Development of inhibitors, probes, and PROTAC provides a complete toolbox to study PARK7 in the living cell

The innovation of combined chemical tools, such as small molecule inhibitors, activity-based probes (ABPs), and proteolysis targeting chimeras (PROTACs) for a specific target, not only advances clinical drug discovery but also provides a chemical toolbox to study the diverse biological perspective of targeted proteins. Here we report the development of such a chemical toolbox for the multifunctional human Parkinson disease protein 7 (PARK7/DJ-1) that has drawn attention as a candidate for drug discovery due to its involvement with Parkinson's disease and cancers. By combining structure-guided design, small library synthesis and high-throughput screening, we identified two compounds, JYQ-164 and JYQ-173, inhibiting PARK7 with high potency in vitro and in cell. These compounds covalently and selectively target its highly conserved and functionally essential residue, Cys106. Based on these compounds, we further developed two cell-permeable fluorescent probes, JYQ-192 and JYQ-196, with a SulfoCy5 dye to visualize PARK7 activity in living cells and a first-in-class PARK7 degrader JYQ-194 that selectively targets PARK7 to proteasomal degradation in human cells. Together, our study provides a valuable toolbox to advance the biology research of PARK7 in a cellular context and opens new opportunities for potential therapeutic application.