Cardiac Myosin Binding Protein-C: Structure, Function, and Regulation

心肌肌球蛋白结合蛋白-C(cMyBP-C)突变导致年轻个体猝死 患有家族性肥厚型心肌病。尽管它在临床上很重要，而且它与 心脏的肌动蛋白分子马达，在了解cMyBP-C是如何 调节心脏能量的产生。此外，cMyBP-C在p-肾上腺素能之后被磷酸化 刺激，表明cMyBP-C本身可能以磷酸化依赖的方式调节。 本计划项目(3个项目和3个核心)将提供全面的分子理解 CMyBP-C的功能，它的磷酸化调节，以及它对心肌收缩能力的影响。使用最新状态- 艺术技术，我们将通过广泛的研究来表征cMyBP-C的结构和功能 从整个心脏的力学到单个cMyBP-C分子与 肌动蛋白分子马达。项目1将使用高分辨率三维电子显微镜 重建以表征cMyBP-C的结构及其肌节组织，提供洞察力 到它的功能能力。项目2将使用激光陷阱来评估cMyBP-C的调制能力 肌动球蛋白在单分子水平上产生动力，而项目3将使用转基因小鼠 确定cMyBP-C可能的肌动蛋白结合及其磷酸化对心功能影响的模型 在各种生理条件下。心室和心脏纤维的表征和整合 核心(核心B)将收集心脏性能和纤维机械数据，以桥接生理 单分子研究和整体动物研究之间的差距。此外，核心将提供一个建模 将来自所有生理水平的数据集成到cMyBP-C机制模型的平台 功能性。小鼠和cMyBP-C蛋白生产核心(Core C)将产生突变的小鼠 CMyBP-C及其突变型cMyBP-C蛋白在肌动蛋白结合和磷酸化的体外表达 域名。这些心脏和蛋白质将通过不同的项目在所有解剖水平上进行研究。这个 计划项目的长期目标是：1)确定cMyBP-C的分子结构和肌节 组织；2)确定cMyBP-C如何在磷酸化依赖的 方式；3)确定为什么cMyBP-C磷酸化的改变与心力衰竭有关 人类。

Mutations in cardiac myosin binding protein-C (cMyBP-C) lead to sudden death in young individuals with Familial Hypertrophic Cardiomyopathy. Despite Its clinical importance and its association with the actomyosin molecular motor of the heart, a significant gap still remains in understanding how cMyBP-C modulates cardiac power production. In addition, cMyBP-C is phosphorylated following p-adrenergic stimulation, suggesting that cMyBP-C Itself may be regulated in a phosphorylation-dependent manner. This Program Project (3 projects and 3 cores) will provide a comprehensive molecular understanding of cMyBP-C function, its regulation by phosphorylation, and its impact on cardiac contractility. Using state-ofthe- art techniques, we will characterize cMyBP-C's structure and function through studies ranging from the mechanics of the whole heart down to interactions between a single cMyBP-C molecule and the actomyosin molecular motor. Project #1 will use high resolution 3-dimensional electron microscopic reconstruction to characterize the structure of cMyBP-C and its sarcomeric organization, providing insight to its functional capacity. Project #2 will use the laser trap to assess cMyBP-C's ability to modulate actomyosin power production at the single molecule level, while Project #3 will use transgenic mouse models to define the role of cMyBP-C's putative actin-binding and its phosphorylation on cardiac function under various physiological conditions. The Ventricular and Cardiac Fiber Characterization and Integration Core (Core B) will gather the ventricular performance and fiber mechanical data to bridge the physiological gap between the single molecule and whole animal studies. In addition, the Core will provide a modeling platform to integrate the data from all physiological levels into a mechanistic model of cMyBP-C functionality. The Mouse and cMyBP-C Protein Production Core (Core C) will generate mice with mutant cMyBP-C and in vitro expression of mutant cMyBP-C protein at its actin-binding and phosphorylation domains. These hearts and protein will be studied at all anatomical levels by the various projects. The Program Project's long term goals are to: 1) define cMyBP-C's molecular structure and sarcomeric organization; 2) determine how cMyBP-C modulates cardiac function in a phosphorylation-dependent manner; 3) define why alterations in cMyBP-C phosphorylation are associated with heart failure in humans.