Hammond D C, Lesnaw J A
School Of Biological Sciences, University of Kentucky, Lexington 40506.
Virology. 1987 Oct;160(2):330-5. doi: 10.1016/0042-6822(87)90003-1.
The ts mutant F1 of vesicular stomatitis virus, New Jersey serotype, directs the synthesis of undermethylated 5'-terminal cap structures in vitro. In order to determine the relationship between the ts and hypomethylation phenotypes, a spontaneous revertant rev(ts)F1 of the ts phenotype was analyzed. The revertant retained the hypomethylation phenotype. The four cap structures (GpppA, 7mGpppA, GpppAm, and 7mGpppAm) synthesized in mutant and revertant-directed reactions in the presence of low as well as high concentrations of AdoMet were resolved by HPLC. Quantitation of the data and analysis of cap substrate to product ratios revealed that despite apparent similarities between the two hypomethylation phenotypes, the functional lesions in F1 and rev(ts)F1 were different. F1 displayed an AdoMet concentration-dependent alteration in the GpppA----GpppAm reaction and an AdoMet concentration-independent alteration in the GpppA----7mGpppA reaction. In contrast, rev(ts)F1 displayed AdoMet concentration-dependent alterations in the reactions GpppA----7mGpppA and GpppAm----7mGpppAm.
新泽西血清型水疱性口炎病毒的温度敏感（ts）突变体F1在体外指导合成低甲基化的5'-末端帽结构。为了确定ts表型和低甲基化表型之间的关系，对ts表型的自发回复体rev(ts)F1进行了分析。该回复体保留了低甲基化表型。在存在低浓度和高浓度S-腺苷甲硫氨酸（AdoMet）的情况下，通过高效液相色谱（HPLC）解析了在突变体和回复体指导的反应中合成的四种帽结构（GpppA、7mGpppA、GpppAm和7mGpppAm）。数据定量和帽底物与产物比率分析表明，尽管两种低甲基化表型之间存在明显相似性，但F1和rev(ts)F1中的功能损伤是不同的。F1在GpppA→GpppAm反应中表现出AdoMet浓度依赖性变化，在GpppA→7mGpppA反应中表现出AdoMet浓度非依赖性变化。相比之下，rev(ts)F1在GpppA→7mGpppA和GpppAm→7mGpppAm反应中表现出AdoMet浓度依赖性变化。
