Deubiquitinating and Interferon Antagonism Activities of Coronavirus Papain-Like Proteases
Deubiquitinating and Interferon Antagonism Activities of Coronavirus Papain-Like Proteases
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冠状病毒类木瓜蛋白酶的去泛素化和干扰素拮抗活性
DOI：
10.1128/jvi.02406-09
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发表时间：
2010-05-01
影响因子：
5.4
通讯作者：
Baker, Susan C.
中科院分区：
文献类型：
--
作者：
Clementz, Mark A.;Chen, Zhongbin;Baker, Susan C.
冠状病毒编码多功能蛋白，这些蛋白对病毒复制和阻断对病毒感染的先天免疫反应至关重要。其中一个多功能结构域是冠状病毒木瓜蛋白酶（PLP），它处理病毒复制酶多蛋白，具有去泛素化（DUB）活性，并拮抗I型干扰素（IFN）的诱导。本文研究了人冠状病毒NL63和严重急性呼吸综合征（SARS）冠状病毒PLP结构域的DUB和IFN拮抗活性，以确定DUB活性是否介导干扰素拮抗。我们发现NL63 PLP2从细胞底物上解偶联泛素（Ub）和Ub系分子ISG15，并处理赖氨酸-48和赖氨酸-63连接的多泛素链。这种PLP2 DUB活性依赖于完整的催化半胱氨酸残基。我们证明了与PLP2 DUB活性相反，PLP2介导的干扰素拮抗不需要酶活性。此外，添加阻断冠状病毒蛋白酶/DUB活性的抑制剂并没有消除干扰素的拮抗作用。这些结果表明，冠状病毒plp介导的干扰素拮抗作用的一个成分不依赖于蛋白酶和DUB活性。总的来说，这些结果证明了冠状病毒PLP结构域作为病毒蛋白酶、DUB和IFN拮抗剂的多功能性质，并表明这些独立的活性可能为抗病毒治疗提供多个靶点。
ABSTRACT Coronaviruses encode multifunctional proteins that are critical for viral replication and for blocking the innate immune response to viral infection. One such multifunctional domain is the coronavirus papain-like protease (PLP), which processes the viral replicase polyprotein, has deubiquitinating (DUB) activity, and antagonizes the induction of type I interferon (IFN). Here we characterized the DUB and IFN antagonism activities of the PLP domains of human coronavirus NL63 and severe acute respiratory syndrome (SARS) coronavirus to determine if DUB activity mediates interferon antagonism. We found that NL63 PLP2 deconjugated ubiquitin (Ub) and the Ub-line molecule ISG15 from cellular substrates and processed both lysine-48- and lysine-63- linked polyubiquitin chains. This PLP2 DUB activity was dependent on an intact catalytic cysteine residue. We demonstrated that in contrast to PLP2 DUB activity, PLP2-mediated interferon antagonism did not require enzymatic activity. Furthermore, addition of an inhibitor that blocks coronavirus protease/DUB activity did not abrogate interferon antagonism. These results indicated that a component of coronavirus PLP-mediated interferon antagonism was independent of protease and DUB activity. Overall, these results demonstrate the multifunctional nature of the coronavirus PLP domain as a viral protease, DUB, and IFN antagonist and suggest that these independent activities may provide multiple targets for antiviral therapies.