METABOLISM OF HISTONE FRACTIONS .6. DIFFERENCES IN PHOSPHORYLATION OF HISTONE FRACTIONS DURING CELL CYCLE
METABOLISM OF HISTONE FRACTIONS .6. DIFFERENCES IN PHOSPHORYLATION OF HISTONE FRACTIONS DURING CELL CYCLE
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DOI：
10.1016/0003-9861(73)90051-9
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发表时间：
1973-01-01
影响因子：
3.9
通讯作者：
TOBEY, RA
中科院分区：
文献类型：
--
作者：
GURLEY, LR;WALTERS, RA;TOBEY, RA
使用新的“异亮氨酸限制”方法同步中国仓鼠细胞在早期G1期的存在和不存在的DNA合成的组蛋白组分的磷酸化。使用制备电泳，组蛋白f1磷酸化被认为是依赖于细胞周期的位置，是不存在的G1-逮捕和G1-穿越细胞和活跃的S期。在G1期阻滞的细胞，这是已知的表现出F1营业额的F1磷酸化的情况下，表明F1磷酸化是不是一个强制性的F1营业额过程的一部分。与组蛋白f1相反，发现组蛋白f2 a2磷酸化与细胞周期位置无关，当DNA合成基本上不存在时，在G1-穿越状态中以相等的幅度发生，当DNA合成活跃时，在S-期发生。当细胞被逮捕在G1-状态的异亮氨酸剥夺，f2 a2磷酸化继续活跃，发生在56%的G1-穿越状态中观察到的速率。这些结果表明，组蛋白f2 a2的磷酸化不依赖于f2 a2的合成，不依赖于DNA的合成，也不依赖于组蛋白f1的磷酸化。由于f2 a2在G1期阻滞的细胞中被积极磷酸化，已知这些细胞在各种类型的RNA（包括信使）的合成中以及在G1期穿越和S期细胞中是活跃的，我们认为组蛋白f2 a2的磷酸化应该继续被考虑在关于DNA模板活性激活的模型中。
Phosphorylation of histone fractions in the presence and absence of DNA synthesis was measured using the new “isoleucine-limiting” method for synchronizing Chinese hamster cells in early G1-phase. Using preparative electrophoresis, histone f1 phosphorylation was found to be dependent upon cell-cycle position, being absent in G1-arrested and G1-traversing cells and active in the S-phase. The absence of f1 phosphorylation in G1-arrested cells, which are known to exhibit f1 turnover, indicates that f1 phosphorylation is not an obligatory part of the f1 turnover process. In contrast to histone f1, it was found that histone f2a2 phosphorylation is independent of cell-cycle position, occurring with equal magnitude in the G1-traversing state when DNA synthesis is essentially absent and in the S-phase when DNA synthesis is active. When cells were arrested in the G1-state by isoleucine deprivation, f2a2 phosphorylation continued to be active, occurring at 56% of the rate observed in the G1-traversing state. These results indicate that phosphorylation of histone f2a2 is independent of f2a2 synthesis, independent of DNA synthesis, and independent of histone f1 phosphorylation. Because f2a2 is actively phosphorylated in G1-arrested cells known to be active in the synthesis of various types of RNA (including messenger) as well as in G1-traversing and S-phase cells, we feel that phosphorylation of histone f2a2 should continue to be considered in models concerning activation of DNA template activity.