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+参与细胞寿命的各个方面。 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，并在膜上稳态和下层稳定性调节膜稳定性，并调节膜稳态和下层的casscadeScadeScadeScadeScadeScade cascade。这些渠道大量表达并积极参与循环系统和神经系统的生理学，并与中风的病理生理学以及许多神经系统疾病有关，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和罐子的理解少得多，主要是由于其分子鉴定涉及的困难。 2008年，我们的实验室确定TMEM16A和TMEM16家族中的16B构成了长期寻求的CACC。我最近证明，TMEM16F而不是作为CACC，而是形成具有小型单通道电导（SCAN）和最小阴离子渗透性的小型CAN通道。我们的体外和体内实验进一步说明，在血液凝结过程中，脂质在血小板中杂乱和TMEM16F敲除小鼠在血小板中的脂质需要出血缺陷，并且在CAROTID动脉血栓形成中表现出出血的缺陷，并且与CA2+依赖性磷酸磷酸磷酸磷酸化磷酸化（ps）相关。该建议的重点是定义Ca2+活化的TMEM16通道的分子特性及其在血小板和小脑Purkinje细胞中的细胞功能。在目标I中，我将确定对离子选择性和Ca2+结合至关重要的关键残基，以了解TMEM16通道功能的分子机制。在AIM II中，我将使用电生理学和体外/体内成像技术的组合研究血小板和小脑Purkinje细胞中TMEM16F扫描通道的生理功能。对该建议的研究将有助于在分子水平上了解TMEM16通道，有助于定义其生理功能，并提供见解以开发新的治疗剂以靶向这些通道以预防和治疗神经系统疾病和中风。