Heterodimerization and cross-desensitization between the μ-opioid receptor and the chemokine CCR5 receptor
Heterodimerization and cross-desensitization between the μ-opioid receptor and the chemokine CCR5 receptor
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DOI：
10.1016/j.ejphar.2003.10.033
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发表时间：
2004-01-12
影响因子：
5
通讯作者：
Liu-Chen, LY
中科院分区：
文献类型：
--
作者：
Chen, CG;Li, J;Liu-Chen, LY
μ-阿片受体激动剂和CC趋化因子之间的交叉脱敏显示发生在免疫细胞和中枢神经系统中。然而，这些细胞不允许在细胞水平上检查潜在的机制，由于受体的低水平和混合群体。在这项研究中，我们研究了在中国仓鼠卵巢（CHO）细胞中共表达的μ阿片和趋化因子CCR 5受体之间的交叉脱敏可能的相互作用和生化机制。在表达两种受体的细胞中，血凝素（HA）标记的μ-阿片受体与FLAG（Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys）标记的趋化因子受体CCR 5共免疫沉淀，但在用两种受体之一转染的细胞混合物中没有，表明两种受体形成异源二聚体。用β-阿片受体激动剂DAMGO（[D-Ala（2），N-Me-Phe（4），Gly（5）-ol]-脑啡肽），趋化因子RANTES（调节活化，正常T细胞表达和分泌）（CCL 5）或两者治疗，不影响免疫共沉淀的水平。DAMGO和RANTES（CCL 5）诱导共表达两种受体的CHO细胞的趋化性，与DAMGO或RANTES（CCL 5）预孵育可显著抑制另一种受体引起的趋化性。DAMGO预处理增强了趋化因子CCR 5受体的磷酸化，降低了RANTES（CCL 5）促进的[S-35] GTP γ S结合。相反，RANTES（CCL 5）预孵育略微增加μ阿片受体的磷酸化，并显著降低DAMGO诱导的[S-35] GTP γ S结合。这些结果表明，任一受体的活化影响了另一受体的G蛋白偶联，可能是由于受体的磷酸化增强。两种受体之间的异源二聚化可能有助于观察到的交叉脱敏。(C)2003 Elsevier B. V.保留所有权利。
Cross-desensitization between mu-opioid receptor agonists and CC chemokines was shown to occur in immune cells and in the central nervous system. However, these cells do not permit examination of potential mechanisms at cellular levels due to low levels and mixed populations of receptors. In this study, we investigated possible interactions and biochemical mechanisms of cross-desensitization between the mu-opioid and chemokine CCR5 receptors coexpressed in Chinese hamster ovary (CHO) cells. Hemagglutinin (HA)-tagged mu-opioid receptor coimmunoprecipitated with FLAG (Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys)-tagged chemokine receptor CCR5 in cells expressing the two receptors, but not in a mixture of cells transfected with one of the two receptors, indicating that the two receptors form heterodimers. Treatment with the eta-opioid receptor agonist DAMGO ([D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin), the chemokine RANTES (Regulated on Activation, Normal T cell-Expressed and -Secreted) (CCL5), or both, did not affect the level of coimmunoprecipitation. DAMGO and RANTES (CCL5) induced chemotaxis in CHO cells coexpressing both receptors, and preincubation with either DAMGO or RANTES (CCL5) profoundly inhibited chemotaxis caused by the other. DAMGO pretreatment enhanced phosphorylation of the chemokine CCR5 receptor and reduced RANTES (CCL5)-promoted [S-35]GTPgammaS binding. Conversely, RANTES (CCL5) preincubation slightly increased phosphorylation of the mu-opioid receptor and significantly reduced DAMGO-induced [S-35]GTPgammaS binding. These results indicate that activation of either receptor affected G protein coupling of the other, likely due to enhanced phosphorylation of the receptor. Heterodimerization between the two receptors may contribute to the observed cross-desensitization. (C) 2003 Elsevier B.V. All rights reserved.