Structural and functional studies of the TRPM2 channel

TRPM2通道的结构和功能研究

• 批准号: 10413415
• 负责人: Juan Du
• 金额: $ 9.82万
• 依托单位: VAN ANDEL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10413415
• 关键词: Adenosine Diphosphate Ribose; Agonist; Alzheimer' s Disease; Apoptosis; Binding; Binding Sites; Biological; Biological Assay; Body Temperature; Brain; Brain Injuries; C-terminal; Calcium; Cardiovascular system; Cell Death; Cell membrane; Cell physiology; Cells; Characteristics; Coiled-Coil Domain; Complex; Consensus; Cryoelectron Microscopy; Curcumin; Cyclic ADP-Ribose; Data; Development; Diabetes Mellitus; Electrophysiology (science); Family; Family member; Fever; Foundations; Homologous Gene; Human; Immune; Immune response; Inflammation; Ion Channel; Ion Channel Protein; Ions; Knowledge; Link; Lysosomes; Metabolism; Mission; Mitochondria; Molecular; Molecular Structure; N-terminal; Nerve; Neurodegenerative Disorders; Nucleotides; Oxidative Stress; Pathologic; Permeability; Pharmaceutical Preparations; Pharmacology; Physiologic Thermoregulation; Physiological Processes; Play; Protons; Public Health; Research; Research Project Grants; Rhizome; Role; Solid; Stroke; Structure; Tissues; Tumeric; United States National Institutes of Health; Vascular Smooth Muscle; Work; X-Ray Crystallography; Zebrafish; experimental study; insulin secretion; interdisciplinary approach; novel; novel therapeutics; particle; prevent; pyrophosphatase; receptor; simulation; sulfated glycoprotein 2

Project Summary Body temperature is strictly maintained in a narrow range to protect the delicate nerves in the brain and other body tissues, because improper body temperature gives rise to fever, brain injury, and stroke. TRPM2 is the major warmth-sensing receptor in the brain regulating core body temperature and preventing overheating as fever occurs. TRPM2 is a Ca2+-permeable, nonselective ion channel that is highly expressed in brain but is also found in the heart, vascular and smooth muscle, and immune cells. It is uniquely activated by Ca2+ and ADP ribose (ADPR), a product of the metabolism of NAD+ and a secondary messenger released upon oxidative stress. The activation of TRPM2 results in both Ca2+ entry across the plasma membrane and Ca2+ release from lysosomes. Therefore, TRPM2 plays fundamental role in Ca2+-dependent array of physiological processes and cellular functions from insulin secretion to immune response to cell death. It has been implicated in Alzheimer disease, stroke, and other neurodegenerative diseases. TRPM2 belongs to the TRPM (melastatin-like transient receptor potential) subfamily of the TRP superfamily. Despite sharing the characteristic TRPM N-terminal homology regions (MHRs) and C-terminal coiled-coil domains, TRPM2 is uniquely assembled with a C-terminal NHDT9-H domain, a homolog to the human mitochondrial ADP-ribose pyrophosphatase NUDT9. Functional studies, including binding assays, electrophysiology, and molecular simulations, provided a consensus view that ADPR binds to the NUDT9-H domain, but proof of the ADPR binding site is lacking, and the molecular basis for the action of the agonist ADPR on TRPM2 in the presence of calcium remains unknown. The gating of TRPM2 is further modulated by many molecules and ions that range from protons to nucleotides (cyclic ADPR, AMP, 8-Br-cADPR) to curcumin (which is isolated from rhizomes of Curcuma longa), acting by way of multiple mechanisms. At present, we don’t know where these molecules and ions bind to TRPM2 or how they activate the channel or modulate its function. We have obtained two cryo-EM structures of zebrafish TRPM2 in the apo/closed and ADPR/Ca2+-bound open state, with the latter representing the first active state of TRPM family members. We identified a novel ADPR binding site that is located outside the NUDT9-H domain and was completely unknown before. Building on this preliminary data, we propose to continue the structural studies of TRPM2 combined with complementary electrophysiology experiments, binding assays, and X-ray crystallography, which will define the molecular basis for a comprehensive gating mechanism and pharmacology. These advances will provide a solid foundation for developing new drugs against neurodegenerative diseases and for a deeper understanding the function of the entire TRPM family.

项目摘要 严格维持体温，以保护大脑和其他 身体组织，因为体温不当会引起发烧，脑损伤和中风。 TRPM2是 大脑中的主要温暖感受体控制核心体温并防止过热 发烧发生。 TRPM2是Ca2+ - 可渗透的非选择性离子通道，在大脑中高度表达，但IS 它被Ca2+唯一激活 ADP Ribose（ADPR），NAD+代谢的产物和次要信使发布 氧化应激。 TRPM2的激活导致CA2+进入质膜和Ca2+ 从溶酶体释放。因此，TRPM2在CA2+依赖性生理阵列中扮演基本角色 从胰岛素分泌到对细胞死亡的免疫反应的过程和细胞功能。它一直 在阿尔茨海默氏病，中风和其他神经退行性疾病中实施。 TRPM2属于TRP超家族的TRPM（蓝绿色瞬变受体电位）。 尽管共享特征性的TRPM N末端同源区（MHR）和C端盘绕螺旋。 域，trpm2与C端NHDT9-H域唯一组装在一起，这是人类的同源物 线粒体ADP-核糖焦磷酸酶NUDT9。功能研究，包括结合测定， 电生理学和分子模拟提供了共识的观点，即ADPR与NUDT9-H结合 域，但缺乏ADPR结合位点的证明，而动作的作用的分子基础 在钙存在下TRPM2上的ADPR仍然未知。 TRPM2的门控进一步调制 从质子到核苷酸的许多分子和离子（环状ADPR，AMP，8-BR-CADPR）到 姜黄素（从姜黄的根茎中分离出来），通过多种机制作用。在 目前，我们不知道这些分子和离子在哪里与Trpm2结合或它们如何激活通道或 调节其功能。 我们在apo/note和adpr/ca2+bound Open中获得了斑马鱼TRPM2的两个冷冻EM结构 国家，后者代表了TRPM家庭成员的第一个活跃状态。我们确定了一个新颖的adpr 绑定位点位于NUDT9-H域外，以前是完全未知的。建立 此初步数据，我们建议继续进行TRPM2的结构研究与完整的结合 电生理实验，结合测定和X射线晶体学，这将定义分子 综合门控机制和药理学的基础。这些进步将提供坚实的 开发针对神经退行性疾病的新药的基础和更深入的理解 整个TRPM家族的功能。