Zhu Chun-Yu, Zheng Fang-Liang, She Xiao-Shuang, Zhao Dan, Gu Ying, Duan Yan-Ting, Chang Alan K, Liu Hong-Sheng
Key Laboratory of Animal Resource and Epidemic Disease Prevention of Liaoning Province, College of Life Science of Liaoning University, Shenyang, 110036, People's Republic of China.
Virus Genes. 2015 Apr;50(2):238-44. doi: 10.1007/s11262-015-1166-0. Epub 2015 Feb 3.
Non-structural protein 1 (NS1) is an important virulence factor encoded by influenza A virus. NS1 can interact with a variety of host cell proteins to interfere with the host innate immune response and to promote effective viral replication. Our previous work has shown that only the effector domain of NS1 (amino acid residues 74-230/237) is sufficient to interact with nucleolar and coiled-body phosphoprotein 1 (NOLC1). To investigate the exact region of NS1 that interacts with NOLC1, we used only the effector domain of NS1 and constructed various mutants having different deletions, and then tested their ability to interact with NOLC1 via pull-down assay. Only the mutant containing amino acid residues 104-200 showed positive interaction with NOLC1. To further determine the key amino acids of the NS1 effector domain which are crucial for interaction with NOLC1, several mutants containing a single amino acid substitution were made and their interaction with NOLC1 was tested. Only the mutant D120A or R195A showed reduced binding with NOLC1, suggesting that D120 and R195 were crucial to the binding of NS1 to NOLC1. This study lays the foundation for further research aiming at furthering our understanding of the interaction between NS1 and host cells.
非结构蛋白1（NS1）是甲型流感病毒编码的一种重要毒力因子。NS1可与多种宿主细胞蛋白相互作用，干扰宿主固有免疫反应并促进病毒有效复制。我们之前的研究表明，只有NS1的效应结构域（氨基酸残基74 - 230/237）足以与核仁及卷曲体磷蛋白1（NOLC1）相互作用。为了研究NS1与NOLC1相互作用的确切区域，我们仅使用NS1的效应结构域构建了各种具有不同缺失的突变体，然后通过下拉试验测试它们与NOLC1相互作用的能力。只有包含氨基酸残基104 - 200的突变体与NOLC1呈现阳性相互作用。为了进一步确定NS1效应结构域中对于与NOLC1相互作用至关重要的关键氨基酸，制备了几个含有单个氨基酸取代的突变体，并测试它们与NOLC1的相互作用。只有突变体D120A或R195A与NOLC1的结合减少，这表明D120和R195对于NS1与NOLC1的结合至关重要。本研究为旨在进一步加深我们对NS1与宿主细胞相互作用理解的进一步研究奠定了基础。
