Regulation of Thermo-TRP Ion Channels by Protein Signalling Complexes and Ubiquitinational Modification

蛋白质信号复合物和泛素化修饰对 Thermo-TRP 离子通道的调节

• 批准号: G0801387/1
• 负责人: Xuming Zhang
• 金额: $ 64.32万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=G0801387%2F1
• 关键词: Regulation; Thermo; TRP; Ion; Channels

The sensation and discrimination of ambient temperature are initiated by somatosensory neurons which convey thermal information from the skin and peripheral tissues to the brain, from sensory neurons a group of ion channels, termed as thermo-TRP channels, were identified and recognized as the thermosensors responsible for the detection of a wide range of temperature ranging from extreme cold to extreme heat. Six thermo-TRP channels has been reported including TRPV1, TRPV2, TRPV3, TRPV4, TRPM8 and TRPA1, with TRPV1 serving as the heat sensor; TRPM8 as the cold tranducer and TRPA1 as the extreme cold mediator. Thermo-TRP channels also enable us to detect environmental irritants, and are implicated in diversity of pathological processes including thermal, mechanical hyperalgesia, inflammatory and chemical-induced pain, which is believed to be mediated by TRPV1 and TRPA1 ion channel; and cold analgesia, which is caused by the activation of TRPM8 ion channel. You may have such an experience of immersing your burning hands into cooling water to have a relief, a process involving activation of TRPV1 and TRPM8 ion channel, respectively. During inflammation and tissue damage released inflammatory mediators such as NGF, bradykinin sensitizes TRPV1 and TRPA1 ion channel, explaining the most aspects of heat hyperalgesia and inflammatory pain. In contrast, bradykinin instead inhibited TRPM8 ion channel and thus making pain getting worse by sensitizing TRPV1 and inhibiting otherwise TRPM8 mediated analgesic effect. We will be interested in finding out how bradykinin produced inhibitory effect on TRPM8 channel; particularly we ask whether it?s caused by G protein signalling complexes. Remarkably we also identified PKCbeta as the endogenous TRPV1 binding protein to inhibit TRPV1 channel maturation and function, and found several thermo-TRP channels had constitutive and regulated modification of ubiquitination, a form of protein modification and acting as a sorting signal destined for degradation. We will be interested in dissecting out how PKCbeta downreguates TRPV1, and how ubiquitination regulates thermo-TRP channel trafficking and function with an ultimate aim to understanding how those thermo-TRP channels are differently modulated by even the same inflammatory mediators and signalling molecules, understanding their molecular determinants underlying those processes would provide fundamental basis to develop attractive novel drugs for the pain relief and treatment of hyperalgesia. We will investigate those queries using a combination of molecular biological, cell biological, electrophysiological approaches together with confocal imaging in both transfected HEK293 cells and DRG neurons.

环境温度的感觉和辨别是由躯体感觉神经元启动的，躯体感觉神经元将热信息从皮肤和外周组织传递到大脑，从感觉神经元中鉴定出一组离子通道，称为热TRP通道，并被认为是负责检测从极冷到极热的宽范围温度的温度传感器。TRPV 1是热感受器，TRPM 8是冷传导器，TRPA 1是极冷介质。Thermo-TRP通道也使我们能够检测环境刺激物，并参与多种病理过程，包括热，机械痛觉过敏，炎症和化学诱导的疼痛，这被认为是由TRPV 1和TRPA 1离子通道介导的;和冷镇痛，这是由TRPM 8离子通道激活引起的。你可能有这样的经历，将你燃烧的手浸入冷却水中以缓解，这一过程分别涉及TRPV 1和TRPM 8离子通道的激活。在炎症和组织损伤过程中释放的炎性介质如神经生长因子（NGF）、缓激肽（bradykinin）可增敏TRPV 1和TRPA 1离子通道，解释了热痛敏和炎性痛的大部分机制。相反，缓激肽反而抑制TRPM 8离子通道，从而通过致敏TRPV 1和抑制TRPM 8介导的镇痛作用使疼痛变得更糟。我们将有兴趣找出缓激肽如何产生对TRPM 8通道的抑制作用，特别是我们问是否？由G蛋白信号复合物引起。值得注意的是，我们还鉴定了PKC β作为内源性TRPV 1结合蛋白，以抑制TRPV 1通道成熟和功能，并发现几种热TRP通道具有泛素化的组成性和调节性修饰，泛素化是蛋白质修饰的一种形式，并作为注定降解的分选信号。我们将有兴趣剖析PKC β如何下调TRPV 1，以及泛素化如何调节热TRP通道的运输和功能，最终目的是了解这些热TRP通道如何被相同的炎症介质和信号分子不同地调节，了解这些过程背后的分子决定因素将为开发有吸引力的新型止痛和治疗药物提供基础痛觉过敏我们将使用分子生物学、细胞生物学、电生理学方法结合共聚焦成像在转染的HEK 293细胞和DRG神经元中研究这些查询。