Communication between neighboring ryanodine receptor channels in skeletal muscle

本课题的目的是了解骨骼肌兰尼碱受体的偶联功能 通道（RyRs）。RyR是位于细胞膜中的细胞内钙释放通道， 细胞内钙储存，在那里它们形成有序的阵列。在细胞刺激后，RyR组短暂开放， 并迅速向胞质溶胶中释放抽搐肌收缩所需的大量钙。的 这些钙释放事件的特征强烈表明，参与RyRs的工作， 同步，它们都在几毫秒内一起激活和停用。目前还不清楚 RyRV通信以同步它们在细胞中的门控。因此，很难理解 异常兴奋-收缩偶联的发生，如在各种肌肉疾病中发现的，包括那些 （恶性高热，中央核心疾病），其中编码RyR 1的基因突变已被发现。 鉴定 由于RyR是细胞内通道，因此电生理研究需要细胞细分、通道 分离并重建成人工脂质双层。几乎所有这些双层研究的报告都描述了 单个（个体）RyR 1或多个RyR的独立行为。只有A医生。马克斯实验室（马克思等 等人，1998; 2000）描述了如果 FK 506结合蛋白（FKBP）分子与通道相关。这一过程，新的领域 称之为“耦合门控”。尽管了解钙释放的重要性， 关于这种RyR 1间的通信，其他信息是已知的。在过去的几年里，PI发展了 方法和积累的初步数据，明确证明研究渠道的可行性 与他的双层系统结合。因此，本提案的目标是确定 用于耦合门控的RyR通道之间的通信。这项建议的具体目标是： 具体目标#1：定义RyR 1通道之间的通信机制。这一目标被细分为 在三个子目标中：A）定义ATP/Mg 2+在RyR 1配位中的作用; B）定义Ca 2+在RyR 1配位中的作用。 C）定义FKBP 12（钙稳定蛋白1）和其他辅助蛋白的作用。

The goal of this project is to understand the coupled function of skeletal muscle ryanodine receptor channels (RyRs). The RyRs are intracellular calcium release channels located in the membranes of intracellular calcium stores, where they form orderly arrays. After cell stimuli, groups of RyRs briefly open and rapidly release to the cytosol the bulk of calcium required for the twitch muscle contraction. The characteristics of these calcium release events strongly indicate that the participating RyRs work in synchrony and they all activate and deactivate together within few milliseconds. It is still unknown how RyRVs communicate for synchronizing their gating in cells. Consequently, it is difficult to understand the genesis of anomalous excitation-contraction coupling as found in various muscle diseases, including those (Malignant Hyperthermia, Central Core Disease) where mutations in the genes encoding RyR1 have been identified. As RyRs are intracellular channels, electrophysiological studies require cell subfractionation, channel isolation and reconstitution into artificial lipid bilayers. Nearly all reports from these bilayers studies describe a single (individual) RyR1 or independent behavior of multiple RyRs. Only Dr. A. Marks's laboratory (Marx et al, 1998; 2000) described neighboring RyRs (2-4 channels) that gated with synchronous coordination if FK506 binding protein (FKBP) molecules were associated with the channels. This process, new for the field of ion channels, was named "coupled gating". Despite its importance to understand calcium release, little else is known about this inter-RyR1 communication. During the last years, the PI has developed methodologies and accumulated preliminary data that clearly evidence the feasibility of studying channels coupling with his bilayer system. Consequently, the goal of this proposal is to define the mechanisms of communication between RyR channels for coupled gating. The specific aims of this proposal is: Specific Aim #1: Define the mechanisms of communication between RyR1 channels. This aim is subdivided in three sub-Aims: A) Define the role of ATP/Mg2+ in RyR1 coordination; B) Define the role of Ca2+ in coordinated gating; and C) Define the role of FKBP12 (Calstabilinl) and other ancillary proteins.