Subramanian K N
Nucleic Acids Res. 1982 Jun 11;10(11):3475-86. doi: 10.1093/nar/10.11.3475.
The effect of in vitro methylation at the HpaII sites in polyoma DNA on viral gene expression and the maintenance of the methyl groups upon replication in vivo were examined. Most of the methylatable sites are located in the early region coding for the viral large T antigen which is essential for the replication and infectivity of the viral DNA. Methylated or mock-methylated polyoma DNA produced the same number of virus plaques appearing at the same time post-transfection in either case. The lack of effect on the infectivity of the viral DNA indicates that the expression of the T antigen gene was not inhibited by methylation. Replication in vivo of the DNA also resulted in a total loss of the methyl groups introduced in vitro. These results underscore basic differences between the behavior of an autonomously functioning papovavirus DNA and the animal cell DNA vis-a-vis methylation at CpG sites. These differences might be due to subtle variations in the mechanism of regulation of gene expression and replication in the two systems.
研究了多瘤病毒DNA中HpaII位点的体外甲基化对病毒基因表达的影响以及体内复制时甲基基团的维持情况。大多数可甲基化位点位于编码病毒大T抗原的早期区域，该抗原对于病毒DNA的复制和感染性至关重要。在两种情况下，甲基化或模拟甲基化的多瘤病毒DNA在转染后相同时间产生的病毒蚀斑数量相同。对病毒DNA感染性缺乏影响表明T抗原基因的表达未被甲基化抑制。DNA在体内的复制也导致体外引入的甲基基团完全丢失。这些结果强调了自主发挥功能的乳头瘤多瘤病毒DNA与动物细胞DNA在CpG位点甲基化行为上的基本差异。这些差异可能是由于两个系统中基因表达和复制调控机制的细微变化所致。
