State Key Laboratory for Molecular Virology and Genetic Engineering, National Institute for Viral Disease Control and Prevention, China CDC 100 Ying Xin Jie, Xuan Wu Qu, Beijing 100052, China.
Virol J. 2010 May 17;7:99. doi: 10.1186/1743-422X-7-99.
Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spreads rapidly and has a high case-mortality rate. The nucleocapsid protein (NP) of SARS-CoV may be critical for pathogenicity. This study sought to discover the host proteins that interact with SARS-CoV NP.
Using surface plasmon resonance biomolecular interaction analysis (SPR/BIA) and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry, we found that only the proteasome subunit p42 from human fetal lung diploid fibroblast (2BS) cells bound to SARS-CoV NP. This interaction was confirmed by the glutathione S-transferase (GST) fusion protein pulldown technique. The co-localization signal of SARS-CoV NP and proteasome subunit p42 in 2BS cells was detected using indirect immunofluorescence and confocal microscopy. p42 is a subunit of the 26S proteasome; this large, multi-protein complex is a component of the ubiquitin-proteasome pathway, which is involved in a variety of basic cellular processes and inflammatory responses.
To our knowledge, this is the first report that SARS-CoV NP interacts with the proteasome subunit p42 within host cells. These data enhance our understanding of the molecular mechanisms of SARS-CoV pathogenicity and the means by which SARS-CoV interacts with host cells.
严重急性呼吸综合征相关冠状病毒（SARS-CoV）传播迅速，病死率高。SARS-CoV 的核衣壳蛋白（NP）可能对其致病性至关重要。本研究旨在发现与 SARS-CoV NP 相互作用的宿主蛋白。
利用表面等离子体共振生物分子相互作用分析（SPR/BIA）和基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱法，我们发现只有人胎肺二倍体成纤维细胞（2BS）中的蛋白酶体亚基 p42 与 SARS-CoV NP 结合。GST 融合蛋白下拉技术证实了这种相互作用。通过间接免疫荧光和共聚焦显微镜检测到 SARS-CoV NP 和蛋白酶体亚基 p42 在 2BS 细胞中的共定位信号。p42 是 26S 蛋白酶体的一个亚基；这种大型多蛋白复合物是泛素蛋白酶体途径的组成部分，参与多种基本的细胞过程和炎症反应。
据我们所知，这是首次报道 SARS-CoV NP 在宿主细胞内与蛋白酶体亚基 p42 相互作用。这些数据增强了我们对 SARS-CoV 致病分子机制以及 SARS-CoV 与宿主细胞相互作用方式的理解。
