Deubiquitination activity associated with hepatitis E virus putative papain-like cysteine protease
Deubiquitination activity associated with hepatitis E virus putative papain-like cysteine protease
复制标题
DOI：
10.1099/vir.0.033738-0
复制
发表时间：
2011-09-01
影响因子：
3.8
通讯作者：
Lole, Kavita S.
中科院分区：
文献类型：
--
作者：
Karpe, Yogesh A.;Lole, Kavita S.
戊型肝炎病毒（HEV）ORF 1蛋白（pORF 1）含有甲基转移酶（MetT）、木瓜蛋白酶样半胱氨酸蛋白酶（PCP）、RNA解旋酶（Hel）和RNA依赖性RNA聚合酶（RdRp）结构域。ORF 1序列分析显示在664和1205处有两个共有的LXGG切割位点。LXGG序列被病毒和细胞去泛素化酶识别。使用荧光底物-泛素-7-氨基-4-甲基香豆素（AMC）、IFN-刺激的基因15（ISG 15）-AMC、Nedd 8-AMC和SUMO-AMC测试包含HEV ORF 1的预测MetT-PCP结构域的蛋白质的去泛素化活性。MetT-PCP裂解所有四种底物，但ISG 15-AMC的加工更稳健。该蛋白不加工具有保守的（1205）LXGG位点的Hel和RdRp结构域。MetT-PCP进行ISG 15缀合的细胞蛋白的去SG化，这表明在对抗细胞抗病毒途径中的可能作用。
Hepatitis E virus (HEV) ORF1 protein (pORF1) contains methyltransferase (MetT), papain-like cysteine protease (PCP), RNA helicase (Hel) and RNA-dependent RNA polymerase (RdRp) domains. ORF1 sequence analysis showed two consensus LXGG cleavage sites at 664 and 1205. LXGG sequence is recognized by viral and cellular deubiquitinating enzymes. The protein encompassing the predicted MetT-PCP domains of HEV ORF1 was tested for deubiquitinating activity using fluorogenic substrates - ubiquitin-7-amino-4-methylcoumarin (AMC), IFN-stimulated gene 15 (ISG15)-AMC, Nedd8-AMC and SUMO-AMC. MetT-PCP cleaved all four substrates but processing of ISG15-AMC was more robust. There was no processing of the Hel and RdRp domains having the conserved (1205) LXGG site by the protein. MetT-PCP carried out delSGylation of the ISG15-conjugated cellular proteins, suggesting a possible role in combating cellular antiviral pathways.