Temperature-Dependent Gating of Vanilloid Receptors

香草酸受体的温度依赖性门控

• 批准号: 8421285
• 负责人: FENG QIN
• 金额: $ 29.77万
• 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/8421285
• 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来检测环境线索。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。这项研究的长期目标是了解通道如何获得强大的热敏感性。我们将重点关注香草酸受体 TRPV1，它是热 TRP 亚家族的创始成员。该通道在疼痛传导中发挥着关键作用，并在外周感觉神经元中大量表达，似乎充当检测和整合有害刺激的网关。我们之前的研究在识别 TRPV1 热敏感性的起源方面取得了进展，并表明该通道在其 N 末端包含模块化热传感器域。我们建议利用这些发现对温度依赖性门控的基本机制进行全面的生物物理研究，使用已被证明可以成功理解其他类型离子通道门控的方法。目标 1 重点关注热传感器的物理基础。要测试的假设是 N 末端结构域负责 TRPV1 同源物的不同温度表型。通过剖析表型差异的分子决定因素，我们将识别有助于温度传感的残基和子结构域。目标 2 检查传感域和亚基之间的相互作用。我们将测试亚基之间热传感的协同性，描述各个亚基热传感事件对通道开放的贡献，并探讨其他刺激对热敏感性的影响。这些结果将揭示TRPV1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 解决热传感器域与通道门的耦合问题。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 TRPV1 中连接热传感和门控的温度门控通路。我们的方法涉及从异源表达系统中的重组通道进行膜片钳记录，结合快速温度刺激和动力学分析来揭示激活过程中发生的分子事件，以及诱变来识别受体的功能域。热 TRP 通道是开发新型镇痛药物的有吸引力的离子通道靶标，这些镇痛药物可以作用于产生疼痛的外周伤害感受器。通过深入了解这些通道的功能，拟议的研究将有助于促进选择性药物开发，用于治疗炎症、周围神经损伤、糖尿病和单纯疱疹引起的热痛觉过敏等病症。