Schneider E, Müller B, Schindler R
Biochim Biophys Acta. 1985 Aug 21;825(4):375-83. doi: 10.1016/0167-4781(85)90064-8.
Two heat-sensitive (arrested in G1 at 39.5 degrees C) and two cold-sensitive (arrested in G1 at 33 degrees C) clonal cell-cycle mutants of the murine P-815-X2 mastocytoma line were tested for DNA polymerase alpha, beta and gamma activities. After transfer of mutant cells to the respective nonpermissive temperature, DNA polymerase alpha activities decreased more slowly than relative numbers of cells in S phase. Furthermore, numbers of DNA-synthesizing cells decreased to near-zero levels, whereas polymerase alpha activities in arrested cells were as high as 15-40% of control values. After return of arrested cells to the permissive temperature, polymerase alpha activities increased essentially in parallel with relative numbers of cells in S phase. In contrast to the changes in thymidine kinase (Schneider, E., Müller, B. and Schindler, R. (1983) Biochim. Biophys. Acta 741, 77-85), the decrease of polymerase alpha during entry of cells into proliferative quiescence thus appears to be under rather relaxed control, while after return of arrested cells to the permissive temperature the increase in polymerase alpha is tightly coupled with reentry of cells into S phase. For DNA polymerase beta and gamma activities, no obvious correlation with changes in the proliferative state of cells was detected.
对鼠源P - 815 - X2肥大细胞瘤系的两个热敏性（在39.5℃时停滞于G1期）和两个冷敏性（在33℃时停滞于G1期）克隆细胞周期突变体进行了DNA聚合酶α、β和γ活性的检测。将突变细胞转移至各自的非允许温度后，DNA聚合酶α活性的下降比处于S期的细胞相对数量下降得更慢。此外，DNA合成细胞的数量降至接近零的水平，而停滞细胞中的聚合酶α活性高达对照值的15% - 40%。将停滞细胞恢复到允许温度后，聚合酶α活性的增加基本上与处于S期的细胞相对数量平行。与胸苷激酶的变化情况相反（施奈德，E.，米勒，B.和辛德勒，R.（1983年）《生物化学与生物物理学报》741卷，第77 - 85页），细胞进入增殖静止期时聚合酶α的下降似乎受到的控制较为宽松，而将停滞细胞恢复到允许温度后，聚合酶α的增加与细胞重新进入S期紧密相关。对于DNA聚合酶β和γ活性，未检测到与细胞增殖状态变化的明显相关性。
