Bovine herpesvirus-1 (BoHV-1) is a major cause of rhinotracheitis and vulvovaginitis in cattle. VP8, the major tegument protein of BoHV-1, is essential for viral replication in the host. VP8 is phosphorylated by the viral kinase US3, mediating its translocation to the cytoplasm. VP8 remains nuclear when not phosphorylated. Interestingly, VP8 has a significant presence in mature BoHV-1YmVP8, in which the VP8 phosphorylation sites are mutated. This suggests that VP8 might be packaged during primary envelopment of BoHV-1. This was investigated by mass spectrometry and Western blotting, which showed VP8, as well as VP22, to be constituents of the primary enveloped virions. VP8 and VP22 were shown to interact via co-immunoprecipitation experiments, in both BoHV-1-infected and VP8-transfected cells. VP8 and VP22 also co-localised with one another and with nuclear lamin-associated protein 2 in BoHV-1-infected cells, suggesting an interaction between VP8 and VP22 in the perinuclear region. In cells infected with VP22-deleted BoHV-1 (BoHV-1ΔUL49), VP8 was absent from the primary enveloped virions, implying that VP22 might be critical for the early packaging of VP8. In conclusion, a novel VP22-dependent mechanism for packaging of VP8 was identified, which may be responsible for a significant amount of VP8 in the viral particle.

中文翻译：

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VP8 是牛疱疹病毒 1 的主要被膜蛋白，在早期被膜形成过程中以 VP22 依赖性方式部分包装

牛疱疹病毒-1 (BoHV-1) 是牛鼻气管炎和外阴阴道炎的主要原因。VP8 是 BoHV-1 的主要外皮蛋白，对于病毒在宿主中的复制至关重要。VP8 被病毒激酶 US3 磷酸化，介导其易位至细胞质。VP8 未磷酸化时仍为核。有趣的是，VP8 在成熟的 BoHV-1YmVP8 中显着存在，其中 VP8 磷酸化位点发生突变。这表明 VP8 可能在 BoHV-1 的初级包裹期间被包装。这通过质谱和蛋白质印迹进行了研究，结果表明 VP8 和 VP22 是初级包膜病毒体的成分。在 BoHV-1 感染和 VP8 转染的细胞中，VP8 和 VP22 显示通过免疫共沉淀实验相互作用。VP8 和 VP22 在 BoHV-1 感染的细胞中也相互共定位，并与核层粘连蛋白相关蛋白 2 共定位，表明核周区域中 VP8 和 VP22 之间存在相互作用。在用 VP22 缺失的 BoHV-1 (BoHV-1ΔUL49) 感染的细胞中，初级包膜病毒粒子中不存在 VP8，这意味着 VP22 可能对 VP8 的早期包装至关重要。总之，鉴定了一种新的 VP22 依赖性包装 VP8 的机制，这可能是病毒颗粒中大量 VP8 的原因。