LIGAND-INDUCED ENDOCYTOSIS OF EPIDERMAL GROWTH-FACTOR RECEPTORS THAT ARE DEFECTIVE IN BINDING ADAPTER PROTEINS
LIGAND-INDUCED ENDOCYTOSIS OF EPIDERMAL GROWTH-FACTOR RECEPTORS THAT ARE DEFECTIVE IN BINDING ADAPTER PROTEINS
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DOI：
10.1073/pnas.92.19.8719
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发表时间：
1995-09-12
影响因子：
11.1
通讯作者：
GILL, GN
中科院分区：
文献类型：
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作者：
NESTEROV, A;WILEY, HS;GILL, GN
配体激活的表皮生长因子受体（EGFR）与包被的坑适配器蛋白（AP 2）在体内，这意味着在内化过程中的受体保留在包被的坑的机制。使用体外结合试验，我们将接头结合决定簇定位于EGFR的残基970-991，并通过与对应于该序列的合成肽竞争来确认特异性。缺乏这种AP 2结合决定簇的突变型EGFR在体内不与AP 2相关，但表现出与野生型对应物难以区分的内化和下调动力学。免疫细胞化学证实配体诱导的突变EGFR的内化。这些数据表明，内吞决定簇是不同的AP 2结合决定簇和过程以外的协会与AP 2调节EGFR的内吞作用。
Ligand-activated epidermal growth factor receptors (EGFRs) associate with coated pit adaptor proteins (AP2) in vivo, implying a mechanism for receptor retention in coated pits during internalization. Using an in vitro binding assay, we localized the adaptor binding determinant to residues 970-991 of EGFRs and confirmed specificity by competition with a synthetic peptide corresponding to this sequence. A mutant EGFR lacking this AP2 binding determinant did not associate with AP2 in vivo but demonstrated internalization and down-regulation kinetics indistinguishable from its wildtype counterpart. Immunocytochemistry confirmed ligand-induced internalization of the mutant EGFR. These data suggest that endocytic determinants are distinct from AP2 binding determinants and that processes other than association with AP2 regulate endocytosis of EGFRs.