Basis of Muscle Dysfunction in Malignant Hyperthermia and Central Core Disease

骨骼肌兰尼定受体(RYR1)调节肌浆网钙释放 (Sr)在人类中枢性核心病(CCD)和药物遗传综合征中储存和突变， 恶性高热(MH)。尽管RyR1的MH和Ccd突变被认为会改变肌质网钙离子 释放通道功能和肌肉兴奋-收缩(EC)偶联，其机制 影响导致肌肉表型变化的这些疾病的特征尚不清楚。这个项目 将使用转基因MH和CD敲入小鼠来提供基本机制的详细分析 通过RYR1疾病突变改变体内肌肉功能。这个项目的长期目标是定义 MH/CD基因突变改变细胞内钙稳态和细胞/分子机制 完整肌肉的兴奋-收缩(EC)耦合。我们的总体假设是：MH和CD突变 MH/CCD区1和2通过改变关键的Intra和 RYR1内的分子间相互作用以及RYR1与电压依赖性钙通道之间的相互作用 T-小管膜，而RyR1区域3孔区的Cd-选择性突变破坏钙离子 渗透到航道中。为了验证这一假设，我们建议：1.创建三个新的MH/CD 小鼠品系并分析突变对咖啡因反应的肌肉收缩特性的影响 和温度，2.分析突变对RYR1结构的影响 RyR1基因MH/Ccd突变对肌管和肌细胞内钙稳态和双向DHPR-RyR1偶联的影响 从MH/CD敲入小鼠获得的成人肌纤维，以及4评估MH/CD突变的影响 原位释放通道对RyR1配体的激活和局部结合钙的增加的敏感性。 此应用程序将两位合作者聚集在一起，他们都高度致力于阐明基本原理 MH和CCD的病理生理机制，但谁处理这些问题的方式截然不同，但是 免费赠送的方式。这一结合将产生一个独特的跨学科项目，该项目将决定 MH/CCD病突变改变RyR1结构和调节亚细胞内钙的机制 运输/处理机制、肌肉EC偶联和肌质网钙存储/封存。结果将是 钙离子调节异常对其他疾病的广泛意义

The skeletal muscle ryanodine receptor (RYR1) regulates Ca2+ release from the sarcoplasmic reticulum (SR) stores and is mutated in human central core disease (CCD) and in the pharmacogenetic syndrome, malignant hyperthermia (MH). Although MH and CCD mutations in RyR1 are thought to alter SR Ca2+ release channel function and muscle excitation-contraction (EC) coupling, the mechanisms by which these effects result in phenotypic changes in muscle characteristic of these disorders are unknown. This project will use transgenic MH and CCD knock-in mice to provide detailed analyses of the fundamental mechanisms by which RYR1 disease mutations alter in vivo muscle function. The long-term goal of this project is to define the cellular/molecular mechanisms and principles by which MH/CCD mutations alter Ca2+ homeostasis and excitation-contraction (EC) coupling in intact muscle. Our overall hypothesis is: MH and CCD mutations in MH/CCD regions 1 and 2 enhance voltage- and Ca2+-gated SR release by altering crucial intra and intermolecular interactions within RYR1 and between RYR1 and the voltage dependent Ca2+ channel in the t-tubule membrane, while CCD-selective mutations in the region 3 pore region of RyR1 disrupt Ca2+ permeation through the channel. To test this hypothesis, we propose to: 1. Create three new MH/CCD mouse lines and analyze the effects of the mutations on muscle contractile properties in response to caffeine and temperature, 2. Analyze the effects of the mutations on RYR1 structure, S.Assess the effects of MH/CCD mutations in RyR1 on Ca2+ homeostasis and bi-directional DHPR-RyR1 coupling in myotubes and adult muscle fibers obtained from MH/CCD knock-in mice, and 4 Evaluate the effects of MH/CCD mutations on in situ release channel sensitivity to activation by RyR1 ligands and local increases in junctional Ca2+. This application brings together two collaborators, both highly committed to elucidating fundamental mechanisms of MH and CCD pathophysiology, but who approach the problems in very different, but complimentary ways. This union will result in a uniquely interdisciplinary project that will determine the mechanisms by which MH/CCD disease mutations alter RyR1 structure and regulation, subcellular Ca2+ transport/handling mechanisms, muscle EC coupling, and SR Ca2+ storage/sequestration. Results will have broad implications for other disorders of Ca2+ dysregulation in