Molecular dissection of nuclear entry-competent SV40 during infection
Molecular dissection of nuclear entry-competent SV40 during infection
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DOI：
10.1016/j.virusres.2006.10.001
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发表时间：
2007-03-01
期刊：
影响因子：
5
通讯作者：
Kasamatsu, Harumi
中科院分区：
文献类型：
--
作者：
Nakanishi, Akira;Li, Peggy P.;Kasamatsu, Harumi
为了建立病毒感染，SV40必须暴露病毒粒子结构内部的核定位信号（NLSs），以便通过与宿主核输入机制（包括输入蛋白α和输入蛋白β）的相互作用进入细胞核。检测SV40在感染细胞中与进口蛋白结合的时间过程。病毒DNA在感染后1.5 h与输入蛋白α结合，在感染后3 h与输入蛋白β核输入受体结合。只有一小部分含有病毒DNA的细胞内化SV40被这两种进口蛋白结合。这个部分被称为“核进入能力SV40”，比病毒粒子略小，但重要的是，比病毒染色质大，含有Vp1和Vp3。此外，抗输入蛋白或抗vp3免疫复合物中的内化病毒DNA对DNase I敏感，而成熟病毒粒子中的病毒DNA则具有抗性。所有这些结果表明，一旦SV40进入细胞质，它就会经历结构修饰，使病毒粒子的NLSs暴露于核进入。(c) 2006 Elsevier B.V.版权所有
To establish viral infection, SV40 must expose nuclear localization signals (NLSs) that are internal in the virion architecture in order to enter the nucleus via interaction with the host's nuclear import machinery, which includes importin alpha and importin beta. The time course for SV40 association with the importins in infected cells was examined. The viral DNA associated with importin alpha by 1.5 It post infection, before associating with the importin beta nuclear import receptor, by 3 h post infection. Only a small fraction of cell-intemalized SV40 that contained viral DNA was bound by the two importins. This fraction, termed "nuclear entry-competent SV40," was slightly smaller than the virion but, importantly, was larger than the viral chromatin and contained both Vp1 and Vp3. Furthermore, the internalized viral DNA in either anti-importin or anti-Vp3 immune complexes was sensitive to DNase I, whereas the viral DNA in mature virions was resistant. All these results suggest that once SV40 enters the cytoplasm, it undergoes an architectural modification that exposes the virion's NLSs for nuclear entry. (c) 2006 Elsevier B.V. All rights reserved.