Molecular Atlas of the Cardiac Intercalated Disc

项目总结 这项拨款建议研究控制成人心脏电活动的分子机制。 心室肌细胞。我们的重点是心脏间盘(ID)，该细胞的一个区域被认为是 兴奋性和繁殖，然而，仅根据其分子组成的部分特征，调节 和功能。我们的目标是通过整合邻近性和视觉蛋白质组学来获得这种结构的地图， 基因组学、生理学和分子特定生理学。我们将研究控制心脏，以及那些有缺陷的心脏 在蛋白亲和素-2(PKP2)中，是一种ID分子，当突变时会在年轻人中导致致命的心律失常。 ID首先被描述为细胞膜在端端贴合部位的交错排列 成人心室肌细胞，有三种电子致密结构：缝隙连接、桥粒和贴壁 交汇点(后来重新定义为混合交汇点或区域组合1)。最近的研究表明，ID还托管 电生理学的基础蛋白质复合体。事实上，自从它被描述为一种 电子密度高的结构，ID作为一个节点出现，聚集了所有涉及的分子结构 电活动方面：钙离子的兴奋、复极化、传播和控制。 尽管已知ID在细胞功能中的重要性，但对其分子仍有很大的认识差距 其组成及其不同的功能作用。这种限制的部分原因是，与其他 膜包裹的细胞成分(如线粒体)，ID作为单个细胞器还没有分离出来 考虑到它复杂的几何结构，以及它对细胞内部开放而不受其限制的事实，这是可能的 属于自己的。在这里，我们通过结合邻近性和视觉蛋白质组学来绕过这些限制。互动者名单 将作为查询基因组学和表型数据的平台，并指导特定分子的研究。 心律失常是常见的，使人虚弱，在许多情况下，是致命的。在以下方面取得了进展： 设备和侵入性策略的开发，尽管它们是复杂的和拯救生命的，也可以 对心脏造成无法挽回的严重损害。在医学治疗的背景下，心律失常领域 一直落后于其他领域(例如癌症治疗)，对分子组成的深入了解 它们的相互依赖导致了可以减缓或阻止疾病的化学制剂的发现 进步。我们并不认为我们的研究可以阻止心律失常。但我们确实相信，关于 参与节律控制的分子元素可以带来更好的风险评估、诊断、预防和 心理治疗。ID是一个集中了多种节律控制分子的区域，因此，它是一个完美的靶子 应用以接近为基础的方法来促进我们对心率控制的了解。

PROJECT SUMMARY This grant proposes research on the molecular mechanisms that control the electrical activity of adult cardiac ventricular myocytes. Our focus is on the cardiac intercalated disc (ID), a region of the cell recognized as key to excitability and propagation and yet, only partly characterized in terms of its molecular composition, regulation and function. Our objective is to obtain a map of this structure by integrating proximity and visual proteomics, genomics, physiomics and molecule-specific physiology. We will study control hearts as well as those deficient in Plakophilin-2 (PKP2), an ID molecule that when mutated can cause lethal arrhythmias in the young. The ID was first described as an interdigitation of cell membranes at the site of end-end apposition between adult ventricular myocytes, hosting three electron-dense structures: gap junctions, desmosomes and adherens junctions (later redefined as mixed junctions or area composita1). More recent work shows that the ID also hosts protein complexes fundamental to electrophysiology. In fact, more than 70 years since it was described as an electron-dense structure, the ID emerges as a node that congregates the molecular machinery involved in all aspects of electrical activity: excitation, repolarization, propagation and control of Ca2+i. Despite the known importance of the ID in cell function, there is a wide knowledge gap regarding its molecular composition and its varied functional roles. Part of this limitation results from the fact that, as opposed to other membrane-wrapped cell components (e.g., mitochondria), isolation of the ID as a single organelle has not been possible given its complex geometry, and the fact that it is open to the cell interior without a limiting barrier of its own. Here, we circumvent these limitations by combining proximity and visual proteomics. The list of interactors will serve as a platform to query genomics and phenotype data, and to guide molecule-specific studies. Cardiac arrhythmias are common, debilitating and in many cases, fatal. Progress has been made in the development of devices and invasive strategies which, as sophisticated and life-saving as they are, can also cause serious and irreparable damage to the heart. In the context of medical therapy, the field of arrhythmias has been lagging behind others (e.g., cancer therapy), where a deep understanding of molecular components and their interdependence have led to the discovery of chemical agents that can slow down or arrest disease progression. We do not claim that our study can stop arrhythmias. But we do believe that knowledge of the molecular elements involved in rhythm control can lead to better risk assessment, diagnosis, prevention and therapy. The ID is a domain that concentrates multiple rhythm-control molecules and as such, a perfect target for applying proximity-based methods to advance our knowledge on the control of the heart rhythm.