Mechanism of (−)‐Englerin A and calcium binding on the human TRPC5 channel

Abstract The natural product (−)‐Englerin A (EA) selectively inhibits renal cancer cell growth by potently activating TRPC4 and TRPC5‐containing ion channels. However, its binding site on these channels has remained elusive. In this study, we present two cryo‐EM structures of human TRPC5 in complex with EA at 2.5 and 2.6 Å resolution, which reveal the EA‐binding site and identify two major conformations influenced by calcium. EA binds between the pore helix and S5/S6 helices of hTRPC5, forming critical hydrophobic and polar interactions that underscore its specificity. Calcium binding at the intracellular domain of TRPC5 induces structural changes that stabilize the domain in a compact conformation. These findings expand our understanding of the structural pharmacology of TRPC5 and provide a framework for investigating calcium regulation in TRPC channels.