PHASE SEPARATION TUNES THE STABILITY AND DYNAMICS OF G-QUADRUPLEX AND I-MOTIF DNA IN THE NUCLEI OF LIVING CELLS.

ABSTRACT: G-quadruplexes and i-motifs are non-canonical DNA structures that are important not only as targets of gene regulation in cancer therapy, but also as nanotools with biomedical applications. However, their apparent in vitro stabilities and dynamics cast doubt upon their physiological relevance and utility in vivo. Here we investigate folding of the thrombin-binding aptamer G-quadruplex and the TAA(C₅TAA)₄ i-motif. We use fast relaxation imaging, which couples fluorescence microscopy with laser-induced temperature jumps, to quantify the stability and dynamics of FRET-labelled constructs in vitro and in the nuclei of living cells. Our work suggests that the stability and kinetics of i-motif and G-quadruplex DNA are carefully tuned by phase separation to fit the se

SUBMITTER: Patel B 

PROVIDER: S-EPMC12236694 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature