Gao M, Matusick-Kumar L, Hurlburt W, DiTusa S F, Newcomb W W, Brown J C, McCann P J, Deckman I, Colonno R J
Department of Virology, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543-4000.
J Virol. 1994 Jun;68(6):3702-12. doi: 10.1128/JVI.68.6.3702-3712.1994.
The herpes simplex virus type 1 protease and related proteins are involved in the assembly of viral capsids. The protease encoded by the UL26 gene can process itself and its substrate ICP35, encoded by the UL26.5 gene. To better understand the functions of the protease in infected cells, we have isolated a complementing cell line (BMS-MG22) and constructed and characterized a null UL26 mutant virus, m100. The mutant virus failed to grow on Vero cells and required a complementing cell line for its propagation, confirming that the UL26 gene product is essential for viral growth. Phenotypic analysis of m100 shows that (i) normal amounts of the c and d forms of ICP35 were produced, but they failed to be processed to the cleaved forms, e and f; (ii) viral DNA replication of the mutant proceeded at near wild-type levels, but DNA was not processed to unit length or encapsidated; (iii) capsid structures were observed in thin sections of m100-infected Vero cells by electron microscopy, but assembly of VP5 into hexons of the capsid structure was conformationally altered; and (iv) nuclear localizations of the protease and ICP35 are independent of each other, and the function(s) of Na, at least in part, is to direct the catalytic domain N(o) to the nucleus.
单纯疱疹病毒1型蛋白酶及相关蛋白参与病毒衣壳的组装。由UL26基因编码的蛋白酶可对自身及其由UL26.5基因编码的底物ICP35进行加工处理。为了更好地理解该蛋白酶在受感染细胞中的功能，我们分离出了一个互补细胞系（BMS-MG22），构建并鉴定了一个UL26基因缺失突变病毒m100。该突变病毒无法在Vero细胞上生长，其增殖需要互补细胞系，这证实了UL26基因产物对病毒生长至关重要。对m100的表型分析表明：（i）产生了正常量的ICP35的c和d形式，但它们未能被加工成裂解形式e和f；（ii）突变体的病毒DNA复制以接近野生型的水平进行，但DNA未被加工成单位长度或进行衣壳化；（iii）通过电子显微镜在感染m100的Vero细胞的超薄切片中观察到了衣壳结构，但VP5组装到衣壳结构的六邻体中的构象发生了改变；（iv）蛋白酶和ICP35的核定位彼此独立；并且至少部分地，Na的功能是将催化结构域N(o)引导至细胞核。
