Cyclin-Dependent Kinase Inhibits Reinitiation of a Normal S-Phase Program during G2 in Fission Yeast
Cyclin-Dependent Kinase Inhibits Reinitiation of a Normal S-Phase Program during G2 in Fission Yeast
复制标题
DOI：
10.1128/mcb.00185-09
复制
发表时间：
2009-08-01
影响因子：
5.3
通讯作者：
Nurse, Paul
中科院分区：
文献类型：
--
作者：
Kiang, Lee;Heichinger, Christian;Nurse, Paul
为了在每个细胞周期中实现一次基因组的忠实复制，在G(2)中阻止了S期的重新启动，并且限制了起源在S期的重新启动。我们研究了裂变酵母在G(2)阶段的转录阻滞。当G(2)/M周期蛋白依赖性激酶（CDK）活性耗尽时，DNA合成被认为是重复的S期，没有有丝分裂，但事实并非如此。我们在这里发现G(2)/M CDK在G(2)中缺失时，诱导了重复的S期，这与正常的G(1)/S转录和细胞大小加倍有关。大多数正常的有丝分裂s期起源被利用，尽管效率不同，而且整个基因组的复制基本上是相等的。我们得出结论，CDK在G(2)期间抑制S期的重新启动，如果G(2)/M CDK被耗尽，复制的结果是诱导一个基本正常的S期程序，只有起源使用和效率的微小差异。
To achieve faithful replication of the genome once in each cell cycle, reinitiation of S phase is prevented in G(2) and origins are restricted from refiring within S phase. We have investigated the block to rereplication during G(2) in fission yeast. The DNA synthesis that occurs when G(2)/M cyclin-dependent kinase (CDK) activity is depleted has been assumed to be repeated rounds of S phase without mitosis, but this has not been demonstrated to be the case. We show here that on G(2)/M CDK depletion in G(2), repeated S phases are induced, which are correlated with normal G(1)/S transcription and attainment of doublings in cell size. Mostly normal mitotic S-phase origins are utilized, although at different efficiencies, and replication is essentially equal across the genome. We conclude that CDK inhibits reinitiation of S phase during G(2), and if G(2)/M CDK is depleted, replication results from induction of a largely normal S-phase program with only small differences in origin usage and efficiency.