Electrophysiological basis of sour taste transduction

酸味转导的电生理基础

基本信息

批准号：
10627899
负责人：
Sue C. Kinnamon
金额：
$ 47.96万
依托单位：
UNIVERSITY OF SOUTHERN CALIFORNIA
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10627899
关键词：
Acids Action Potentials Animals Applications Grants Behavior Behavior assessment Behavioral Brain region Brown Fat Calcium Cell Separation Cells Circumvallate Papilla Citrus Fruit Cytosol Data Defect Detection Development Diabetes Mellitus Diet Disease Electrophysiology (science)Epithelium Exhibits Family Fire - disasters Food Funding Fungiform Papilla Gene Expression Profile Gene Family Genes Goals Homologous Gene Human Hypertension In Situ Hybridization Integral Membrane Protein Investigation Ion Channel Ions Knock-out Knockout Mice Laboratories Maintenance Mammals Measures Mediating Membrane Modeling Molecular Mouse Strains Mus Mutate Nature Nerve Obesity Operant Conditioning Palate Physiological Physiological Processes Play Potassium Channel Property Protein Isoforms Protons Receptor Cell Reporter Role Salts Sensory Signal Transduction Sodium Chloride Stimulus Sweetening Agents System Taste Buds Taste Perception Testing Tongue Type III Epithelial Receptor Cell Xenopus oocyte cell type combat defined contribution dietary experimental study genetic testing immunocytochemistry improved in vivo lipid metabolism member novel patch clamp promoter receptor receptor function response screening sensor taste stimuli taste system taste transduction

项目摘要

Project Summary The broad goal of the proposed experiments is to identify key molecules that allow mammals to detect basic tastes and generate electrical responses that are conducted to brain regions. Molecular mechanisms of taste reception have been a subject of intense investigation over the last 30 years, with great strides made in identifying receptors for bitter, sweet and umami. Much less is known about the nature and function of receptors for sour, the taste that allows us to detect acids in spoiled foods or citrus fruits. In this proposal, we will begin to unravel this problem as we test the contribution of the newly discovered otopetrin proton channels in the transduction of acidic and ionic tastes. These experiments build on the progress made in the last grant application, where we used a combination of cellular, molecular and functional approaches to identify the pH sensitive ion channels in Type III taste receptor cells (TRCs) that mediate sour taste. Notably, we described a novel proton-selective ionic current that is likely to be a key component of sour taste transduction. In the last funding period, we successfully identified the gene that encodes the proton channel, through functional screening of genes enriched in Type III TRCs. Among 41 genes tested, we identified one, encoding the transmembrane protein Otop1 that upon expression induced a proton current in both Xenopus oocytes and HEK-293 cells. Interestingly, Otop1 was first identified as a gene mutated in mice with vestibular defects (“tilted” or tlt) but its function in the vestibular system and elsewhere in the body was not understood. Building on these new results, we propose three specific aims to test the role of the Otop channels in taste signaling. The first aim will examine the functional distribution of Otop1 across the tongue and palate epithelium, allowing us to answer the question of whether Otop1 is the sole ion channel mediating proton influx in the gustatory system. In the second aim, we will measure cellular responses to acids in wildtype and Otop1 KO mice in order to determine the degree to which Otop1 contributes to sensory responses, ex vivo. In the third aim, we will measure responses from gustatory nerves and assess behavioral thresholds for acid detection in wildtype and Otop1 KO mice to determine the extent to which Otop1 mediates responses to sour taste stimuli in vivo. Together our experiments will allow us to determine if Otop1 functions as a sour taste receptor. Our efforts to identify mechanisms of taste transduction may allow the development of taste modifiers that can be used to enhance palatability of food, reducing the need to add sweeteners that contribute to the development of diabetes or salts that contribute to hypertension. Moreover, the proposed experiments will provide basic information regarding the functional properties of this new family of proton channels that will help us understand their contributions to diverse physiological processes, including brown fat metabolism and the development and maintenance of the vestibular system.

