The UL25 gene product of herpes simplex virus type 1 is involved in uncoating of the viral genome
The UL25 gene product of herpes simplex virus type 1 is involved in uncoating of the viral genome
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DOI：
10.1128/jvi.00257-08
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发表时间：
2008-07-01
影响因子：
5.4
通讯作者：
Stow, Nigel D.
中科院分区：
文献类型：
--
作者：
Preston, Valerie G.;Murray, Jill;Stow, Nigel D.
对单纯疱疹病毒1型UL25-零突变KUL25NS的研究表明，衣壳相关的UL25蛋白在病毒DNA的衣壳化后期是必需的。我们之前对UL25温度敏感（ts）突变体ts1204的研究也表明，UL25在病毒生长周期的早期阶段（可能在渗透宿主细胞的阶段）起作用。我们重新检查了这个突变，发现它在基因组的其他地方有一个额外的ts突变。将ts1204 UL25突变体转移到野生型（wt）病毒DNA中，分离并鉴定了UL25突变体ts1249，以阐明UL25在病毒感染初期的功能。病毒感染细胞的间接免疫荧光分析和原位杂交分析表明，突变体ts1249在穿透宿主细胞方面没有受损，但在非允许温度下存在脱衣缺陷。当被ts1249感染的细胞在允许的温度下孵育，使病毒基因组脱衣，随后转移到限制温度，dna包装缺陷是明显的。结果表明，ts1249与KUL25NS一样，在DNA包装后期存在阻滞，且包装后的基因组比全长基因组短。对在非允许温度下产生的ts1249衣壳的检查显示，与wt衣壳相比，它们含有较少的UL25蛋白，从而可能解释ts1249无法包装全长病毒DNA。
Studies on the herpes simplex virus type 1 UL25-null mutant KUL25NS have shown that the capsid-associated UL25 protein is required at a late stage in the encapsidation of viral DNA. Our previous work on UL25 with the UL25 temperature-sensitive (ts) mutant ts1204 also implicated UL25 in a role at very early times in the virus growth cycle, possibly at the stage of penetration of the host cell. We have reexamined this mutant and discovered that it had an additional ts mutation elsewhere in the genome. The ts1204 UL25 mutation was transferred into wild-type (wt) virus DNA, and the UL25 mutant ts1249 was isolated and characterized to clarify the function of UL25 at the initial stages of virus infection. Indirect immunofluorescence assays and in situ hybridization analysis of virus-infected cells revealed that the mutant ts1249 was not impaired in penetration of the host cell but had an uncoating defect at the nonpermissive temperature. When ts1249-infected cells were incubated initially at the permissive temperature to allow uncoating of the viral genome and subsequently transferred to the restrictive temperature, a DNA-packaging defect was evident. The results suggested that ts1249, like KUL25NS, had a block at a late stage of DNA packaging and that the packaged genome was shorter than the full-length genome. Examination of ts1249 capsids produced at the nonpermissive temperature revealed that, in comparison with wt capsids, they contained reduced amounts of UL25 protein, thereby providing a possible explanation for the failure of ts1249 to package full-length viral DNA.