Hepatitis C virus core protein interacts with the cytoplasmic tail of lymphotoxin-beta receptor
Hepatitis C virus core protein interacts with the cytoplasmic tail of lymphotoxin-beta receptor
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DOI：
10.1128/jvi.71.2.1301-1309.1997
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发表时间：
1997-02-01
影响因子：
5.4
通讯作者：
Lai, MMC
中科院分区：
文献类型：
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作者：
Matsumoto, M;Hsieh, TY;Lai, MMC
丙型肝炎病毒（HCV）核心蛋白是一种多功能蛋白。我们研究了它是否可以与细胞蛋白相互作用，从而有助于病毒的发病机制。使用HCV核心蛋白作为诱饵，在酵母双杂交筛选系统中筛选人肝脏cDNA文库，我们分离出了几个编码与HCV核心蛋白相互作用的细胞蛋白的阳性克隆。有趣的是，这些克隆中超过一半编码肿瘤坏死因子受体家族的成员之一的光敏素-β受体（LT β R）的胞质结构域。体外谷胱甘肽S-转移酶融合蛋白结合试验和蛋白质-蛋白质印迹试验证实它们的结合是直接和特异的。结合位点被定位在LT β R胞质尾区的58个氨基酸区域内。HCV核心蛋白中的结合位点位于从N末端起的氨基酸残基36至91内，对应于蛋白质的亲水区域。在哺乳动物细胞中，发现核心蛋白与膜结合的LT β R相关。由于LT β R参与外周淋巴器官的生发中心形成和发育调节、淋巴结发育和凋亡信号传导，HCV核心蛋白与LT β R的结合提示该病毒蛋白具有免疫调节功能的可能性，并可能解释HCV的病毒持久性和发病机制。
Hepatitis C virus (HCV) core protein is a multifunctional protein. We examined whether it can interact with cellular proteins, thus contributing to viral pathogenesis. Using the HCV core protein as a bait to screen a human liver cDNA library in a yeast two-hybrid screening system, we have isolated several positive clones encoding cellular proteins that interact with the HCV core protein. Interestingly, more than half of these clones encode the cytoplasmic domain of lymphotoxin-beta receptor (LT beta R), which is a member of the tumor necrosis factor receptor family. Their binding was confirmed by in vitro glutathione S-transferase fusion protein binding assay and protein-protein blotting assay to be direct and specific. The binding sites were mapped within a 58-amino-acid region of the cytoplasmic tail of LT beta R. The binding site in the HCV core protein was localized within amino acid residues 36 to 91 from the N terminus, corresponding to the hydrophilic region of the protein. In mammalian cells, the core protein was found to be associated with the membrane-bound LT beta R. Since the LT beta R is involved in germinal center formation and developmental regulation of peripheral lymphoid organs, lymph node development, and apoptotic signaling, the binding of HCV core protein to LT beta R suggests the possibility that this viral protein has an immunomodulating function and may explain the mechanism of viral persistence and pathogenesis of HCV.