Matsumoto M, Hwang S B, Jeng K S, Zhu N, Lai M M
Howard Hughes Medical Institute,University of Southern California School of Medicine, Los Angeles, California, 90033, USA.
Virology. 1996 Apr 1;218(1):43-51. doi: 10.1006/viro.1996.0164.
Hepatitis C virus (HCV) core protein constitutes a viral nucleocapsid and may possess multiple functions. In this study, we demonstrated the homotypic interaction and multimerization of HCV core protein in vitro and in vivo. By using a yeast two-hybrid system, we showed that the amino-terminal hydrophilic portion (amino acids 1-115) of the core protein could interact with itself. Deletion analysis mapped the interacting domain within amino acid residues 36-91. The homotypic interaction of the core protein was also confirmed by in vitro protein-protein blotting assay using the recombinant HCV core proteins and by its binding to the glutathione S-transferase core fusion protein. The biological significance of the core protein self-interactions was demonstrated by the detection of multimeric forms of the core protein in mammalian cells. The domain responsible for multimerization was determined to be within the amino-terminal hydrophilic region (amino acids 1-115). Both the membrane-bound and the free core proteins exist in dimeric and multimeric forms, suggesting that multimerization of the HCV core protein occurred at an early stage of viral assembly and that the multimer forms may be involved in multiple functions of the core protein.
丙型肝炎病毒（HCV）核心蛋白构成病毒核衣壳，可能具有多种功能。在本研究中，我们在体外和体内证实了HCV核心蛋白的同型相互作用和多聚化。通过使用酵母双杂交系统，我们表明核心蛋白的氨基末端亲水区（氨基酸1 - 115）可与自身相互作用。缺失分析确定了氨基酸残基36 - 91内的相互作用结构域。使用重组HCV核心蛋白的体外蛋白质印迹分析及其与谷胱甘肽S - 转移酶核心融合蛋白的结合也证实了核心蛋白的同型相互作用。通过检测哺乳动物细胞中核心蛋白的多聚体形式证明了核心蛋白自身相互作用的生物学意义。确定负责多聚化的结构域在氨基末端亲水区（氨基酸1 - 115）内。膜结合型和游离型核心蛋白均以二聚体和多聚体形式存在，这表明HCV核心蛋白的多聚化发生在病毒组装的早期阶段，并且多聚体形式可能参与核心蛋白的多种功能。
