SfN 2025 – Electrophysiological Characterization of Functional and Pharmacological Effects of TMEM175 Wild Type, Gain-of-Function and Loss-of-Function Lysosomal Coding Variants

TMEM175 is a proton-activated lysosomal ion channel that regulates lysosomal pH and autophagy, and mutations in this channel have been linked to Parkinson’s disease risk. Sygnature Discovery developed recombinant HEK-293 cell lines expressing TMEM175 wild type (WT), gain-of-function (GoF) and loss-of-function (LoF) variants to examine proton and ceasium conductance using the SycroPatch 384i automated electrophysiology platform. Electrophysiological characterization included pH sensitivity, proton-activated and caesium currents, and pharmacological modulation using a known activator (DCPIB) and inhibitor (4-AP). Results revealed expected pH-dependent channel responses, variant-specific shifts in sensitivity, and clear potency changes under different pH conditions. This high-throughput assay enables rapid profiling of TMEM175 modulators and provides a translational platform to explore the role of lysosomal ion channel function in Parkinson’s disease.