Critical role of Dengue Virus NS1 protein in viral replication
Critical role of Dengue Virus NS1 protein in viral replication
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DOI：
10.1007/s12250-014-3459-1
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发表时间：
2014-06-01
影响因子：
5.5
通讯作者：
Yuan, Zhiming
中科院分区：
文献类型：
--
作者：
Fan, Jingjing;Liu, Yi;Yuan, Zhiming
登革病毒（DENV）非结构蛋白1（NS 1）是一种高度保守的46-kDa蛋白，含有2个糖基化位点（Asn-130和Asn-207）和12个保守的半胱氨酸（Cys）残基。在这里，我们进行了定点诱变，以产生病毒株TSV 01的系统突变体。随后的分析结果表明，在NS 1中的第二个N-连接聚糖Asn-207处的丙氨酸取代延迟了病毒RNA的合成，减小了病毒空斑的大小，并减弱了细胞病变效应。Cys位点的三个突变体（Cys-4、Cys-55、Cys-291）和C末端缺失（Delta C）突变体显著损害RNA合成，并因此消除病毒生长，而Asn-130和Glu-173处的丙氨酸突变导致与野生型（WT）病毒相似的表型。进一步的分析表明，Asn-207突变略微延迟了病毒的复制。这些结果表明NS 1中的三个保守的二硫键和第二个N-连接的聚糖是DENV-2复制所必需的。
Dengue virus (DENV) nonstructural protein 1 (NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites (Asn-130 and Asn-207) and 12 conserved cysteine (Cys) residues. Here, we performed site-directed mutagenesis to generate systematic mutants of viral strain TSV01. The results of the subsequent analysis showed that an alanine substitution at the second N-linked glycan Asn-207 in NS1 delayed viral RNA synthesis, reduced virus plaque size, and weakened the cytopathic effect. Three mutants at Cys sites (Cys-4, Cys-55, Cys-291) and a C-terminal deletion (Delta C) mutant significantly impaired RNA synthesis, and consequently abolished viral growth, whereas alanine mutations at Asn-130 and Glu-173 resulted in phenotypes that were similar to the wild-type (WT) virus. Further analysis showed that the Asn-207 mutation slightly delayed viral replication. These results suggest that the three conserved disulfide bonds and the second N-linked glycan in NS1 are required for DENV-2 replication.