An evolutionarily conserved gene family encodes proton-selective ion channels

The proton channel behind sour taste Although many proteins that form ion channels in cell membranes have been described, none that selectively conduct protons into eukaryotic cells have been identified. Tu et al. used a genetic screen to pinpoint candidate genes that might encode such a protein from mouse taste receptor cells (see the Perspective by Montell). They identified the known protein otopetrin and showed that it conferred proton conductance when expressed in cultured human cells. Their results indicate that otopetrin may function in sensory recognition of sour (acidic) taste in humans and other organisms. Science , this issue p. 1047 ; see also p. 991