A selective inverse agonist for central cannabinoid receptor inhibits mitogen-activated protein kinase activation stimulated by insulin or insulin-like growth factor 1 - Evidence for a new model of receptor/ligand interactions
A selective inverse agonist for central cannabinoid receptor inhibits mitogen-activated protein kinase activation stimulated by insulin or insulin-like growth factor 1 - Evidence for a new model of receptor/ligand interactions
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DOI：
10.1074/jbc.272.35.22330
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发表时间：
1997-08-29
影响因子：
4.8
通讯作者：
Casellas, P
中科院分区：
文献类型：
--
作者：
Bouaboula, M;Perrachon, S;Casellas, P
在本研究中，我们发现转染人中枢大麻素受体 (CB1) 的中国仓鼠卵巢 (CHO) 细胞在丝裂原激活蛋白激酶 (MAPK) 和腺苷酸环化酶水平上均表现出较高的组成活性。这些活性可以被 CB1 选择性配体 SR 141716A 阻断，该配体充当反向激动剂。此外，结合研究表明，鸟嘌呤核苷酸降低了激动剂 CP-55,940 的结合，这是一种通常在激动剂中观察到的效果，而它增强了 SR 141716A 的结合，这是反向激动剂的一种特性。出乎意料的是，我发现 SR 141716A 的 CB1 介导作用包括抑制百日咳毒素敏感受体酪氨酸激酶（如胰岛素或胰岛素）的 MAPK 活化。胰岛素样生长因子 1 受体，但不是百日咳毒素不敏感受体酪氨酸激酶，如成纤维细胞生长因子受体。当用 Mas-7（一种乳酪类似物）刺激细胞时，我们也观察到类似的结果，直接激活 G(i) 蛋白。此外，SR 141716A 抑制 CHO-CB1 细胞膜中 CP-55,940 或 Mas-7 诱导的鸟苷 5'-0-（硫代三磷酸）摄取，这表明，除了抑制自体激活的 CB1 之外，SR 141716A 还可以传递阻断 G(i) 蛋白的生物信号，从而消除大部分 G(i) 介导的反应。 SR 141716A 对缺乏 CB1 受体的 CHO 细胞中胰岛素或 IGF1 的 MAPK 激活没有影响，排除了 SR 141716A 与 G(i) 蛋白直接相互作用的可能性。这支持了 G(i) 蛋白可能充当负性细胞内信号串扰分子的观点。从这些原始结果中，我们提出了一种新的受体/配体模型。互动。
In the present study, we showed that Chinese hamster ovary (CHO) cells transfected with human central cannabinoid receptor (CB1) exhibit high constitutive activity at both levels of mitogen-activated protein kinase (MAPK) and adenylyl cyclase, These activities could be blocked by the CB1-selective ligand, SR 141716A, that functions as an inverse agonist. Moreover, binding studies showed that guanine nucleotides decreased the binding of the agonist CP-55,940, an effect usually observed with agonists, whereas it enhanced the binding of SR 141716A, a property of inverse agonists, Unexpectedly, me found that CB1-mediated effects of SR 141716A included inhibition of MAPK activation by pertussis toxin-sensitive receptor-tyrosine kinase such as insulin or insulin-like growth factor 1 receptors but not by pertussis toxin-insensitive receptor-tyrosine kinase such as the fibroblast growth factor receptor, We also observed similar results when cells were stimulated with Mas-7, a mastoparan analog, that directly activates the G(i) protein. Furthermore, SR 141716A inhibited guanosine 5'-0-(thiotriphosphate) uptake induced by CP-55,940 or Mas-7 in CHO-CB1 cell membranes, This indicates that, in addition to the inhibition of autoactivated CB1, SR 141716A can deliver a biological signal that blocks the G(i) protein and consequently abrogates most of the G(i)-mediated responses, By contrast, SR 141716A had no effect on MAPK activation by insulin or IGF1 in CHO cells lacking CB1 receptors, ruling out the possibility of a direct interaction of SR 141716A with the G(i) protein, This supports the notion that the G(i) protein may act as a negative intracellular signaling cross-talk molecule, From these original results, which considerably enlarge the biological properties of the inverse agonist, we propose a novel model for receptor/ligand interactions.