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

基本信息

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
项目类别：
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

项目摘要

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、免疫系统流动性和炎症反应这三者在癌症中发挥着重要作用。因此，这两种受体都是有希望的靶点。疗法，目前正在开发靶向化合物 CXCR4 和 ACKR3 配体的临床试验。尽管 CXCR4 和 ACKR3 是共同的激动剂，但 CXCR4 发出的信号却截然不同。与其他经典 G 蛋白偶联受体 (GPCR) 一样，通过 G 蛋白和 β-抑制蛋白，仅 ACKR3 CXCR4 和 ACKR3 的配对结构相似，并且以相似的方式结合 CXCL12。 CXCR4 受体似乎通过不同的机制激活，对 CXCR4 的变化极其敏感。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。离线时，ACKR3 是混杂的，几乎所有测试的配体都充当激动剂。转化为有偏信号是一个悬而未决的问题，我建议研究 CXCL12 信号是如何产生的。这些受体通过解决配体如何影响受体构象和次级构象来解释与激酶和 β-抑制蛋白的相互作用该提议的中心假设是这些相互作用将对于经典和非典型受体来说是不同的，并且所提出的实验的结果将提供对受体水平偏向信号传导的深入了解将通过三个具体目标来实现：通过确定 CXCL12 结合诱导的 ACKR3 的高结构重排复合物的分辨率晶体结构所得到的结构将通过以下方式揭示特定的相互作用。 CXCL12 结合诱导的非典型受体和激活的结构基础。 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，这些磷酸盐在其中掺入，以及磷酸化的模式如何修饰改变 β-arrestin 相互作用和信号传导目标 3：确定 β-arrestin 如何相互作用。 CXCL12 刺激 CXCR4，通过电子显微镜对复合物进行成像，最终解决了 CXCL12:CXCR4:β-arrestin 复合物的结构，这些研究将呈现出无与伦比的观点。研究经典和非典型 GPCR 如何表现受体介导的偏向激动作用。这些受体对自然刺激的反应将最终促进未来的药物开发。