Schmale H, Holtgreve-Grez H, Christiansen H
Institut für Zellbiochemie und Klinische Neurobiologie, Universität Hamburg, FRG.
Nature. 1990 Jan 25;343(6256):366-9. doi: 10.1038/343366a0.
Sensory transduction in taste and olfaction, the principal chemical senses, seems to be mediated by membrane-associated proteins on the apical surfaces of the respective receptor cells. The recent isolation and characterization of soluble 'odorant-binding proteins' secreted from the nasal glands of rat, cow and frog, led to the hypothesis that these proteins function as necessary cofactors in olfactory transduction by concentrating and delivering odorants to the receptors. The primary reception of taste stimuli occurs in specialized neuroepithelial receptor cells bundled in taste buds that are clustered in various types of papillae in the lingual epithelium of the tongue. Small tubulo-alveolar salivary glands, the von Ebner's glands, are located beneath the circumvallate and the foliate papillae. Their ducts open exclusively into the trough at the base of the papillae. Taste buds located in the medial and lateral walls of the papillae open with their taste pores into the trough and consequently are in direct contact with the secretions of von Ebner's glands. Here we report the molecular cloning and characterization of a protein of relative molecular mass 18,000 that is highly expressed in von Ebner's glands. Like the odorant-binding proteins, this protein shows similarity to members of a protein superfamily of hydrophobic molecule transporters, indicating that pre-receptor events could also be necessary for the concentration and delivery of sapid molecules in the gustatory system, and emphasizing the close relationship of taste and olfaction.
味觉和嗅觉是主要的化学感觉，其感觉转导似乎是由各自受体细胞顶端表面的膜相关蛋白介导的。最近从大鼠、牛和青蛙的鼻腺中分离并鉴定出可溶性“气味结合蛋白”，这引发了一种假说，即这些蛋白通过浓缩并将气味剂传递给受体，在嗅觉转导中作为必要的辅助因子发挥作用。味觉刺激的初始接收发生在聚集于舌部舌上皮各种乳头内的味蕾中的特化神经上皮受体细胞中。微小管泡状唾液腺，即埃伯纳腺，位于轮廓乳头和叶状乳头下方。它们的导管仅开口于乳头基部的沟中。位于乳头内侧壁和外侧壁的味蕾通过其味孔开口于沟中，因此与埃伯纳腺的分泌物直接接触。在此我们报告一种相对分子质量为18,000的蛋白的分子克隆及特征分析，该蛋白在埃伯纳腺中高度表达。与气味结合蛋白一样，这种蛋白与疏水分子转运蛋白超家族的成员具有相似性，这表明在味觉系统中，受体前事件对于呈味分子的浓缩和传递可能也是必要的，并强调了味觉和嗅觉之间的密切关系。
