A new inhibitor of the β-arrestin/AP2 endocytic complex reveals interplay between GPCR internalization and signalling.
A new inhibitor of the β-arrestin/AP2 endocytic complex reveals interplay between GPCR internalization and signalling.
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DOI：
10.1038/ncomms15054
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发表时间：
2017-04-18
影响因子：
16.6
通讯作者：
Bouvier M
中科院分区：
文献类型：
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作者：
Beautrait A;Paradis JS;Zimmerman B;Giubilaro J;Nikolajev L;Armando S;Kobayashi H;Yamani L;Namkung Y;Heydenreich FM;Khoury E;Audet M;Roux PP;Veprintsev DB;Laporte SA;Bouvier M
除了G蛋白偶联受体（GPCR）脱敏和内吞作用外，β-阻滞蛋白向配体刺激的GPCR募集可促进非典型信号级联反应。由于缺乏选择性分析工具，区分β-阻滞蛋白募集对受体和β-阻滞蛋白促进的内吞作用在受体信号传导中的各自贡献受到限制。在这里，我们使用虚拟筛选和基于细胞的实验相结合，发现了一种小分子，它可以选择性地抑制β-阻滞蛋白和网格蛋白接头蛋白AP2的β2-适应蛋白亚基之间的相互作用，而不会干扰受体/β-阻滞蛋白复合物的形成。这种选择性β-抑制素/β -适应素抑制剂（Barbadin）阻断激动剂促进的典型β-肾上腺素能（β2AR）、v2 -血管加压素（V2R）和血管紧张素ii -1型（AT1R）受体的内吞作用，但不影响β-抑制素非依赖性（转铁蛋白）或ap2非依赖性（内皮素-a）受体的内化。有趣的是，Barbadin完全阻断了V2R刺激的ERK1/2激活，减弱了V2R和β2AR促进的cAMP积累，支持了β-阻滞蛋白/ ap2依赖性信号通路在G蛋白依赖性和非依赖性途径中的概念。β -阻滞蛋白在调节GPCR信号传导和贩运的机制中发挥核心作用。在这里，作者发现了β-阻滞蛋白和网格蛋白接头蛋白AP-2的β2适应蛋白亚基之间相互作用的选择性抑制剂，他们利用它来剖析β-阻滞蛋白/β2适应蛋白相互作用在GPCR信号传导中的作用。
In addition to G protein-coupled receptor (GPCR) desensitization and endocytosis, β-arrestin recruitment to ligand-stimulated GPCRs promotes non-canonical signalling cascades. Distinguishing the respective contributions of β-arrestin recruitment to the receptor and β-arrestin-promoted endocytosis in propagating receptor signalling has been limited by the lack of selective analytical tools. Here, using a combination of virtual screening and cell-based assays, we have identified a small molecule that selectively inhibits the interaction between β-arrestin and the β2-adaptin subunit of the clathrin adaptor protein AP2 without interfering with the formation of receptor/β-arrestin complexes. This selective β-arrestin/β2-adaptin inhibitor (Barbadin) blocks agonist-promoted endocytosis of the prototypical β2-adrenergic (β2AR), V2-vasopressin (V2R) and angiotensin-II type-1 (AT1R) receptors, but does not affect β-arrestin-independent (transferrin) or AP2-independent (endothelin-A) receptor internalization. Interestingly, Barbadin fully blocks V2R-stimulated ERK1/2 activation and blunts cAMP accumulation promoted by both V2R and β2AR, supporting the concept of β-arrestin/AP2-dependent signalling for both G protein-dependent and -independent pathways. Beta-arrestins play central roles in the mechanisms regulating GPCR signalling and trafficking. Here the authors identify a selective inhibitor of the interaction between β-arrestin and the β2-adaptin subunit of the clathrin adaptor protein AP-2, which they use to dissect the role of the β-arrestin/β2-adaptin interaction in GPCR signalling.