Multiple regions in dengue virus capsid protein contribute to nuclear localization during virus infection
Multiple regions in dengue virus capsid protein contribute to nuclear localization during virus infection
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DOI：
10.1099/vir.0.83264-0
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发表时间：
2008-05-01
影响因子：
3.8
通讯作者：
Sittisombut, Nopporn
中科院分区：
文献类型：
--
作者：
Sangiambut, Sutha;Keelapang, Poonsook;Sittisombut, Nopporn
在感染过程中，许多黄病毒的衣壳（C）蛋白定位于几种感染细胞系的细胞核和核仁; C蛋白核定位的基础和意义仍然知之甚少。在这项研究中，双丙氨酸取代突变被引入到三个先前提出的核定位信号中（在位置6-9，73-76和85-100）和四个活的突变体，c（K6 A，K7 A），C（K6 A，K7 A），（K73 A，K74 A），c（R85 A，K86 A）和c（R97 A，R98 A）在蚊细胞系中产生，其中很少观察到C蛋白核定位。间接免疫荧光分析显示，虽然C蛋白存在于整个感染与登革热血清型2亲本病毒的PS和Vero细胞的细胞核中，在C（K73 A，K74 A）和C（R85 A，K86 A）的取代突变导致消除核定位在PS细胞和显着减少在Vero细胞。突变体c（K6 A，K7 A）和c（R97 A，R98 A）仅在PS细胞中在感染后期表现出减少的核定位。所有四种突变体在PS、Vero和C6/36细胞中均表现出复制减少，但核定位与病毒生长特性之间缺乏相关性。登革病毒C蛋白内的独特的二元残基，其中许多位于溶剂暴露侧的C蛋白同源二聚体，有助于其在病毒感染期间定位于细胞核的能力。
During infection, the capsid (C) protein of many flaviviruses localizes to the nuclei and nucleoli of several infected cell lines; the underlying basis and significance of C protein nuclear localization remain poorly understood. In this study, double alanine-substitution mutations were introduced into three previously proposed nuclear-localization signals (at positions 6-9, 73-76 and 85-100) of dengue virus C protein, and four viable mutants, c(K6A,K7A), c(K73A,K74A), c(R85A,K86A) and c(R97A,R98A), were generated in a mosquito cell line in which C protein nuclear localization was rarely observed. Indirect immunofluorescence analysis revealed that, whilst C protein was present in the nuclei of PS and Vero cells throughout infection with a dengue serotype 2 parent virus, the substitution mutations in c(K73A,K74A) and c(R85A,K86A) resulted in an elimination of nuclear localization in PS cells and marked reduction in Vero cells. Mutants c(K6A,K7A) and c(R97A,R98A) exhibited reduced nuclear localization at the late period of infection in PS cells only. All four mutants displayed reduced replication in PS, Vero and C6/36 cells, but there was a lack of correlation between nuclear localization and viral growth properties. Distinct dibasic residues within dengue virus C protein, many of which were located on the solvent-exposed side of the C protein homodimer, contribute to its ability to localize to nuclei during virus infection.