The ORF3 protein of hepatitis E virus binds to Src homology 3 domains and activates MAPK
The ORF3 protein of hepatitis E virus binds to Src homology 3 domains and activates MAPK
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DOI：
10.1074/jbc.m101546200
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发表时间：
2001-11-09
影响因子：
4.8
通讯作者：
Sahal, D
中科院分区：
文献类型：
--
作者：
Korkaya, H;Jameel, S;Sahal, D
戊型肝炎病毒 (HEV) 是戊型肝炎的病原体，戊型肝炎是一种急性病毒性肝炎。 HEV 的生物学和发病机制仍知之甚少。我们使用体外结合测定表明 HEV ORF3 蛋白 (pORF3) 与许多细胞信号转导途径蛋白结合。这包括蛋白酪氨酸激酶 Sre、Hck 和 Fyn、磷脂酰肌醇 3-激酶的 p85 α 调节亚基、磷脂酶 C γ 和接头蛋白 Grb2。使用酵母双杂交测定进一步确认 pORF3-Grb2 相互作用。这种结合涉及 pORF3 中富含脯氨酸的区域以及细胞蛋白中的 src 同源 3 (SH3) 结构域。使用竞争测定和计算机辅助建模来评估 pORF3-SH3 复合物的结合表面和相互作用能。在表达 pORF3 的细胞中，发现 pp60(src) 与 80 kDa 蛋白相关，但在这些细胞中未观察到 Src 激酶的激活。然而，表达 pORF3 的细胞中 ERK 的活性和核定位增加。这些研究表明 pORF3 是一种参与细胞信号传导调节的病毒调节蛋白。 HEV 的 ORF3 蛋白似乎是由引起急性且主要自限性感染的病毒编码的 SH3 结构域结合蛋白的第一个例子。
The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Sre, Hck, and Fyn, the p85 alpha regulatory subunit of phosphatidylinositol 3-kinase, phospholipase C gamma and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3-SH3 complex. In pORF3-expressing cells, pp60(src) was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.