SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication
SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication
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SUMO 修饰可稳定肠道病毒 71 聚合酶 3D，促进病毒复制。
DOI：
10.1128/jvi.01756-16
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发表时间：
2016-12-01
影响因子：
5.4
通讯作者：
Wang, Hanzhong
中科院分区：
文献类型：
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作者：
Liu, Yan;Zheng, Zhenhua;Wang, Hanzhong
越来越多的证据表明，病毒劫持细胞蛋白质以绕过宿主免疫系统。泛素化和SUMO化是广泛研究的翻译后修饰（PTM），在各种生物学过程中发挥关键作用。据报道，宿主和病毒蛋白的泛素化和SUMO化之间的相互作用导致不同的功能后果。肠道病毒71（EV 71）是一种属于小核糖核酸病毒科的RNA病毒，是手足口病的常见病因。关于宿主PTM系统如何与肠道病毒相互作用知之甚少。在这里，我们证明了3D蛋白，一个RNA依赖的RNA聚合酶（RdRp）的EV 71，是由小泛素样修饰剂1（SUMO-1）在感染过程中和体外修饰。通过生物信息学预测结合定点突变确定K159和L150/D151/L152残基负责3D SUMO化。此外，引物依赖性聚合酶试验表明，SUMO化位点的突变损害3D聚合酶活性和病毒复制。此外，3D以SUMO依赖的方式被泛素化，SUMO化对于3D稳定性至关重要，这可能是由于两个PTM之间的相互作用。重要的是，增加EV 71感染的细胞中SUMO-1的水平增强了SUMO化和3D泛素化水平，导致EV 71的复制增强。这些结果共同表明，SUMO和泛素协同调节EV 71感染，无论是通过SUMO-泛素杂合链或泛素共轭暴露的赖氨酸残基通过SUMO化。我们的研究为病毒如何利用细胞途径促进其复制提供了新的见解。重要信息肠道病毒71型（EV 71）感染通常会导致儿童神经系统疾病，EV 71型是大多数死亡的原因。基于对病毒与宿主细胞相互作用的更好理解，可以开发针对肠道病毒的抗病毒药物。SUMO化作为一种动态的细胞翻译后修饰过程，调控着细胞内蛋白质的整体定位、相互作用、稳定性和酶活性。然而，关于SUMO化如何通过靶向病毒聚合酶直接影响病毒复制的知之甚少。在此，我们发现EV 71聚合酶3D在EV 71感染期间和体外被SUMO化。此外，SUMO化位点进行了测定，体外聚合酶测定表明，SUMO化位点的突变可能会损害聚合酶的合成。重要的是，3D以SUMO化依赖的方式被泛素化，这增强了病毒聚合酶的稳定性。我们的研究结果表明，这两种修饰可能协同增强病毒复制。我们的研究可能提供一个新的治疗策略，对病毒复制。
Accumulating evidence suggests that viruses hijack cellular proteins to circumvent the host immune system. Ubiquitination and SUMOylation are extensively studied posttranslational modifications (PTMs) that play critical roles in diverse biological processes. Cross talk between ubiquitination and SUMOylation of both host and viral proteins has been reported to result in distinct functional consequences. Enterovirus 71 (EV71), an RNA virus belonging to the family Picornaviridae, is a common cause of hand, foot, and mouth disease. Little is known concerning how host PTM systems interact with enteroviruses. Here, we demonstrate that the 3D protein, an RNA-dependent RNA polymerase (RdRp) of EV71, is modified by small ubiquitin-like modifier 1 (SUMO-1) both during infection and in vitro. Residues K159 and L150/D151/L152 were responsible for 3D SUMOylation as determined by bioinformatics prediction combined with site-directed mutagenesis. Also, primer-dependent polymerase assays indicated that mutation of SUMOylation sites impaired 3D polymerase activity and virus replication. Moreover, 3D is ubiquitinated in a SUMO-dependent manner, and SUMOylation is crucial for 3D stability, which may be due to the interplay between the two PTMs. Importantly, increasing the level of SUMO-1 in EV71-infected cells augmented the SUMOylation and ubiquitination levels of 3D, leading to enhanced replication of EV71. These results together suggested that SUMO and ubiquitin cooperatively regulated EV71 infection, either by SUMO-ubiquitin hybrid chains or by ubiquitin conjugating to the exposed lysine residue through SUMOylation. Our study provides new insight into how a virus utilizes cellular pathways to facilitate its replication.IMPORTANCEInfection with enterovirus 71 (EV71) often causes neurological diseases in children, and EV71 is responsible for the majority of fatalities. Based on a better understanding of interplay between virus and host cell, antiviral drugs against enteroviruses may be developed. As a dynamic cellular process of posttranslational modification, SUMOylation regulates global cellular protein localization, interaction, stability, and enzymatic activity. However, little is known concerning how SUMOylation directly influences virus replication by targeting viral polymerase. Here, we found that EV71 polymerase 3D was SUMOylated during EV71 infection and in vitro. Moreover, the SUMOylation sites were determined, and in vitro polymerase assays indicated that mutations at SUMOylation sites could impair polymerase synthesis. Importantly, 3D is ubiquitinated in a SUMOylation-dependent manner that enhances the stability of the viral polymerase. Our findings indicate that the two modifications likely cooperatively enhance virus replication. Our study may offer a new therapeutic strategy against virus replication.