Possible Direction of Drug Discovery Based on Single-Molecule Live Imaging

In conventional drug discovery, particularly for small molecules, investigating a small compound that matches the structure of the target molecule and alters its activity has been a crucial process. On the other hand, artificially regulating the activity of a target molecule that is inherently present in cells or organisms and involved in a physiological function can cause various side effects. One possible approach to overcoming this side effect problem is to explore molecules that affect the behavior or motility of molecules related to diseases. If a screening method is developed to search for drugs that target only specific motions of the target molecules, a new concept of motility-targeted drug discovery will be created. In this review article, single-molecule live imaging -a core technology for analyzing the motility of molecules in living cells and organisms -is introduced by describing examples of single-molecule imaging, such as membrane receptors and RNAs. The potential of single-molecule imaging to contribute to drug discovery is also discussed.