STRUCTURE AND IN VIVO FUNCTION OF CARDIAC CONTRACTILE PR

该项目的长期目标是研究功能 工作心脏中突变蛋白表达的相关性。 使用 心脏特异性转基因过表达技术，现在 可能取代收缩蛋白同种型，特别是在 心室，从而建立功能后果 在动物的一生中， 各种外部和内部刺激。 具体目标1将创建一个 携带突变的肌球蛋白结合蛋白C（MyBP-C）的动物， 已被证明会导致家族性肥厚型心肌病， 确定这种突变是否会导致心脏功能下降 在运动和纤维水平，以及疾病的动物模型是否 可以被创建。 SPECIFIC AIM 2将测试替换 心室形式的必需肌球蛋白轻链， 基因工程物种将导致一种动物， 心脏功能必需肌球蛋白轻链的氨基末端 被假设在决定收缩性中起主要作用。一 突变的必需轻链，缺少部分"系链"区， 被认为是减缓跨桥周期，将被用来取代 心室和心房中的内源性物质。 cDNA将是 与心脏特异性α-肌球蛋白重链启动子连接， 产生了多个转基因小鼠品系。 SPECIFIC AIM 3将研究 突变蛋白表达的剂量依赖性后果， 分析置换程度不同的多条线路， 以了解其生理和病理后果。变化 将在分子、生物化学、细胞、结构 整个器官和动物水平，以直接建立 替代品的后果。 SPECIFIC AIM 4将尝试营救 基因定义的心肌病， 心脏功能增强的药物。 这些模型将 探索的基本结构/功能的关系， 收缩蛋白，并应导致动物与增强和 受损的心脏功能通常可用于 了解这些过程在补偿和 心衰

The long term goal of this project is to investigate the functional correlates of mutant protein expression in the working heart. Using the technique of cardiac-specific transgenic overexpression, it is now possible to replace the contractile protein isoforms specifically in the cardiac compartment and thereby establish the functional consequences of the mutation over the lifetime of the animal as it is subjected to various external and internal stimuli. SPECIFIC AIM 1 will create an animal carrying a mutated myosin binding protein C (MyBP-C) that has been shown to cause familial hypertrophic cardiomyopathy, in order to determine whether such a mutation results in decreased cardiac function at the motor and fiber levels and whether an animal model of the disease can be created. SPECIFIC AIM 2 will test the hypothesis that replacing the ventricular form of the essential myosin light chain with a genetically engineered species will lead to an animal with enhanced cardiac function. The amino terminus of the essential myosin light chain is hypothesized to play a major role in determining contractility. A mutated essential light chain, lacking part of the "tether" region which is believed to slow down the cross bridge cycle, will be used to replace the endogenous species in the ventricles and atria. The cDNA will be linked to the cardiac-specific alpha-myosin heavy chain promoter and multiple lines of transgenic mice generated. SPECIFIC AIM 3 will study the dose-dependent consequences of mutant protein expression by analyzing multiple lines in which the degree of replacement varies, in order to understand the physiologic and pathogenic consequences. Changes will be measured at the molecular, biochemical, cellular, structural, whole organ and animal levels in order to directly establish the consequences of replacements. SPECIFIC AIM 4 will attempt to rescue genetically defined cardiomyopathies by breeding them into a background that has intrinsically enhanced cardiac function. These models will explore both the basic structure/function relationships of the contractile proteins, and should result in animals with enhanced and compromised cardiac function that will be generally useful in understanding the roles these processes play in both compensation and heart failure.