DIRECT COUPLING OF OPIOID RECEPTORS TO BOTH STIMULATORY AND INHIBITORY GUANINE NUCLEOTIDE-BINDING PROTEINS IN F-11 NEUROBLASTOMA SENSORY NEURON HYBRID-CELLS
DIRECT COUPLING OF OPIOID RECEPTORS TO BOTH STIMULATORY AND INHIBITORY GUANINE NUCLEOTIDE-BINDING PROTEINS IN F-11 NEUROBLASTOMA SENSORY NEURON HYBRID-CELLS
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DOI：
10.1073/pnas.90.7.3019
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发表时间：
1993-04-01
影响因子：
11.1
通讯作者：
MAKMAN, MH
中科院分区：
文献类型：
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作者：
CRUCIANI, RA;DVORKIN, B;MAKMAN, MH
有证据表明，在 F-11（神经母细胞瘤-背根神经节神经元）杂交细胞中，除了普遍接受的与抑制性和“其他”G 蛋白 G(i) 和 G(o) 的连接外，阿片受体还直接与刺激性 G 蛋白（鸟嘌呤核苷酸结合蛋白）G(s) 连接。用霍乱毒素处理完整的 F-11 细胞，阿片类激动剂 [D-Ala2、D-Leu5] 脑啡肽与 F-11 细胞膜的特异性结合减少了 35%，而剩余的结合保留了与激动剂的高亲和力。根据 ADP-核糖基化研究，在这些条件下，霍乱毒素影响 G(s) 的 a 亚基 (G(s)alpha)，但对 G(i/o) 的 α 亚基 (G(i/o)alpha) 没有影响。百日咳毒素治疗使高亲和力阿片受体激动剂结合减少约 50%；即使百日咳毒素已经选择性且基本上完全地灭活了 G(i/o)α，剩余的结合也具有高亲和力。同时使用两种毒素进行治疗会产生累加效应，使特异性结合减少约 80%。虽然阿片类激动剂如预期抑制毛喉素刺激的 F-11 细胞腺苷酸环化酶活性，但阿片类药物也刺激基础腺苷酸环化酶活性，表明与 G(s) 以及 G(i) 相互作用。霍乱毒素治疗减弱了阿片类药物对基础腺苷酸环化酶的刺激，而百日咳毒素治疗则增强了刺激。相反，阿片类药物对毛喉素刺激活性的抑制作用被百日咳毒素减弱，但不被霍乱毒素减弱。结论是阿片受体的一个子集可能直接与 G(s) 连接，从而介导腺苷酸环化酶的刺激。这种 G(s)-腺苷酸环化酶相互作用被认为是我们之前对感觉神经元和 F-11 细胞的研究中发现的阿片类药物新的兴奋性电生理反应的原因。
Evidence is presented for linkage of opioid receptors directly to the stimulatory G protein (guanine nucleotide-binding protein), G(s), in addition to the generally accepted linkage to the inhibitory and ''other'' G proteins, G(i) and G(o), in F-11 (neuroblastoma-dorsal root ganglion neuron) hybrid cells. Treatment of intact F-11 cells with cholera toxin decreased specific binding of the opioid agonist [D-Ala2, D-Leu5]enkephalin to F-11 cell membranes by 35%, with the remaining binding retaining high affinity for agonist. Under these conditions cholera toxin influenced the a subunit of G(s) (G(s)alpha) but had no effect on the alpha subunit of G(i/o) (G(i/o)alpha), based on ADP-ribosylation studies. Pertussis toxin treatment decreased high-affinity opioid agonist binding by about 50%; remaining binding was also of high affinity, even though pertussis toxin had inactivated G(i/o)alpha selectively and essentially completely. Simultaneous treatment with both toxins had an additive effect, reducing specific binding by about 80%. While opioid agonists inhibited forskolin-stimulated adenylate cyclase activity of F-11 cells as expected, opioids also stimulated basal adenylate cyclase activity, indicative of interaction with G(s) as well as G(i). Cholera toxin treatment attenuated opioid-stimulation of basal adenylate cyclase, whereas pertussis toxin treatment enhanced stimulation. In contrast, inhibition by opioid of forskolin-stimulated activity was attenuated by pertussis toxin but not by cholera toxin. It is concluded that a subset of opioid receptors may be linked directly to G(s) and thereby mediate stimulation of adenylate cyclase. This G(s)-adenylate cyclase interaction is postulated to be responsible for the novel excitatory electrophysiologic responses to opioids found in our previous studies of sensory neurons and F-11 cells.