Live-Cell Imaging of the Binding between a Chemical Drug and Its Target Proteins Based on Intracellular Redistribution of the Target Proteins.

In modern pharmacology, obtaining an in-depth understanding of the interaction of chemical drugs with their target proteins is essential for drug discovery and the advancement of precision medicine. However, detecting these drug-protein interactions in living cells remains challenging owing to the lack of reliable methodologies. The current study presents a robust strategy involving the redistribution of target proteins in cells and applying a cotranslocation-based cellular assay for monitoring drug-target interactions in living cells. This technique utilizes an enhanced green fluorescent protein (EGFP)-tagged drug target protein that is translocated from the cytoplasm to the plasma membrane when exposed to a biotin-conjugated drug and phorbol 12-myristate 13-acetate (PMA). This movement is facilitated by the membrane-translocation properties of the C1A-mRFP-streptavidin fusion protein, which anchors the biotinylated small-molecule drug and facilitates the spatial redistribution of its target proteins. This system provides a dynamic tool for the real-time observations of drug-protein binding events within cellular environments.