Wells V, Mallucci L
Exp Cell Res. 1985 Jul;159(1):27-36. doi: 10.1016/s0014-4827(85)80034-3.
To determine whether the 2-5A system has a role in the regulation of cell growth we have examined all constituents of the 2-5A pathway in mouse embryo fibroblasts undergoing one cycle of division at the tertiary stage under conditions where a high degree of uniformity is maintained within each stage of the cycle. Levels of the 2-5A synthetase increased up to tenfold late in S phase and declined as cells moved through G2. A similar but smaller increase in the 2-5A-dependent ribonuclease was observed, whereas activity of the 2'5' phosphodiesterase was highest in quiescent cells. At the time of maximum synthetase levels no phosphorylated 2-5A could be detected in the intact cell. Endogenous interferon (IFN) was found in the culture supernatants in increasing concentration with cell cycle progression and addition of antibodies to IFN reduced the increase in synthetase seen in late S. Treatment of cells with a growth inhibitor that cells produce also affected synthetase activity.
为了确定2-5A系统在细胞生长调节中是否起作用，我们在三级阶段处于一个分裂周期的小鼠胚胎成纤维细胞中，在细胞周期的每个阶段都保持高度一致性的条件下，检查了2-5A途径的所有成分。2-5A合成酶的水平在S期后期增加了多达10倍，并随着细胞进入G2期而下降。观察到2-5A依赖性核糖核酸酶有类似但较小的增加，而2',5'-磷酸二酯酶的活性在静止细胞中最高。在合成酶水平最高时，完整细胞中未检测到磷酸化的2-5A。在培养上清液中发现内源性干扰素（IFN）随着细胞周期的进展浓度增加，添加抗IFN抗体可减少S期后期合成酶的增加。用细胞产生的生长抑制剂处理细胞也会影响合成酶的活性。
