African swine fever virus protease, a new viral member of the SUMO-1-specific protease family
African swine fever virus protease, a new viral member of the SUMO-1-specific protease family
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DOI：
10.1074/jbc.m006844200
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发表时间：
2001-01-05
影响因子：
4.8
通讯作者：
Salas, ML
中科院分区：
文献类型：
--
作者：
Andrés, G;Alejo, A;Salas, ML
非洲猪瘟病毒(ASFV)是一种复杂的DNA病毒，它在Gly-Gly-Xaa位点使用多蛋白加工作为一种策略来产生病毒颗粒的几个主要核心成分。病毒基因S273R编码一个31 kDa的蛋白，含有一个“核心区”，具有L相扑专一性蛋白和腺病毒蛋白水解酶所特有的保守催化残基。利用COS细胞表达系统，发现蛋白pS273R能够以特定的方式切割病毒多蛋白pp62和pp220，产生与ASFV感染细胞相同的中间产物和成熟产物。此外，蛋白pS273R与腺病毒蛋白水解酶和SUMO-1特异性酶一样，也是一种半胱氨酸蛋白酶，因为它的活性被预测的催化组氨酸和半胱氨酸残基的突变所取消，并被巯基封闭剂抑制。蛋白pS273R在感染后后期表达，定位于细胞质病毒工厂，在那里发现与病毒前体和成熟病毒粒子相关。在病毒粒子中，蛋白质存在于核壳中，核壳也是病毒多蛋白产物所在的区域。ASFV蛋白酶的鉴定将使我们更好地了解多蛋白加工在病毒组装中的作用，并可能有助于我们对新出现的SUMO-1特异性蛋白酶家族的了解。
African swine fever virus (ASFV) is a complex DNA virus that employs polyprotein processing at Gly-Gly-Xaa sites as a strategy to produce several major core components of the viral particle. The virus gene S273R encodes a 31-kDa protein that contains a "core domain" with the conserved catalytic residues characteristic of SUMO-l-specific proteases and the adenovirus protease. Using a COS cell expression system, it was found that protein pS273R is capable of cleaving the viral polyproteins pp62 and pp220 in a specific way giving rise to the same intermediates and mature products as those produced in ASFV-infected cells. Furthermore, protein pS273R, like adenovirus protease and SUMO-1-specific enzymes, is a cysteine protease, because its activity is abolished by mutation of the predicted catalytic histidine and cysteine residues and is inhibited by sulfhydryl-blocking reagents. Protein pS273R is expressed late after infection and is localized in the cytoplasmic viral factories, where it is found associated with virus precursors and mature virions. In the virions, the protein is present in the core shell, a domain where the products of the viral polyproteins are also located. The identification of the ASFV protease will allow a better understanding of the role of polyprotein processing in virus assembly and may contribute to our knowledge of the emerging family of SUMO-1-specific proteases.