Dynamic Mechanisms of Membrane Channel Gating by CryoEM

项目摘要 成孔膜通道是许多复杂生物现象的中心介质;例如 同步我们心脏的收缩和我们大脑中的电化学信号，检测光，声音， 触觉，味觉和嗅觉的变化这种能力依赖于用于 在空间和时间上调节其细胞活性。我们的研究小组致力于了解 这些类型的现象是由细胞间通信的非常复杂的策略编排的， 通过差距结。我们的目标是发展一个分子和原子水平的机械理解， 缝隙连接是如何协调细胞间通讯的为了达到这种细节水平，我们正在结合 电子冷冻显微镜（CryoEM）的独特功能，以及计算建模和靶向 生物物理和功能研究，以解决几个基本问题，如：i）如何做差距 连接选择性地控制细胞之间的化学信息流？（二）活动情况如何 由生理信号和药理学试剂进行变构调节？iii）间隙连接组装， 结构和功能与局部脂质/细胞环境相结合？尽管他们的生理和 医学相关性，膜蛋白仍然只代表~4%的蛋白质结构数据库。然而，在这方面， 高分辨率CryoEM领域的最新进展，加上膜蛋白的进展， 生物化学和原位成像技术，正在开始彻底改变我们在结构上的方式， 描述这些蛋白质。有了这些工具，我们正在解决几个关于gap的关键问题 结组装、选择性和调节。我们的调查结果预计将提供一个 架构框架和机械知识所需的合理发展的目标 针对一系列缝隙连接相关疾病的治疗，例如失明、耳聋、心律失常、中风 和癌症。

Project Summary Pore-forming membrane channels are central mediators of many complex biological phenomena; such as synchronizing the contraction of our heart and electro-chemical signals in our brain, and detecting light, sound, touch, taste and smells of the world around us. This ability is dependent upon dynamic mechanism used to spatially and temporally modulate their cellular activity. Our research group is focused on understanding how these types of phenomena are choreographed by remarkably complex strategies of cell-to-cell communication, through the gap junctions. We aim to develop a molecular and atomic-level of mechanistic understanding of how gap junctions coordinate inter-cellular communication. To achieve this level of detail, we are combining the unique power of electron cryo-microscopy (CryoEM), together with computational modeling and targeted biophysical and functional studies to address several fundamental questions, such as: i) How do the gap junctions selectively control the flow of chemical information between cells? ii) How are their activities allosterically modulated by physiological signals and pharmacological agents? iii) How gap junction assembly, structure and function is coupled with the local lipid/cellular environment? Despite their physiological and medical relevance, membrane proteins still only represent ~4% of the protein structure database. However, recent advances in the field of high-resolution CryoEM, coupled with advancements in membrane protein biochemistry and in situ imaging technologies, are beginning to revolutionize the way we structurally characterize these proteins. With these tools in hand, we are addressing several key questions about gap junction assembly, selectivity and regulation. The results of our investigations are expected to provide an architectural framework and the mechanistic knowledge required for the rational development of targeted therapies against a range of gap junction related diseases, such as blindness, deafness, arrhythmia, stroke and cancers.