Antagonist interaction with the human 5-HT(7) receptor mediates the rapid and potent inhibition of non-G-protein-stimulated adenylate cyclase activity: a novel GPCR effect.
Antagonist interaction with the human 5-HT(7) receptor mediates the rapid and potent inhibition of non-G-protein-stimulated adenylate cyclase activity: a novel GPCR effect.
复制标题
拮抗剂与人 5-HT(7) 受体的相互作用介导非 G 蛋白刺激的腺苷酸环化酶活性的快速有效抑制：一种新型 GPCR 效应。
DOI：
10.1111/j.1476-5381.2010.01194.x
复制
发表时间：
2011
影响因子：
7.3
通讯作者：
Teitler,M
中科院分区：
文献类型：
--
作者：
Klein,MT;Teitler,M
背景和声明人5-羟色胺7（h5-HT 7）受体是Gs-偶联的，刺激细胞内信号分子cAMP的产生。此前，我们报道了h5-HT 7受体的一种新特性：假不可逆拮抗剂不可逆地抑制毛喉素刺激（非受体介导）的cAMP产生。在此，我们试图确定竞争性拮抗剂是否也影响毛喉素刺激的活性，以及这种作用是否在其它Gs偶联受体中是常见的。实验方法表达h5-HT 7受体或其它感兴趣的受体的重组细胞系短暂暴露于拮抗剂;然后用毛喉素刺激cAMP的产生，并通过免疫竞争性测定进行定量。关键词在稳定表达h5-HT 7受体的人胚肾293细胞中，所有竞争性拮抗剂几乎100%抑制毛喉素刺激的cAMP产生。这种作用对百日咳毒素不敏感，即不是Gi/o介导的。抑制毛喉素刺激活性的效力与h5-HT 7结合亲和力密切相关（r2= 0.91），表明拮抗剂通过h5-HT 7受体抑制毛喉素。氯氮平（一种典型的竞争性h5-HT 7拮抗剂）的效力和最大效应不受不同毛喉素浓度的影响。拮抗剂与H5-HT 6，人β1，β2和β 3肾上腺素能受体的相互作用并没有抑制forskolin的activity.CONCLUSIONS AND IMPLICATIONS的抑制腺苷酸环化酶，作为衡量forskolin的活性，是一个潜在的属性拮抗剂与H5-HT 7受体的相互作用，然而，这不是一个共同的属性的其他Gs-偶联受体。这种现象可能与h5‐ HT 7受体在人体生理中所起的作用有关。开发不会引起这种效应的h5-HT 7拮抗剂将有助于阐明其机制，并阐明其可能的生理相关性。
BACKGROUND AND PURPOSEThe human 5‐hydroxytryptamine7(h5‐HT7) receptor is Gs‐coupled and stimulates the production of the intracellular signalling molecule cAMP. Previously, we reported a novel property of the h5‐HT7receptor: pseudo‐irreversible antagonists irreversibly inhibit forskolin‐stimulated (non‐receptor‐mediated) cAMP production. Herein, we sought to determine if competitive antagonists also affect forskolin‐stimulated activity and if this effect is common among other Gs‐coupled receptors.EXPERIMENTAL APPROACHRecombinant cell lines expressing h5‐HT7receptors or other receptors of interest were briefly exposed to antagonists; cAMP production was then stimulated by forskolin and quantified by an immunocompetitive assay.KEY RESULTSIn human embryonic kidney 293 cells stably expressing h5‐HT7receptors, all competitive antagonists inhibited nearly 100% of forskolin‐stimulated cAMP production. This effect was insensitive to pertussis toxin, that is, not Gi/o‐mediated. Potency to inhibit forskolin‐stimulated activity strongly correlated with h5‐HT7binding affinity (r2= 0.91), indicating that the antagonists acted through h5‐HT7receptors to inhibit forskolin. Potency and maximal effects of clozapine, a prototypical competitive h5‐HT7antagonist, were unaffected by varying forskolin concentration. Antagonist interaction with h5‐HT6, human β1, β2, and β3adrenoceptors did not inhibit forskolin's activity.CONCLUSIONS AND IMPLICATIONSThe inhibition of adenylate cyclase, as measured by forskolin's activity, is an underlying property of antagonist interaction with h5‐HT7receptors; however, this is not a common property of other Gs‐coupled receptors. This phenomenon may be involved in the roles played by h5‐HT7receptors in human physiology. Development of h5‐HT7antagonists that do not elicit this effect would aid in the elucidation of its mechanisms and shed light on its possible physiological relevance.