and aging. Revealing the structure and function of telomere RNA will be essential for understanding telomere biology and telomere-related diseases. In fact, others and we have shown by NMR and x-ray crystallography that human telomere RNA forms G-quadruplex structures. More recently, we found that human telomere RNA forms a G-quadruplex dimer in the living cells by employing a light-switching probe. Recently, researches concerning the telomere RNA G-quadruplexes have made much progress. This review highlights the structures and topologies for telomere RNA G-quadruplex and recent efforts in the design of telomere RNA G-quadruplex ligands; outlines the future challenges in the field.