Peluso R W, Lamb R A, Choppin P W
J Virol. 1977 Jul;23(1):177-87. doi: 10.1128/JVI.23.1.177-187.1977.
Polypeptide synthesis in three different cell types infected with simian virus 5 has been examined using high-resolution polyacrylamide slab gel electrophoresis, and all of the known viral polypeptides have been identified above the host cell background. The polypeptides were synthesized in infected cells in unequal proportions, which are approximately the same as they are found in virions, suggesting that their relative rates of synthesis are controlled. The nucleocapsid polypeptide (NP) was the first to be detected in infected cells, and by 12 to 14 h the other virion structural polypeptides were identified, except for the polypeptides comprising the smaller glycoprotein (F). However, a glycosylated precursor (F(0)) with a molecular weight of 66,000 was found in each cell type, and pulse-chase experiments suggested that this precursor was cleaved to yield polypeptides F(1) and F(2). No other proteolytic processing was found. In addition to the structural polypeptides, the synthesis of five other polypeptides, designated I through V, has been observed in simian virus 5-infected cells. One of these (V), with a molecular weight of 24,000, was found in all cells examined and may be a nonstructural viral polypeptide. In contrast, there are polypeptides present in uninfected cells that correspond in size to polypeptides I through IV, and similar polypeptides have also been detected in increased amounts in cells infected with Sendai virus. These findings, and the fact that the synthesis of all four of these polypeptides is not increased in every cell type, suggest that they represent host polypeptides whose synthesis may be enhanced upon infection. When a high salt concentration was used to decrease host cell protein synthesis in infected cells, polypeptides IV and (to a lesser extent) I were synthesized in relatively greater amounts than other cellular polypeptides, as were the viral polypeptides. The possibility that these polypeptides may play some role in virus replication is discussed.
利用高分辨率聚丙烯酰胺平板凝胶电泳检测了感染猿猴病毒5的三种不同细胞类型中的多肽合成情况，并且在宿主细胞背景之上鉴定出了所有已知的病毒多肽。这些多肽在受感染细胞中的合成比例不均等，这与它们在病毒粒子中的比例大致相同，表明它们的相对合成速率受到控制。核衣壳多肽（NP）是在受感染细胞中最早被检测到的，到12至14小时时，除了构成较小糖蛋白（F）的多肽外，其他病毒粒子结构多肽都已被鉴定出来。然而，在每种细胞类型中都发现了一种分子量为66,000的糖基化前体（F(0)），脉冲追踪实验表明该前体被切割产生多肽F(1)和F(2)。未发现其他蛋白水解加工过程。除了结构多肽外，在感染猿猴病毒5的细胞中还观察到另外五种多肽的合成，分别命名为I至V。其中一种（V）分子量为24,000，在所有检测的细胞中都有发现，可能是一种非结构病毒多肽。相比之下，未感染细胞中存在与多肽I至IV大小相对应的多肽，并且在感染仙台病毒的细胞中也检测到了数量增加的类似多肽。这些发现以及这四种多肽在每种细胞类型中的合成并非都增加这一事实表明，它们代表宿主多肽，其合成可能在感染后增强。当使用高盐浓度降低受感染细胞中的宿主细胞蛋白质合成时，多肽IV和（程度较轻的）I与病毒多肽一样，比其他细胞多肽合成的量相对更多。文中讨论了这些多肽可能在病毒复制中发挥某种作用的可能性。