项目概要拟议实验的总体目标是确定使哺乳动物能够检测基本物质的关键分子。味觉并产生传导至大脑区域的电反应。过去 30 年来，接待一直是深入研究的主题，在识别苦味、甜味和鲜味受体对于受体的性质和功能知之甚少。对于酸味，这种味道使我们能够检测变质食品或柑橘类水果中的酸。在本提案中，我们将开始检测。当我们测试新发现的奥托普林质子通道在这些实验建立在上一次资助所取得的进展的基础上。应用中，我们结合使用细胞、分子和功能方法来确定 pH 值值得注意的是，我们描述了介导酸味的 III 型味觉受体细胞 (TRC) 中的敏感离子通道。新型质子选择性离子电流可能是酸味转导的关键组成部分。资助期间，我们通过功能筛选，成功鉴定出编码质子通道的基因在测试的 41 个基因中，我们鉴定了一个编码跨膜的基因。蛋白质 Otop1 在表达后会在非洲爪蟾卵母细胞和 HEK-293 细胞中诱导质子电流。有趣的是，Otop1 首次被鉴定为在具有前庭缺陷（“倾斜”或 tlt）的小鼠中发生突变的基因，但其基于这些新结果，人们对前庭系统和身体其他部位的功能尚不清楚。我们提出了三个具体目标来测试 Otop 通道在味觉信号传导中的作用。 Otop1 在舌头和上颚上皮的功能分布，使我们能够回答这个问题在第二个目标中，我们研究 Otop1 是否是介导质子流入的唯一离子通道。将测量野生型和 Otop1 KO 小鼠中细胞对酸的反应，以确定酸的程度其中 Otop1 有助于离体感觉反应。在第三个目标中，我们将测量来自的反应。味觉神经并评估野生型和 Otop1 KO 小鼠酸检测的行为阈值我们的实验共同确定了 Otop1 在体内介导对酸味刺激的反应的程度。将使我们能够确定 Otop1 是否作为酸味受体发挥作用。转导可以开发可用于增强食物适口性的味道调节剂，减少添加导致糖尿病发展的甜味剂或导致糖尿病的盐的需要此外，拟议的实验将提供有关功能性高血压的基本信息。这个新的质子通道家族的特性将帮助我们了解它们对不同领域的贡献生理过程，包括棕色脂肪代谢以及前庭的发育和维持系统。

项目成果

期刊论文数量（12）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Activation Stoichiometry and Pore Architecture of TRPA1 Probed with Channel Concatemers.

用通道串联体探测 TRPA1 的激活化学计量和孔结构。

DOI：
发表时间：
2018
期刊：
影响因子：
4.6
作者：
Ye, Wenlei;Tu, Yu;Cooper, Alexander J;Zhang, Zheng;Katritch, Vsevolod;Liman, Emily R
通讯作者：
Liman, Emily R

A proton current associated with sour taste: distribution and functional properties.

与酸味相关的质子流：分布和功能特性。

DOI：
发表时间：
2015-07
期刊：
影响因子：
0
作者：
Bushman, Jeremy D;Ye, Wenlei;Liman, Emily R
通讯作者：
Liman, Emily R

Structures of the otopetrin proton channels Otop1 and Otop3.

奥托普林质子通道 Otop1 和 Otop3 的结构。

DOI：
发表时间：
2019
期刊：
影响因子：
16.8
作者：
Saotome, Kei;Teng, Bochuan;Tsui, Che Chun Ale;Lee, Wen;Tu, Yu;Kaplan, Joshua P;Sansom, Mark S P;Liman, Emily R;Ward, Andrew B
通讯作者：
Ward, Andrew B

Salty Taste: From Transduction to Transmitter Release, Hold the Calcium.

咸味：从传导到递质释放，稳住钙。