Loret Sandra, Guay Ginette, Lippé Roger
Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada.
J Virol. 2008 Sep;82(17):8605-18. doi: 10.1128/JVI.00904-08. Epub 2008 Jul 2.
The herpes simplex virus type 1 (HSV-1) genome is contained in a capsid wrapped by a complex tegument layer and an external envelope. The poorly defined tegument plays a critical role throughout the viral life cycle, including delivery of capsids to the nucleus, viral gene expression, capsid egress, and acquisition of the viral envelope. Current data suggest tegumentation is a dynamic and sequential process that starts in the nucleus and continues in the cytoplasm. Over two dozen proteins are assumed to be or are known to ultimately be added to virions as tegument, but its precise composition is currently unknown. Moreover, a comprehensive analysis of all proteins found in HSV-1 virions is still lacking. To better understand the implication of the tegument and host proteins incorporated into the virions, highly purified mature extracellular viruses were analyzed by mass spectrometry. The method proved accurate (95%) and sensitive and hinted at 8 different viral capsid proteins, 13 viral glycoproteins, and 23 potential viral teguments. Interestingly, four novel virion components were identified (U(L)7, U(L)23, U(L)50, and U(L)55), and two teguments were confirmed (ICP0 and ICP4). In contrast, U(L)4, U(L)24, the U(L)31/U(L)34 complex, and the viral U(L)15/U(L)28/U(L)33 terminase were undetected, as was most of the viral replication machinery, with the notable exception of U(L)23. Surprisingly, the viral glycoproteins gJ, gK, gN, and U(L)43 were absent. Analyses of virions produced by two unrelated cell lines suggest their protein compositions are largely cell type independent. Finally, but not least, up to 49 distinct host proteins were identified in the virions.
1型单纯疱疹病毒(HSV-1)基因组包含在一个由复杂的被膜层和外部包膜包裹的衣壳中。定义不明确的被膜在整个病毒生命周期中起着关键作用,包括将衣壳递送至细胞核、病毒基因表达、衣壳出芽以及获取病毒包膜。目前的数据表明,被膜化是一个动态且连续的过程,始于细胞核并在细胞质中继续。超过二十多种蛋白质被认为或已知最终会作为被膜添加到病毒粒子中,但其精确组成目前尚不清楚。此外,仍缺乏对HSV-1病毒粒子中发现的所有蛋白质的全面分析。为了更好地理解被膜和整合到病毒粒子中的宿主蛋白质的影响,通过质谱分析了高度纯化的成熟细胞外病毒。该方法被证明是准确的(95%)且灵敏的,并暗示了8种不同的病毒衣壳蛋白、13种病毒糖蛋白和23种潜在的病毒被膜。有趣的是,鉴定出了四种新的病毒粒子成分(U(L)7、U(L)23、U(L)50和U(L)55),并确认了两种被膜(ICP0和ICP4)。相比之下,未检测到U(L)4、U(L)24、U(L)31/U(L)34复合物以及病毒U(L)15/U(L)28/U(L)33末端酶,大多数病毒复制机制也未检测到,U(L)23是一个显著的例外。令人惊讶的是,病毒糖蛋白gJ、gK、gN和U(L)43缺失。对两种不相关细胞系产生的病毒粒子的分析表明,它们的蛋白质组成在很大程度上与细胞类型无关。最后但同样重要的是,在病毒粒子中鉴定出了多达49种不同的宿主蛋白质。