Drastic rise of intracellular adenosine(5')tetraphospho(5')adenosine correlates with onset of DNA synthesis in eukaryotic cells.
Drastic rise of intracellular adenosine(5')tetraphospho(5')adenosine correlates with onset of DNA synthesis in eukaryotic cells.
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细胞内腺苷 (5) 四磷酸 (5) 腺苷的急剧增加与真核细胞 DNA 合成的开始相关。
DOI：
10.1111/j.1432-1033.1984.tb07897.x
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
F. Grummt
中科院分区：
文献类型：
--
作者：
C. Weinmann;A. Hedl;I. Grummt;W. Albert;F. Ferdinand;R. Friis;G. Pierron;W. Moll;F. Grummt
基于用于 ATP 测量的荧光素/荧光素酶方法，开发了一种腺苷 (5') 四磷酸 (5') 腺苷 (Ap4A) 测定方法，该方法可以测定细胞提取物中皮摩尔量的未标记 Ap4A。在真核细胞中，该方法产生的 Ap4A 水平从 0.01 µM 到 13 µM 不等，具体取决于细胞的生长、细胞周期、转化和分化状态。对 G1 停滞的小鼠 3T3 和幼仓鼠肾成纤维细胞进行有丝分裂刺激后，Ap4A 池在 G1 期进展过程中逐渐增加 1000 倍，在 S 期达到约 10 µM 的最大 Ap4A 浓度。如果暴露于外部促有丝分裂刺激剂（过量血清）并同时暴露于抑制进入 S 期的同步剂（羟基脲），静止的 3T3 细胞会在“定型”但复制前状态下达到高水平的 Ap4A（1 µM）。当在去除刺激物后的不同时间去除DNA复制的阻断时，发现DNA合成的承诺衰减与Ap4A库的收缩相关。缺乏明确 G1 期的细胞（V79 肺成纤维细胞，绒泡菌）即使在有丝分裂期间也具有高基础水平的 Ap4A（约 0.3 microM）。从这个高水平开始，Ap4A 浓度在 S 期仅增加约十倍。使用感染了转化缺陷型温度敏感病毒突变体（td-ts）的鸡胚细胞进行的温度下调实验表明，35℃下转化状态的表达伴随着细胞Ap4A池的十倍增加。用干扰素处理指数生长的人类细胞，同时抑制 DNA 合成，导致细胞内 Ap4A 水平在 20 小时内降低十倍。根据这些结果和先前报道的结果，讨论了 Ap4A 作为细胞周期和增殖控制“第二信使”的可能性，证明 Ap4A 是哺乳动物 DNA 聚合酶 α 的配体，触发静止哺乳动物细胞中的 DNA 复制，并在启动 DNA 合成中具有活性。
An assay of adenosine(5')tetraphospho(5')adenosine (Ap4A), based on the luciferin/luciferase method for ATP measurement, was developed, which allows one to determine picomolar amounts of unlabeled Ap4A in cellular extracts. In eukaryotic cells this method yielded levels of Ap4A varying from 0.01 microM to 13 microM depending on the growth, cell cycle, transformation, and differentiation state of cells. After mitogenic stimulation of G1-arrested mouse 3T3 and baby hamster kidney fibroblasts the Ap4A pools gradually increased 1000-fold during progression through the G1 phase reaching maximum Ap4A concentrations of about 10 microM in the S phase. Quiescent 3T3 cells reach a high level of Ap4A (1 microM) in a 'committed' but prereplicative state if exposed to an external mitogenic stimulant (excess of serum) and simultaneously to a synchronizer which inhibits entry into the S phase (hydroxyurea). When the block for DNA replication was removed at varying times after removal of the stimulant decay of commitment to DNA synthesis was found correlated with a shrinkage of the Ap4A pool. Cells lacking a defined G1 phase (V79 lung fibroblasts, Physarum) possess a constitutively high base level of Ap4A (about 0.3 microM) even during mitosis. From this high level, Ap4A concentration increases only about tenfold during the S phase. Temperature-down-shift experiments, using chick embryo cells infected with transformation-defective temperature-sensitive viral mutants(td-ts), have shown that the expression of the transformed state at 35 degrees C is accompanied by a tenfold increase of the cellular Ap4A pool. Treatment of exponentially growing human cells with interferon leads, concomitantly with an inhibition of DNA syntheses, to a tenfold decrease in intracellular Ap4A levels within 20 h. The possibility of Ap4A being a 'second messenger' of cell cycle and proliferation control is discussed in the light of these results and those reported previously demonstrating that Ap4A is a ligand of mammalian DNA polymerase alpha, triggers DNA replication in quiescent mammalian cells and is active in priming DNA synthesis.
二腺苷 5,5"-P1,P4-四磷酸结合蛋白与 HeLa 细胞 DNA 聚合酶 α 的关联。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Rapaport,E;Zamecnik,PC;Baril,EF
通讯作者：
Baril,EF
核 DNA 复制的启动：形成定向复制前细胞状态的证据。
DOI：
10.1073/pnas.78.9.5677
发表时间：
1981
影响因子：
11.1
作者：
Das,M
通讯作者：
Das,M