A sugar transporter as a candidate for the outer hair cell motor

Forces developed by cochlear outer hair cells (OHCs) are responsible for th e sharp tuning that underlies sensitivity and frequency selectivity in the ear. OHCs exhibit a voltage-dependent motility involving a 'motor' protein embedded in the basolateral membrane. The motor has so far resisted molecul ar identification. Here we provide evidence that it may be related to a fru ctose transporter. We show that OHCs are able to transport this sugar selec tively and that the sugar alters electrical properties of the OHC motor. Th ese data can be combined into an integrated model of a sugar carrier, that makes the novel prediction, demonstrated here, that such 'neutral' transpor ters can be voltage dependent.