Actin-Modulating Protein Cofilin Is Involved in the Formation of Measles Virus Ribonucleoprotein Complex at the Perinuclear Region
Actin-Modulating Protein Cofilin Is Involved in the Formation of Measles Virus Ribonucleoprotein Complex at the Perinuclear Region
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DOI：
10.1128/jvi.01819-15
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发表时间：
2015-08
影响因子：
5.4
通讯作者：
R. Koga;Yukihiko Sugita;T. Noda;Y. Yanagi;S. Ohno
中科院分区：
文献类型：
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作者：
R. Koga;Yukihiko Sugita;T. Noda;Y. Yanagi;S. Ohno
在麻疹病毒（MV）感染的细胞中，由病毒基因组和核衣壳(N)蛋白、磷蛋白(P)蛋白和大蛋白组成的核糖核蛋白（RNP）复合物在核周区域组装并合成病毒rna。参与RNP复合物形成的细胞蛋白在很大程度上是未知的。在本报告中，我们发现cofilin，一种肌动蛋白调节宿主蛋白，与MV N蛋白相互作用，并帮助RNP复合物的形成。利用短发夹RNA敲低cofilin可减少病毒感染后RNP复合物的形成，以及质粒介导的病毒N和P蛋白表达后RNP复合物样结构的形成。较低水平的RNP复合物的形成导致病毒RNA合成的减少。在MV感染后，3位丝氨酸残基（酶活性形式）上的Cofilin磷酸化增加，并且磷酸化形式的Cofilin优先包含在复合物中。这些结果表明，cofilin通过增加RNP复合物的形成和病毒RNA的合成，在MV复制中起重要作用。许多RNA病毒在被感染的细胞内诱导一种称为核糖核蛋白（RNP）复合物的结构，在这种结构中发生病毒RNA合成。它由病毒基因组和包含病毒RNA聚合酶的蛋白质组成。参与RNP复合物形成的细胞蛋白在很大程度上是未知的。在这篇报道中，我们发现cofilin是一种肌动蛋白调节宿主蛋白，与麻疹病毒（MV）核衣壳蛋白结合，并在MV RNP复合物的形成和MV RNA的合成中发挥重要作用。酶失活的cofilin磷酸化形式的水平在MV感染后增加，并且磷酸化形式优先与RNP复合物相关。我们用cofilin确定的发现将有助于我们更好地理解RNP复合物在病毒感染细胞中形成的机制，并开发针对RNP复合物的新抗病毒药物。
ABSTRACT In measles virus (MV)-infected cells, the ribonucleoprotein (RNP) complex, comprised of the viral genome and the nucleocapsid (N) protein, phosphoprotein (P protein), and large protein, assembles at the perinuclear region and synthesizes viral RNAs. The cellular proteins involved in the formation of the RNP complex are largely unknown. In this report, we show that cofilin, an actin-modulating host protein, interacts with the MV N protein and aids in the formation of the RNP complex. Knockdown of cofilin using the short hairpin RNA reduces the formation of the RNP complex after MV infection and that of the RNP complex-like structure after plasmid-mediated expression of MV N and P proteins. A lower level of formation of the RNP complex results in the reduction of viral RNA synthesis. Cofilin phosphorylation on the serine residue at position 3, an enzymatically inactive form, is increased after MV infection and the phosphorylated form of cofilin is preferentially included in the complex. These results indicate that cofilin plays an important role in MV replication by increasing formation of the RNP complex and viral RNA synthesis. IMPORTANCE Many RNA viruses induce within infected cells the structure called the ribonucleoprotein (RNP) complex in which viral RNA synthesis occurs. It is comprised of the viral genome and proteins that include the viral RNA polymerase. The cellular proteins involved in the formation of the RNP complex are largely unknown. In this report, we show that cofilin, an actin-modulating host protein, binds to the measles virus (MV) nucleocapsid protein and plays an important role in the formation of the MV RNP complex and MV RNA synthesis. The level of the phosphorylated form of cofilin, enzymatically inactive, is increased after MV infection, and the phosphorylated form is preferentially associated with the RNP complex. Our findings determined with cofilin will help us better understand the mechanism by which the RNP complex is formed in virus-infected cells and develop new antiviral drugs targeting the RNP complex.