A Modular Engineered DNA Nanodevice for Precise Profiling of Telomerase RNA Location and Activity

Increased telomerase activity has been considered as a conspicuous sign of human cancers. The catalytic cores of telomerase involve a reverse transcriptase and the human telomerase RNA (hTR). However, current detection of telomerase is largely limited to its activity at the tissue and single-cell levels. To reveal the precise distribution of subcellular hTR and telomerase activity, here a modular engineered DNA nanodevice (DNA-ND) is designed capable of imaging hTR and telomerase activity in cytoplasm and nucleus, enabling colocalization analysis. DNA-ND is a modular DNA complex comprising hTR and telomerase activity detection modules, which respectively sense intercellular hTR and telomerase activity via target-sensitive allosteric transition of DNA switches, actuating orthogonal activation of fluorescence signals to achieve in situ co-imaging of hTR and telomerase activity. By integrating DNA-ND with specific localized signals, the DNA-ND based precise profiling of colocalization of hTR and telomerase activity in different cell lines as well as their dynamic changes during pharmacological interventions is demonstrated. Notably, the results suggest that the locations of hTR and telomerase activity are not exactly overlapped, indicating the influence of intracellular environment on the binding of hTR to telomerase.