Characterization of the herpes simplex virus (HSV)-1 tegument protein VP1-2 during infection with the HSV temperature-sensitive mutant tsB7
Characterization of the herpes simplex virus (HSV)-1 tegument protein VP1-2 during infection with the HSV temperature-sensitive mutant tsB7
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DOI：
10.1099/vir.0.012492-0
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发表时间：
2009-10-01
影响因子：
3.8
通讯作者：
O'Hare, P.
中科院分区：
文献类型：
--
作者：
Abaitua, F.;Souto, R. N.;O'Hare, P.
VP1-2 由单纯疱疹病毒 (HSV) 的 UL36 基因编码，是一种大型结构蛋白，在疱疹病毒科中保守，组装到外皮中，对于病毒复制至关重要。目前的证据表明，VP1-2 是覆盖和包膜过程的核心组成部分，并且在衣壳运输和进入中也发挥着重要作用。然而，对 VP1-2 功能的任何详细机制理解仍然有限。本研究表征了 HSV-1 tsB7 的复制，HSV-1 tsB7 是一种温度敏感突变体，由于 VP1-2 功能缺陷而限制在不允许的温度下。使用表达绿色荧光蛋白融合的 VP16 蛋白的 tsB7 病毒来追踪主要外皮蛋白的积累和位置。在允许的温度下感染并转移到不允许的温度后，感染性病毒的产生停止。 VP1-2 与 VP16 和其他病毒体蛋白一起积聚在改变的胞质簇中。此外，与免疫荧光结果相关，电子显微镜显示异常的胞质衣壳簇和包膜块。由于 VP1-2 包含泛素特异性蛋白酶结构域，因此还在非允许温度下检查了 tsB7 感染期间泛素缀合蛋白的出现。在细胞质簇中观察到泛素特异性缀合物的惊人过度积累，与 VP1-2 簇重叠并相邻。这些结果与 VP1-2 在组装途径中的可能功能以及 tsB7 缺陷的性质有关。
VP1-2, encoded by the UL36 gene of herpes simplex virus (HSV), is a large structural protein, conserved across the family Herpesviridae, that is assembled into the tegument and is essential for virus replication. Current evidence indicates that VP1-2 is a central component in the tegumentation and envelopment processes and that it also possesses important roles in capsid transport and entry. However, any detailed mechanistic understanding of VP1-2 function(s) remains limited. This study characterized the replication of HSV-1 tsB7, a temperature-sensitive mutant restricted at the non-permissive temperature due to a defect in VP1-2 function. A tsB7 virus expressing green fluorescent protein-fused VP16 protein was used to track the accumulation and location of a major tegument protein. After infection at the permissive temperature and shift to the non-permissive temperature, the production of infectious virus ceased. VP1-2 accumulated in altered cytosolic clusters, together with VP16 and other virion proteins. Furthermore, correlating with the results of immunofluorescence, electron microscopy demonstrated abnormal cytosolic capsid clustering and a block in envelopment. As VP1-2 encompasses a ubiquitin-specific protease domain, the occurrence of ubiquitin-conjugated proteins during tsB7 infection was also examined at the non-permissive temperature. A striking overaccumulation was observed of ubiquitin-specific conjugates in cytoplasmic clusters, overlapping and adjacent to the VP1-2 clusters. These results are discussed in relation to the possible functions of VP1-2 in the assembly pathway and the nature of the defect in tsB7.