Pairs of Vp1 cysteine residues essential for simian virus 40 infection
Pairs of Vp1 cysteine residues essential for simian virus 40 infection
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DOI：
10.1128/jvi.79.6.3859-3864.2005
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发表时间：
2005-03-01
影响因子：
5.4
通讯作者：
Kasamatsu, H
中科院分区：
文献类型：
--
作者：
Li, PP;Nakanishi, A;Kasamatsu, H
猿猴病毒40 （SV40）主要衣壳蛋白Vp1在细胞内折叠和五聚体化过程中发生瞬时二硫键结合（P. P. Li， A. Nakanishi， S. W. Clark，和H. Kasamatsu, Proc. Natl.）。学会科学。美国99:1353-1358,2002)。我们研究了SV40感染对Vp1半胱氨酸对的需求。我们的分析确定了三个Vp1双半胱氨酸突变组合，通过检测斑块形成来消除生存能力。突变Cys49-Cys87对或Cys87-Cys254对导致突变体Vp1s的核定位无效和积累减少，缺陷以显性阴性方式扩展到野生型次要衣壳蛋白Vp2/3和在同一细胞中表达的亲和标记的重组Vp1。Cys87-Cys207对的突变保留了衣壳蛋白的核定位和正常积累，但减少了病毒样颗粒的产生。我们的研究结果与Cys49、Cys87和Cys254在Vp1的折叠和细胞质核运输中的作用以及Cys87和Cys207在感染性颗粒的组装中的作用一致。这些发现表明，某些Vp1半胱氨酸残基之间的瞬时二硫键形成在SV40感染的两个阶段起作用：在细胞质中的Vp1折叠和寡聚化期间和在细胞核中的病毒粒子组装期间。
Transient disulfide bonding occurs during the intracellular folding and pentamerization of simian virus 40 (SV40) major capsid protein Vp1 (P. P. Li, A. Nakanishi, S. W. Clark, and H. Kasamatsu, Proc. Natl. Acad. Sci. USA 99:1353-1358, 2002). We investigated the requirement for Vp1 cysteine pairs during SV40 infection. Our analysis identified three Vp1 double-cysteine mutant combinations that abolished viability as assayed by plaque formation. Mutating the Cys49-Cys87 pair or the Cys87-Cys254 pair led to ineffective nuclear localization and diminished accumulation of the mutant Vp1s, and the defect extended in a dominant-negative manner to the wild-type minor capsid proteins Vp2/3 and an affinity-tagged recombinant Vp1 expressed in the same cells. Mutating the Cys87-Cys207 pair preserved the nuclear localization and normal accumulation of the capsid proteins but diminished the production of virus-like particles. Our results are consistent with a role for Cys49, Cys87, and Cys254 in the folding and cytoplasmic-nuclear trafficking of Vp1 and with a role for Cys87 and Cys207 in the assembly of infectious particles. These findings suggest that transient disulfide bond formation between certain Vp1 cysteine residues functions at two stages of SV40 infection: during Vp1 folding and oligomerization in the cytoplasm and during virion assembly in the nucleus.