Structural Rearrangements in GABA-A Receptors

GABA-A 受体的结构重排

基本信息

批准号：
7799256
负责人：
CYNTHIA M CZAJKOWSKI
金额：
$ 31.49万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-02-15 至 2013-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7799256
关键词：
Address Affect Affinity Agonist Anesthetics Anti-Anxiety Agents Barbiturates Benzodiazepines Binding Binding Sites Brain Convulsants Critiques Cysteine DNA Sequence Rearrangement Data Defect Disease Drug Design Drug Modulation Drug effect disorder Drug usage Elements Engineering Environment Epilepsy Ethanol Exhibits Extracellular Domain Fluorescence Fluorescent Probes GABA Receptor GABA-A Receptor Gated Ion Channel Genes Glycine Receptors Goals Health Ion Channel Kinetics Knowledge Label Lead Learning Ligand Binding Ligands Link Location Maps Measurement Mediating Membrane Modification Molecular Molecular Structure Motion Movement Muscle relaxants Mutation Myasthenia Neurons Neurotransmitters Occupations Oocytes Outcome Paper Patch-Clamp Techniques Pathway interactions Pentobarbital Perfusion Pharmaceutical Preparations Phase Physiologic pulse Play Positioning Attribute Principal Investigator Process Protein Dynamics Proteins Publishing Receptor Activation Relative (related person)Research Resolution Rest Role SR-95531 Site Solutions Staging Steroids Structural Models Structure Suggestion System Temperature Testing Therapeutic Time Weight Work Xenopus oocyte barbituric acid salt desensitization disease-causing mutation extracellular flash photolysis flexibility fluorophore gamma-Aminobutyric Acid hypnotic innovation interest millisecond neurosteroids novel strategies patch clamp prevent programs public health relevance receptor receptor function research study response sedative simulation synaptic inhibition theories voltage

项目摘要

DESCRIPTION (provided by applicant): Gamma-aminobutyric acid type A receptors (GABAARs) mediate the majority of synaptic inhibition in the brain and are modulated by a variety of clinically important drugs, such as benzodiazepines, barbiturates, steroids, anesthetics and anti-convulsants. Furthermore, GABAAR mutations have recently been linked to epilepsy. The long-term goal of our research program is to understand the function of the GABAAR in terms of its molecular structure. While recent crystallographic advances have provided valuable structural models of the GABAAR, achieving a full understanding of function also requires knowledge of protein dynamics. GABAARs exist in at least three interconvertible states with distinct functions: inactive/closed, active/open, and desensitized/closed. Very little is known about the protein motions that occur during these structural transitions, which are regulated by neurotransmitter and drug binding. We will use fluorescence recording of site-specific labels in GABAARs expressed in Xenopus oocytes to study the structural rearrangements underlying activation, desensitization, and drug modulation as they occur in real time. We propose to study 1) agonist, partial-agonist and antagonist induced rearrangements, 2) global protein motions, 3) pentobarbital induced structural changes and 4) protein motions during desensitization. The experiments will be interpreted with the aid of recently elucidated atomic- level structures to gain a deeper understanding of the molecular mechanisms underlying the function of GABAARs and their relatives. We cannot hope to predict the actions of a drug or ligand or predict the outcome of a disease-causing mutation in the GABAAR without dissecting the movements in the protein that mediate its function. The research proposed here utilizes an innovative new approach that will enable us to learn how GABAARs function in health and disease states. PUBLIC HEALTH RELEVANCE: The opening and closing of ligand-gated ion channels, which lie in the membranes of nerve cells, regulate information flow throughout the brain. Defects in these channels lead to wide variety of diseases, such as myasthenia, hyperekplexia and epilepsy. These channels are also the targets of a number of clinically used drugs, including muscle relaxants, sedative-hypnotics, anti-convulsants, anxiolytics and anesthetics. We cannot hope to predict the actions of a drug, design safer and more effective drugs, develop better therapeutic strategies or predict the outcome of a disease-causing mutation without knowledge of how these channels work at a molecular level. The research proposed here utilizes an innovative new approach that will increase our understanding of how one type of ion channel, the GABAAR, functions in health and disease and will establish testable hypotheses for elucidating how other related ligand-gated ion channels function.

描述（由申请人提供）：Aγ-氨基丁酸A型受体（GABAARS）介导了大脑中的大多数突触抑制作用，并由多种临床上重要的药物进行调节，例如苯并二氮卓类药物，巴比妥类药物，类固醇，麻醉和麻醉和抗氧气。此外，Gabaar突变最近与癫痫有关。我们的研究计划的长期目标是了解Gabaar的分子结构的功能。尽管最近的晶体学进步提供了Gabaar的有价值的结构模型，但对功能的全面了解也需要了解蛋白质动力学。 GABAARS至少存在具有不同功能的至少三个可相互互动状态：非活动/闭合，活动/开放和脱敏/封闭。关于在这些结构过渡期间发生的蛋白质运动的知之甚少，这些蛋白质受到神经递质和药物结合的调节。我们将使用在爪蟾卵母细胞中表达的GABAARS中特定地点标签的荧光记录来研究实时激活，脱敏和药物调节的基础结构重排。我们建议研究1）激动剂，部分动力学和拮抗剂诱导的重排，2）全球蛋白质运动，3）戊巴比妥诱导的结构变化和4）脱敏过程中的蛋白质运动。实验将在最近阐明的原子水平结构的帮助下进行解释，以更深入地了解Gabaars及其亲属功能的分子机制。我们不能希望预测药物或配体的作用，也不能预测Gabaar中引起疾病突变的结果，而不会剖析蛋白质中介导其功能的运动。这里提出的研究采用了一种创新的新方法，该方法将使我们能够了解Gabaars在健康和疾病状态中的运作方式。公共卫生相关性：位于神经细胞膜中的配体门控离子通道的开放和关闭，调节整个大脑的信息流。这些通道中的缺陷导致各种各样的疾病，例如肌无力，过度孔和癫痫。这些通道也是多种临床使用药物的靶标，包括肌肉松弛剂，镇静性 - 高音药物，抗激动剂，抗焦虑药和麻醉药。我们不能希望预测药物的作用，设计更安全，更有效的药物，制定更好的治疗策略或预测引起疾病的突变的结果，而不了解这些通道如何在分子水平上起作用。此处提出的研究采用了一种创新的新方法，这将增加我们对一种类型的离子通道，Gabaar，在健康和疾病中发挥作用的理解，并将建立可检验的假设，以阐明其他相关配体配方离子通道的功能。