Temperature-Dependent Gating of Vanilloid Receptors

香草酸受体的温度依赖性门控

• 批准号: 8642659
• 负责人: FENG QIN
• 金额: $ 29.8万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8642659
• 关键词: Address; Adult; Adverse effects; Affect; Afferent Neurons; Amino Acid Sequence; Analgesics; Biological Process; Biophysics; Cell Cycle Kinetics; Chimera organism; Complex; Coupling; Cues; Data; Degenerative polyarthritis; Dependence; Detection; Development; Diabetes Mellitus; Disease; Drug Targeting; Drug effect disorder; Esthesia; Event; Exhibits; Family; Funding; Goals; Heating; Herpes Simplex Infections; Homologous Gene; Individual; Inflammation; Institute of Medicine (U.S.); Ion Channel; Ion Channel Gating; Kinetics; Knowledge; Link; Malignant Neoplasms; Modeling; Molecular; Molecular Biology; Mutagenesis; N-terminal; Nerve Endings; Nociceptors; Pain; Pain management; Pathology; Pathway interactions; Patients; Peripheral; Peripheral Nerves; Peripheral nerve injury; Phenotype; Physiological; Play; Proteins; Publications; Recombinants; Research; Role; Site; Stimulus; Symptoms; System; TRP channel; TRPV1 gene; Techniques; Temperature; Temperature Sense; Testing; Thermal Hyperalgesias; Time; United States National Institutes of Health; Vanilloid; Variant; Work; base; capsaicin receptor; cost; detector; drug development; drug discovery; insight; medical attention; member; molecular site; novel; patch clamp; protein function; public health relevance; receptor; sensor; stoichiometry

DESCRIPTION (provided by applicant): Thermal sensation and pain use ion channels for detection of environmental cues. Thermal TRP channels, members of the transient receptor potential superfamily, are the principal detectors of thermal stimuli. These channels have a steep temperature dependence compared to other proteins. The long term goal of this research is to understand how the channels obtain their strong thermal sensitivity. We will focus on the vanilloid receptor TRPV1, a founding member of the thermal TRP subfamily. The channel plays a pivotal role in pain transduction and is abundantly expressed in peripheral sensory neurons where it appears to act as a gateway for detection and integration of noxious stimuli. Our previous research made progress in identifying the origin of thermal sensitivity of TRPV1, and showed that the channel contains modular thermal sensor domains in its N-terminus. We propose to take advantage of these findings to perform a comprehensive biophysical study on the fundamental mechanisms of temperature-dependent gating, using approaches that have proven successful for understanding other types of ion channel gating. Aim 1 focuses on the physical basis of thermal sensors. The hypothesis to be tested is that the N-terminal domain is responsible for distinct temperature phenotypes of TRPV1 homologs. By dissecting the molecular determinants of the phenotypic differences, we will identify the residues and subdomains contributing to temperature sensing. Aim 2 examines the interactions between sensing domains and subunits. We will test the cooperativity of thermal sensing between subunits, delineate the contribution of individual subunit thermal sensing events to channel opening, and probe the influence of thermal sensitivity by other stimuli. The results will unravel complex mechanisms by which TRPV1 achieves a dynamic thermal sensitivity for its physiological function over broad temperature ranges. Aim 3 addresses the coupling of the thermal sensor domain with the channel gate. We will test several regions throughout the channel and determine the allosteric mechanisms by which they control temperature activation. The results will illuminate the temperature-gating pathway in TRPV1 that links thermal sensing and gating. Our approach involves patch-clamp recording from recombinant channels in heterologous expression systems, combined with fast temperature stimulation and kinetic analysis to unravel the molecular events occurring during activation, along with mutagenesis to identify functional domains of the receptor. Thermal TRP channels are attractive ion-channel targets for the development of novel analgesic drugs that could act peripherally at nociceptors where pain is generated. With insight into how the channels function, the proposed studies will help prompt the selective drug development for treatment of pathologies such as thermal hyperalgesia due to inflammation, peripheral nerve injury, diabetes and herpes simplex.

描述（由申请人提供）：热感觉和疼痛使用离子通道检测环境线索。热TRP通道是瞬时受体电位超家族的成员，是热刺激的主要检测器。与其他蛋白质相比，这些通道具有陡峭的温度依赖性。本研究的长期目标是了解通道如何获得其强热敏性。我们将专注于香草素受体TRPV 1，热TRP亚家族的创始成员。该通道在疼痛传导中起着关键作用，并且在外周感觉神经元中大量表达，在外周感觉神经元中它似乎充当检测和整合有害刺激的门户。我们的前期研究在确定TRPV 1的热敏性起源方面取得了进展，并表明该通道在其N端含有模块化的热传感器结构域。我们建议利用这些发现进行全面的生物物理学研究的基本机制的温度依赖性门控，使用的方法，已被证明是成功的理解其他类型的离子通道门控。目标1侧重于热传感器的物理基础。待检验的假设是N-末端结构域负责TRPV 1同源物的不同温度表型。通过解剖的表型差异的分子决定因素，我们将确定的残基和子域有助于温度传感。目的2研究传感结构域和亚基之间的相互作用。我们将测试亚基之间的热感觉的协同性，描绘个别亚基的热感觉事件的通道开放的贡献，并探测其他刺激的热敏感性的影响。这些结果将揭示TRPV 1在广泛的温度范围内实现其生理功能的动态热敏感性的复杂机制。目标3解决了热传感器域与沟道栅极的耦合。我们将测试整个通道的几个区域，并确定它们控制温度激活的变构机制。结果将阐明TRPV 1中连接热传感和门控的温度门控通路。我们的方法包括膜片钳记录从重组通道在异源表达系统，结合快速温度刺激和动力学分析，以解开激活过程中发生的分子事件，沿着诱变，以确定功能域的受体。热TRP通道是开发新型镇痛药物的有吸引力的离子通道靶点，其可以外周作用于产生疼痛的伤害感受器。随着对通道功能的深入了解，拟议的研究将有助于促进选择性药物开发，用于治疗炎症，外周神经损伤，糖尿病和单纯疱疹等引起的热痛觉过敏等病理。