Opsins as a new class of evolutionarily conserved taste receptors

视蛋白作为一类新的进化上保守的味觉受体

• 批准号: 10657704
• 负责人: CRAIG MONTELL
• 金额: $ 44.12万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA BARBARA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10657704
• 关键词: Address; Aedes; Amino Acids; Animals; Behavior; Behavioral Assay; Biological Assay; Blood; CRISPR/Cas technology; Catechin; Cellular biology; Chemicals; Clustered Regularly Interspaced Short Palindromic Repeats; Culicidae; Data; Dengue; Detection; Development; Diet; Disease; Disease Vectors; Drosophila genus; Electrophysiology (science); Esthesia; Evolution; Family; Female; Flavonoids; Fruit; G-Protein-Coupled Receptors; Genetic; Goals; Grapefruit; Health; Homologous Gene; Human; Image; Impairment; In Vitro; Insecta; Ligand Binding; Ligands; Light; Mammals; Modality; Modeling; Molecular Genetics; Motivation; Mus; Mutagenesis; Mutant Strains Mice; Mutation; Neurons; Nutrient; Nutritional; Opsin; Organ; Partner in relationship; Persons; Photoreceptors; Plants; Poison; Population; Production; Property; Proteins; Receptor Activation; Receptor Cell; Rhodopsin; Role; Specificity; Taste Buds; Taste Perception; Testing; Tongue; Transgenic Organisms; Vertebrate Photoreceptors; Virus; Visual System; Vitamin A; Work; Yellow Fever; ZIKA; antagonist; behavior test; chromophore; defined contribution; detector; dietary; egg; experience; experimental study; fascinate; feeding; fly; genetic manipulation; human disease; improved; in vitro Assay; in vivo; insect disease vector; interest; male; member; mutant; receptor; response; sugar; tool; transcriptome; transcriptome sequencing; vector

Abstract Opsins are classical G-protein coupled receptors, which for more than a century have been thought to function exclusively as light detectors. However, using Drosophila, we have uncovered multiple, light-independent roles for opsins including detection of bitter tastants. This discovery raises exciting questions, which we propose to address here. Do opsins only respond to bitter compounds, or do they function more broadly in taste sensation? Of particular interest, do opsins serve as taste receptors in other animals, including the mosquito, Aedes (Ae.) aegypti? This vector spreads viruses that cause dengue, yellow fever, and other diseases that afflict millions of people each year. Both male and female Aedes use taste to identify nectar and avoid toxic chemicals, while females use many senses to identify people for blood meals. However, the receptors required for mosquito taste are largely unknown. Another fascinating question is whether opsins serve as taste receptors in mammals. To address these questions, we propose to employ an extensive suite of approaches including electrophysiology, Ca2+ imaging, behavioral assays, cell biology, an in vitro receptor activation assay, and state-of-the art molecular genetics. We will also bring to bear our expertise in Drosophila taste, opsins, and our recent experience performing molecular genetics and behavior in Ae. aegypti and in the mouse. Aim 1 will define the role of a Drosophila opsin in amino acid taste, which in flies is a poorly understood taste modality. Attraction to amino acids increases if the flies are kept on an amino acid deficient diet. We outline experiments to define the contribution of the opsin to this dynamic change in amino acid appeal. We will also test the proposal that the opsin is activated directly by amino acids. Aim 2 will build on our preliminary data that two Ae. aegypti opsins are expressed in the major taste organ, and are required for sensing a flavonoid. The goals of this aim are to reveal the chemical specificity of these opsins in vitro and in vivo, determine whether they act independently or together, and identify the gustatory receptor neurons in which these opsins function. Aim 3 will characterize the roles of opsins in mammalian taste. This aim is supported by preliminary data showing that multiple mouse opsins are expressed in the mouse tongue, and are activated in vitro by bitter compounds, including a flavonoid for which there is no known receptor. In addition, we present preliminary data that the response to this flavonoid is impaired in the opsin mutant. We propose to test the hypothesis that this opsin functions broadly in sensing flavonoids, identify the taste receptor cells that express this and the other “gustatory opsins,” and perform behavioral tests with mutants to characterize the requirements for each opsin for sensing bitter compounds. The results from this project would establish opsins as a new class of taste receptor conserved from insects to mammals. We propose that defining opsins as the first bitter receptors in mosquitoes offers the potential to harness this information to manipulate mosquito behavior and thereby reduce their populations and thus insect-borne disease.

抽象的 视蛋白是经典的 G 蛋白偶联受体，一个多世纪以来一直被认为具有功能 然而，利用果蝇，我们发现了多种专门的、与光无关的作用。 对于视蛋白，包括苦味促味剂的检测，这一发现提出了令人兴奋的问题，我们提出了这些问题。 视蛋白只对苦味化合物有反应，还是在味觉方面发挥更广泛的作用。 特别有趣的是，视蛋白在其他动物（包括蚊子）中充当味觉受体吗？ 埃及伊蚊？这种媒介传播导致登革热、黄热病和其他疾病的病毒。 每年有数百万人遭受这种病的困扰，雄性和雌性伊蚊都利用味觉来识别花蜜并避免有毒物质。 化学物质，而女性使用多种感官来识别人类的血粉，但是，需要受体。 另一个有趣的问题是视蛋白是否具有味道。 为了解决这些问题，我们建议采用一系列广泛的方法。 包括电生理学、Ca2+ 成像、行为测定、细胞生物学、体外受体激活、测定 我们还将利用我们在果蝇味觉、视蛋白和蛋白质方面的专业知识。 我们最近在埃及伊蚊和小鼠中进行分子遗传学和行为的经验将。 定义果蝇视蛋白在氨基酸味觉中的作用，在果蝇中，氨基酸味觉是一种知之甚少的味觉模式。 如果果蝇的饮食缺乏氨基酸，对氨基酸的吸引力就会增加。我们概述了实验。 为了定义视蛋白对氨基酸吸引力动态变化的贡献，我们还将测试 视蛋白直接被氨基酸激活的提议将建立在我们的初步数据之上，即两个 Ae。 埃及伊视蛋白在主要味觉器官中表达，是感知类黄酮的目标所必需的。 这个目的是揭示这些视蛋白在体外和体内的化学特异性，确定它们是否起作用 独立或一起，并识别这些视蛋白在其中发挥作用的味觉受体神经元 Aim 3。 将描述视蛋白在哺乳动物味觉中的作用，这一目标得到了初步数据的支持。 多种小鼠视蛋白在小鼠舌头中表达，并在体外被苦味化合物激活， 包括没有已知受体的黄酮类化合物。此外，我们还提供了初步数据表明 我们建议测试这种视蛋白突变体对这种黄酮类化合物的反应受到损害。 在感知黄酮类化合物方面具有广泛的功能，识别表达这种和其他黄酮类化合物的味觉受体细胞 “味觉视蛋白”，并对突变体进行行为测试，以确定每种视蛋白的需求 该项目的结果将视蛋白确立为一类新的味觉。 我们建议将视蛋白定义为从昆虫到哺乳动物中保守的第一个苦味受体。 蚊子提供了利用这些信息来操纵蚊子行为的潜力，从而 减少它们的数量，从而减少虫媒疾病。