Feline Calicivirus Infection Disrupts Assembly of Cytoplasmic Stress Granules and Induces G3BP1 Cleavage.
Feline Calicivirus Infection Disrupts Assembly of Cytoplasmic Stress Granules and Induces G3BP1 Cleavage.
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DOI：
10.1128/jvi.00647-16
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发表时间：
2016-07-15
影响因子：
5.4
通讯作者：
Locker N
中科院分区：
文献类型：
--
作者：
Humoud MN;Doyle N;Royall E;Willcocks MM;Sorgeloos F;van Kuppeveld F;Roberts LO;Goodfellow IG;Langereis MA;Locker N
为了应对压力，如病毒感染，细胞可以通过将mRNA储存在称为应激颗粒（SG）的细胞隔室中来阻止翻译。这种防御机制通过限制能量和营养物质的使用来促进细胞存活，直到压力得到解决。在某些情况下，它还可以阻断病毒繁殖，因为病毒依赖于宿主细胞资源来产生病毒蛋白。人类诺如病毒是杯状病毒科的一个成员，是全球胃肠炎爆发的罪魁祸首。以往的研究杯状病毒已确定的机制，它们可以篡夺宿主的翻译机器，使用病毒蛋白基因组连接的VPg，或调节宿主蛋白质的合成，通过丝裂原活化蛋白激酶（MAPK）途径。在这里，我们研究了猫杯状病毒（FCV）感染对SG积累的影响。我们发现，FCV感染损害了SGs的组装，尽管真核起始因子eIF 2 α的磷酸化增加，这是应激途径激活的标志。此外，SGs没有积累在FCV感染的细胞，强调与亚砷酸盐或过氧化氢。FCV感染导致SG成核蛋白Ras-GT3活化SH 3结构域结合蛋白（G3 BP 1）的裂解，其由病毒3C样蛋白酶NS 6Pro介导。使用突变分析，我们确定了G3 BP 1内的FCV诱导的切割位点，其不同于先前确定的脊髓灰质炎病毒3C蛋白酶切割位点。最后，我们发现NS 6Pro介导的G3 BP 1切割损害SG组装。与此相反，鼠诺如病毒（MNV）感染并没有影响亚砷酸盐诱导的SG组装或G3 BP 1的完整性，这表明相关的杯状病毒对应激反应途径有不同的影响。重要性人类诺如病毒是病毒性胃肠炎的主要原因，了解它们如何与受感染的宿主细胞相互作用非常重要。猫杯状病毒（FCV）和鼠诺如病毒（MNV）被用作了解诺如病毒生物学的模型。最近的研究表明，应激颗粒的组装是协调应激和抗病毒反应以限制病毒复制的核心。总的来说，我们的研究提供了关于杯状病毒如何通过病毒蛋白酶NS 6Pro靶向成核因子G3 BP 1来损害应力颗粒组装的第一个见解。这项工作为FCV感染期间调节应激途径的宿主-病原体相互作用提供了新的见解。
In response to stress such as virus infection, cells can stall translation by storing mRNAs away in cellular compartments called stress granules (SGs). This defense mechanism favors cell survival by limiting the use of energy and nutrients until the stress is resolved. In some cases it may also block viral propagation as viruses are dependent on the host cell resources to produce viral proteins. Human norovirus is a member of the Caliciviridae family responsible for gastroenteritis outbreaks worldwide. Previous studies on caliciviruses have identified mechanisms by which they can usurp the host translational machinery, using the viral protein genome-linked VPg, or regulate host protein synthesis through the mitogen-activated protein kinase (MAPK) pathway. Here, we examined the effect of feline calicivirus (FCV) infection on SG accumulation. We show that FCV infection impairs the assembly of SGs despite an increased phosphorylation of eukaryotic initiation factor eIF2α, a hallmark of stress pathway activation. Furthermore, SGs did not accumulate in FCV-infected cells that were stressed with arsenite or hydrogen peroxide. FCV infection resulted in the cleavage of the SG-nucleating protein Ras-GTPase activating SH3 domain-binding protein (G3BP1), which is mediated by the viral 3C-like proteinase NS6Pro. Using mutational analysis, we identified the FCV-induced cleavage site within G3BP1, which differs from the poliovirus 3C proteinase cleavage site previously identified. Finally, we showed that NS6Pro-mediated G3BP1 cleavage impairs SG assembly. In contrast, murine norovirus (MNV) infection did not impact arsenite-induced SG assembly or G3BP1 integrity, suggesting that related caliciviruses have distinct effects on the stress response pathway. IMPORTANCE Human noroviruses are a major cause of viral gastroenteritis, and it is important to understand how they interact with the infected host cell. Feline calicivirus (FCV) and murine norovirus (MNV) are used as models to understand norovirus biology. Recent studies have suggested that the assembly of stress granules is central in orchestrating stress and antiviral responses to restrict viral replication. Overall, our study provides the first insight on how caliciviruses impair stress granule assembly by targeting the nucleating factor G3BP1 via the viral proteinase NS6Pro. This work provides new insights into host-pathogen interactions that regulate stress pathways during FCV infection.