Nicotinic Acetylcholine Receptor Structure, Thermal Motion and Gating

描述（由申请人提供）： 博士Michaela Jansen是Myles Akabas博士实验室的博士后研究员。她的长期职业目标是获得一个独立的教师职位，在离子通道和转运蛋白的分子生理学和药理学领域进行研究。她的直接职业目标是开发一个独立的研究计划，这将成为开始独立科学生涯的基础。为了实现这一目标，她将获得独立的资金，并增加她的离子通道和膜运输的基础知识和蛋白质结构功能，生物信息学和分子建模的相关问题。为了增加她的实验技术的剧目，她将学习执行膜片钳记录和单通道分析，分子建模和膜蛋白生物化学。这将在研究肌肉烟碱乙酰胆碱受体（AChR）结构及其在通道激活过程中经历的构象变化的研究项目的背景下完成。烟碱型乙酰胆碱受体介导神经-肌肉接头和大脑中的快速突触传递。最近发表的ACh结合蛋白（AChBP）和电鳐AChR结构的研究为以下具体目的提供了新的认识：1）通过确定特定跨膜片段残基之间的邻近关系来检验4-A分辨率AChR跨膜结构域模型的有效性。2)确定静息和激活状态下M2通道内衬段的热迁移率。3)绘制活化过程中跨膜结构域的结构变化。4)探测M2-M3环周围的蛋白质包装，其参与配体结合至通道门控的转导。结果将验证从4-A分辨率数据推断的结构信息。此外，他们将阐明动态事件，如热和门控引起的运动。AChR与多种神经系统疾病有关，如阿尔茨海默病和帕金森病、注意力缺陷多动障碍、抑郁症、精神分裂症、重症肌无力和尼古丁依赖。了解AChR功能的分子基础是找到这些疾病的改进治疗方法的先决条件。我们的研究结果将为理解致病突变如何干扰功能，临床使用的药物如何调节功能提供有价值的工具，也是设计新药的基础。

DESCRIPTION (provided by applicant): Dr. Michaela Jansen is a postdoctoral fellow in the lab of Dr. Myles Akabas. Her long term career goals are to obtain an independent faculty position performing research in the field of molecular physiology and pharmacology of ion channels and transporters. Her immediate career goals are to develop an independent research program that will form the basis for beginning an independent scientific career. To accomplish this she will obtain independent funding and increase her fundamental knowledge of ion channels and membrane transport and related issues of protein structure-function, bioinformatics and molecular modeling. To increase her repertoire of experimental techniques she will learn to perform patch clamp recording and single channel analysis, molecular modeling and membrane protein biochemistry. This will be accomplished in the context of a research project to study the muscle nicotinic acetylcholine receptor (AChR) structure and the conformational changes it undergoes during channel activation. Nicotinic AChR mediate fast synaptic transmission at the nerve-muscle junction and in the brain. The recent publication of the ACh binding protein (AChBP) and Torpedo AChR structures has allowed new insights into the three dimensional structure provides the basis for the following Specific Aims: 1) To test the validity of the 4-A resolution AChR transmembrane domain model by determining proximity relationships between specific transmembrane segment residues. 2) To determine the thermal mobility of the M2 channel-lining segments in the resting and activated states. 3) To map structural changes in the transmembrane domain during activation. 4) To probe protein packing around the M2-M3 loop that is involved in the transduction of ligand binding to channel gating. The results will validate the structural information inferred from the 4-A resolution data. In addition, they will elucidate dynamic events such as thermal and gating-induced movements. AChR have been implicated in a variety of neurological diseases such as Alzheimer's and Parkinson's disease, Attention deficit hyperactivity disorder, depression, schizophrenia, myasthenia gravis and in nicotine dependence. Understanding the molecular basis of AChR function is a prerequisite for finding improved treatments for these disorders. Our results will provide valuable tools for understanding how disease causing mutations interfere with function, how drugs used clinically modulate function, and also a basis to design new drugs.