Viral GPCR recognition of chemokines and engineered ligands

病毒 GPCR 识别趋化因子和工程配体

基本信息

批准号：
9298587
负责人：
Kenan Christopher GARCIA
金额：
$ 39.5万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-17 至 2021-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9298587
关键词：
Agonist Alpaca BLR1 gene Back Binding Biochemical Biological Models Biology CCR5 gene CX3CL1 gene CXCR4 Receptors CXCR4 gene Cell Surface Receptors Cells Cellular Tropism Chemicals Chemistry Clinical Collaborations Complementarity Determining Regions Complex Crystallization Crystallography Cytomegalovirus Distant Engineering Exhibits Family Fractalkine G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Genetic Glycoproteins Goals HIV HIV Envelope Protein gp120 HIV-1 Human Human Cell Line Immune Immune Evasion Immunity Infection Inflammation Knowledge Laboratories Libraries Ligands Link Mediating Methods Molecular Molecular Conformation Nature Oncogenic Orphan Pathogenesis Play Property Protein Engineering Proteins Protocols documentation Receptor Activation Receptor Signaling Reporting Resolution Role Signal Pathway Signal Transduction Signaling Protein Structural Protein Structure Structure-Activity Relationship Surface System Testing Therapeutic V3 Loop Viral Viral Pathogenesis Virulence Virus Yeasts base chemokine chemokine receptor combinatorial deep sequencing drug discovery env Gene Products experience extracellular feeding human disease immunoregulation nanobodies novel novel strategies novel therapeutics polypeptide protein complex protein structure receptor receptor structure function screening simulation small molecule structural biology

项目摘要

Abstract: Despite a great deal of progress in understanding the structure-function properties of G protein-coupled receptors (GPCR) that serve as receptors for small molecules, there remains a dearth of knowledge about GPCRs that engage protein ligands. There are several classes of GPCR that respond to protein ligands and it is unclear how the mechanisms of recognition and receptor activation relate to those of small molecule ligands. This is an important issue to clarify given that drug discovery efforts are focused almost exclusively on small molecule GPCR, yet many therapeutic opportunities exist for proteins that signal through GPCR. The largest class of proteins that use GPCR as signaling receptors are chemokines, which bind to and signal through a large family of chemokine GPCR. Chemokines are potent immune-modulators, play important roles in inflammation, during infection, and their activities have been implicated in many human diseases. Some viruses have hijacked and `repurposed' chemokine GPCR for immune evasion and to enhance virulence. Viral GPCR can mediate oncogenic transformation and contribute to an array of clinical problems. The P.I.'s laboratory recently made an advance in our understanding of chemokine GPCR structure, by determining the crystal structure of a virally encoded (Human cytomegalovirus - HCMV) GPCR, US28, bound to the human chemokine CX3CL1 (Fractalkine). US28 possesses many interesting functional properties that make it an excellent system to probe mechanisms and structure-function properties of chemokine GPCRs as a whole. For example, US28 is constitutively active, which is important for HCMV pathogenesis, and is the only chemokine GPCR to engage both CXC and CC classes of chemokines. US28 also serves as an entry co-receptor for human immunodeficiency virus type 1 (HIV-1) gp120, which typically uses the human chemokine GPCR CXCR4 and CCR5 as entry receptors. US28 has particularly favorable biochemical properties compared to other chemokine receptors that make it an outstanding system for structure- function analysis. We have robust biochemical and structural access to US28, having developed a high level expression protocol, isolated Alpaca nanobodies, and have the ability to crystallize different complexes of US28 with chemokines and gp120. Here we propose to merge structural efforts on US28- chemokine, US28-gp120, and US28 G-protein complexes, with combinatorial biology to engineer novel chemokine and protein-based surrogate ligands for US28. These studies will collectively probe the structural basis US28-chemokine recognition and signaling properties, elucidate how gp120 HIV engages chemokine GPCR as co-receptors, and explore new therapeutic opportunities for engineering chemokine GPCR ligands with biased signaling properties.

抽象的：尽管在理解 G 蛋白偶联的结构功能特性方面取得了很大进展作为小分子受体的受体（GPCR），目前仍然缺乏知识关于与蛋白质配体结合的 GPCR。有几类 GPCR 对蛋白质有反应配体，目前尚不清楚识别和受体激活机制与配体的机制有何关系小分子配体。鉴于药物发现工作的重点是，这是一个需要澄清的重要问题几乎完全针对小分子 GPCR，但蛋白质存在许多治疗机会通过 GPCR 发出信号。使用 GPCR 作为信号受体的最大一类蛋白质是趋化因子，与趋化因子 GPCR 大家族结合并通过其发出信号。趋化因子是有效的免疫调节剂，在炎症、感染过程及其活性中发挥重要作用与许多人类疾病有关。一些病毒已被劫持并“改变用途” 趋化因子 GPCR 用于免疫逃避和增强毒力。病毒GPCR可介导致癌转化并导致一系列临床问题。 P.I.的实验室最近做了一个通过确定a的晶体结构，我们对趋化因子GPCR结构的理解取得了进展病毒编码（人类巨细胞病毒 - HCMV）GPCR，US28，与人类趋化因子结合 CX3CL1（分形）。 US28 拥有许多有趣的功能特性，使其成为出色的系统来探索趋化因子 GPCR 的整体机制和结构功能特性。为了例如，US28 具有组成型活性，这对于 HCMV 发病机制很重要，并且是唯一的趋化因子 GPCR 结合 CXC 和 CC 类趋化因子。 US28也作为入口人类免疫缺陷病毒 1 型 (HIV-1) gp120 的共同受体，通常使用人类趋化因子 GPCR CXCR4 和 CCR5 作为进入受体。 US28具有特别有利的生化与其他趋化因子受体相比，其特性使其成为结构- 功能分析。我们拥有进入 US28 的强大生化和结构通道，开发了高水平表达方案，分离羊驼纳米抗体，并具有结晶不同的能力 US28 与趋化因子和 gp120 的复合物。在此，我们建议合并 US28- 的结构性努力趋化因子、US28-gp120 和 US28 G 蛋白复合物，通过组合生物学设计新颖 US28 的趋化因子和基于蛋白质的替代配体。这些研究将共同探讨结构基础US28-趋化因子识别和信号传导特性，阐明gp120 HIV如何利用趋化因子GPCR作为共受体，探索新的工程治疗机会具有偏向信号传导特性的趋化因子 GPCR 配体。