消光団を利用したケミカルタグ技術の開発とライブセル超解像イメージングへの応用

抄録

Fluorescence imaging has made it possible to observe biomolecular distribution inside living cells. While a variety of fluorescent proteins are widely used, imaging tools using small-molecular organic fluorophores has attracted much attention due to their superior properties such as photostability. We have developed DeQODE chemical tag technology for genetically targeted fluorescence imaging. In this labeling system, a small-molecular QODE probe consisting of an organic fluorophore and a dinitrophenyl (DNP) quencher is almost non-fluorescent but becomes highly fluorescent upon binding to an anti-DNP single-chain antibody, DeQODE tag, expressed in cells. Since the probe reversibly binds to the tag protein, fluorescent signal can be continuously obtained, even if the bound probe photobleaches by strong excitation usually used in super-resolution imaging, by an exchange reaction in which another intact probe binds to the tag after the photobleaced probe is dissociated. We applied DeQODE chemical tag to live-cell STED microscopy, and achieved continuous super-resolution imaging of synaptic protein Homer in rat hippocampal neurons. This result clearly showed that DeQODE chemical tag technology is a powerful tool for super-resolution imaging by avoiding the problem of photobleaching.