Chemosensory receptors and the basis of specificity

化学感应受体和特异性的基础

• 批准号: 7903521
• 负责人: Steven D Munger
• 金额: $ 12.72万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-14 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7903521
• 关键词: Address; Affinity; Affinity Chromatography; Amino Acids; Behavioral; Behavioral Assay; Binding; Biochemical; Biological Assay; Calorimetry; Cells; Chemicals; Circular Dichroism; Classification; Code; Complex; Complex Mixtures; Cues; Data; Detection; Discrimination; Eating; Environment; Esthesia; Family; Food; G-Protein-Coupled Receptors; GTP-Binding Proteins; Gene Targeting; Goals; Health; In Vitro; Individual; Kinetics; Ligand Binding; Ligand Binding Domain; Ligands; Light; Mammals; Measures; Membrane Proteins; Mus; Mutation; N-terminal; Neurotransmitters; Odors; Opsin; Pheromone; Pheromone Receptors; Photons; Population; Psychophysiology; Retinal Cone; Role; Sensory; Solutions; Specificity; Spectrophotometry; Stimulus; Structure; Structure-Activity Relationship; System; T1R receptor; Taste Perception; Tertiary Protein Structure; Titrations; Variant; Visual system structure; X-Ray Crystallography; base; cell type; extracellular; innovation; insight; member; nutrition; olfactory receptor; protein expression; receptor; receptor structure function; response; sensory system; stimulus sensitivity; sweet receptor; sweet taste perception

DESCRIPTION (provided by applicant): Mammals use several chemosensory systems to detect and encode their chemical environment. How these systems discriminate relevant chemical cues is a major unresolved question. We hypothesize that differences in the stimulus selectivity of different populations of chemosensory cells largely reflects differences in the ligand selectivity and sensitivity of the chemosensory receptors (CRs) expressed therein. Difficulties in obtaining large amounts of receptor protein suitable for biochemical or structural analysis, as well as the small number of CRs for which ligands are known, has hampered efforts to characterize the basis of ligand specificity. One group of CRs, the T1R taste receptors, offers unique advantages that will permit the first systematic analysis of how CR structure/function relationships impact the ability of a chemosensory cell population to detect and discriminate physiologically relevant ligands. We will take advantage of the demonstrated sensitivity of T 1Rs for sweet-tasting ligands, and an extracellular N-terminal ligand-binding domain amenable to biochemical purification and structural characterization, to establish the role of different T1Rs in the detection of sweet tasting stimuli. Aim 1: The structure of the T1R ligand-binding pockets, in the presence and absence of ligands, will be solved by a combination of circular dichroism spectrophotometry and X-ray crystallography of T1R N-terminal domains. Aim 2: To determine the specific contributions of ligand binding to taste function, targeted mutations will be introduced in the ligand-binding pocket of T1R N-terminal domains both in vitro and by gene targeting in mice. Changes in ligand binding kinetics will be measured using isothermal titration calorimetry, while the effects of T1R deletion or mutation on taste function will be assayed by brief-access behavioral tasks where the sensitivity of targeted mice to sweet stimuli will be determined. Together, these studies will provide the first in-depth structural and quantitative analyses of the interactions between chemosensory receptors and their ligands, and will offer important new insights into how individual taste receptors contribute to the detection and discrimination of food cues critical for health and survival.

描述（由申请人提供）：哺乳动物使用多种化学体系统来检测和编码其化学环境。这些系统如何区分相关的化学提示是一个主要的未解决的问题。我们假设，化学感应细胞不同种群的刺激选择性的差异在很大程度上反映了其中表达的化学感应受体（CRS）的配体选择性和灵敏度的差异。获得适合生化或结构分析的大量受体蛋白的困难，以及已知配体的少量CRS，已阻碍了表征配体特异性基础的努力。 T1R味道受体一组CR提供了独特的优势，可以首先系统地分析CR结构/功能关系如何影响化学体感细胞种群检测和区分与生理相关的配体的能力。我们将利用T 1RS对甜味配体的敏感性，以及可对生化纯化和结构表征的细胞外N末端配体结合结构域，以确定不同T1R在检测甜味刺激中的作用。目标1：在存在和不存在配体的情况下，T1R配体结合口袋的结构将通过T1R N末端结构域的圆形二分法分光光度计和X射线晶体学的结合来解决。目标2：为了确定配体与味觉功能的特定贡献，将在体外和通过基因靶向小鼠的基因靶向的T1R N末端结构域的配体结合袋中引入靶向突变。配体结合动力学的变化将使用等温滴定量热法测量，而T1R缺失或突变对味觉功能的影响将通过简短的行为行为任务来测定，在此简介中，靶向小鼠对甜蜜刺激的敏感性将得到确定。这些研究将共同​​提供对化学感受器受体及其配体之间相互作用的第一个深入的结构和定量分析，并将为单个味觉受体如何促进对健康和生存至关重要的食物提示的发现和歧视。

项目成果

Olfactory receptors: G protein-coupled receptors and beyond.

• DOI: 10.1111/j.1471-4159.2009.06085.x
• 发表时间: 2009-06
• 期刊: Journal of neurochemistry
• 影响因子: 4.7
• 作者: Spehr M;Munger SD
• 通讯作者: Munger SD

Variation in the gene TAS2R38 is associated with the eating behavior disinhibition in Old Order Amish women.

• DOI: 10.1016/j.appet.2009.09.011
• 发表时间: 2010-02
• 期刊: APPETITE
• 影响因子: 5.4
• 作者: Dotson, Cedrick D.;Shaw, Hillary L.;Mitchell, Braxton D.;Munger, Steven D.;Steinle, Nanette I.
• 通讯作者: Steinle, Nanette I.

Reduced sweetness of a monellin (MNEI) mutant results from increased protein flexibility and disruption of a distant poly-(L-proline) II helix.

• DOI: 10.1093/chemse/bjr007
• 发表时间: 2011-06
• 期刊: Chemical senses
• 影响因子: 3.5
• 作者: C. Templeton;Saeideh Ostovar pour;J. Hobbs;E. Blanch;S. Munger;G. Conn

Bitter taste receptors influence glucose homeostasis.

• DOI: 10.1371/journal.pone.0003974
• 发表时间: 2008
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Dotson CD;Zhang L;Xu H;Shin YK;Vigues S;Ott SH;Elson AE;Choi HJ;Shaw H;Egan JM;Mitchell BD;Li X;Steinle NI;Munger SD
• 通讯作者: Munger SD