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媒介；例如 使我们心脏的收缩和大脑中的电化学信号同步，并检测光、声音、 触摸、品尝和闻到我们周围的世界。这种能力依赖于用于 在空间和时间上调节它们的细胞活动。我们的研究小组致力于了解 这些类型的现象是由非常复杂的细胞间通信策略编排的， 穿过缝隙连接。我们的目标是发展一种分子和原子水平的机械理解 缝隙连接如何协调细胞间的通讯。为了实现这种级别的细节，我们正在结合 电子冷冻显微镜(CryoEM)的独特力量，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，例如：i)差距是如何 连接选择性地控制细胞之间的化学信息流？二)他们的活动情况如何 受生理信号和药理作用的变构调节？Iii)如何组装缝隙连接， 结构和功能与局部脂质/细胞环境有关吗？尽管他们生理上和 与医学相关，膜蛋白仍然只占蛋白质结构数据库的~4%。然而， 高分辨率低温电子显微镜领域的最新进展以及膜蛋白的研究进展 生物化学和原位成像技术正在开始革命性地改变我们的结构方式 描述这些蛋白质的特征。有了这些工具，我们将解决有关GAP的几个关键问题 结组装、选择性和调节。我们的调查结果预计将提供一个 合理开发目标所需的体系结构框架和机械知识 治疗一系列与缝隙连接相关的疾病，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.