Defining the Polycystin Pharmacophore Through HTS & Computational Biophysics.

Background and Purpose: Polycystins (PKD2, PKD2L1) are voltage-gated and Ca Experimental Approach: HEK293 cells stably expressing PKD2L1 F514A were pharmacologically screened via high-throughput electrophysiology to identify potent polycystin channel modulators. In-silico docking analysis and mutagenesis were used to define the receptor sites of screen hits. Inhibition by membrane-impermeable QX-314 was used to evaluate PKD2L1's binding site accessibility. Key Results: Screen results identify potent PKD2L1 antagonists with divergent chemical core structures and highlight striking similarities between the molecular pharmacology of PKD2L1 and voltage-gated sodium channels. Docking analysis, channel mutagenesis, and physiological recordings identify an open-state accessible lateral fenestration receptor within the pore, and a mechanism of inhibition that stabilizes the PKD2L1 inactivated state. Conclusion and Implication: Outcomes establish the suitability of our approach to expand our chemical knowledge of polycystins and delineates novel receptor moieties for the development of channel-specific antagonists in TRP channel research.