Copeland Anna Maria, Newcomb William W, Brown Jay C
Department of Microbiology and Cancer Center, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
J Virol. 2009 Feb;83(4):1660-8. doi: 10.1128/JVI.01139-08. Epub 2008 Dec 10.
Replication of herpes simplex virus type 1 (HSV-1) involves a step in which a parental capsid docks onto a host nuclear pore complex (NPC). The viral genome then translocates through the nuclear pore into the nucleoplasm, where it is transcribed and replicated to propagate infection. We investigated the roles of viral and cellular proteins in the process of capsid-nucleus attachment. Vero cells were preloaded with antibodies specific for proteins of interest and infected with HSV-1 containing a green fluorescent protein-labeled capsid, and capsids bound to the nuclear surface were quantified by fluorescence microscopy. Results showed that nuclear capsid attachment was attenuated by antibodies specific for the viral tegument protein VP1/2 (UL36 gene) but not by similar antibodies specific for UL37 (a tegument protein), the major capsid protein (VP5), or VP23 (a minor capsid protein). Similar studies with antibodies specific for nucleoporins demonstrated attenuation by antibodies specific for Nup358 but not Nup214. The role of nucleoporins was further investigated with the use of small interfering RNA (siRNA). Capsid attachment to the nucleus was attenuated in cells treated with siRNA specific for either Nup214 or Nup358 but not TPR. The results are interpreted to suggest that VP1/2 is involved in specific attachment to the NPC and/or in migration of capsids to the nuclear surface. Capsids are suggested to attach to the NPC by way of the complex of Nup358 and Nup214, with high-resolution immunofluorescence studies favoring binding to Nup358.
单纯疱疹病毒1型(HSV-1)的复制涉及一个步骤,即亲代衣壳停靠在宿主核孔复合体(NPC)上。然后病毒基因组通过核孔转运到核质中,在那里它被转录和复制以传播感染。我们研究了病毒和细胞蛋白质在衣壳与细胞核附着过程中的作用。用针对感兴趣蛋白质的特异性抗体预加载Vero细胞,并用含有绿色荧光蛋白标记衣壳的HSV-1感染,通过荧光显微镜对结合到核表面的衣壳进行定量。结果表明,针对病毒被膜蛋白VP1/2(UL36基因)的特异性抗体可减弱核衣壳的附着,但针对UL37(一种被膜蛋白)、主要衣壳蛋白(VP5)或VP23(一种次要衣壳蛋白)的类似抗体则不会。用针对核孔蛋白的特异性抗体进行的类似研究表明,针对Nup358的特异性抗体可减弱附着,但针对Nup214的抗体则不会。使用小干扰RNA(siRNA)进一步研究了核孔蛋白的作用。在用针对Nup214或Nup358而非TPR的siRNA处理的细胞中,衣壳与细胞核的附着减弱。这些结果被解释为表明VP1/2参与了与NPC的特异性附着和/或衣壳向核表面的迁移。衣壳被认为是通过Nup358和Nup214的复合体附着到NPC上的,高分辨率免疫荧光研究表明更倾向于与Nup358结合。