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.