Molecular Atlas of the Cardiac Intercalated Disc

项目摘要 该基金旨在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闰盘（ID），这是一个细胞区域，被认为是心脏疾病的关键。 兴奋性和传播性，然而，仅部分表征其分子组成、调节 和功能我们的目标是通过整合邻近和视觉蛋白质组学来获得这种结构的图谱， 基因组学、生理组学和分子特异性生理学。我们将研究控制心脏以及那些缺乏 Plakophilin-2（PKP 2）是一种ID分子，当突变时会导致年轻人致命的心律失常。 ID首先被描述为在端-端并置位点处的细胞膜交错， 成年心室肌细胞，具有三种电子致密结构：缝隙连接、桥粒和粘附体 交叉点（后来重新定义为混合交叉点或复合区1）。最近的研究表明，ID也承载着 电生理学基础的蛋白质复合物。事实上，70多年前， 电子致密的结构，ID作为一个节点出现，聚集了所有参与的分子机制， 电活动方面：Ca 2 +i的激发、复极化、传播和控制。 尽管已知ID在细胞功能中的重要性，但关于其分子生物学特性， 它的组成和各种功能作用。这种限制的部分原因是，与其他限制相反， 膜包裹的细胞组分（例如，线粒体），分离ID作为一个单一的细胞器还没有 考虑到其复杂的几何形状，以及它对细胞内部开放而没有其限制屏障的事实， 自己的.在这里，我们规避这些限制相结合的接近和视觉蛋白质组学。互动者名单 将作为查询基因组学和表型数据的平台，并指导分子特异性研究。 心律失常是常见的，使人衰弱，在许多情况下是致命的。取得了进展 设备和侵入性策略的发展，尽管它们是复杂的和拯救生命的，也可以 会对心脏造成严重的无法弥补的损伤在医学治疗的背景下，心律失常领域 已经落后于其他人（例如，癌症治疗），其中对分子成分的深入了解 它们之间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 进展我们并不声称我们的研究可以阻止心律失常。但我们相信 参与节律控制的分子元素可以导致更好的风险评估、诊断、预防和 疗法ID是一个集中了多种节律控制分子的区域，因此是一个完美的目标 应用基于邻近的方法来提高我们对心律控制的认识。

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.