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: 10033970
• 负责人: Wei Lu
• 金额: $ 57.98万
• 依托单位: VAN ANDEL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10033970
• 关键词: Affinity; Agonist; Amino Acids; Binding; Binding Sites; Blood flow; Brain; Brain Injuries; Brugada syndrome; California; Calmodulin; Cardiac; Cardiovascular Diseases; Charge; Collaborations; Complex; Cryoelectron Microscopy; Dependence; Diabetes Mellitus; Disease; Drug Targeting; Electrophysiology (science); Environment; Family; Family member; Foundations; Functional disorder; Future; Glucose; Heart; Homologous Gene; Human; Immune response; Ion Channel; Ion Channel Gating; Ischemic Stroke; Kinetics; Knowledge; Ligand Binding; Ligands; Link; Liposomes; Maps; Metals; Mission; Molecular; Mutagenesis; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Outcome; Pharmaceutical Preparations; Pharmacology; Pharmacology Study; Phosphatidylinositol 4,5-Diphosphate; Physiology; Play; Polymers; Property; Proteins; Public Health; Research; Research Project Grants; Resolution; Rest; Role; Signal Transduction; Site; Smooth Muscle Myocytes; Specificity; Stimulus; Stroke; Structure; Structure of beta Cell of islet; TRP channel; TRPM5 gene; Taste Bud Cell; Taste Perception; Therapeutic Agents; United States National Institutes of Health; Vascular Smooth Muscle; Work; Zebrafish; analog; base; brain tissue; cerebral artery; constriction; desensitization; drug action; drug development; experimental study; impaired glucose tolerance; inhibitor/antagonist; insight; insulin secretion; member; nanodisk; novel therapeutics; particle; patch clamp; preservation; pressure; receptor; reconstitution; sensor; 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, 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.

项目摘要 严格调节从心脏到大脑的血液流向大脑，以保护精致的脑组织，因为不当 血流会导致许多心血管疾病和脑损伤。 TRPM4是主要的 细胞内血管平滑肌细胞中血液流动中的血流 压力改变。 TRPM4的突变或功能障碍与许多心血管疾病有关， 包括中风和布鲁加达综合症。 TRPM4及其最接近的同源物TRPM5是Ca2+激活的， 非选择性的电压门控离子通道。 TRPM5在胰腺β细胞中高度表达，并且 TRPM5中的功能障碍或突变与II型糖尿病和肥胖有关。此外，TRPM4和 味蕾细胞中的TRPM5在味觉信号中起重要作用，而两个通道的丧失废除了 检测苦，甜或鲜味刺激的能力。两者合计，TRPM4和TRPM5范围很广 生理学和病理生理学中的作用。 TRPM4和TRPM5均属于TRPM（Melastatin样瞬态受体电位），亚家族 TRP超家族，它们是仅有的两个成员，可用于Ca2+。缺乏正规的积极 带电的电压感应域使TRPM4和TRPM5感应电压是一个谜。尽管 在共享45％的氨基酸身份，TRPM4和M5具有不同的功能和药理特性 动力学和对药物的敏感性的术语。武田加州公司之间建立了合作。 我们的实验室研究了TRPM5在治疗糖尿病中的重要作用。高亲和力的药物 针对Takeda提供的TRPM5和潜在的未来药物开发加强了我们关于 研究这两个渠道的药理学。目前，我们不理解分子的细节 通道以电压依赖性方式激活，如何通过小分子调节它们 在特定地点与它们结合，如何通过各种药物区分它们或它们的通道功能 由其他蛋白质（例如钙调蛋白）调节。 以解决封闭状态下第一个人类TRPM4结构的成功为基础，我们建议继续 TRPM4和TRPM5及其药理学的冷冻EM研究结合了互补 电生理实验和与武田的合作。该提议的结果将定义 这些离子通道的电压依赖性门控活性，配体识别和 用于调节器的作用。这些进步又将为开发新的治疗性提供基础 反对心血管疾病和糖尿病的药物，并更深入地了解 电压门控的TRPM家庭成员。