Otopetrin 1 (OTOP1)

Otopetrin 1 (OTOP1) is a dimeric transmembrane protein forming a proton-selective ion channel, comprised of 12 transmembrane segments organized into structurally similar N and C domains. OTOP1 is essential in mammals for two major physiological processes: sour taste perception (acting as the primary receptor for extracellular protons in taste buds) and otoconia biomineral formation in the inner ear, which is necessary for vestibular function. OTOP1 channel activity is regulated by extracellular pH and by key residues in extracellular loops, with its gating and permeation pathway still under active investigation. Structural studies reveal a unique channel architecture among ion channels, with lipid interactions that may modulate function. While not yet a therapeutic target, OTOP1's roles suggest potential relevance in sensory disorders and vestibular disease.

Other names

Proton channel OTOP1OTOP1hOtop1Otopetrin-1Otopetrin family protein

For inhibitors (like zinc ions): channel blockade leading to reduced proton currents. No approved drugs target OTOP1 clinically.