CYCLIN PCNA IS THE AUXILIARY PROTEIN OF DNA POLYMERASE-DELTA
CYCLIN PCNA IS THE AUXILIARY PROTEIN OF DNA POLYMERASE-DELTA
复制标题
DOI：
10.1038/326515a0
复制
发表时间：
1987-04-02
期刊：
影响因子：
64.8
通讯作者：
MACDONALDBRAVO, H
中科院分区：
文献类型：
--
作者：
BRAVO, R;FRANK, R;MACDONALDBRAVO, H
鉴定正常细胞在细胞周期中表达受调控的细胞蛋白对于理解细胞增殖控制机制至关重要。一种相对分子质量为36000 （Mr36K）的核蛋白，其合成与细胞的增殖状态相关，已在人类、小鼠、仓鼠和禽类的几种细胞类型中被鉴定出来1 - 5。细胞周期蛋白的合成速率在静止细胞中非常低，在DNA合成前不久的血清刺激后，细胞周期蛋白的合成速率会增加几倍6,7。免疫荧光和放射自显影研究表明，细胞周期蛋白在S期的细胞核染色模式具有顺序的外观，DNA合成与细胞周期蛋白阳性核之间存在明显的相关性7 - 10。增殖细胞核抗原（PCNA）8,11 - 13和细胞周期蛋白具有许多共同的性质，并且已经证明两者是相同的12,14。最近，从小牛胸腺中分离出了一种DNA聚合酶-δ对低引物/模板比率的模板具有催化活性所必需的蛋白质。我们在这里报告细胞周期蛋白和DNA聚合酶-δ的辅助蛋白是相同的。
Identification of the cellular proteins whose expression is regulated during the cell cycle in normal cells is essential for understanding the mechanisms involved in the control of cell proliferation. A nuclear protein called cyclin of relative molecular mass 36,000 (Mr36K), whose synthesis correlates with the proliferative state of the cell, has been identified in several cell types of human, mouse, hamster and avian origin1–5. The rate of cyclin synthesis is very low in quiescent cells and increases several fold after serum stimulation shortly before DNA synthesis6,7. Immunofluorescence and autoradiography studies have shown that the nuclear staining patterns of cyclin during S phase have a sequential order of appearance and a clear correlation can be found between DNA synthesis and cyclin positive nuclei7–10. The proliferating cell nuclear antigen (PCNA)8,11–13and cyclin have many common properties and it has been shown that these two are identical12,14. Recently a protein which is required by DNA polymerase-δ for its catalytic activity with templates having low primer/template ratios has been isolated from calf thymus15. We report here that cyclin and the auxiliary protein of DNA polymerase-δ are identical.