Hrs interacts with sorting nexin 1 and regulates degradation of epidermal growth factor receptor
Hrs interacts with sorting nexin 1 and regulates degradation of epidermal growth factor receptor
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DOI：
10.1074/jbc.m004129200
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发表时间：
2001-03-09
影响因子：
4.8
通讯作者：
Li, L
中科院分区：
文献类型：
--
作者：
Chin, LS;Raynor, MC;Li, L
肝细胞生长因子调节酪氨酸激酶底物（Hrs）是酵母液泡蛋白分选（Vps）蛋白Vps 27 p的哺乳动物同源物;然而，Hrs在溶酶体运输中的作用尚不清楚。在这里，我们报告了Hrs与分选连接蛋白1（SNX 1）相互作用，SNX 1是最近鉴定的酵母Vps 5 p的哺乳动物同源物，其识别表皮生长因子受体（EGFR）的溶酶体靶向编码并参与受体的溶酶体运输。生化分析表明，Hrs和SNX 1是存在于细胞溶质和膜相关池中的普遍存在的蛋白质，Hrs和SNX的结合发生在细胞膜上，而不是在胞质溶胶中。此外，内源性SNX 1和Hrs形成类似于550-kDa的复合物，不包括EGFR。免疫荧光和亚细胞分级分离研究表明，Hrs和SNX 1共定位于早期内体，通过缺失分析，我们已经定位了Hrs和SNX 1的结合结构域，介导了它们的关联。Hrs或其SNX 1结合域的过表达抑制配体诱导的EGFR降解，但不影响组成型或配体诱导的受体介导的内吞作用。这些结果表明，Hrs可能通过其与SNX 1的相互作用来调节溶酶体运输。
Hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) is a mammalian homologue of yeast vacuolar protein sorting (Vps) protein Vps27p; however, the role of Hrs in lysosomal trafficking is unclear. Here, we report that Hrs interacts with sorting nexin 1 (SNX1), a recently identified mammalian homologue of yeast Vps5p that recognizes the lysosomal targeting code of epidermal growth factor receptor (EGFR) and participates in lysosomal trafficking of the receptor, Biochemical analyses demonstrate that Hrs and SNX1 are ubiquitous proteins that exist in both cytosolic and membrane-associated pools, and that the association of Hrs and SNX occurs on cellular membranes but not in the cytosol. Furthermore, endogenous SNX1 and Hrs form a similar to 550-kDa complex that excludes EGFR. Immunofluorescence and subcellular fractionation studies show that Hrs and SNX1 colocalize on early endosomes, By using deletion analysis, we have mapped the binding domains of Hrs and SNX1 that mediate their association. Overexpression of Hrs or its SNX1-binding domain inhibits ligand-induced degradation of EGFR, but does not affect either constitutive or ligand-induced receptor-mediated endocytosis. These results suggest that Hrs may regulate lysosomal trafficking through its interaction with SNX1.