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：
10488181
负责人：
Krishna Rajarathnam
金额：
$ 20万
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 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10488181
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是A类蛋白偶联受体（GPCR），播放A 在将血液中性粒细胞引导到感染和损伤部位中的至关重要作用。 CXCR2中的失调激活导致宿主组织损伤和疾病。 CXCL1在两个不同位点结合CXCR2：n- 末端结构域（IS-I，趋化因子独有）和受体外细胞定义的凹槽循环/跨膜螺旋（IS-II，与所有A类受体共享）。分子基础哪种趋化因子结合两个不同的位点确定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。我们提出CXCL1在CXCR2的IT-I处结合，最初的强制性步骤，触发对site-II必不可少的结构和动态变化互动。我们将使用结合核磁力的混合策略来检验假设共振（NMR）光谱和分子动力学（MD）模拟。我们将确定结构并表征位点-I CXCL1-CXCR2 N末端的构象动力学的作用使用NMR光谱法（AIM 1）。我们将生成CXCL1的结构模型通过合并位点-I NMR结构和以前的结构与N末端结构域的CXCR2结合确定CXCR2结构，并使用扩展的MD模拟来描述CXCL1如何结合 SITE-I与II II的受体接合（AIM 2）。我们将表征CXCL1 SITE-I和site-II如何从AIM 1和2鉴定出的残基使用细胞测定法介导CXCR2激活（AIM 3）。这些研究将为CXCR2激活和将推进设计破坏CXCR2激活并减轻疾病的治疗剂。