Carter T H, Blanton R A
J Virol. 1978 Nov;28(2):450-6. doi: 10.1128/JVI.28.2.450-456.1978.
The kinetics of accumulation of early virus RNA in the cytoplasm of KB cells infected at 40.5 degrees C by wild-type (WT) adenovirus type 5 and a temperature-sensitive "early" mutant, H5ts125 (ts125), were compared by hybridization of unlabeled RNA in solution to the (3)H-labeled l strand of Ad5 DNA HindIII restriction endonuclease fragment A. In the presence of 1-beta-d-arabinofuranosylcytosine, A(l) RNA accumulated in WT-infected cells for 9 h and then decreased in concentration to 6% of the 9-h concentration by 18 h. In ts125-infected cells, A(l) RNA accumulated for 12 h and then remained at the same concentration for at least 6 h thereafter. The concentrations of virus RNA from the four early transcription regions of the genome were measured at 15 h in cells infected at 40.5 degrees C in the presence of 1-beta-d-arabinofuranosylcytosine by: (i) ts125 and WT; (ii) two other ts early mutants, ts107 and ts149; and (iii) a revertant of ts125. The revertant and ts149, a mutant from a different complementation group than ts125, both accumulated all early virus cytoplasmic RNA species in amounts similar to, or less than, WT. However, both ts125 and ts107, independently isolated mutations in the 72,000-molecular-weight (72K) DNA-binding protein gene, accumulated cytoplasmic early RNA in excess of that found in WT infection. This pattern of RNA accumulation with the mutants and WT virus was the same in the nuclei as in the cytoplasm at 40.5 degrees C. At 32 degrees C, however, the abundance of nuclear virus RNA from all four early regions was the same in cells infected by either ts125 or WT. Differences in the relative abundance of nuclear RNA from the four early regions were observed in cells infected at 40.5 and 32 degrees C, but were not dependent upon the infecting virus genotype. These results are consistent with autoregulation of early gene expression by the 72K protein and support the hypothesis that the 72K protein either decreases the rate of early virus transcription or increases the rate of virus RNA degradation in the nucleus.
通过将溶液中未标记的RNA与腺病毒5型（Ad5）DNA HindIII限制性内切酶片段A的³H标记的l链杂交，比较了在40.5℃下被野生型（WT）腺病毒5型和温度敏感的“早期”突变体H5ts125（ts125）感染的KB细胞胞质中早期病毒RNA的积累动力学。在存在1-β-D-阿拉伯呋喃糖基胞嘧啶的情况下，WT感染细胞中A(l) RNA积累9小时，然后在18小时时浓度降至9小时浓度的6%。在ts125感染的细胞中，A(l) RNA积累12小时，然后在此后至少6小时保持在相同浓度。在存在1-β-D-阿拉伯呋喃糖基胞嘧啶的情况下，于40.5℃感染的细胞中，在15小时时测量了来自基因组四个早期转录区域的病毒RNA浓度，这些细胞分别被以下病毒感染：(i) ts125和WT；(ii) 另外两个ts早期突变体ts107和ts149；(iii) ts125的一个回复突变体。该回复突变体和ts149（来自与ts125不同互补组的突变体）积累的所有早期病毒胞质RNA种类的量与WT相似或低于WT。然而，ts125和ts107（72,000分子量（72K）DNA结合蛋白基因中的独立分离突变）积累的胞质早期RNA超过了WT感染时的量。在40.5℃下，突变体和WT病毒的这种RNA积累模式在细胞核和细胞质中是相同的。然而，在32℃时，ts125或WT感染的细胞中来自所有四个早期区域的核病毒RNA丰度相同。在40.5℃和32℃感染的细胞中观察到来自四个早期区域的核RNA相对丰度存在差异，但不依赖于感染病毒的基因型。这些结果与72K蛋白对早期基因表达的自动调节一致，并支持以下假设：72K蛋白要么降低早期病毒转录速率，要么增加细胞核中病毒RNA的降解速率。
