The Role of T1r Taste Receptors in Gustation

描述(申请人提供)：我们研究项目的长期目标是了解脊椎动物的味觉系统是如何传递信号和编码信息的。特别重要的是G蛋白偶联受体(GPCRs)及其偶联G蛋白。在过去的十年里，我们已经鉴定和鉴定了几种味觉转导元件，包括味觉受体(TLR3)、G蛋白((-Gustducin)、(-转导蛋白)、G(13)和离子通道(Trpm5)。这一竞争延续的范围包括TLR味觉受体在味觉转导和编码中的作用，与这些受体共表达和偶联的G蛋白，以及在TLR阳性的味觉细胞中表达的瞬时受体潜力(TRP)通道。我们将使用多学科方法，应用分子生物学、转基因、行为和电生理技术来实现以下具体目标。1.确定味觉细胞是否表达TLR4。2.确定哪些TLR受体与TLR4共表达。3.确定哪些G蛋白亚基与TLR受体共表达。4.确定哪些TRP通道与TLR受体共表达。5.异源表达TLR受体。6.用Caimaging监测表达TLR受体的细胞的反应。7.建立TLR受体缺失的单、双、三基因敲除小鼠。8.研究TLR基因敲除小鼠的行为学特征。9.对TLR基因敲除小鼠进行电生理学研究。10.产生缺乏Trpm5的基因敲除小鼠。11.建立在TLR2和TLR3阳性味觉细胞中表达Trpm5的转基因小鼠。12.研究Trpm5转基因小鼠的行为特征。13.对Trpm5转基因小鼠进行电生理学研究。这些研究的结果将为味觉转导和编码的分子机制提供重要的新见解。TLR受体参与糖和甜味剂的检测。对其功能模式的分子知识可能会导致开发新的有效的无热量甜味剂，这可能有助于体重控制计划，以限制肥胖和肥胖相关疾病。味觉和代谢障碍，如味觉障碍和恶病质，经常与几种类型的癌症一起发生。从这一建议中获得的知识应该会进一步加深我们对味觉障碍的分子基础的理解，并可能导致有效的干预。

DESCRIPTION (provided by applicant): The long-term objective of our research program is to understand how the vertebrate gustatory system transduces signals and encodes information. Of particular importance are the G protein-coupled receptors (GPCRs) and their coupled G proteins. During the past decade we have identified and characterized several taste transduction elements, including taste receptors (Tlr3), G proteins ((-gustducin, (-transducin, G(13) and ion channels (Trpm5). The scope of this Competing Continuation encompasses the roles in taste transduction and coding of Tlr taste receptors, the G proteins co-expressed with and coupled to these receptors, and the transient receptor potential (Trp) channels expressed in Tlr-positive taste cells. We will use a multidisciplinary approach applying molecular biological, transgenic, behavioral and electrophysiological techniques to achieve the following Specific Aims. 1. To determine if taste cells express Tlr4. 2. To determine which Tlr receptors are co-expressed with Tlr4. 3. To determine which G protein subunits are co-expressed with Tlr receptors. 4. To determine which Trp channels are co-expressed with Tlr receptors. 5. To heterologously express Tlr receptors. 6. To use Caimaging to monitor responses of cells expressing the Tlr receptors. 7. To generate single, double and triple knockout mice lacking Tlr receptors. 8. To behaviorally characterize the Tlr knockout mice. 9. To electrophysiologically characterize the Tlr knockout mice. 10. To generate knockout mice lacking Trpm5. 11. To generate transgenic mice expressing Trpm5 in Tlr2- and Tlr3-positive taste cells. 12. To behaviorally characterize the Trpm5 transgenic mice. 13. To electrophysiologically characterize the Trpm5 transgenic mice. The results of these studies will provide significant new insights into the molecular mechanisms underlying taste transduction and coding. The Tlr receptors are involved in the detection of sugars and sweeteners. A molecular knowledge of their mode of function may lead to the development of novel effective non-caloric sweeteners that may be useful in weight control programs to limit obesity and obesity-related diseases. Gustatory and metabolic disorders such as malgeusia, dysgeusia and cachexia frequently occur in conjunction with several types of cancer. The knowledge gained from this proposal should further our understanding of the molecular bases of taste disorders and may lead to effective intervention.