Human P2X4 receptor gating is modulated by a stable cytoplasmic cap and a unique allosteric pocket.

ABSTRACT: P2X receptors (P2XRs) are adenosine 5'-triphosphate (ATP)-gated ion channels comprising homomeric and heteromeric trimers of seven subtypes (P2X1-P2X7) that confer different rates of desensitization. The helical recoil model of P2XR desensitization proposes stability of the cytoplasmic cap sets the rate of desensitization, but timing of its formation is unclear for slow-desensitizing P2XRs. We report cryo-electron microscopy structures of full-length wild-type human P2X4 receptor in apo closed, antagonist-bound inhibited, and ATP-bound desensitized states. Because the apo closed and antagonist-bound inhibited state structures of this slow-desensitizing P2XR include an intact cytoplasmic cap while the ATP-bound desensitized state structure does not, the cytoplasmic cap is formed before agon

SUBMITTER: Shi H 

PROVIDER: S-EPMC11740937 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature