RNA Synthesis by Vesicular Stomatitis Virus and a Small Plaque Mutant: Effects of Cycloheximide
RNA Synthesis by Vesicular Stomatitis Virus and a Small Plaque Mutant: Effects of Cycloheximide
复制标题
水泡性口炎病毒和小斑块突变体的 RNA 合成：放线菌酮的作用
作者：
G. Wertz;M. Levine
在体外、鸡胚和小鼠L-细胞培养中研究了水泡性口炎病毒野生型（L1 VSV）和一种噬斑大小的小突变体（S2 VSV）的病毒RNA合成。在感染L1或S2 VSV的CE或L细胞中合成的病毒特异性RNA具有相同的大小类别，12至15 S、28 S和38 S。主要的差异在于每个大小类别产生的RNA的比例。L1 VSV总是合成较大比例的38 S RNA，S2 VSV产生较大比例的12至15 S RNA。S2和L1 VSV在体外和细胞培养中均表现出RNA转录酶活性。体外反应产物相同，均为12 ~ 15 S。在放线菌酮存在下，CE或L-细胞培养物中病毒体相关转录酶的产物对于两种病毒也是相同的，但与体外产物不同之处在于制备了28 S和12至15 S RNA。在感染后不同时间添加放线菌酮的效果表明，S2和L1 VSV都需要早期（0-2 h）合成新的蛋白质，以启动和维持病毒RNA合成的正常速率。然而，在L1 VSV感染的RNA合成的总体速率成为独立的蛋白质合成后2小时，而在S2 VSV感染的速率没有。对于任何一种病毒，在没有蛋白质合成的情况下都不会发生38 S RNA的合成。此外，连续的38 S RNA生产需要连续的蛋白质合成。在S2−或L1 VSV感染的CE或L细胞中加入放线菌酮后，38 S RNA的产生在30分钟内停止，这些细胞已经开始合成38 S形式。环己酰亚胺诱导的38 S RNA合成的停止伴随着12至15 S和28 S RNA在L1 VSV感染的细胞中的生产显着增加，但没有增加的小RNA种类的合成发生在S2 VSV感染的细胞。
The synthesis of viral RNA by wild-type vesicular stomatitis virus (L1VSV) and a small, plaque-size mutant (S2VSV) was studied in vitro and in chicken embryo (CE) and mouse L-cell cultures. Virus-specific RNA synthesized in CE or L cells infected with either L1 or S2VSV at low multiplicity was of the same size classes, 12 to 15S, 28S, and 38S. The major differences were in the proportion of RNA produced of each size class. L1VSV always synthesized larger proportions of 38S RNA, and S2VSV produced larger proportions of 12 to 15S RNA. Both S2 and L1VSV exhibited RNA transcriptase activity in vitro and in cell culture. The products of the in vitro reaction were the same, 12 to 15S for both. The products of the virion-associated transcriptase in CE or L-cell cultures in the presence of cycloheximide were also the same for both viruses but differed from the in vitro products in that 28S and 12 to 15S RNA were made. The effects of addition of cycloheximide at various times after infection demonstrated that new protein synthesis is required early (0-2 h) for both S2 and L1VSV to initiate and maintain the normal rate of viral RNA synthesis. However, the overall rate of RNA synthesis in L1VSV infections became independent of protein synthesis after 2 h whereas the rate in S2VSV infections did not. With either virus, synthesis of 38S RNA did not occur in the absence of protein synthesis. Moreover, continuous 38S RNA production required continuous protein synthesis. Production of 38S RNA ceased within 30 min after addition of cycloheximide to S2− or L1VSV-infected CE or L cells that had already begun to synthesize the 38S form. The cycloheximide-induced cessation of 38S RNA synthesis was accompanied by a marked increase in production of 12 to 15S and 28S RNA in L1VSV-infected cells, but no increase in synthesis of small RNA species occurred in S2VSV-infected cells.