An evolutionarily conserved gene family encodes proton-selective ion channels
Ion channels form the basis for cellular electrical signaling. Despite the scores of genetically identified ion channels selective for other monatomic ions, only one type of proton-selective ion channel has been found in eukaryotic cells. By comparative transcriptome analysis of mouse taste receptor cells, we identified Otopetrin1 (Otop1), a protein required for development of gravity-sensing otoconia in the vestibular system, as forming a proton-selective ion channel. We found that murine Otop1 is enriched in acid-detecting taste receptor cells and is required for their Zn2+-sensitive proton conductance. Two related murine genes, Otop2 and Otop3, and a Drosophila ortholog also encode proton channels. Evolutionary conservation of the gene family and its widespread tissue distribution suggest a broad role for proton channels in physiology and pathophysiology.
USC Dornsife graduate student Yu-Hsiang Tu and Emily Liman, USC Dornsife biological sciences professor
Emily Liman, Heather Turner, Daniel Artiga, Bochuan Teng and Yu-Hsiang Tu (seated)