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: 7564748
• 负责人: JAMES B AMES
• 金额: $ 22.55万
• 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/7564748
• 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（由申请人提供）：总体目标是阐明新的神经元结合蛋白（CABP）的分子结构，功能和目标识别，该蛋白（CABP）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有关。 CABP1同工型与肌醇1、4、5-三磷酸（INSP3）受体特别相互作用，该受体是内质网膜上重要的钙释放通道。神经元INSP3受体调节的缺陷会促进过多的Ca2+释放，从而导致胞质Ca2+过载，最终导致神经元细胞死亡。内源性抑制蛋白（如CABP1）或结构模仿该抑制作用的治疗剂（例如CAC2+诱导的神经元凋亡，抑制INSP3受体活性）抑制了INSP3受体活性，因此可能是降低神经变性过程的有吸引力的方法。这项研究的长期目标是确定钙和CABP1调节INSP3受体的原子级结构基础。该工作分为三个特定的目的：第一个目的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基于目标识别的结构决定因素。第二个目的是测量钙和靶标与CABP1的能量和动力学，并探测CABP1和INSP3受体之间的Ca2+依赖性接触，以帮助识别所有涉及CA2+敏感通道传输的调节区域。第三个目的是确定与INSP3受体中的功能抑制剂和配体结合域结合的CABP1的原子分辨率结构。这些结构将有助于鉴定这些蛋白质中重要的氨基酸残基，这些氨基酸残基可能是针对钙通道抑制性药物的基本原理设计的。公共卫生相关性：细胞中的钙离子（Ca2+）对于传输和调节正常脑功能的神经信号很重要。我们研究的目的是了解细胞信号过程中细胞Ca2+通过离子通道的传递如何调节细胞CA2+的转运。