Taste receptor cells express voltage-dependent potassium channels in a cell age-specific manner

Two voltage-dependent potassium channels, KCNQ1 and KCNH2, are expressed in the taste buds and were identified as strong candidates involved in the repolarization of taste receptor cells expressing phospholipase C-beta 2 and TRPM5 (beta 2/M5-TRCs). In cell type-specific expression, KCNQ1 was expressed in most taste bud cells, including beta 2/M5-TRCs, whereas KCNH2 was expressed in a subset of beta 2/M5-TRCs with no correlation with their taste modality, such as sweet or bitter taste reception. Expression of KCNH2 was restricted to young beta 2/M5-TRCs. These results suggest that taste bud cells other than beta 2/M5-TRCs are depolarized by some stimuli and also that beta 2/M5-TRCs have cell age-dependent molecular mechanisms of repolarization.