Structural Basis of chemokine CXCL1 recognition with CXCR2 receptor

趋化因子 CXCL1 与 CXCR2 受体识别的结构基础

基本信息

批准号：
10218891
负责人：
Krishna Rajarathnam
金额：
$ 25.29万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-13 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10218891
关键词：
Acute Disease Address Affinity Automobile Driving Binding Binding Proteins Binding Sites Brain CCR5 gene CCR6 gene CXCL1 gene CXCR4 gene Cellular Assay Characteristics Charge Chronic Disease Clinical Communicable Diseases Complex Coupled Cryoelectron Microscopy Crystallization Data Disease Docking Functional disorder G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Grant Heart Human Hybrids Hydrophobicity IL8 gene IL8RB gene Infection Inflammatory Injury Interleukin-8B Receptor Knowledge Lung Measurement Measures Mediating Methods Molecular Molecular Conformation Motion N-terminal NMR Spectroscopy Nature Neutrophil Infiltration Nuclear Magnetic Resonance Organ Outcome Play Process Proteins Receptor Activation Research Proposals Role Sequence Analysis Signal Transduction Site Specificity Structural Models Structure Testing Therapeutic Tissues Variant base beta-arrestin chemokine chemokine receptor design dimer drug development extracellular flexibility insight molecular dynamics monomer mutant neutrophil public health relevance receptor response spatiotemporal tool trafficking

项目摘要

Chemokine CXCL1, and its receptor CXCR2, a class-A G protein-coupled receptor (GPCR), play a crucial role in directing blood neutrophils to sites of infection and injury. A dysregulation in CXCR2 activation results in host tissue damage and disease. CXCL1 binds CXCR2 at two distinct sites: N- terminal domain (Site-I, unique to chemokines) and a groove defined by the receptor extracellular loops/transmembrane helices (Site-II, shared with all class A receptors). The molecular basis by which chemokine binding two distinct sites determine CXCR2 activation is not known. Structures and sequence analyses reveal that chemokine and receptor residues that mediate binding are either unstructured or conformationally dynamic. We propose that CXCL1 binding at Site-I of CXCR2, the initial obligatory step, triggers structural and dynamic changes that are essential for Site-II interactions. We will test our hypothesis using a hybrid strategy that combines nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations. We will determine the structure and characterize the role of conformational dynamics of Site-I CXCL1-CXCR2 N-terminal domain complex using NMR spectroscopy (Aim 1). We will generate a structural model of CXCL1 bound to CXCR2 at the N-terminal domain by merging Site-I NMR structure and previously determined CXCR2 structure, and use extended MD simulations to describe how CXCL1 bound at Site-I engages the receptor at Site-II (Aim 2). We will characterize how CXCL1 Site-I and Site-II residues identified from Aims 1 and 2 mediate CXCR2 activation using cellular assays (Aim 3). These studies will provide critical insights into the molecular mechanisms underlying CXCR2 activation and will advance designing therapeutics that disrupt CXCR2 activation and alleviate disease.

趋化因子 CXCL1 及其受体 CXCR2（一种 A 类 G 蛋白偶联受体 (GPCR)）发挥着在引导血液中性粒细胞到达感染和损伤部位方面发挥着至关重要的作用。 CXCR2 失调激活会导致宿主组织损伤和疾病。 CXCL1 在两个不同的位点结合 CXCR2：N- 末端结构域（Site-I，趋化因子特有）和由细胞外受体定义的凹槽环/跨膜螺旋（位点 II，与所有 A 类受体共享）。分子基础为哪个趋化因子结合两个不同位点决定 CXCR2 激活尚不清楚。结构和序列分析表明介导结合的趋化因子和受体残基是非结构化或构象动态。我们建议 CXCL1 结合在 CXCR2 的位点 I，初始强制性步骤，触发对 Site-II 至关重要的结构和动态变化互动。我们将使用结合核磁的混合策略来检验我们的假设共振（NMR）光谱和分子动力学（MD）模拟。我们将确定位点 CXCL1-CXCR2 N 端的结构并表征其构象动力学的作用使用 NMR 光谱分析域复合物（目标 1）。我们将生成 CXCL1 的结构模型通过合并 Site-I NMR 结构和之前的结构，在 N 端结构域处与 CXCR2 结合确定了 CXCR2 结构，并使用扩展 MD 模拟来描述 CXCL1 如何在位点 I 与位点 II 的受体结合（目标 2）。我们将描述 CXCL1 Site-I 和 Site-II 如何表征使用细胞测定（目标 3）从目标 1 和 2 中鉴定出的残基介导 CXCR2 激活。这些研究将为 CXCR2 激活和潜在分子机制提供重要见解将推进破坏 CXCR2 激活并减轻疾病的疗法的设计。