Influenza B virus ribonucleoprotein is a potent activator of the antiviral kinase PKR.
Influenza B virus ribonucleoprotein is a potent activator of the antiviral kinase PKR.
复制标题
DOI：
10.1371/journal.ppat.1000473
复制
发表时间：
2009-06
期刊：
影响因子：
6.7
通讯作者：
Wolff T
中科院分区：
文献类型：
--
作者：
Dauber B;Martínez-Sobrido L;Schneider J;Hai R;Waibler Z;Kalinke U;García-Sastre A;Wolff T
潜伏激酶PKR的激活是脊椎动物细胞对病毒感染的一种强大的先天防御反应，它是由病毒双链RNA的识别触发的，导致翻译关闭。我们对PKR抗病毒特性的理解中的一个主要差距涉及流感和其他具有负链RNA基因组的病毒表达的激酶激活分子的性质，因为这些病原体产生的dsRNA很少或根本没有检测到。在这里，我们系统地研究了B型流感病毒对PKR的激活及其对病毒致病性的影响。生化分析表明，PKR被病毒核糖核蛋白(VRNP)复合体激活，vRNP复合体含有带有5‘-三磷酸基团的单链RNA。重组病毒的细胞生物学检测表明，vRNP在感染后期的核浆转运是PKR激活的强烈触发因素。此外，我们的分析为先前观察到的B型流感病毒NS1蛋白抑制PKR激活提供了机制解释，我们在这里证明这依赖于PKR和NS1‘S dsRNA结合域之间的复杂形成。这种相互作用对致病性的高度意义在于，表达dsRNA结合缺陷NS1蛋白的减毒流感病毒分别在PKR缺陷细胞和小鼠中被拯救以获得高复制和毒力。总之，我们的研究为脊椎动物重要的抗病毒防御机制提供了新的见解，并导致我们提出了一种新的由胞质vRNP复合体激活PKR的模型，该模型也可能适用于其他负链RNA病毒。当病毒感染脊椎动物细胞时，蛋白激酶PKR通过识别病毒双链(DS)RNA而启动强烈的先天防御反应，导致蛋白质合成停止，从而阻断病毒的传播。然而，PKR针对流感和其他负链RNA基因组病毒的有效抗病毒反应的激活是一个难题，因为以前的尝试未能在感染这些病毒的细胞中检测到dsRNA。在这里，我们确定了流感病毒核糖核蛋白(RNP)中的基因组RNA是潜伏期PKR的非典范激活因子。细胞生物学检查表明，病毒RNP从细胞核转移到细胞质为PKR的激活提供了强烈的刺激。此外，我们通过显示B型流感病毒的PKR和NS1蛋白在感染细胞中形成一个复合体来抑制PKR的激活，从而深入了解其发病机制。这种相互作用似乎对病毒的致病性至关重要，因为NS1突变病毒的强烈减弱在很大程度上挽救了PKR缺陷的小鼠和细胞。综上所述，这些发现为流感病毒诱导和抑制PKR提出了一种新的模式，该模式也可能适用于具有相似基因组结构的病毒。
Activation of the latent kinase PKR is a potent innate defense reaction of vertebrate cells towards viral infections, which is triggered by recognition of viral double-stranded (ds) RNA and results in a translational shutdown. A major gap in our understanding of PKR's antiviral properties concerns the nature of the kinase activating molecules expressed by influenza and other viruses with a negative strand RNA genome, as these pathogens produce little or no detectable amounts of dsRNA. Here we systematically investigated PKR activation by influenza B virus and its impact on viral pathogenicity. Biochemical analysis revealed that PKR is activated by viral ribonucleoprotein (vRNP) complexes known to contain single-stranded RNA with a 5′-triphosphate group. Cell biological examination of recombinant viruses showed that the nucleo-cytoplasmic transport of vRNP late in infection is a strong trigger for PKR activation. In addition, our analysis provides a mechanistic explanation for the previously observed suppression of PKR activation by the influenza B virus NS1 protein, which we show here to rely on complex formation between PKR and NS1's dsRNA binding domain. The high significance of this interaction for pathogenicity was revealed by the finding that attenuated influenza viruses expressing dsRNA binding-deficient NS1 proteins were rescued for high replication and virulence in PKR-deficient cells and mice, respectively. Collectively, our study provides new insights into an important antiviral defense mechanism of vertebrates and leads us to suggest a new model of PKR activation by cytosolic vRNP complexes, a model that may also be applicable to other negative strand RNA viruses. Upon viral infection of vertebrate cells, a vigorous innate defense response is initiated via the recognition of viral double-stranded (ds) RNA by the protein kinase PKR, resulting in the cessation of protein synthesis and subsequent blockage of viral propagation. The activation of PKR's potent antiviral response against influenza and other viruses with a negative strand RNA genome has presented a conundrum, however, as previous attempts failed to detect dsRNA in cells infected with these viruses. Here, we identify genomic RNA within the ribonucleoprotein (RNP) of influenza viruses as a non-canonical activator of the latent kinase PKR. Cell biological examinations revealed that the transfer of viral RNP from the nucleus to the cytoplasm provides a strong stimulus for PKR activation. Moreover, we provide insight into mechanisms of pathogenesis by showing PKR and the NS1 protein of influenza B virus forms a complex in infected cells, which inhibits PKR activation. This interaction seems to be crucial for viral pathogenicity, as a strong attenuation of NS1 mutant viruses was largely rescued in PKR-deficient mice and cells. Taken together, these findings suggest a new model for the induction and inhibition of PKR by influenza virus that may also apply to viruses with a similar genome structure.
登录
查看更多内容
影响因子：
5.4
作者：
Donelan, NR;Dauber, B;García-Sastre, A
通讯作者：
García-Sastre, A
DOI：
10.1073/pnas.84.22.8140
发表时间：
1987-11-01
影响因子：
11.1
作者：
HSU, MT;PARVIN, JD;PALESE, P
通讯作者：
PALESE, P
影响因子：
5.4
作者：
Kochs, Georg;Garcia-Sastre, Adolfo;Martinez-Sobrido, Luis
通讯作者：
Martinez-Sobrido, Luis
影响因子：
5.4
作者：
Ehrhardt, Christina;Wolff, Thorsten;Ludwig, Stephan
通讯作者：
Ludwig, Stephan
影响因子：
5.4
作者：
Elton, D;Simpson-Holley, M;Digard, P
通讯作者：
Digard, P