Cross-interactions of two p38 mitogen-activated protein (MAP) kinase inhibitors and two cholecystokinin (CCK) receptor antagonists with the CCK1 receptor and p38 MAP kinase
Cross-interactions of two p38 mitogen-activated protein (MAP) kinase inhibitors and two cholecystokinin (CCK) receptor antagonists with the CCK1 receptor and p38 MAP kinase
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DOI：
10.1074/jbc.m408851200
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发表时间：
2005-06-03
影响因子：
4.8
通讯作者：
Martinez, J
中科院分区：
文献类型：
--
作者：
Morel, C;Ibarz, G;Martinez, J
虽然SB202190和SB203580被描述为特异性p38 MAP激酶抑制剂，但一些报道表明，其他酶也对SB203580敏感。利用药理学方法，我们首次报道了化合物SB202190和SB203580能够直接和选择性地与g蛋白偶联受体（即胆囊收缩素受体亚型CCK1）相互作用，但不能与CCK2受体相互作用。我们证明了这些化合物在通常用于抑制蛋白激酶的浓度下是CCK1受体的非竞争性拮抗剂。通过嵌合构建CCK2受体，我们确定了两个CCK1受体胞内环参与了SB202190和SB203580的结合。我们还发现两种CCK拮抗剂L364,718和L365,260能够调节p38丝裂原活化蛋白（MAP）激酶的活性。通过报告基因策略和免疫印迹实验，我们证明了两种CCK拮抗剂选择性地抑制p38 MAP激酶的酶活性。激酶测定表明，这种抑制是由两种CCK拮抗剂直接相互作用引起的。分子模拟表明，这种相互作用发生在p38 MAP激酶的ATP结合口袋中。这些结果表明，SB202190和SB203580与CCK1受体结合，因此，在表达该受体的模型中应谨慎使用这些化合物。我们还发现两种CCK受体拮抗剂L364,718和L365,260直接与p38 MAP激酶相互作用并抑制其活性。这些发现表明CCK1受体与p38 MAP激酶ATP结合位点具有结构相似性。它们为从CCK1受体配体结构设计新的MAP激酶抑制剂家族或基于p38 MAP激酶抑制剂结构设计新的CCK1受体配体开辟了道路。
Although SB202190 and SB203580 are described as specific p38 MAP kinase inhibitors, several reports have indicated that other enzymes are also sensitive to SB203580. Using a pharmacological approach, we report for the first time that compounds SB202190 and SB203580 were able to directly and selectively interact with a G-protein-coupled receptor, namely the cholecystokinin receptor subtype CCK1, but not with the CCK2 receptor. We demonstrated that these compounds were non-competitive antagonists of the CCK1 receptor at concentrations typically used to inhibit protein kinases. By chimeric construction of the CCK2 receptor, we determined the involvement of two CCK1 receptor intracellular loops in the binding of SB202190 and SB203580. We also showed that two CCK antagonists, L364,718 and L365,260, were able to regulate p38 mitogen-activated protein ( MAP) kinase activity. Using a reporter gene strategy and immunoblotting experiments, we demonstrated that both CCK antagonists inhibited selectively the enzymatic activity of p38 MAP kinase. Kinase assays suggested that this inhibition resulted from a direct interaction with both CCK antagonists. Molecular modeling simulations suggested that this interaction occurs in the ATP binding pocket of p38 MAP kinase. These results suggest that SB202190 and SB203580 bind to the CCK1 receptor and, as such, these compounds should be used with caution in models that express this receptor. We also found that L364,718 and L365,260, two CCK receptor antagonists, directly interacted with p38 MAP kinase and inhibited its activity. These findings suggest that the CCK1 receptor shares structural analogies with the p38 MAP kinase ATP binding site. They open the way to potential design of either a new family of MAP kinase inhibitors from CCK1 receptor ligand structures or new CCK1 receptor ligands based on p38 MAP kinase inhibitor structures.