Elementary Events of Intracellular Calcium Signaling

细胞内钙信号传导的基本事件

• 批准号: 8337322
• 负责人: IAN PARKER
• 金额: $ 48.22万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8337322
• 关键词: Address; Alzheimer' s Disease; Amyloid; Architecture; Biophotonics; Calcium; Calcium Oscillations; Calcium Signaling; Cell Death; Cell membrane; Cell physiology; Cells; Cessation of life; Complex; Computer software; Custom; Cytosol; Data; Detection; Diffusion; Disease; Dyes; Endoplasmic Reticulum; Event; Extracellular Fluid; Feedback; Gated Ion Channel; Generations; Goals; Heart failure; Image; Image Analysis; Imagery; Imaging Techniques; Imaging technology; Individual; Inositol; Ion Channel Gating; Ions; Kinetics; Label; Lasers; Lead; Life; Maps; Mediating; Membrane; Microscopy; Monitor; Movement; Noise; Optics; Pathogenesis; Pathway interactions; Pattern; Peptides; Photobleaching; Physiological; Plasma; Play; Population; Predisposition; Prions; Process; Property; Proteins; Receptor Signaling; Recruitment Activity; Regulation; Resolution; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Site; Spatial Distribution; Specificity; Spottings; Synaptic Transmission; Techniques; Technology; Time; Writing; amyloid peptide; base; brain cell; cell motility; cell type; improved; millisecond; monomer; nano; nanometer; neuronal cell body; novel; optical imaging; photolysis; polyglutamine; receptor; release of sequestered calcium ion into cytoplasm; second messenger; single molecule; spatiotemporal; stoichiometry; technique development; tool

DESCRIPTION (provided by applicant): The entry of Ca2+ ions into the cytosol from the extracellular fluid and from endoplasmic reticulum (ER) stores is used as a signaling mechanism by virtually all cell types to regulate functions as diverse as electrical excitability, secretion, proliferation and cell death. Improved optical technology now enables visualization of a hierarchy of Ca2+ signaling events, ranging from openings of single-channel Ca2+-permeable channels ('fundamental' events), concerted openings of clustered channels ('elementary' events) and propagating Ca2+ waves. The localized free [Ca2+] elevations arising through individual and clustered channels serve autonomous signaling functions, and their activity may further be coordinated through Ca2+ diffusion and Ca2+-induced Ca2+ release to propagate global cellular Ca2+ waves. Fundamental and elementary events thus form hierarchical building blocks underlying the complex spatiotemporal Ca2+ signals that permit graded and selective regulation of cell functions. Elucidation of their generation, interaction and functional consequences is, therefore, pivotal to understand the physiological functioning of the ubiquitous Ca2+ messenger pathway and its involvement in disease. Our overall goal is to elucidate, at the single-channel level, how cells generate the hierarchy of Ca2+ signals and how disruptions in Ca2+ signaling may be involved in disease pathogenesis. We focus on physiological Ca2+ signals generated by the ubiquitous inositol trisphosphate second messenger pathway, and on the pathogenic Ca2+-permeable pores formed by amyloid oligomers implicated in Alzheimer's disease. By utilizing novel biophotonic tools that now enable the optical imaging of calcium flux through individual channels and the localization and tracking of channel proteins with nanometer precision we aim to: (i) Further refine optical and analytical techniques for simultaneously monitoring Ca2+ flux through hundreds of individual channels in the plasma membrane and ER of intact cells. (ii) Elucidate how the activity of individual IP3 receptors (IP3R) at a release site is orchestrated to generate elementary Ca2+ puffs. (iii) Employ superresolution imaging techniques to determine the nanoscopic spatial distribution of IP3R, and how this impacts their functioning. (iv) Simultaneously monitor Ca2+ flux and peptide stoichiometry of individual amyloid pores to study fundamental mechanisms of membrane incorporation, channel gating and ion permeation.

描述（由申请人提供）：Ca2+离子从细胞外液和内质网（ER）库进入细胞质，几乎被所有细胞类型用作信号传导机制，以调节电兴奋性、分泌、增殖和细胞死亡等多种功能。改进的光学技术现在可以实现 Ca2+ 信号事件层次结构的可视化，包括单通道 Ca2+ 渗透通道的打开（“基本”事件）、集群通道的协同打开（“基本”事件）和传播 Ca2+ 波。通过单个和集群通道产生的局部游离 [Ca2+] 升高具有自主信号传导功能，并且它们的活动可以通过 Ca2+ 扩散和 Ca2+ 诱导的 Ca2+ 释放进一步协调，以传播全局细胞 Ca2+ 波。因此，基本事件和基本事件形成了复杂时空 Ca2+ 信号的分层构建块，允许细胞功能的分级和选择性调节。因此，阐明它们的产生、相互作用和功能后果对于理解普遍存在的 Ca2+ 信使途径的生理功能及其与疾病的参与至关重要。我们的总体目标是在单通道水平上阐明细胞如何产生 Ca2+ 信号的层次结构以及 Ca2+ 信号传导的破坏如何参与疾病发病机制。我们重点关注普遍存在的肌醇三磷酸第二信使途径产生的生理 Ca2+ 信号，以及与阿尔茨海默病有关的淀粉样蛋白寡聚体形成的致病性 Ca2+ 渗透性孔。通过利用新型生物光子工具，现在可以对通过单个通道的钙通量进行光学成像，并以纳米精度定位和跟踪通道蛋白，我们的目标是：（i）进一步完善光学和分析技术，以同时监测通过完整细胞质膜和内质网中数百个单个通道的 Ca2+ 通量。 (ii) 阐明如何协调释放位点的单个 IP3 受体 (IP3R) 的活性以产生基本 Ca2+ 泡。 (iii) 采用超分辨率成像技术来确定 IP3R 的纳米级空间分布，以及这如何影响其功能。 (iv) 同时监测单个淀粉样蛋白孔的 Ca2+ 通量和肽化学计量，以研究膜掺入、通道门控和离子渗透的基本机制。