Domain-specific function of ShcC docking protein in neuroblastoma cells
Domain-specific function of ShcC docking protein in neuroblastoma cells
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DOI：
10.1038/sj.onc.1208523
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发表时间：
2005-04-28
期刊：
影响因子：
8
通讯作者：
Sakai, R
中科院分区：
文献类型：
--
作者：
Miyake, I;Hakomori, Y;Sakai, R
ShcC是Shc对接蛋白家族成员，具有两个不同的磷酸酪氨酸结合基序，并作为各种受体酪氨酸激酶的Grb 2结合底物传导信号。我们最近发现，一些神经母细胞瘤细胞系，如NB-39-nu细胞，表达过度磷酸化的ShcC和间变性淋巴瘤激酶（ALK）的蛋白复合物，该蛋白复合物通过基因扩增自激活。在这里，我们证明了缺乏Grb 2结合位点的突变体ShcC，3 YF-ShcC的表达，通过阻断ERK和Akt通路，显著损害NB-39-nu细胞的存活，分化和运动性。另一方面，细胞过度表达ShcC或3 YF-ShcC，但不是一个突变的ShcC，缺乏SH 2，表现出降低锚定的独立性和体内致瘤性，这表明一种新的ShcC特异性抑制作用，通过其SH 2结构域对细胞转化。值得注意的是，过表达ShcC抑制细胞脱落后Src家族激酶的持续磷酸化，这可能不依赖于Grb 2结合位点的磷酸化。这表明Src/Fyn-Cas途径被ShcC调节为这些抑制作用的靶点。在恶性神经母细胞瘤细胞系中观察到的ShcC表达和磷酸化的相互变化可以通过ShcC的这些磷酸酪氨酸依赖性和非依赖性功能来解释。
ShcC is a family member of the Shc docking proteins that possess two different phosphotyrosine-binding motifs and conduct signals as Grb2-binding substrates of various receptor tyrosine kinases. We have recently shown that some neuroblastoma cell lines, such as NB-39-nu cells, express a protein complex of hyperphosphorylated ShcC and anaplastic lymphoma kinase (ALK), which is self-activated by gene amplification. Here, we demonstrate that the expression of a mutant ShcC lacking Grb2-binding sites, 3YF-ShcC, significantly impaired the survival, differentiation and motility of NB-39-nu cells by blocking the ERK and Akt pathways. On the other hand, cells overexpressing ShcC or 3YF-ShcC, but not a mutant ShcC that lacks SH2, showed decreased anchorage independency and in vivo tumorigenicity, suggesting a novel ShcC-specific suppressive effect through its SH2 domain on cell transformation. Notably, overexpression of ShcC suppressed the sustained phosphorylation of Src family kinase after cell detachment, which might be independent of phosphorylation of Grb2-binding site. It was indicated that the Src/Fyn-Cas pathway is modulated as a target of these suppressive effects by ShcC. Reciprocal change of ShcC expression and phosphorylation observed in malignant neuroblastoma cell lines might be explained by these phosphotyrosine-dependent and - independent functions of ShcC.