Heterodimerization of human orexin receptor 1 and kappa opioid receptor promotes protein kinase A/cAMP-response element binding protein signaling via a Gαs-mediated mechanism
Heterodimerization of human orexin receptor 1 and kappa opioid receptor promotes protein kinase A/cAMP-response element binding protein signaling via a Gαs-mediated mechanism
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DOI：
10.1016/j.cellsig.2015.03.027
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发表时间：
2015-07-01
影响因子：
4.8
通讯作者：
Bai, Bo
中科院分区：
文献类型：
--
作者：
Chen, Jing;Zhang, Rumin;Bai, Bo
食欲素和强啡肽在下丘脑神经元的相同突触囊泡中共表达，并在可卡因自我给药、脑刺激奖励和腹侧被盖区（VTA）的冲动性中发挥相反的作用，其中多巴胺神经元表达OX 1 R和KORs。然而，共释放肽和两种受体如何共同微调其信号传导和生理/行为效应的详细机制仍不清楚。在这里，我们探索OX 1 R和KOR之间的异二聚体化的可能性，并揭示新的信号转导机制。首先，我们通过单细胞PCR证实了OX 1 R和KOR在大鼠海马神经元中的共表达。此外，OX 1 R和KOR之间的异源二聚化，使用生物发光和荧光共振能量转移（BRET和FRET）检查。我们的数据显示，人OX 1 R和KOR异源二聚体，这种异源二聚体与G α结合，导致蛋白激酶A（PICA）信号通路活性增加，包括细胞内cAMP水平和cAMP反应元件（CRE）荧光素酶报告基因活性上调，导致cAMP反应元件结合蛋白（CREB）磷酸化增加。这些结果支持OX 1 R和KOR异源二聚化可能具有抗抑郁作用的观点。(C)2015 Elsevier Inc. All rights reserved.
Orexin and dynorphin are co-expressed in the same synaptic vesicles of hypothalamic neurons and play opposing roles in cocaine self-administration, brain stimulation reward, and impulsivity in ventral tegmental area (VTA), where dopamine neurons express both OX1R and KORs. However, detailed mechanisms of how the coreleased peptides and both receptors fine-tune their signalings and physiological/behavioral effects together remain unclear. Here we explore the possibility of heterodimerization between OX1R and KOR and reveal novel signal transduction mechanisms. First, we demonstrated co-expression of OX1R and KOR in rat hippocampal neurons by single-cell PCR. Furthermore, heterodimerization between OX1R and KOR was examined using bioluminescence and fluorescence resonance energy transfer (BRET and FRET). Our data revealed that human OX1R and KOR heterodimerize, and this heterodimer associates with G alpha s, leading to increased protein kinase A (PICA) signaling pathway activity, including upregulation of intracellular cAMP levels and cAMP-response element (CRE) luciferase reporter activity, resulting in increased cAMP-response element binding protein (CREB) phosphorylation. These-results support the view that OX1R and KOR heterodimerization might have an antidepressive role. (C) 2015 Elsevier Inc. All rights reserved.