Imaging the Binding between a Chemical Drug and its Target Proteins in Living Cells via CID and Protein Redistribution

<p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="first" dir="auto" id="d1649e100">In contemporary medicine, the interaction between chemical drugs and their target proteins forms the cornerstone of drug discovery and precision therapies. However, the challenge of effectively detecting these drug-target interactions within live cells persists due to a lack of robust methodologies. Here, we introduce an innovative imaging technique that fuses chemically induced dimerization (CID) with protein redistribution, enabling visualization of chemical drug-target interactions in living cells. This approach leverages an EGFP-tagged drug target protein that relocates from the cytoplasm to the plasma membrane when exposed to a biotin-labeled drug and phorbol 12-myristate 13-acetate (PMA). This translocation occurs due to the membrane affinity of the C1A–mRFP–streptavidin (SA) fusion protein, offering a dynamic tool for real-time observation of drug-protein binding in cellular environments.