Cryo-EM Structure of the TRPC1/5 Heteromer Enables Design of Antidepressant and Anxiolytic Drug with Reduced Side Effects

Abstract The TRPC1/5 heteromer exhibits electrophysiological and ligand-binding properties distinct from TRPC5 homomers, enabling tissue-specific cellular regulation. Here we present the cryo-EM structure of the TRPC1/5 heterotetramer at 2.8 Å resolution, revealing an asymmetric assembly of three TRPC5 subunits around one TRPC1 subunit. TRPC1 contributes a unique pore-loop configuration and specialized inter-subunit interfaces that sculpt an asymmetrical ion conduction pathway, altering gating and ion selectivity. The heteromer harbors a ligand-binding pocket at the TRPC1-TRPC5 interface absent in homomeric channels. Using this insight, we design JD03-02, a high-affinity antagonist preferentially targeting this pocket with >10,000-fold selectivity for TRPC1/5 over TRPC5 homomers. In mouse models, JD03-02 produces potent anxiolytic and antidepressant effects with reduced off-target activity. These findings elucidate the structural basis of TRPC1/5 function and can guide precision drug design targeting heteromeric ion channels in neuropsychiatric disorders.