Structural and functional studies of the human TRPM4 and TRPM5 channels

人类 TRPM4 和 TRPM5 通道的结构和功能研究

• 批准号: 10002607
• 负责人: Wei Lu
• 金额: $ 47.5万
• 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: 2019-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10002607
• 关键词: Affinity; Agonist; Amino Acids; Binding; Binding Sites; Blood flow; Brain; Brain Injuries; Brugada syndrome; California; Calmodulin; Cardiac; Cardiovascular Diseases; Cardiovascular system; Cerebrovascular Circulation; Cerebrum; Charge; Collaborations; Complex; Cryoelectron Microscopy; Dependence; Diabetes Mellitus; Disease; Drug Design; Drug usage; Electrophysiology (science); Environment; Family; Family member; Foundations; Functional disorder; Future; Gated Ion Channel; Heart; Heart Block; Homeostasis; Homologous Gene; Human; Immune response; Ion Channel; Ion Channel Gating; Ischemic Stroke; Kinetics; Knowledge; Ligand Binding; Ligands; Link; Lipids; Maps; Mission; Molecular; Mutation; Nature; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Outcome; Pharmaceutical Preparations; Pharmacology; Pharmacology Study; Phosphatidylinositol 4,5-Diphosphate; Physiological Processes; Physiology; Play; Polymers; Property; Proteins; Public Health; Publishing; Reporting; Research; Research Project Grants; Rest; Role; Signal Transduction; Site; Smooth Muscle Myocytes; Specificity; Stimulus; Stroke; Structure; Structure of beta Cell of islet; TRPM5 gene; Taste Bud Cell; Taste Perception; Therapeutic Agents; Titrations; United States National Institutes of Health; Vascular Smooth Muscle; Work; base; brain tissue; cerebral artery; constriction; desensitization; drug development; experimental study; human disease; insight; insulin secretion; interdisciplinary approach; member; novel therapeutics; particle; preservation; pressure; receptor; side effect; small molecule; success; sweet taste perception; taste stimuli; taste transduction; voltage

PROJECT SUMMARY Blood flow from the heart to the brain is strictly regulated to protect the delicate brain tissue, because improper blood flow can give rise to numerous cardiovascular diseases and brain injuries. TRPM4 is one of the major actors regulating blood flow in the vascular smooth muscle cells in the cerebral arteries when intracellular pressure changes. Mutation or dysfunction of TRPM4 is linked to numerous cardiovascular diseases, including stroke and Brugada syndrome. TRPM4 and its closest homolog, TRPM5, are Ca2+-activated, nonselective, voltage-gated ion channels. TRPM5 is highly expressed in pancreatic beta cells, and dysfunction or mutation in TRPM5 is associated in type II diabetes and obesity. In addition, TRPM4 and TRPM5 in the taste bud cells play an important role in taste signaling, and loss of both channels abolishes the ability to detect bitter, sweet, or umami stimuli. Taken together, TRPM4 and TRPM5 have a wide range of roles in physiology and pathophysiology. Both TRPM4 and TRPM5 belong to the TRPM (melastatin-like transient receptor potential) subfamily of the TRP superfamily, and they are the only two members impermeable to Ca2+. The lack of a canonical positively charged voltage-sensing domain makes a mystery of how TRPM4 and TRPM5 sense voltage. Despite sharing 45% amino acid identity, TRPM4 and M5 have distinct functional and pharmacological properties in terms of kinetics and sensitivities to drugs. A collaboration has been built between Takeda California, Inc. and our lab to study the important role of TRPM5 in treatment of diabetes. The high-affinity drugs specifically targeting TRPM5 provided by Takeda and the potential future drug development strengthen our proposal on studying the pharmacology of these two channels. At present, we do not understand, in molecular detail, how the channels are activated in a voltage-dependent manner, how they are modulated by small molecules binding to them at specific sites, how they are distinguished by various drugs, or how their channel functions are modulated by other proteins such as calmodulin. Building on the success of solving the first human TRPM4 structure in closed state (published in Nature), we propose to continue the cryo-EM studies of TRPM4 and TRPM5 and their pharmacology, combined with complementary electrophysiology experiments and collaboration with Takeda. The outcome of this proposal will define the molecular basis for the voltage-dependent gating activity of these ion channels, for ligand recognition, and for the action of modulators. These advances, in turn, will provide a foundation for developing new therapeutic agents against cardiovascular diseases and diabetes and for a deeper understanding of the function of the voltage-gated TRPM family members.

项目概要 从心脏到大脑的血流受到严格调节，以保护脆弱的脑组织，因为不当 血液流动会引起多种心血管疾病和脑损伤。 TRPM4 是主要的之一 细胞内调节脑动脉血管平滑肌细胞血流的演员 压力变化。 TRPM4 的突变或功能障碍与多种心血管疾病有关， 包括中风和布鲁格达综合征。 TRPM4 及其最接近的同源物 TRPM5 是 Ca2+ 激活的， 非选择性电压门控离子通道。 TRPM5 在胰腺 β 细胞中高表达，并且 TRPM5 功能障碍或突变与 II 型糖尿病和肥胖症相关。此外，TRPM4 和 味蕾细胞中的 TRPM5 在味觉信号传导中发挥着重要作用，两个通道的缺失都会导致味觉信号消失 检测苦味、甜味或鲜味刺激的能力。综合起来，TRPM4 和 TRPM5 具有广泛的范围 生理学和病理生理学中的作用。 TRPM4 和 TRPM5 均属于 TRPM（类褪黑素瞬时受体电位）亚家族 TRP超家族中，它们是仅有的两个不透Ca2+的成员。缺乏积极的规范 带电电压感应域使 TRPM4 和 TRPM5 如何感应电压成为一个谜。尽管 TRPM4 和 M5 具有 45% 的氨基酸同一性，在 动力学和药物敏感性方面。武田加利福尼亚公司 (Takeda California, Inc.) 之间已建立合作关系。 和我们的实验室一起研究TRPM5在糖尿病治疗中的重要作用。高亲和力药物具体 针对武田提供的 TRPM5 和未来潜在的药物开发加强了我们的建议 研究这两个通道的药理学。目前，我们不了解分子细节如何 通道以电压依赖性方式激活，它们是如何被小分子调节的 在特定位点与它们结合，如何通过各种药物区分它们，或者它们的通道功能如何 受钙调蛋白等其他蛋白质的调节。 在成功解决第一个封闭状态下的人类 TRPM4 结构（发表在 Nature 上）的基础上，我们 建议继续TRPM4和TRPM5及其药理学的冷冻电镜研究，并结合 补充电生理学实验以及与武田的合作。本提案的结果 将定义这些离子通道的电压依赖性门控活性的分子基础，对于配体 识别以及调节剂的作用。这些进步反过来又将为开发提供基础 针对心血管疾病和糖尿病的新治疗药物，并加深对这些疾病的了解 电压门控TRPM家族成员的功能。