Characterization of the coronavirus M protein and nucleocapsid interaction in infected cells
Characterization of the coronavirus M protein and nucleocapsid interaction in infected cells
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DOI：
10.1128/jvi.74.17.8127-8134.2000
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发表时间：
2000-09-01
影响因子：
5.4
通讯作者：
Makino, S
中科院分区：
文献类型：
--
作者：
Narayanan, K;Maeda, A;Makino, S
冠状病毒包括M、E和S三种被膜蛋白，以及病毒被膜内由基因组核糖核酸和N蛋白组成的核衣壳。我研究了在感染了小鼠冠状病毒的细胞中涉及到的大分子相互作用，小鼠肝炎病毒(MHV)。免疫共沉淀分析表明，感染细胞中存在N蛋白和M蛋白的相互作用。脉冲标记实验表明，新合成的未糖基化的M蛋白与N蛋白在高尔基体前间隔内相互作用，这是MHV萌芽部位的一部分。免疫共沉淀分析进一步表明，M蛋白仅与基因组长度的MHV mRNA1相互作用，而N蛋白与所有MHV mRNAs相互作用。这些数据表明，在感染细胞中，M蛋白与由N蛋白和mRNA1组成的核衣壳相互作用。在没有S蛋白和E蛋白的情况下，M蛋白与核衣壳发生相互作用。核糖核酸酶去除病毒RNA后，细胞内M蛋白-N蛋白的相互作用保持不变。然而，单独表达M蛋白和N蛋白的细胞中不存在M蛋白与N蛋白的相互作用。这些结果表明，虽然M蛋白-N蛋白的相互作用发生在M蛋白-核衣壳复合体中，但M蛋白-N蛋白的相互作用不依赖于病毒RNA，但M蛋白-核衣壳相互作用的启动需要一定的MHV功能(S)。M蛋白-核衣壳相互作用发生在MHV萌发部位附近，很可能代表了MHV基因组特异性包装成MHV颗粒的过程。
Coronavirus contains three envelope proteins, M, E and S, and a nucleocapsid, which consists of genomic RNA and N protein, within the viral envelope. me studied the macromolecular interactions involved in coronavirus assembly in cells infected with a murine coronavirus, mouse hepatitis virus (MHV). Coimmunoprecipitation analyses demonstrated an interaction between N protein and M protein in infected cells. Pulse-labeling experiments showed that newly synthesized, unglycosylated M protein interacted with N protein in a pre-Golgi compartment, which is part of the MHV budding site. Coimmunoprecipitation analyses further revealed that M protein interacted with only genomic-length MHV mRNA, mRNA 1, while N protein interacted with all MHV mRNAs. These data indicated that M protein interacted with the nucleocapsid, consisting of N protein and mRNA 1, in infected cells. The M protein-nucleocapsid interaction occurred in the absence of S and E proteins. Intracellular M protein-N protein interaction was maintained after removal of viral RNAs by RNase treatment. However, the M protein-N protein interaction did not occur in cells coexpressing M protein and N protein alone. These data indicated that while the M protein-N protein interaction, which is independent of viral RNA, occurred in the M protein-nucleocapsid complex, some MHV function(s) was necessary for the initiation of M protein-nucleocapsid interaction. The M protein-nucleocapsid interaction, which occurred near or at the MHV budding site, most probably represented the process of specific packaging of the MHV genome into MHV particles.