Model of a Molecular Proton Sensor in Taste Cells

Abstract

Otopetrins represents a group of membrane proteins that function as proton-selective ion channels. Existing evidence indicates that Otop1, the eponym of the family, is a likely molecular sensor of protons involved in detecting acid stimuli in taste cells of type III. Acid stimuli is believed to initiate an inward current carried by protons through receptive apical membrane to depolarize a type III cell and trigger a train of action potentials driving afferent neurotransmission. While many details of this rather complicated process have not been uncovered yet, mathematical modelling could provide a sufficient insight into sour transduction. Here we present a mathematical model for describing dynamic and transport properties of Otop1 channel. The elaborated model appropriately describes proton currents through Otop1 under different conditions, and it could be employed for further modeling of sour responses of taste cells.