Cell cycle checkpoint control

细胞周期检查点控制

• 批准号: 17370072
• 负责人: MURAKAMI Hiroshi
• 金额: $ 9.34万
• 依托单位: NAGOYA CITY UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17370072/
• 关键词: genetics; gene; cancer

During meiosis, high levels of recombination initiated by DNA double-strand breaks (DSBs) occur only after DNA replication. How DSB formation is coupled to DNA replication is unknown, however. We examined several DNA replication proteins for a role in this coupling in Schizosaccharomyces pombe and now show that ribonucleotide reductase (RNR), the rate-limiting enzyme of deoxyribonucleotide synthesis and the target of the DNA synthesis inhibitor hydroxyurea (HU), is indirectly required for DSB formation linked to DNA replication. In cells in which the function of the DNA replication checkpoint proteins Rad1p, Rad3p, Rad9p, Radl7p, Rad26p, Huslp, or Cdslp was compromised, however, DSB formation occurred at similar frequencies in the absence or presence of HU. The DSBs in the HU-treated mutant cells occurred at normal sites and were associated with recombination. We propose that the sequence of meiotic S phase and initiation of recombination is coordinated by DNA replication checkpoint proteins.The kinase Cdc2p is a central regulator of entry into and progression through nuclear division during mitosis and meiosis in eukaryotes. Cdc2p is activated at the onset of mitosis by dephosphorylation on tyrosine-15, the phosphorylation status of which is determined mainly by the kinase Weel p and the phosphatase Cdc25p. In fission yeast, the forkhead-type transcription factor Mei4p is required for expression of many genes during meiosis, with mei4 mutant cells arresting before meiosis I. The mechanism of cell cycle arrest in mei4 cells has remained unknown, however. We now show that cdc25+ is an important target of Mei4p in control of entry into meiosis I. Forced dephosphorylation of Cdc2p on tyrosine-15 thus induced meiosis I in mei4 mutant cells without a delay, although no spores were formed. We propose that Mei4p acts as a rate-limiting regulator of meiosis I by activating cdc25+ transcription in coordination with other meiotic events.

在减数分裂期间，由DNA双链断裂（DSB）引发的高水平重组仅发生在DNA复制之后。然而，DSB的形成如何与DNA复制相结合尚不清楚。我们研究了几种DNA复制蛋白在裂殖酵母的这种耦合中的作用，现在表明，核糖核苷酸还原酶（RNR），脱氧核糖核苷酸合成的限速酶和DNA合成抑制剂羟基脲（HU）的目标，是间接需要DSB形成连接到DNA复制。然而，在DNA复制检查点蛋白Rad 1 p、Rad 3 p、Rad 9 p、Rad 17 p、Rad 26 p、Huslp或Cdslp的功能受损的细胞中，在不存在或存在HU的情况下，DSB形成以相似的频率发生。HU处理的突变细胞中的DSB发生在正常位点，并与重组有关。我们认为，减数分裂S期的顺序和重组的启动是由DNA复制检查点蛋白协调的，激酶Cdc 2 p是真核生物有丝分裂和减数分裂过程中进入核分裂和通过核分裂进行的中心调节因子。Cdc 2 p在有丝分裂开始时通过酪氨酸-15上的去磷酸化而被激活，酪氨酸-15的磷酸化状态主要由激酶Weel p和磷酸酶Cdc 25 p决定。在裂殖酵母中，叉头型转录因子Mei 4p是减数分裂期间许多基因表达所需的，mei 4突变细胞在减数分裂I之前停止。然而，mei 4细胞中细胞周期停滞的机制仍不清楚。我们现在表明cdc 25+是Mei 4p控制进入减数分裂I的重要靶标。强迫去磷酸化的Cdc 2 p酪氨酸-15，从而诱导减数分裂我在mei 4突变细胞没有延迟，虽然没有孢子形成。我们建议，Mei 4p作为一个限速调节减数分裂I激活cdc 25+转录与其他减数分裂事件的协调。

项目成果

Cdc2p and Cdcl3p is required for cell cycle arrest induced by defective RNA splicing in fission yeast

Cdc2p 和 Cdcl3p 是裂殖酵母中 RNA 剪接缺陷诱导的细胞周期停滞所必需的

• 发表时间: 2005
• 期刊: J Biol Chem 280
• 作者: M.Shimada;C.Namikawa-Yamada;M.Nakanishi;H.Murakami*.
• 通讯作者: H.Murakami*.

A checkpoint control linking meiotic S phase and recombination initiation in fission yeast.

连接裂殖酵母减数分裂 S 期和重组起始的检查点控制。

• 发表时间: 2005
• 期刊: Proc.Natl.Acad.Sci.USA 102
• 作者: Y.Tonami;H.Murakami;K.Shirahige;M.Nakanishi
• 通讯作者: M.Nakanishi

Regulation of Cdc2p and Cdc13p is required for cell cycle arrest induced by defective RNA splicing in fission yeast

• DOI: 10.1074/jbc.m504746200
• 发表时间: 2005-09-23
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Shimada, M;Namikawa-Yamada, C;Murakami, H
• 通讯作者: Murakami, H