Murayama Rikinori, Harada Yuichi, Shibata Toshikatsu, Kuroda Kazumichi, Hayakawa Satoshi, Shimizu Kazufumi, Tanaka Torahiko
Division of Infectious Disease Control, Department of Advanced Medical Science, Nihon University School of Medicine, 30-1 Oyaguchi-kamimachi, Itabashi, Tokyo 173-8610, Japan.
Biochem Biophys Res Commun. 2007 Nov 3;362(4):880-5. doi: 10.1016/j.bbrc.2007.08.091. Epub 2007 Aug 27.
Influenza A virus non-structural protein 1 (NS1) is the most important viral regulatory factor that controls cellular processes to facilitate viral replication. To gain further insight into the role of NS1, we tried to find novel cellular factors that interact with NS1. The complexes of NS1 and target proteins were pulled down from an infected cell lysate using anti-NS1 (A/Udorn/72) single-chain Fv and identified by peptide mass fingerprinting analysis. We identified nucleolin, a multifunctional major nucleolar protein, as a novel NS1-binding protein. The RNA-binding domain of NS1 was responsible for this binding, as judged by a GST (glutathione S-transferase) pull-down assay with the GST-fused functional domains of NS1. By laser confocal microscopy, we observed the co-localization of NS1 with nucleolin most clearly in the nucleoli, indicating that NS1 is interacting with nucleolin during infection. Our results suggest a novel function of NS1, namely, affecting cellular events via interaction with nucleolin.
甲型流感病毒非结构蛋白1（NS1）是控制细胞过程以促进病毒复制的最重要的病毒调节因子。为了进一步深入了解NS1的作用，我们试图寻找与NS1相互作用的新型细胞因子。使用抗NS1（A/Udorn/72）单链Fv从感染细胞裂解物中拉下NS1与靶蛋白的复合物，并通过肽质量指纹分析进行鉴定。我们鉴定出核仁素，一种多功能的主要核仁蛋白，作为一种新型的NS1结合蛋白。通过用NS1的GST（谷胱甘肽S-转移酶）融合功能域进行的GST下拉试验判断，NS1的RNA结合结构域负责这种结合。通过激光共聚焦显微镜，我们最清楚地观察到NS1与核仁素在核仁中共定位，表明NS1在感染过程中与核仁素相互作用。我们的结果提示了NS1的一种新功能，即通过与核仁素相互作用影响细胞事件。
