CHARACTERIZATION OF 2 RNA-POLYMERASE ACTIVITIES INDUCED BY MOUSE HEPATITIS-VIRUS
CHARACTERIZATION OF 2 RNA-POLYMERASE ACTIVITIES INDUCED BY MOUSE HEPATITIS-VIRUS
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DOI：
10.1128/jvi.42.3.847-853.1982
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发表时间：
1982-01-01
影响因子：
5.4
通讯作者：
STOHLMAN, SA
中科院分区：
文献类型：
--
作者：
BRAYTON, PR;LAI, MMC;STOHLMAN, SA
在小鼠肝炎病毒A59株（MHV-A59）感染的细胞中发现了RNA依赖的RNA聚合酶活性。该酶在感染细胞中被诱导，在MHV-A59病毒粒子中未被检测到。在感染早期和晚期检测到两个RNA聚合酶活性高峰。这些聚合酶活性与病毒特异性RNA合成的早、晚时间序列一致。发现两者都与膜组分有关。两种聚合酶的酶学性质有显著差异。在没有Mg2+的情况下，早期聚合酶可以被K+激活，而晚期聚合酶则不能，其最适pH值也低于晚期聚合酶。这些酶显然代表两种不同的RNA聚合酶，在病毒特异性RNA合成中发挥不同的作用。测定了环己亚胺对mhv特异性RNA合成的影响。连续的蛋白质合成是早期和晚期RNA合成所必需的，也可能是早期RNA合成关闭所必需的。
RNA-dependent RNA polymerase activity was found in mouse hepatitis virus strain A59 (MHV-A59)-infected cells. The enzyme was induced in the infected cells and could not be detected in the MHV-A59 virion. Two peaks of RNA polymerase activity, one early and the other late in infection, were detected. These polymerase activities were in temporal sequence with early and late virus-specific RNA sythesis. Both were found to be associated with membrane fractions. There were significant differences in the enzymatic properties of the 2 polymerases. The early polymerase, but not the late polymerase, could be activated by K+ in the absence of Mg2+ and also had a lower optimum pH than the late polymerase. The enzymes apparently represent 2 different species of RNA polymerase and perform different roles in virus-specific RNA synthesis. The effects of cycloheximide on MHV-specific RNA synthesis were determined. Continuous protein synthesis was required for both early and late RNA synthesis and migth also be required for shutoff of early RNA synthesis.