Biased agonsim of CXCL12 stimulation of the atypical and classical receptors, ACKR3 and CXCR4

CXCL12 刺激非典型和经典受体 ACKR3 和 CXCR4 的偏向激动剂

• 批准号: 10347336
• 负责人: Christopher T Schafer
• 金额: $ 2.51万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-16 至 2022-07-06
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10347336
• 关键词: Affect; Affinity; Agonist; Amino Acids; Arrestins; Bar Codes; Binding; C-terminal; CXCL12 gene; CXCR4 Receptors; CXCR4 gene; Cardiovascular system; Cartoons; Clinical Trials; Collaborations; Complex; Coupled; Couples; Coupling; Crystallization; Development; Disease; Drug Targeting; Electron Microscopy; Future; G protein coupled receptor kinase; G-Protein-Coupled Receptors; GTP-Binding Proteins; Goals; Image; Immune system; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Lead; Ligands; Link; Malignant Neoplasms; Mediating; Membrane; Modification; Molecular Conformation; Mutagenesis; Mutate; Negative Staining; Neoplasm Metastasis; Output; Pattern; Pharmacology; Phosphorylation; Phosphorylation Site; Phosphotransferases; Play; Point Mutation; Protein Analysis; Protein Isoforms; Proteins; Research; Resolution; Role; Signal Pathway; Signal Transduction; Stimulus; Structure; System; Tail; Testing; Therapeutic; Translating; Universities; X-Ray Crystallography; antagonist; beta-arrestin; cancer cell; cell motility; chemokine; chemokine receptor; drug development; drug discovery; experimental study; improved; inhibitor; inorganic phosphate; insight; mutant; protein structure; receptor; receptor binding; recruit; response; scaffold; side effect; targeted treatment; tumor

Project Abstract CXCL12 stimulation of the chemokine receptors CXCR4 and ACKR3 drives cellular migration during development, immune system mobility, and inflammatory responses. The trio plays a major role in cancers where they promote metastasis and tumor proliferation. Thus, both receptors are promising targets for therapeutics, with ongoing clinical trials of compounds targeting CXCR4 and ACKR3 ligands in development. Despite the common agonist, CXCR4 and ACKR3 have decidedly different responses. While CXCR4 signals through both G proteins and β-arrestins like other classical G protein-coupled receptors (GPCRs), ACKR3 only couples with arrestins. . CXCR4 and ACKR3 are structurally alike and bind CXCL12 in a similar manner, yet the receptors appear to activate by different mechanisms. CXCR4 is extremely sensitive to changes to the chemokine interaction, with single-point mutations leading the high-affinity agonist to act as an antagonist. Conversely, ACKR3 is promiscuous, with nearly all ligands tested acting as agonists. How these differences translate into the biased signaling is an open question. I propose to investigate the how the CXCL12 signal is interpreted by these receptors by resolving how the ligand affects the receptor conformation and the secondary interactions with kinases and β-arrestins. The central hypothesis of this proposal is that these interactions will be different for the classical and atypical receptors and the results of the presented experiments will provide insights into receptor-level biased signaling. This hypothesis will be pursued by three specific aims. Aim 1: Identify the structural rearrangements of ACKR3 induced by CXCL12 binding by determining the high resolution crystal structure of the complex. The resulting structure will reveal the specific interactions through an atypical receptor that are induced by CXCL12 binding and structural basis of activation. Aim 2: Determine how CXCL12-activated ACKR3 is phosphorylated and interacts with β-arrestin. This aim will determine what kinases phosphorylate the ACKR3, where those phosphates are incorporated and how the pattern of modification alters β-arrestin interactions and signaling. Aim 3: Determine how β-arrestin interacts with CXCL12-stimulated CXCR4 by imaging the complex with electron microscopy and ultimately resolving the structure of the CXCL12:CXCR4:β-arrestin complex. Together, these studies will present an unparalleled view into how receptor-mediated biased agonism is manifested by classical and atypical GPCRs. Determining how these receptors respond the natural stimulus will ultimately facilitate future drug development.

项目摘要 CXCL12刺激趋化因子受体CXCR4和ACKR3驱动细胞迁移。 发育，免疫系统的活动性和炎症反应。三人在取消中起主要作用 它们促进转移和肿瘤增殖。那两个受体都是有希望的目标 治疗剂，正在进行的针对CXCR4和ACKR3配体发育中的化合物的临床试验。 尽管有共同的激动剂，但CXCR4和ACKR3的反应绝对不同。而CXCR4信号 通过G蛋白和β-arrestin，例如其他经典G蛋白偶联受体（GPCR），仅ACKR3 夫妻有逮捕。 。 CXCR4和ACKR3在结构上相似，并以类似的方式结合CXCL12 接收器似乎通过不同的机制激活。 CXCR4对变化非常敏感 趋化因子相互作用，单点突变导致高亲和力激动剂充当拮抗剂。 相反，ACKR3是混杂的，几乎所有配体都被测试充当激动剂。这些差异如何 转换为偏见的信号是一个悬而未决的问题。我建议研究CXCL12信号的方式 这些受体通过解决配体如何影响受体构象和次级来解释 与激酶和β-arrestin的相互作用。该提议的核心假设是这些相互作用将 对于经典和非典型接收器而言有所不同，并且提出的实验的结果将提供 对受体级别偏置信号传导的见解。该假设将由三个具体目标提出。目标1： 通过确定较高的 分辨率的晶体结构。最终的结构将通过 由CXCL12结合和激活的结构基础诱导的非典型接收器。目标2：确定 CXCL12激活的ACKR3如何被磷酸化并与β-arrestin相互作用。这个目标将决定什么 激酶磷酸化ACKR3，其中这些磷酸盐被掺入，以及如何 修改会改变β-arrestin的相互作用和信号传导。 AIM 3：确定β-arrestin如何与 通过用电子显微镜对复合物进行成像，并最终解决CXCL12刺激的CXCR4 CXCL12：CXCR4：β-arrestin复合物的结构。这些研究将共同​​提出无与伦比的观点 经典和非典型GPCR表现出受体介导的偏置激动剂的表现。确定如何 这些受体反应自然刺激最终将支持未来的药物开发。