Involvement of Actin-Regulating Factor Cofilin in the Inclusion Body Formation and RNA Synthesis of Human Parainfluenza Virus Type 3 via Interaction With the Nucleoprotein
Involvement of Actin-Regulating Factor Cofilin in the Inclusion Body Formation and RNA Synthesis of Human Parainfluenza Virus Type 3 via Interaction With the Nucleoprotein
复制标题
肌动蛋白调节因子 Cofilin 通过与核蛋白相互作用参与人副流感病毒 3 型包涵体形成和 RNA 合成
DOI：
10.3389/fmicb.2019.00095
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发表时间：
2019-02-01
影响因子：
5.2
通讯作者：
Zhang, Guangyuan
中科院分区：
文献类型：
--
作者：
Li, Yinshuang;Zhang, Chaoliang;Zhang, Guangyuan
人副流感病毒3型（HPIV 3）是引起新生儿和婴幼儿严重呼吸道疾病的主要病原体之一。它能在感染细胞中诱导包涵体。HPIV 3 IB由病毒核蛋白（N）和磷蛋白（P）以及一些细胞因子组成，是高效病毒合成的独特平台。虽然几项研究已经证明了IB的形成，但对HPIV 3 IB形成中涉及的细胞蛋白知之甚少。实时荧光定量PCR检测细胞松弛素D处理后，我们发现细胞骨架的肌动蛋白微丝是HPIV 3 RNA合成所必需的。通过免疫共沉淀和免疫荧光分析发现，肌动蛋白调节蛋白cofilin通过与N蛋白相互作用参与N-P诱导的IBs复合物中IBs的形成。RNA干扰敲低细胞cofilin后，病毒IB形成减少，因此病毒RNA合成和蛋白质表达水平也受到抑制。此外，HPIV 3感染后，cofilin的失活形式p-cofilin的表达增加，其磷酸化是与N-P复合物相互作用和IBs形成所必需的。我们进一步确定了cofilin与N蛋白相互作用的区域位于C端。我们的发现首次表明细胞cofilin参与HPIV 3 IBs的形成，并且与N的相互作用对于cofilin帮助IBs形成和增强病毒RNA合成至关重要。
Human parainfluenza virus type 3 (HPIV3) is one of the primary pathogens that causing severe respiratory tract diseases in newborns and infants. It could induce inclusion bodies (IBs) in infected cells. Comprised of viral nucleoprotein (N) and phosphoprotein (P), as well as some cellular factors, HPIV3 IBs are unique platform for efficient viral synthesis. Although several studies have demonstrated the formation of IBs, little is known about cellular proteins involved in HPIV3 IBs formation. By quantitative real-time PCR assays after cytochalasin D treatment, we found actin microfilaments of the cytoskeleton were indispensible for HPIV3 RNA synthesis. Using co-immunoprecipitation and immunofluorescence assays, an actin-modulating protein, cofilin was found to involve in the IBs formation through interaction with the N protein in N–P induced IBs complex. Viral IBs formation reduced upon RNA interference knockdown of cellular cofilin, thus viral RNA synthesis and protein expression level were also suppressed. What’s more, the inactive form of cofilin, p-cofilin was increased after HPIV3 infection, and phosphorylation of cofilin was required for interacting with N–P complex and IBs formation. We further identified that the regions in cofilin interacting with N protein lies in the C-terminus. Our findings for the first time to state that cellular cofilin involves in HPIV3 IBs and interaction with N is critical for cofilin to aid IBs formation and enhancing viral RNA synthesis.