Fine-Tuning of GPCR-Chemokine Interactions. Design and Identification of Chemokine Analogues as Receptor Agonists, Biased Agonists, and Antagonists.
Fine-Tuning of GPCR-Chemokine Interactions. Design and Identification of Chemokine Analogues as Receptor Agonists, Biased Agonists, and Antagonists.
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GPCR-趋化因子相互作用的微调。
DOI：
10.1021/acs.biochem.8b01266
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发表时间：
2019
期刊：
影响因子：
2.9
通讯作者：
Navarro,Javier
中科院分区：
文献类型：
--
作者：
Navarro,Javier
趋化因子通过引导白细胞的迁移在免疫防御中发挥重要作用，并且作为肿瘤发生和转移的关键促进剂。本研究探讨了识别和激活两个同源趋化因子受体，CXCR 1和CXCR 2，使用CXCL 8类似物与保守的Glu 4Leu 5Arg 6（ELR）三联体中的残基取代的分子机制。CXCL 8类似物与CXCR 1结合的分析与CXCR 1信号识别的双位点模型一致，而CXCL 8类似物与CXCR 2结合的分析支持CXCR 2信号识别的单位点模型。CXCL 8-Arg 6 His类似物刺激表达CXCR 1的细胞中的钙释放、ERK 1/2的磷酸化和趋化性。然而，CXCL 8-Arg 6 His不能刺激表达CXCR 2的细胞中的钙释放和趋化性，尽管它刺激ERK 1/2的磷酸化，表明CXCL 8-Arg 6 His作为经典的CXCR 2偏向激动剂起作用。CXCL 8-Glu 4AlaLeu 5AlaArg 6 His类似物在表达CXCR 1和CXCR 2的细胞中无活性。这些发现表明CXCL 8中的Glu 4Leu 5基序对于CXCR 1和CXCR 2的活化是必需的。重要的是，CXCL 8-Glu 4AlaLeu 5AlaArg 6 His特异性阻断表达CXCR 1的细胞的钙释放和趋化性，但不阻断表达CXCR 2的细胞的钙释放和趋化性。CXCL 8-Glu 4AlaLeu 5AlaArg 6 His是第一个被鉴定的CXCR 1特异性拮抗剂。CXCL 8-ELR 6 H与CXCR 1的结合在负责钙释放的受体活化结构域处产生了Zn 2+配位位点，因为ZnCl 2特异性地阻断CXCL 8-Arg 6 His诱导的钙释放而不影响CXCL 8诱导的钙释放。这项工作为进一步探索趋化因子受体的激活机制提供了基础，并将有助于设计下一代CXCR 1和CXCR 2的调节剂。
Chemokines play important roles in immune defense by directing migration of leukocytes and serve as key promoters of tumorigenesis and metastasis. This study explores the molecular mechanisms of recognition and activation of two homologous chemokine receptors, CXCR1 and CXCR2, using CXCL8 analogues with residue substitutions in the conserved Glu4Leu5Arg6 (ELR) triad. Analysis of the binding of CXCL8 analogues to CXCR1 is consistent with the two-site model for signal recognition of CXCR1, whereas analysis of the binding of CXCL8 analogues to CXCR2 supported a single-site model for signal recognition of CXCR2. The CXCL8-Arg6His analogue stimulated calcium release, phosphorylation of ERK1/2, and chemotaxis in cells expressing CXCR1. However, CXCL8-Arg6His failed to stimulate calcium release and chemotaxis in cells expressing CXCR2, although it stimulated phosphorylation of ERK1/2, indicating that CXCL8-Arg6His operated as a classical CXCR2 biased agonist. The CXCL8-Glu4AlaLeu5AlaArg6His analogue was inactive in cells expressing CXCR1 and CXCR2. These findings suggest that the Glu4Leu5 motif in CXCL8 is essential for activation of CXCR1 and CXCR2. Importantly, CXCL8-Glu4AlaLeu5AlaArg6His blocked specifically the calcium release and chemotaxis of cells expressing CXCR1 but not of cells expressing CXCR2. CXCL8-Glu4AlaLeu5AlaArg6His was identified as the first specific CXCR1 antagonist. The binding of CXCL8-ELR6H to CXCR1 created a Zn2+coordination site at the receptor activation domain responsible for calcium release, as ZnCl2specifically blocked CXCL8-Arg6His-induced calcium release without affecting CXCL8-induced calcium release. This work provides the basis for further exploration of the activation mechanisms of chemokine receptors and will assist in the design of the next generation of modulators of CXCR1 and CXCR2.