Structure and Function of Neuronal Calcium Binding Proteins (CaBPs)

神经元钙结合蛋白 (CaBP) 的结构和功能

• 批准号: 7825439
• 负责人: JAMES B AMES
• 金额: $ 22.29万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7825439
• 关键词: Affect; Affinity; Amino Acids; Binding; Brain; CabP1; Calcium; Calcium Channel; Calcium ion; Calcium-Binding Proteins; Calcium-Sensing Receptors; Cells; Critiques; Data; Defect; Endoplasmic Reticulum; Exhibits; Family; Figs - dietary; Goals; Inositol; Ion Channel; Kinetics; Ligand Binding; Ligand Binding Domain; Link; Measures; Membrane; Molecular Structure; Mutagenesis; N Domain; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Nuclear Magnetic Resonance; Nucleic Acid Regulatory Sequences; Pharmaceutical Preparations; Process; Protein Isoforms; Proteins; Regulation; Research; Resolution; Retina; Retinal; Signal Transduction; Site; Solutions; Spin Labels; Structure; Testing; Therapeutic; Therapeutic Agents; Work; Writing; base; design; inhibitor/antagonist; insight; mutant; neuron apoptosis; neuron loss; prevent; public health relevance; receptor; relating to nervous system; research study; sensor; small molecule

DESCRIPTION (provided by applicant): The overall objectives are to elucidate the molecular structure, function and target recognition of a new family of neuronal calcium-binding proteins (CaBPs) that modulate the activity of neuronal calcium channels and are linked to various retinal and neurodegenerative diseases. The CaBP1 isoform interacts specifically with the inositol 1, 4, 5-trisphosphate (InsP3) receptor that serves as an important calcium release channel on the endoplasmic reticulum membrane. Defects in the regulation of neuronal InsP3 receptors promote excessive Ca2+ release, causing an overload of cytosolic Ca2+ that eventually results in neuronal cell death. Inhibition of InsP3 receptor activity by an endogenous inhibitory protein like CaBP1 or therapeutic agents that structurally mimic this inhibition will promote channel closure, which may prevent Ca2+-induced neuronal apoptosis and therefore could be an attractive way of slowing down the process of neurodegeneration. The long term goal of this research will be to determine the atomic-level structural basis for the regulation of InsP3 receptors by calcium and CaBP1. The work is divided into three specific aims: The first aim is to determine the structures of CaBP1 in solution by nuclear magnetic resonance and elucidate the calcium-induced conformational changes and structural determinants that underlie target recognition. The second aim is to measure the energetics and kinetics of calcium and target binding to CaBP1 and to probe Ca2+-dependent contacts between CaBP1 and the InsP3 receptor to help identify all regulatory regions involved in Ca2+-sensitive channel gating. The third aim is to determine the atomic- resolution structures of CaBP1 bound to the functional suppressor and ligand-binding domains in the InsP3 receptor. The structures will help identify important amino acid residues in these proteins that may be targeted in the rationale design of calcium channel inhibitory drugs. PUBLIC HEALTH RELEVANCE: Calcium ion (Ca2+) in the cell is important for transmitting and regulating neural signals for normal brain function. The goal of our research is to understand how calcium sensor proteins in the brain and retina regulate the transport of cellular Ca2+ through ion channels during cell signaling.

描述(申请人提供)：总体目标是阐明一种新的神经元钙结合蛋白(CaBP)家族的分子结构、功能和靶点识别，该家族调节神经元钙通道的活动，并与各种视网膜和神经退行性疾病有关。CaBP1亚型与肌醇1，4，5-三磷酸(InsP3)受体特异性地相互作用，InsP3受体是内质网膜上重要的钙释放通道。神经元InsP3受体的调节缺陷促进了细胞内过量的钙释放，导致细胞内钙超载，最终导致神经细胞死亡。用CaBP1等内源性抑制蛋白或结构上模拟InsP3受体活性的治疗剂抑制InsP3受体活性将促进通道关闭，从而阻止钙离子诱导的神经元凋亡，因此可能是一种有吸引力的减缓神经退行性变过程的方法。这项研究的长期目标将是确定钙和CaBP1调节InsP3受体的原子水平结构基础。本工作分为三个具体目标：第一个目标是通过核磁共振确定CaBP1在溶液中的结构，并阐明钙诱导的构象变化和支持目标识别的结构决定因素。第二个目的是测量钙和靶与CaBP1结合的能量学和动力学，并探索CaBP1和InsP3受体之间的钙依赖联系，以帮助确定参与钙敏感通道门控的所有调节区。第三个目的是确定CaBP1与InsP3受体的功能抑制域和配体结合域结合的原子分辨结构。这些结构将有助于识别这些蛋白质中的重要氨基酸残基，这些氨基酸残基可能成为钙通道抑制药物的基本设计目标。与公众健康相关：细胞中的钙离子(Ca~(2+))对于传递和调节神经信号以维持正常的大脑功能非常重要。我们研究的目的是了解大脑和视网膜中的钙感受器蛋白如何在细胞信号传递过程中通过离子通道调节细胞内钙离子的运输。