Cellular Poly(C) Binding Proteins 1 and 2 Interact with Porcine Reproductive and Respiratory Syndrome Virus Nonstructural Protein 1β and Support Viral Replication
Cellular Poly(C) Binding Proteins 1 and 2 Interact with Porcine Reproductive and Respiratory Syndrome Virus Nonstructural Protein 1β and Support Viral Replication
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DOI：
10.1128/jvi.05177-11
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发表时间：
2011-12-01
影响因子：
5.4
通讯作者：
Pattnaik, Asit K.
中科院分区：
文献类型：
--
作者：
Beura, Lalit K.;Dinh, Phat X.;Pattnaik, Asit K.
猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus，PRRSV）感染给世界养猪业造成了巨大的经济损失。参与PRRSV生命周期的细胞因子的鉴定不仅可以更好地理解病毒生物学，而且还具有开发抗病毒治疗药物的潜力。PRRSV非结构蛋白1（nsp 1）在感染宿主中至少参与两种重要功能：（i）介导病毒亚基因组（sg）mRNA转录和（ii）抑制宿主的先天免疫应答机制。为了进一步了解病毒nsp 1在这些过程中的作用，使用nsp 1 β（nsp 1的蛋白水解加工功能产物）作为诱饵，我们已经确定了细胞多聚（C）结合蛋白1和2（PCBP 1和PCBP 2）作为其两个相互作用伙伴。PCBP 1和PCBP 2与nsp 1 β的相互作用通过感染细胞和/或质粒转染细胞中的免疫共沉淀以及体外结合试验得到证实。在PRRSV感染MARC-145细胞期间，细胞质PCBP 1和PCBP 2部分共定位于病毒复制-转录复合物。此外，重组纯化的PCBP 1和PCBP 2被发现结合病毒5'非翻译区（5' UTR）。小干扰RNA（siRNA）介导的PCBP 1和PCBP 2在细胞中的沉默导致显着减少的PRRSV基因组复制和转录，而对初始多蛋白合成没有不利影响。总体而言，这里呈现的结果指向PCBP 1和PCBP 2在调节PRRSV RNA合成中的重要作用。
Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine results in substantial economic losses to the swine industry worldwide. Identification of cellular factors involved in PRRSV life cycle not only will enable a better understanding of virus biology but also has the potential for the development of antiviral therapeutics. The PRRSV nonstructural protein 1 (nsp1) has been shown to be involved in at least two important functions in the infected hosts: (i) mediation of viral subgenomic (sg) mRNA transcription and (ii) suppression of the host's innate immune response mechanisms. To further our understanding of the role of the viral nsp1 in these processes, using nsp1 beta, a proteolytically processed functional product of nsp1 as bait, we have identified the cellular poly(C)-binding proteins 1 and 2 (PCBP1 and PCBP2) as two of its interaction partners. The interactions of PCBP1 and PCBP2 with nsp1 beta were confirmed both by coimmunoprecipitation in infected cells and/or in plasmid-transfected cells and also by in vitro binding assays. During PRRSV infection of MARC-145 cells, the cytoplasmic PCBP1 and PCBP2 partially colocalize to the viral replication-transcription complexes. Furthermore, recombinant purified PCBP1 and PCBP2 were found to bind the viral 5' untranslated region (5'UTR). Small interfering RNA (siRNA)-mediated silencing of PCBP1 and PCBP2 in cells resulted in significantly reduced PRRSV genome replication and transcription without adverse effect on initial polyprotein synthesis. Overall, the results presented here point toward an important role for PCBP1 and PCBP2 in regulating PRRSV RNA synthesis.