Nozawa Naoki, Daikoku Tohru, Yamauchi Yohei, Takakuwa Hiroki, Goshima Fumi, Yoshikawa Tetsushi, Nishiyama Yukihiro
Laboratory of Virology, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Japan.
Virus Genes. 2002 Jun;24(3):257-66. doi: 10.1023/a:1015332716927.
We have raised a rabbit polyclonal antiserum against a recombinant 6x His-tagged herpes simplex virus type 2 (HSV-2) UL7 fusion protein expressed in Escherichia coli. The antiserum specifically reacted with a 33 kDa protein in HSV-1 and HSV-2-infected cell lysates, and was used to characterize the UL7 gene product of HSV-2. The UL7 protein was produced in the late phase of infection, and its synthesis was highly inhibited, but not abolished by the addition of acyclovir (ACV). The UL7 protein associated with extracellular virions and also with all types of capsids, including A, B, and C capsids, though the association seemed to be weak. Indirect immunofluorescence studies revealed that at 9 h postinfection, UL7 specific fluorescence was detected in part or all of the nucleus, and the specific fluorescence colocalized with the scaffold protein ICP35. However, at later times postinfection, the UL7 protein was mainly detected as a mass in a juxtanuclear cytoplasmic region. In addition, transmission immunoelectron microscopy (TIEM) confirmed the association of the UL7 protein with intracellular capsids and virions in HSV-2-infected cells. The HSV-2 UL7 protein contained a domain highly conserved in all herpesviruses, part of which exhibited a homology with domains in the fission yeast Schizosaccharomyces pombe DNA topoisomerase III. We discuss the possibility that the UL7 protein may play a supplementary role in the viral DNA cleavage/packaging process.
我们制备了一种兔多克隆抗血清，其针对在大肠杆菌中表达的重组6x组氨酸标签的单纯疱疹病毒2型（HSV-2）UL7融合蛋白。该抗血清与HSV-1和HSV-2感染的细胞裂解物中的一种33 kDa蛋白发生特异性反应，并用于鉴定HSV-2的UL7基因产物。UL7蛋白在感染后期产生，其合成受到高度抑制，但添加阿昔洛韦（ACV）后并未完全消除。UL7蛋白与细胞外病毒粒子相关，也与所有类型的衣壳相关，包括A、B和C型衣壳，尽管这种关联似乎较弱。间接免疫荧光研究表明，在感染后9小时，在部分或全部细胞核中检测到UL7特异性荧光，且特异性荧光与支架蛋白ICP35共定位。然而，在感染后期，UL7蛋白主要在近核细胞质区域以聚集物形式被检测到。此外，透射免疫电子显微镜（TIEM）证实了HSV-2感染细胞中UL7蛋白与细胞内衣壳和病毒粒子的关联。HSV-2 UL7蛋白包含一个在所有疱疹病毒中高度保守的结构域，其中一部分与粟酒裂殖酵母DNA拓扑异构酶III中的结构域具有同源性。我们讨论了UL7蛋白可能在病毒DNA切割/包装过程中发挥辅助作用的可能性。
