Human telomere RNA and DNA form an intermolecular G-quadruplex

Abstract

For a long time, telomeres have been considered to be transcriptionally silent. Recently, Azzalin et al. demonstrated that telomeres are transcribed into telomeric repeat-containing RNA (TERRA) in mammalian cells. The telomere RNA was found to localize at the telomere DNA. These findings raise a possibility of that telomere RNA may be involved in an intermolecular G-quadruplex with the telomere DNA. In the current studies, we found that human telomere RNA and telomere DNA sequence can form hybrid-type parallel G-quadruplex structure. These results provide valuable information to allow understanding of the roles of human telomeric RNA in chromosome ends regulation and protection.