Cell Entry-Independent Role for the Reovirus μ1 Protein in Regulating Necroptosis and the Accumulation of Viral Gene Products.
Cell Entry-Independent Role for the Reovirus μ1 Protein in Regulating Necroptosis and the Accumulation of Viral Gene Products.
复制标题
呼肠孤病毒μ1 蛋白在调节坏死性凋亡和病毒基因产物积累中的细胞进入独立作用。
DOI：
10.1128/jvi.00199-19
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发表时间：
2019
影响因子：
5.4
通讯作者：
Danthi,Pranav
中科院分区：
文献类型：
--
作者：
Roebke,KatherineE;Danthi,Pranav
呼肠孤病毒外衣壳蛋白μ1调节感染细胞中的细胞死亡。为了区分传入的、与captain相关的和新合成的μ1的作用，我们使用了小干扰RNA（siRNA）介导的敲低。新合成的μ1蛋白的丢失不影响HeLa细胞的凋亡性细胞死亡，但增强L929细胞的坏死性凋亡。μ1的敲低也影响病毒复制的方面。我们发现，虽然μ1敲低导致感染性病毒子代从感染细胞释放减少，但病毒负链RNA、正链RNA和μ1 siRNA未靶向的蛋白质的积累程度大于对照siRNA处理的细胞。此外，我们观察到当μ1被敲低时，这些病毒产物对盐酸胍（GuHCl）（靶向负链合成以产生双链RNA）抑制的敏感性降低。μ1敲低后，细胞死亡对GuHCl处理的敏感性也较低。我们的研究表明，μ1的缺乏允许新合成的核心的转录活性增强，从而积累病毒基因产物。我们推测，由于μ1敲低增强这些基因产物的积累和检测增强受体相互作用蛋白3（RIP 3）依赖的细胞death.IMPORTANCEWe使用哺乳动物呼肠孤病毒作为模型来研究病毒感染如何导致细胞死亡。在这里，我们试图确定病毒因子如何调节细胞死亡。我们的工作突出了呼肠孤病毒外衣壳蛋白μ1在限制诱导称为坏死性凋亡的坏死形式的细胞死亡中的先前未知的作用。通过坏死性凋亡诱导细胞死亡需要在感染后期检测到病毒基因产物; μ1通过这种机制限制细胞死亡，因为它阻止了触发细胞死亡的病毒基因产物的过度积累。
The reovirus outer capsid protein μ1 regulates cell death in infected cells. To distinguish between the roles of incoming, capsid-associated, and newly synthesized μ1, we used small interfering RNA (siRNA)-mediated knockdown. Loss of newly synthesized μ1 protein does not affect apoptotic cell death in HeLa cells but enhances necroptosis in L929 cells. Knockdown of μ1 also affects aspects of viral replication. We found that, while μ1 knockdown results in diminished release of infectious viral progeny from infected cells, viral minus-strand RNA, plus-strand RNA, and proteins that are not targeted by the μ1 siRNA accumulate to a greater extent than in control siRNA-treated cells. Furthermore, we observed a decrease in sensitivity of these viral products to inhibition by guanidine hydrochloride (GuHCl) (which targets minus-strand synthesis to produce double-stranded RNA) when μ1 is knocked down. Following μ1 knockdown, cell death is also less sensitive to treatment with GuHCl. Our studies suggest that the absence of μ1 allows enhanced transcriptional activity of newly synthesized cores and the consequent accumulation of viral gene products. We speculate that enhanced accumulation and detection of these gene products due to μ1 knockdown potentiates receptor-interacting protein 3 (RIP3)-dependent cell death.IMPORTANCEWe used mammalian reovirus as a model to study how virus infections result in cell death. Here, we sought to determine how viral factors regulate cell death. Our work highlights a previously unknown role for the reovirus outer capsid protein μ1 in limiting the induction of a necrotic form of cell death called necroptosis. Induction of cell death by necroptosis requires the detection of viral gene products late in infection; μ1 limits cell death by this mechanism because it prevents excessive accumulation of viral gene products that trigger cell death.