Ectodomain cleavage of ErbB-4 - Characterization of the cleavage site and m80 fragment
Ectodomain cleavage of ErbB-4 - Characterization of the cleavage site and m80 fragment
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DOI：
10.1074/jbc.m302111200
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发表时间：
2003-10-03
影响因子：
4.8
通讯作者：
Carpenter, G
中科院分区：
文献类型：
--
作者：
Cheng, QC;Tikhomirov, O;Carpenter, G
ErbB-4 受体酪氨酸激酶的胞外域裂解产生 80 kDa (m80) 的膜相关片段，该片段已进行 N 端测序。获得的序列显示该片段的N末端以ErbB-4的Ser-652开始。当对应于ErbB-4残基646-657的12残基肽与重组肿瘤坏死因子-α-转换酶一起温育时，获得代表残基646-651和652-657的片段。这些数据表明 ErbB-4 的胞外域裂解发生在 His-651 和 Ser-652 之间，将裂解位点置于胞外域茎区内，位于跨膜结构域之前约 8 个残基处。一些实验已经表征了 m80 ErbB-4 片段的其他方面。用泛 ErbB 酪氨酸激酶抑制剂抑制 ErbB-4 酪氨酸激酶活性表明，激酶活性对于调蛋白依赖性而非 12-O-十四烷酰佛波醇-13-乙酸酯诱导的 ErbB-4 胞外域裂解和 m80 片段的形成严格需要。当使用调蛋白或 12-O-十四烷酰佛波醇-13-乙酸酯处理细胞产生 m80 ErbB-4 片段时，该片段与完整的 ErbB-2 结合。然而，该片段不与完整的 ErbB-4 分子结合。
Ectodomain cleavage of the ErbB-4 receptor tyrosine kinase generates a membrane-associated fragment of 80 kDa (m80) that has been subjected to N-terminal sequencing. The sequence obtained shows that the N terminus of this fragment begins with Ser-652 of ErbB-4. When a 12-residue peptide corresponding to ErbB-4 residues 646-657 was incubated with recombinant tumor necrosis factor-alpha-converting enzyme, fragments representing residues 646-651 and 652-657 were obtained. These data indicate that ectodomain cleavage of ErbB-4 occurs between His-651 and Ser-652, placing the cleavage site within the ectodomain stalk region approximately 8 residues prior to the transmembrane domain. Several experiments have characterized other aspects of the m80 ErbB-4 fragment. Inhibition of ErbB-4 tyrosine kinase activity with pan-ErbB tyrosine kinase inhibitors indicates that kinase activity is stringently required for heregulin-dependent, but not 12-O-tetradecanoylphorbol-13-acetate-induced, ErbB-4 ectodomain cleavage and formation of the m80 fragment. When the m80 ErbB-4 fragment is generated by cell treatment with heregulin or 12-O-tetradecanoylphorbol-13-acetate, the fragment associates with intact ErbB-2. However, this fragment does not associate with the intact ErbB-4 molecule.