The Ankrd 13 family of UIM-bearing proteins regulates EGF receptor endocytosis from the plasma membrane.
The Ankrd 13 family of UIM-bearing proteins regulates EGF receptor endocytosis from the plasma membrane.
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DOI：
10.1091/mbc.e11-09-0817
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发表时间：
2012-04
影响因子：
3.3
通讯作者：
Komada M
中科院分区：
文献类型：
--
作者：
Tanno H;Yamaguchi T;Goto E;Ishido S;Komada M
Ankrd 13A、13B和13D构成了一个携带泛素相互作用基序（UIM）的细胞质蛋白家族。它们被固定在质膜上，在那里它们识别标记在配体激活的EGF受体上的lys63连接的多泛素链，并从哺乳动物细胞表面调节EGF受体的内吞作用。细胞表面蛋白的泛素依赖性内吞作用机制尚不完全清楚。在这里，我们研究了锚蛋白重复结构域（Ankrd） 13A、13B和13D蛋白在这一过程中的作用，它们构成了一个功能未知的泛素相互作用基序（UIM）承载蛋白家族。用表皮生长因子（EGF）刺激人HeLa细胞可快速诱导Ankrd 13蛋白通过UIMs与泛素化EGF受体（EGFR）直接结合。当Ankrd 13蛋白被uim依赖的单泛素化时，这种结合被抑制，这表明它们的活性受到自身泛素化的调节。Ankrd 13蛋白特异性结合到lys -63连接的泛素链上，这与之前关于EGFR主要发生lys -63连接的泛素化的报道一致。Ankrd 13蛋白通过中心区域和UIMs锚定在质膜上，在那里它们与EGFR共定位。最后，野生型和截断突变型Ankrd 13蛋白的过表达强烈抑制了egf处理细胞表面泛素化EGFR的快速内吞作用。我们得出结论，Ankrd 13蛋白通过在质膜上与EGFR的lys -63连接的多泛素片段结合，调节配体激活的EGFR的快速内化。
Ankrd 13A, 13B, and 13D constitute a family of ubiquitin-interacting motif (UIM)-bearing cytoplasmic proteins. They are anchored to the plasma membrane, where they recognize the Lys63-linked polyubiquitin chains tagged to ligand-activated EGF receptor and regulate the endocytosis of EGF receptor from the cell surface in mammalian cells. The mechanism of ubiquitin-dependent endocytosis of cell surface proteins is not completely understood. Here we examine the role of the ankyrin repeat domain (Ankrd) 13A, 13B, and 13D proteins, which constitute a functionally unknown family of ubiquitin-interacting motif (UIM)–bearing proteins, in the process. Stimulation of human HeLa cells with epidermal growth factor (EGF) rapidly induced direct binding of Ankrd 13 proteins to ubiquitinated EGF receptor (EGFR) via the UIMs. The binding was inhibited when the Ankrd 13 proteins underwent UIM-dependent monoubiquitination, suggesting that their activity is regulated by ubiquitination of themselves. Ankrd 13 proteins bound specifically to Lys-63–linked ubiquitin chains, which was consistent with a previous report that EGFR mainly undergoes Lys-63–linked polyubiquitination. Ankrd 13 proteins were anchored, via the central region and UIMs, to the plasma membrane, where they colocalized with EGFR. Finally, overexpression of wild-type as well as truncated-mutant Ankrd 13 proteins strongly inhibited rapid endocytosis of ubiquitinated EGFR from the surface in EGF-treated cells. We conclude that by binding to the Lys-63–linked polyubiquitin moiety of EGFR at the plasma membrane, Ankrd 13 proteins regulate the rapid internalization of ligand-activated EGFR.