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: 8074898
• 负责人: JAMES B AMES
• 金额: $ 22.03万
• 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 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8074898
• 关键词: Affect; Affinity; Amino Acids; Binding; Brain; Calcium; Calcium Channel; Calcium ion; Calcium-Binding Proteins; Calcium-Sensing Receptors; Cells; Data; Defect; Endoplasmic Reticulum; Exhibits; Family; Goals; Health; 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 Diseases; Signal Transduction; Site; Solutions; Spin Labels; Structure; Testing; Therapeutic; Therapeutic Agents; Work; Writing; base; design; inhibitor/antagonist; insight; mutant; neuron apoptosis; neuron loss; prevent; 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（由申请人提供）：总体目标是阐明神经元钙结合蛋白（CaBP）新家族的分子结构、功能和靶标识别，该蛋白调节神经元钙通道的活性并与各种视网膜和神经退行性疾病相关。 CaBP1 同工型与肌醇 1,4,5-三磷酸 (InsP3) 受体特异性相互作用，后者是内质网膜上重要的钙释放通道。神经元 InsP3 受体调节缺陷会促进 Ca2+ 过度释放，导致胞质 Ca2+ 超载，最终导致神经元细胞死亡。通过 CaBP1 等内源性抑制蛋白或结构上模拟这种抑制的治疗剂抑制 InsP3 受体活性将促进通道闭合，这可能会阻止 Ca2+ 诱导的神经元凋亡，因此可能是减缓神经变性过程的一种有吸引力的方法。这项研究的长期目标是确定钙和 CaBP1 调节 InsP3 受体的原子水平结构基础。这项工作分为三个具体目标：第一个目标是通过核磁共振确定溶液中 CaBP1 的结构，并阐明钙诱导的构象变化和目标识别基础的结构决定因素。第二个目标是测量钙和靶标与 CaBP1 结合的能量学和动力学，并探测 CaBP1 和 InsP3 受体之间的 Ca2+ 依赖性接触，以帮助识别参与 Ca2+ 敏感通道门控的所有调节区域。第三个目标是确定 CaBP1 与 InsP3 受体中的功能抑制子和配体结合域结合的原子分辨率结构。这些结构将有助于识别这些蛋白质中的重要氨基酸残基，这些残基可能是钙通道抑制药物的基本原理设计的目标。公共健康相关性：细胞中的钙离子 (Ca2+) 对于传输和调节正常大脑功能的神经信号非常重要。我们研究的目的是了解大脑和视网膜中的钙传感器蛋白如何在细胞信号传导过程中通过离子通道调节细胞 Ca2+ 的运输。