Ca2+ activated TMEM16 channels and their physiological roles in the brain

Ca2 激活 TMEM16 通道及其在大脑中的生理作用

基本信息

批准号：
8678311
负责人：
Huanghe Yang
金额：
$ 9万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8678311
关键词：
Address Anions Apoptosis Ataxia Binding Biology Biophysics Biosensor Bleeding time procedure Blood Cells Blood Platelets Blood coagulation Brain Cardiovascular system Carotid Artery Thrombosis Cations Cell membrane Cell physiology Cells Chemicals Chloride Channels Coupling Data Defect Drug Targeting Electrophysiology (science)Epilepsy Exhibits Family Family member Functional disorder Genetic Hemorrhage Homeostasis Imaging Techniques In Vitro Ion Channel Ions Kinetics Knockout Mice Laboratories Life Lilium Link Lipids Membrane Modification Molecular Molecular Genetics Monitor Movement Disorders Mus Muscle Muscle Contraction Mutation Myocardial Infarction Nervous system structure Neurons Neurosciences Outcome Pain Permeability Pharmacology Phosphatidylserines Phospholipids Physiological Physiology Play Potassium Property Purkinje Cells Regulation Reporting Resistance Role Signal Transduction Site-Directed Mutagenesis Stroke Structure Testing Thrombosis Thrombotic Stroke Training Tremor Work base cellular imaging comparative experience improved in vivo in vivo imaging insight member mutant nervous system disorder neurotransmission novel novel strategies novel therapeutics patch clamp prevent public health relevance research study tool

项目摘要

DESCRIPTION (provided by applicant): Ca2+ is involved in every aspect of cellular life. Ca2+-activated ion channels, mainly Ca2+-activated K+ (KCa) channels, Ca2+-activated Cl- channels (CaCC) and Ca2+-activated non-selective cation (CAN channels), sense changes of internal Ca2+ level and actively regulate membrane excitability, ion homeostasis and downstream cell signaling cascade. These channels are abundantly expressed and actively involved in the physiology of the circulatory and nervous systems, and have been linked to pathophysiology of stroke and many neurological disorders, such as epilepsy, pain, and movement disorders including ataxia and tremor. Compared with KCa channels, CaCCs and CANs are much less understood mainly due to the difficulties involved in their molecular identification. In 2008, our laboratory identified that TMEM16A and 16B in the TMEM16 family form the long- sought CaCCs. I recently demonstrated that TMEM16F, instead of being a CaCC, forms a novel CAN channel with small single channel conductance (SCAN) and minimal anion permeability. Our in vitro and in vivo experiments further illustrate that TMEM16F-SCAN channels are required for lipid scrambling in platelets during blood coagulation and TMEM16F knockout mice exhibit bleeding defects and protection in carotid artery thrombosis associated with platelet deficiency in Ca2+-dependent phosphatidylserine (PS) exposure. The focus of this proposal is to define the molecular properties of Ca2+-activated TMEM16 channels and their cellular functions in platelets and in cerebellar Purkinje cells. In Aim I, I will pinpoint the key residues that are important for ion selectivity and Ca2+ binding to understand the molecular mechanisms underlying the functions of TMEM16 channels. In Aim II, I will investigate the physiological functions of the TMEM16F-SCAN channels in platelets and cerebellar Purkinje cells using a combination of electrophysiology and in vitro/in vivo imaging techniques. Studies of this proposal will facilitate the understanding of TMEM16 channels at the molecular level, help define their physiological functions, and provide insights to develop new therapeutics to target these channels to prevent and treat neurological disorders and stroke.

描述（由申请人提供）：Ca2+ 参与细胞生命的各个方面。 Ca2+激活的离子通道，主要是Ca2+激活的K+（KCa）通道、Ca2+激活的Cl-通道（CaCC）和Ca2+激活的非选择性阳离子（CAN通道），感知内部Ca2+水平的变化并主动调节膜兴奋性，离子稳态和下游细胞信号级联。这些通道大量表达并积极参与循环和神经系统的生理学，并且与中风和许多神经系统疾病的病理生理学有关，例如癫痫、疼痛和运动障碍（包括共济失调和震颤）。与 KCa 通道相比，CaCC 和 CAN 的了解要少得多，主要是由于它们的分子鉴定困难。 2008年，我们的实验室鉴定出TMEM16家族中的TMEM16A和16B形成了人们长期寻找的CaCC。我最近证明，TMEM16F 不是 CaCC，而是形成一种新颖的 CAN 通道，具有较小的单通道电导 (SCAN) 和最小的阴离子渗透性。我们的体外和体内实验进一步表明，在凝血过程中，TMEM16F-SCAN 通道是血小板中脂质扰乱所必需的，并且 TMEM16F 敲除小鼠在与 Ca2+ 依赖性磷脂酰丝氨酸 (PS) 暴露中血小板缺乏相关的颈动脉血栓形成中表现出出血缺陷和保护作用。该提案的重点是定义 Ca2+ 激活的 TMEM16 通道的分子特性及其在血小板和小脑浦肯野细胞中的细胞功能。在目标 I 中，我将查明对离子选择性和 Ca2+ 结合非常重要的关键残基，以了解 TMEM16 通道功能背后的分子机制。在目标 II 中，我将结合电生理学和体外/体内成像技术研究血小板和小脑浦肯野细胞中 TMEM16F-SCAN 通道的生理功能。对该提案的研究将有助于在分子水平上理解 TMEM16 通道，帮助定义其生理功能，并为开发针对这些通道的新疗法以预防和治疗神经系统疾病和中风提供见解。