Activation and Inhibition Mechanisms of Calcium-Activated Nonselective Cation Channels

钙激活非选择性阳离子通道的激活和抑制机制

• 批准号: 10503201
• 负责人: Juan Du
• 金额: $ 66.28万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10503201
• 关键词: Address; Amino Acid Motifs; Binding; Binding Sites; Brugada syndrome; CRISPR/Cas technology; Calcium; Cardiac; Cardiovascular system; Cations; Cells; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Cryoelectron Microscopy; DNA Sequence Alteration; Data; Disease; Exhibits; Fluorometry; Human; Immune system; Inherited; Intervention; Ion Channel; Knock-in Mouse; Knowledge; Lead; Link; Membrane; Membrane Potentials; Methods; Modeling; Molecular; Molecular Conformation; Monitor; Monovalent Cations; Mutation; Nervous system structure; Organ; Permeability; Pharmacologic Substance; Phenotype; Physiological; Play; Process; Property; Role; Side; Signal Transduction; Site; Skin; Structure; Syndrome; TRPM5 gene; Testing; Tissues; base; disease phenotype; fluorescence imaging; gain of function; gain of function mutation; human disease; inhibitor; interdisciplinary approach; mouse model; mutant; novel; patch clamp; skin disorder; voltage

Project Summary Ca2+-activated nonselective cation (CAN) channels are among a few ion channels that convert intracellular Ca2+ signaling into changes in membrane potential, in contrast to most ion channels that directly or indirectly use membrane potential to regulate intracellular Ca2+ signaling. This unique property allows CAN channels to play critical roles in many tissues and organs. While the existence of CAN channels has been known for decades, recent evidence has established that monovalent cation-permeable TRPM4 and TRPM5 are the long sought for CAN channels. Indeed, numerous TRPM4 mutations are linked to severe human diseases, e.g., cardiac conduction block, Bragada syndrome, PSEK (a skin disease). Despite their functional significance, little is known about the molecular mechanisms governing TRPM4&5 channels activity. Ca2+ is the only known physiological activator for them, though membrane potential also regulates channel activity but only in the presence of Ca2+. However, while the Ca2+-binding sites have been identified by cryo-EM studies, how Ca2+ and voltage activate TRPM4&5 channels remains unknown. Furthermore, while most known disease-causing TRPM4 mutations lead to a gain-of-function phenotype, no effective inhibitor for TRPM4&5 is currently available. Based on our preliminary functional data on TRPM4 Ca2+ and voltage activation, our discovery of novel TRPM4 mutations causing human skin disease, a new disease-causing mutant channel CRISPR mouse model exhibiting skin phenotypes, and our recent discovery of a novel TRPM4 inhibition process, we plan to use a multidisciplinary approach aiming at revealing the fundamental mechanisms of TRPM4&5 activation and inhibition.

项目摘要 CA2+激活的非选择性阳离子（CAN）通道是转换的几个离子通道之一 与大多数离子相比 直接或间接使用膜电位调节细胞内Ca2+的通道 信号。这种独特的属性允许CAN通道在许多组织中起关键作用，并且 器官。虽然CAN渠​​道的存在已知数十年，但最近的证据 已经确定单价阳离子 - 可渗透的TRPM4和TRPM5是长期寻求的 用于罐头通道。实际上，许多TRPM4突变与严重的人类疾病有关 例如，心脏传导阻滞，布拉加达综合征，psek（一种皮肤病）。尽管他们 功能意义，关于trpm4＆5的分子机制知之甚少 通道活动。 CA2+是唯一已知的生理激活剂，尽管膜 潜力还可以调节通道活性，但仅在Ca2+存在下。但是， CA2+结合位点已通过冷冻EM研究确定，CA2+和电压如何激活 TRPM4和5通道仍然未知。此外，虽然最著名的致病 TRPM4突变导致功能型表型，没有有效的TRPM4和5的抑制剂 目前可用。根据我们在TRPM4 CA2+和电压上的初步功能数据 激活，我们发现新型TRPM4突变引起人皮肤病的发现，这是一种新的 引起疾病的突变通道CRISPR小鼠模型表现出皮肤表型，我们的 最近发现了一种新型TRPM4抑制过程，我们计划使用多学科 旨在揭示TRPM4和5激活的基本机制的方法 抑制。