Ali M A, Forghani B, Cantin E M
Department of Neurology, City of Hope National Medical Center, Duarte, California 91010, USA.
Virology. 1996 Feb 1;216(1):278-83. doi: 10.1006/viro.1996.0061.
The 2.3-kb BamHI-U DNA fragment (map units 0.319-0.335) of herpes simplex virus type 1 (HSV-1) genome contains the complete UL25 open reading frame (ORF). It specifies an essential viral protein reported previously to be involved in virus penetration and capsid assembly (C. Addison, F. J. Rixon, J. W. Palfreyman, M. O'Hara, and V. G. Preston, Virology 138, 246-259, 1984). To identify the protein encoded by the UL25 gene, the UL25 ORF was cloned in a eukaryotic expression vector (p91023) downstream of the adenovirus major late promoter to generate the expression plasmid p9-UL25. Synthesis of a 60-kDa protein was observed in COS-7 cells transfected with p9-UL25 plasmid DNA, but not in cells transfected with p91023 control plasmid DNA. To identify and characterize the UL25 protein from HSV-1-infected cells, we prepared a rabbit antiserum by using UL25-GST fusion protein expressed in Escherichia coli as immunogen. This rabbit antiserum readily immunoprecipitated the 60-kDa UL25 protein from HSV-1-infected cells. In HSV-1-infected cells, UL25 protein was expressed as a late (gamma) or a leaky late (gamma 1) viral protein. The rabbit antiserum raised against HSV-1 UL25 protein immunoprecipitated a UL25-homologue of identical size from HSV-2-infected cells. However, the reactivity of the antiserum with HSV-2 UL25-homologue was weaker than compared to the corresponding HSV-1 protein. Consistent with its classification as a virion component, the UL25 protein was found to be associated with purified HSV-1 virions.
单纯疱疹病毒1型（HSV-1）基因组的2.3kb BamHI-U DNA片段（图谱单位0.319 - 0.335）包含完整的UL25开放阅读框（ORF）。它编码一种必需的病毒蛋白，先前报道该蛋白参与病毒穿透和衣壳组装（C. 艾迪生、F. J. 里克森、J. W. 帕尔弗里曼、M. 奥哈拉和V. G. 普雷斯顿，《病毒学》138，246 - 259，1984）。为了鉴定由UL25基因编码的蛋白质，将UL25 ORF克隆到真核表达载体（p91023）中腺病毒主要晚期启动子的下游，以产生表达质粒p9-UL25。在用p9-UL25质粒DNA转染的COS-7细胞中观察到了60kDa蛋白的合成，但在用p91023对照质粒DNA转染的细胞中未观察到。为了鉴定和表征来自HSV-1感染细胞的UL25蛋白，我们使用在大肠杆菌中表达的UL25-GST融合蛋白作为免疫原制备了兔抗血清。这种兔抗血清很容易从HSV-1感染的细胞中免疫沉淀出60kDa的UL25蛋白。在HSV-1感染的细胞中，UL25蛋白作为晚期（γ）或渗漏晚期（γ1）病毒蛋白表达。针对HSV-1 UL25蛋白产生的兔抗血清从HSV-2感染的细胞中免疫沉淀出了相同大小的UL25同源物。然而，与相应的HSV-1蛋白相比，该抗血清与HSV-2 UL25同源物的反应性较弱。与它作为病毒粒子成分的分类一致，发现UL25蛋白与纯化的HSV-1病毒粒子相关。
