Antagonistic Effects of Cellular Poly(C) Binding Proteins on Vesicular Stomatitis Virus Gene Expression
Antagonistic Effects of Cellular Poly(C) Binding Proteins on Vesicular Stomatitis Virus Gene Expression
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DOI：
10.1128/jvi.05179-11
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发表时间：
2011-09-01
影响因子：
5.4
通讯作者：
Pattnaik, Asit K.
中科院分区：
文献类型：
--
作者：
Dinh, Phat X.;Beura, Lalit K.;Pattnaik, Asit K.
免疫沉淀和随后的质谱分析的细胞蛋白表达水泡性口炎病毒（VSV）P蛋白鉴定的聚（C）结合蛋白2（PCBP 2）的P蛋白相互作用的蛋白之一。为了研究PCBP 2在病毒生命周期中的作用，我们研究了这种蛋白质的耗尽或过表达对VSV生长的影响。小干扰RNA介导的PCBP 2沉默促进VSV复制。相反，PCBP 2在转染细胞中的过表达抑制VSV生长。进一步的研究表明，PCBP 2负调控总体病毒mRNA积累和随后的基因组复制。免疫共沉淀和免疫荧光显微镜研究表明，PCBP 2相互作用和共定位与VSV P蛋白在病毒感染的细胞。P-PCBP 2相互作用不会导致与病毒N和L蛋白形成蛋白复合物的水平降低，也不会诱导P蛋白降解。另外，与PCBP 2同源的poly（C）结合蛋白家族成员PCBP 1也被发现与P蛋白相互作用，在初级转录水平抑制病毒mRNA的合成，而不影响次级转录或基因组复制。PCBP 1对VSV复制的抑制作用不如PCBP 2明显。总体而言，这里呈现的结果表明，细胞PCBP 2和PCBP 1通过影响病毒基因表达来拮抗VSV生长，并突出了这两种细胞蛋白在限制病毒感染中的重要性。
Immunoprecipitation and subsequent mass spectrometry analysis of the cellular proteins from cells expressing the vesicular stomatitis virus (VSV) P protein identified the poly(C) binding protein 2 (PCBP2) as one of the P protein-interacting proteins. To investigate the role of PCBP2 in the viral life cycle, we examined the effects of depletion or overexpression of this protein on VSV growth. Small interfering RNA-mediated silencing of PCBP2 promoted VSV replication. Conversely, overexpression of PCBP2 in transfected cells suppressed VSV growth. Further studies revealed that PCBP2 negatively regulates overall viral mRNA accumulation and subsequent genome replication. Coimmunoprecipitation and immunofluorescence microscopic studies showed that PCBP2 interacts and colocalizes with VSV P protein in virus-infected cells. The P-PCBP2 interaction did not result in reduced levels of protein complex formation with the viral N and L proteins, nor did it induce degradation of the P protein. In addition, PCBP1, another member of the poly(C) binding protein family with homology to PCBP2, was also found to interact with the P protein and inhibit the viral mRNA synthesis at the level of primary transcription without affecting secondary transcription or genome replication. The inhibitory effects of PCBP1 on VSV replication were less pronounced than those of PCBP2. Overall, the results presented here suggest that cellular PCBP2 and PCBP1 antagonize VSV growth by affecting viral gene expression and highlight the importance of these two cellular proteins in restricting virus infections.