The clathrin adaptor Dab2 recruits EH domain scaffold proteins to regulate integrin β1 endocytosis.
The clathrin adaptor Dab2 recruits EH domain scaffold proteins to regulate integrin β1 endocytosis.
复制标题
网格蛋白适配器 Dab2 招募 EH 结构域支架蛋白来调节整合素 β1 内吞作用。
DOI：
10.1091/mbc.e11-12-1007
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发表时间：
2012
影响因子：
3.3
通讯作者：
Cooper,JonathanA
中科院分区：
文献类型：
--
作者：
Teckchandani,Anjali;Mulkearns,ErinE;Randolph,TimothyW;Toida,Natalie;Cooper,JonathanA
内吞衔接蛋白促进货物招聘和网格蛋白包被的小窝成核。原型网格蛋白衔接子AP2通过结合货物、网格蛋白和辅助蛋白（包括Eps同源（EH）结构域蛋白Eps15和interstin）介导货物募集、成熟和凹坑的切断。然而，网格蛋白介导的内吞作用的一些货物进行有效的AP2耗尽的细胞。我们发现，Dab2，另一个内吞适配器，也结合到Eps15和interstin。EH结构域蛋白的缺失改变了网格蛋白结构的数量和大小，并分别损害了Dab2和AP 2依赖性货物整合素β1和转铁蛋白受体的内吞作用。为了测试Dab2与EH结构域蛋白结合对于内吞作用的重要性，我们突变了EH结构域结合位点。该突变体定位于具有整合素β1、AP 2和减少量的Eps15的网格蛋白结构。有趣的是，虽然整合素β1内吞受损，转铁蛋白受体内化不受影响。令人惊讶的是，尽管网格蛋白结构含有Dab2和AP 2，但整合素β1和转铁蛋白定位在单独的凹坑中。这些数据表明，Dab2介导的EH结构域蛋白的募集选择性地驱动Dab2货物整合素β1的内化。我们建议，衔接子可能需要绑定到他们的货物，以调节EH结构域蛋白和有效地内化。
Endocytic adaptor proteins facilitate cargo recruitment and clathrin-coated pit nucleation. The prototypical clathrin adaptor AP2 mediates cargo recruitment, maturation, and scission of the pit by binding cargo, clathrin, and accessory proteins, including the Eps-homology (EH) domain proteins Eps15 and intersectin. However, clathrin-mediated endocytosis of some cargoes proceeds efficiently in AP2-depleted cells. We found that Dab2, another endocytic adaptor, also binds to Eps15 and intersectin. Depletion of EH domain proteins altered the number and size of clathrin structures and impaired the endocytosis of the Dab2- and AP2-dependent cargoes, integrin β1 and transferrin receptor, respectively. To test the importance of Dab2 binding to EH domain proteins for endocytosis, we mutated the EH domain–binding sites. This mutant localized to clathrin structures with integrin β1, AP2, and reduced amounts of Eps15. Of interest, although integrin β1 endocytosis was impaired, transferrin receptor internalization was unaffected. Surprisingly, whereas clathrin structures contain both Dab2 and AP2, integrin β1 and transferrin localize in separate pits. These data suggest that Dab2-mediated recruitment of EH domain proteins selectively drives the internalization of the Dab2 cargo, integrin β1. We propose that adaptors may need to be bound to their cargo to regulate EH domain proteins and internalize efficiently.