Molecular mechanisms and regulation of the calcium pump in the heart

心脏钙泵的分子机制和调节

• 批准号: 9152400
• 负责人: Lennane Michel Espinoza-Fonseca
• 金额: $ 28.64万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-25 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9152400
• 关键词: Address; Algorithms; Back; Binding; Biophysics; Ca(2+)-Transporting ATPase; Calcium; Cardiac; Cardiac Myocytes; Cells; Collaborations; Communication; Complex; Computer Assisted; Computer Simulation; Coupled; Crystallography; Data; Detection; Diastole; Docking; Functional disorder; Goals; Health; Heart; Heart failure; Human; Ions; Kinetics; Libraries; Life; Ligands; Lipid Bilayers; Maps; Measures; Mediating; Membrane Proteins; Methods; Modeling; Molecular; Morbidity - disease rate; Pathway interactions; Phosphorylation; Physiological; Play; Protein Isoforms; Pump; Regulation; Resolution; Role; Running; SERCA2a; Sarcoplasmic Reticulum; Spectrum Analysis; Structural Models; Structure; Testing; Therapeutic; Time; United States; Water; Work; base; computer studies; design; drug discovery; feeding; flexibility; frontier; high throughput screening; molecular dynamics; mortality; phospholamban; research study; response; simulation; skeletal; small molecule; spatiotemporal; virtual

Project Summary The long-term goal of this project is to elucidate the molecular mechanisms and regulation of the calcium pump (sarcoplasmic reticulum Ca2+-ATPase, SERCA) in the heart. SERCA clears cytosolic Ca2+ in cardiomyocytes, thus playing a central role in Ca2+ regulation in the heart. SERCA is regulated by phospholamban (PLB), a 52-residue phosphorylation-regulated membrane protein that inhibits the activity of the pump. A key molecular dysfunction in heart failure (HF) involves impaired Ca2+ transport during diastole, usually associated with insufficient SERCA expression and unaltered PLB levels, thus yielding lower SERCA activity due to PLB inhibition. Therefore, there is an urgent need for time-resolved, atomistic characterization of SERCA activation and SERCA-PLB regulation to understand the molecular basis of Ca2+ dysregulation, and to design appropriate approaches to HF. These mechanisms are complex, requiring structural changes and interdomain allosteric communication pathways that are difficult to determine experimentally. Since complete experimental characterization of these changes is likely to remain an intractable problem, we propose to use molecular simulations as a complementary approach. The central hypothesis of this project is that molecular simulations at appropriate spatiotemporal scales are uniquely suited to provide a time-resolved detection of SERCA mechanisms and regulation at a level of resolution currently inaccessible through experiments alone. The high-resolution mechanistic information from these studies can be directly used for computer-aided discovery of hits that activate SERCA through specifically targeting the SERCA-PLB interaction. To verify and consolidate these hypotheses, we have developed a robust battery of computational biophysics and virtual high-throughput screening approaches to SERCA and SERCA-PLB. Three Specific Aims will be pursued: (1) Map ligand-induced structural changes associated with SERCA activation. (2) Determine the molecular mechanisms for PLB regulation of SERCA. (3) Perform a structure-based search of hits that activate SERCA. For this project, we focus on skeletal SERCA1a because crystal structures have been obtained only for this isoform, but the structural results from our simulations are directly applicable to cardiac SERCA2a because there are no significant differences in the kinetics and function of both isoforms, including regulation by PLB. The simulation work will be closely coupled to experimental studies through collaborations; the combination of structural and functional data will provide the experimental tests necessary to verify our simulations and refine our structural models. Activation of SERCA is a widely pursued therapeutic goal in heart failure, and this project has great potential for pushing important frontiers in our understanding of SERCA function and regulation, ultimately enabling a more rational approach to address a critical problem in human health.

项目摘要 该项目的长期目标是阐明细胞凋亡的分子机制和调控。 钙泵（肌浆网Ca 2 +-ATP酶，SERCA）。SERCA清除细胞内Ca 2+， 心肌细胞，从而在心脏中的Ca 2+调节中发挥核心作用。SERCA由以下机构监管： 受磷蛋白（PLB），一种52个残基磷酸化调节的膜蛋白，可抑制 泵。心力衰竭（HF）中的一个关键分子功能障碍涉及在心力衰竭期间受损的Ca 2+转运， 通常与SERCA表达不足和PLB水平不变相关，因此产生较低的SERCA 活性由于PLB抑制。因此，迫切需要时间分辨的，原子的表征， SERCA激活和SERCA-PLB调节，以了解Ca 2+失调的分子基础， 设计适当的HF方法。这些机制很复杂，需要进行结构改革， 结构域间变构通讯途径难以通过实验确定。自完成 这些变化的实验表征可能仍然是一个棘手的问题，我们建议使用 分子模拟作为一种补充方法。这个项目的核心假设是， 适当时空尺度的模拟非常适合提供时间分辨的检测 目前仅通过实验无法达到的分辨率水平的SERCA机制和调节。 从这些研究中获得的高分辨率机理信息可直接用于计算机辅助 发现通过特异性靶向SERCA-PLB相互作用激活SERCA的命中。验证和 巩固这些假设，我们已经开发了一个强大的计算生物物理和虚拟电池 SERCA和SERCA-PLB的高通量筛选方法。将追求三个具体目标：（1） 图配体诱导的结构变化与SERCA激活。(2)测定分子 PLB调节SERCA的机制。(3)对激活SERCA的命中进行基于结构的搜索。 对于这个项目，我们专注于骨骼SERCA 1a，因为晶体结构已经获得了只有这个 同种型，但我们模拟的结构结果直接适用于心脏SERCA 2a，因为 两种亚型的动力学和功能（包括PLB的调节）没有显著差异。 模拟工作将通过合作与实验研究紧密结合; 结构和功能数据将提供必要的实验测试，以验证我们的模拟和完善 我们的结构模型。SERCA的激活是心力衰竭中广泛追求的治疗目标，并且这一点是值得注意的。 该项目具有推动我们理解SERCA功能的重要前沿的巨大潜力， 监管，最终能够采取更合理的方法来解决人类健康的关键问题。