Nuclear Marginalization of Host Cell Chromatin Associated with Expansion of Two Discrete Virus-Induced Subnuclear Compartments during Baculovirus Infection
Nuclear Marginalization of Host Cell Chromatin Associated with Expansion of Two Discrete Virus-Induced Subnuclear Compartments during Baculovirus Infection
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DOI：
10.1128/jvi.00490-08
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发表时间：
2008-04
影响因子：
5.4
通讯作者：
T. Nagamine;Y. Kawasaki;A. Abe;S. Matsumoto
中科院分区：
文献类型：
--
作者：
T. Nagamine;Y. Kawasaki;A. Abe;S. Matsumoto
摘要染色质结构在细胞周期中受到严格的调控。由于病毒DNA复制区室的形成，DNA病毒偶尔会干扰宿主细胞染色质的空间组织。为了研究杆状病毒感染细胞中的染色质行为，我们构建了表达荧光蛋白标记的组蛋白H4分子的重组质粒，并通过其在活感染细胞中的瞬时表达来可视化染色质的细胞内定位。与其他DNA病毒类似，杆状病毒家蚕核型多角体病毒诱导BmN细胞核内染色质的边缘迁移，同时伴随病毒DNA复制区室（病毒发生基质（VS））的扩增。然而，在感染的后期，另一个病毒诱导的亚核区室--基质周区（PR）也被排除在染色质定位区之外。如果晚期基因产物如PR蛋白（例如，封闭衍生病毒的包膜蛋白）表达，尽管VS扩增被废除，但病毒DNA合成的阻断未能抑制染色质重新定位。相反，染色质变得边缘化伴随PR扩张，这表明PR直接有助于染色质替换。此外，染色质被排除在未感染的细胞中诱导的4个杆状病毒基因，即1，lef 3，p143，和hr的共转染相对较大的亚核结构。省略任何4个基因，但是，未能导致形成的大结构或染色质排斥。区室化和染色质排斥之间的这种相关性表明，病毒分子的染色质排他特性至少部分地支持病毒感染细胞的核区室化的可能性。
ABSTRACT Chromatin structure is strictly regulated during the cell cycle. DNA viruses occasionally disturb the spatial organization of the host cell chromatin due to formation of the viral DNA replication compartment. To examine chromatin behavior in baculovirus-infected cells, we constructed recombinant plasmids expressing fluorescent protein-tagged histone H4 molecules and visualized the intracellular localization of chromatin by their transient expression in live infected cells. Similar to other DNA viruses, the baculovirus Bombyx mori nucleopolyhedrovirus induced marginal relocation of chromatin within the nuclei of BmN cells, simultaneously with expansion of the viral DNA replication compartment, the virogenic stroma (VS). In the late stage of infection, however, the peristromal region (PR), another virus-induced subnuclear compartment, was also excluded from the chromatin-localizing area. Provided that late-gene products such as PR proteins (e.g., envelope proteins of the occlusion-derived virus) were expressed, blockage of viral DNA synthesis failed to inhibit chromatin relocation, despite abrogation of VS expansion. Instead, chromatin became marginalized concomitantly with PR expansion, suggesting that the PR contributes directly to chromatin replacement. In addition, chromatin was excluded from relatively large subnuclear structures that were induced in uninfected cells by cotransfection with four baculovirus genes, ie1, lef3, p143, and hr. Omission of any of the four genes, however, failed to result in formation of the large structures or chromatin exclusion. This correlation between compartmentalization and chromatin exclusion suggests the possibility that a chromatin-exclusive property of viral molecules, at least in part, supports nuclear compartmentalization of virus-infected cells.