Ohmoto Makoto, Matsumoto Ichiro, Misaka Takumi, Abe Keiko
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Chem Senses. 2006 Oct;31(8):739-46. doi: 10.1093/chemse/bjl016. Epub 2006 Jul 27.
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-beta2 and TRPM5 (beta2/M5-TRCs). In cell type-specific expression, KCNQ1 was expressed in most taste bud cells, including beta2/M5-TRCs, whereas KCNH2 was expressed in a subset of beta2/M5-TRCs with no correlation with their taste modality, such as sweet or bitter taste reception. Expression of KCNH2 was restricted to young beta2/M5-TRCs. These results suggest that taste bud cells other than beta2/M5-TRCs are depolarized by some stimuli and also that beta2/M5-TRCs have cell age-dependent molecular mechanisms of repolarization.
两种电压依赖性钾通道，即KCNQ1和KCNH2，在味蕾中表达，并被确定为参与表达磷脂酶C-β2和瞬时受体电位阳离子通道M型5（TRPM5）的味觉受体细胞（β2/M5-TRCs）复极化的有力候选者。在细胞类型特异性表达中，KCNQ1在大多数味蕾细胞中表达，包括β2/M5-TRCs，而KCNH2在一部分β2/M5-TRCs中表达，与其味觉模式（如甜味或苦味感受）无关。KCNH2的表达仅限于年轻的β2/M5-TRCs。这些结果表明，除β2/M5-TRCs之外的味蕾细胞会因某些刺激而去极化，并且β2/M5-TRCs具有细胞年龄依赖性的复极化分子机制。
