Collagenase-3 binds to a specific receptor and requires the low density lipoprotein receptor-related protein for internalization
Collagenase-3 binds to a specific receptor and requires the low density lipoprotein receptor-related protein for internalization
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DOI：
10.1074/jbc.274.42.30087
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发表时间：
1999-10-15
影响因子：
4.8
通讯作者：
Partridge, NC
中科院分区：
文献类型：
--
作者：
Barmina, OY;Walling, HW;Partridge, NC
我们以前已经在UMR 106-01大鼠成骨肉瘤细胞中发现了一个胶原酶-3的特异性受体，它介导了该配体的结合、内化和降解。在目前的研究中，我们发现胶原酶-3的结合是钙依赖的，并且发生在各种类型的细胞中，包括成骨细胞和成纤维细胞。我们的证据也支持胶原酶-3结合和内化的两步机制，涉及特定的胶原酶-3受体和低密度脂蛋白受体相关蛋白。配基印迹分析表明，I-125-胶原酶-3与UMR 106-01细胞中存在的两种蛋白质(类似于170 kDa和类似于600 kDa)特异结合。Western blotting鉴定该600 kDa蛋白为低密度脂蛋白受体相关蛋白。我们的数据表明170 kDa的蛋白是一种特异性的胶原酶-3受体。低密度脂蛋白受体相关蛋白缺失的小鼠胚胎成纤维细胞结合但不能内化胶原酶-3，而UMR 106-01和野生型小鼠胚胎成纤维细胞结合并内化胶原酶-3。39 kDa受体相关蛋白抑制内化，但不是结合。我们得出结论，胶原酶-3的内化需要低密度脂蛋白受体相关蛋白的参与，并提出了该配体的细胞表面相互作用需要两个受体的顺序贡献的模型，胶原酶-3受体作为高亲和力的主要结合部位，低密度脂蛋白受体相关蛋白介导内化。
We have previously identified a specific receptor for collagenase-3 that mediates the binding, internalization, and degradation of this ligand in UMR 106-01 rat osteoblastic osteosarcoma cells. In the present study, we show that collagenase-3 binding is calcium-dependent and occurs in a variety of cell types, including osteoblastic and fibroblastic cells. We also present evidence supporting a two-step mechanism of collagenase-3 binding and internalization involving both a specific collagenase-3 receptor and the low density lipoprotein receptor-related protein. Ligand blot analysis shows that I-125-collagenase-3 binds specifically to two proteins (similar to 170 kDa and similar to 600 kDa) present in UMR 106-01 cells. Western blotting identified the 600-kDa protein as the low density lipoprotein receptor-related protein. Our data suggest that the 170-kDa protein is a specific collagenase-3 receptor. Low density lipoprotein receptor-related protein-null mouse embryo fibroblasts bind but fail to internalize collagenase-3, whereas UMR 106-01 and wildtype mouse embryo fibroblasts bind and internalize collagenase-3. Internalization, but not binding, is inhibited by the 39-kDa receptor-associated protein. We conclude that the internalization of collagenase-3 requires the participation of the low density lipoprotein receptor-related protein and propose a model in which the cell surface interaction of this ligand requires a sequential contribution from two receptors, with the collagenase-3 receptor acting as a high affinity primary binding site and the low density lipoprotein receptor-related protein mediating internalization.