Discovery and Characterization of a G Protein-Biased Agonist That Inhibits β-Arrestin Recruitment to the D2 Dopamine Receptor
Discovery and Characterization of a G Protein-Biased Agonist That Inhibits β-Arrestin Recruitment to the D2 Dopamine Receptor
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DOI：
10.1124/mol.113.090563
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发表时间：
2014-07-01
影响因子：
3.6
通讯作者：
Sibley, David R.
中科院分区：
文献类型：
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作者：
Free, R. Benjamin;Chun, Lani S.;Sibley, David R.
一项高通量筛选活动使用钙动员法对380,000多个小分子文库进行了询问，以寻找新型D2多巴胺受体调节剂。初步筛选的活性激动剂化合物检测了D2多巴胺受体的正交信号活性，包括cAMP调节和β -抑制素募集。尽管大多数随后确认的撞击激活了所有被测试的信号通路，但有几种化合物显示出刺激β -抑制素募集的能力减弱。其中一种化合物（MLS1547； 5-氯-7-[（4-吡啶-2-酰基哌嗪-1-酰基）甲基]喹啉-8-醇）是D2受体介导的G蛋白连接信号的高效激动剂，但两种不同的试验表明，它不会招募β -抑制素。然而，这种化合物确实可以对抗多巴胺刺激的D2受体的β -抑制素募集。为了进一步研究MLS1547的化学支架，我们对MLS1547的24个类似物进行了表征，分析了它们抑制cAMP积累或刺激β -抑制蛋白募集的能力。许多类似物与MLS1547相似，它们表现出抑制cAMP积累的激动剂活性，但不刺激β -抑制素募集（即，它们具有高度偏倚）。相比之下，其他类似物表现出不同程度的G蛋白信号偏倚。这些结果为利用药效团建模和分子对接分析建立该系列化合物功能选择性的初步构效关系提供了基础。总之，我们已经鉴定并表征了一种D2多巴胺受体的新型G蛋白偏倚激动剂，并鉴定了可能有助于其偏倚信号特性的结构特征。
A high-throughput screening campaign was conducted to interrogate a 380,000+ small-molecule library for novel D2 dopamine receptor modulators using a calcium mobilization assay. Active agonist compounds from the primary screen were examined for orthogonal D2 dopamine receptor signaling activities including cAMP modulation and beta-arrestin recruitment. Although the majority of the subsequently confirmed hits activated all signaling pathways tested, several compounds showed a diminished ability to stimulate beta-arrestin recruitment. One such compound (MLS1547; 5-chloro-7-[(4-pyridin-2-ylpiperazin-1-yl)methyl]quinolin-8-ol) is a highly efficacious agonist at D2 receptor-mediated G protein-linked signaling, but does not recruit beta-arrestin as demonstrated using two different assays. This compound does, however, antagonize dopamine-stimulated beta-arrestin recruitment to the D2 receptor. In an effort to investigate the chemical scaffold of MLS1547 further, we characterized a set of 24 analogs of MLS1547 with respect to their ability to inhibit cAMP accumulation or stimulate beta-arrestin recruitment. A number of the analogs were similar to MLS1547 in that they displayed agonist activity for inhibiting cAMP accumulation, but did not stimulate beta-arrestin recruitment (i.e., they were highly biased). In contrast, other analogs displayed various degrees of G protein signaling bias. These results provided the basis to use pharmacophore modeling and molecular docking analyses to build a preliminary structure-activity relationship of the functionally selective properties of this series of compounds. In summary, we have identified and characterized a novel G protein-biased agonist of the D2 dopamine receptor and identified structural features that may contribute to its biased signaling properties.