Human Umami Taste: Genetics of Psychophysical Traits

氨基酸（特别是谷氨酸）的鲜味和甜味是两种食欲的味道品质，对于我们对蛋白质和碳水化合物（能量）宏量营养素的健康吸引力至关重要。食欲蛋白质味觉系统可能的进化压力是我们的营养需求：获得膳食蛋白质来源对生存至关重要，而营养蛋白质缺乏症（Kwashiorkor）是发展中国家儿童死亡的主要原因之一。尽管它在饮食选择中的重要性，但人类的鲜味仍然是五种味觉品质中了解最少的一种，其遗传和分子决定因素在很大程度上仍然未知。在味觉受体细胞内发现的三类谷氨酸受体与响应氨基酸和核糖核苷酸的细胞信号传导相关：（i）TAS 1 R，（ii）代谢型-GluR，和（iii）离子型-NMDA受体。然而，它们各自在人类鲜味味觉感知中的作用尚不清楚。这项工作的长期目标是阐明人类对“鲜味”的感觉的遗传和分子机制。拟议项目的目标是澄清这三类受体的作用，以确定其他基因可能参与人类鲜味味觉感知，并在功能上测试与鲜味表型相关的变异受体。本提案的具体目标是： I.识别与鲜味盲症相关的变异基因和/或全基因组位点。二.表征与谷氨酸受体SNP相关的任何鲜味感知表型。三.在表达分析中定义变异谷氨酸受体刺激反应功能。

The umami taste of amino acids (especially glutamate) and sweetness are the two appetitive taste qualities that are critical for our healthy attraction to protein and carbohydrate (energy) macronutrients. The likely evolutionary pressure for an appetitive protein taste system is our nutritional need: access to sources of dietary protein is essential for survival and kwashiorkor (dietary protein deficiency) is one of the leading causes of death in children in developing countries. Despite its importance in dietary selection, human umami taste remains one of the most poorly understood of the five taste qualities and its genetic and molecular determinants remain largely unknown. Three classes of glutamate receptors found within taste receptor cells have been associated with cell signaling in response to amino acids and ribonucleotides: (i) TAS1Rs, (ii) metabotropic-GluRs, and (iii) ionotropic-NMDA receptors. However, their respective roles in human umami taste perception are not known. The long term goal of the proposed work is to elucidate genetic and molecular mechanisms that are responsible for the human sensation of `umami' taste. The objectives of the proposed project are to clarify the roles of these three receptor classes, to identify other genes that may be involved with human umami taste perception, and to functionally test variant receptors associated with umami phenotypes. The specific Aims of this Proposal are: I. Identify variant genes and/or genome-wide loci associated with umami blindness. II. Characterize any umami perceptual phenotypes related to glutamate receptor SNPs. III. Define variant glutamate receptor stimulus-response functions in expression assays.