Control of DNA Replication and Cell Division

DNA 复制和细胞分裂的控制

• 批准号: 6765925
• 负责人: TERESA S WANG
• 金额: $ 37.6万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6765925
• 关键词: DNA directed DNA polymerase; DNA repair; DNA replication; Saccharomyces; cell cycle; cell growth regulation; fungal genetics; gene expression; gene mutation; phosphorylation; proliferating cell nuclear antigen

DESCRIPTION (provided by applicant): The overall goal of this research program is to investigate how eukaryotic cells respond to replication perturbations in order to maintain the genomic stability by using fission yeast as the model organism. When faced with chromosomal perturbations, eukaryotic organisms activate a complex set of signal transduction response pathways called checkpoints to regulate cell-cycle transition, to facilitate DNA repair or in some cases to induce apoptosis. Failure of these responses results in genomic instability, which can promote tumor development. In addition, cells have evolved other processes to deal with the genomic perturbations to restart replication. Cells can use a large repertoire of translesional DNA polymerases to perform either error-free or error-prone synthesis, which has the potential to generate point mutations and single base frameshifts. Cells can also use recombination/repair to restart replication, which has the potential of inducing deletion mutations in cells. Mutations in replication genes often induce a mutator phenotype characterized by deletion mutations and point mutations. Little is known about how checkpoints respond to the replication perturbations caused by replication mutants. Our recent studies have shown that mutations in checkpoint genes significantly affect the mutator phenotype in the replication mutants. These findings have led us to hypothesize: In response to genomic perturbation, the checkpoint-clamp recruits translesional polymerases onto chromatin for mutagenic synthesis which generates point mutations and recruits recombination/repair factor(s) to promote deletion mutations. In contrast, Cds1 kinase regulates the recombination/repair factors to prevent deletion mutations. Together these processes will facilitate recovery from a stalled replication to restart DNA replication. Specific Aims proposed to test this hypothesis are: (1). How do the checkpoint clamp and/or checkpoint-clamp-loader recruit translesional polymerases for mutagenic synthesis in order to restart a stalled replication fork? (2). How does the checkpoint effector kinase Cds1 function in preventing deletion mutations to occur, and does the checkpoint clamp/clamp-loader promote deletion mutations in cells to prevent replication fork from collapse and to restart a stalled replication fork?

描述（由申请人提供）： 该研究计划的总体目标是研究真核细胞如何对复制扰动的反应，以通过使用裂变酵母作为模型生物来维持基因组稳定性。当面对染色体扰动时，真核生物会激活一组复杂的信号转导响应途径，称为检查点，以调节细胞周期过渡，以促进DNA修复或在某些情况下诱导细胞凋亡。这些反应的失败导致基因组不稳定性，这可以促进肿瘤的发展。此外，细胞还发展了其他过程，以处理重新启动复制的基因组扰动。细胞可以使用大量的跨性DNA聚合酶曲目执行无错误或容易出现错误的合成，这可能会产生点突变和单个碱基移状。细胞还可以使用重组/修复来重新启动复制，这有可能诱导细胞缺失突变。复制基因中的突变通常诱导以缺失突变和点突变为特征的突变表型。关于检查点如何响应由复制突变体引起的复制扰动的响应知之甚少。我们最近的研究表明，检查点基因中的突变显着影响复制突变体中的突变器表型。这些发现导致我们假设：为了响应基因组扰动，检查点钳募集了跨乳腺聚合酶到染色质上以进行诱变合成，从而产生点突变并募集重组/修复因子（S）以促进缺失突变。相反，CDS1激酶调节重组/修复因子以防止缺失突变。这些过程一起将有助于从停滞的复制恢复到重新启动DNA复制。 提议检验此假设的具体目的是： （1）。检查点夹夹和/或检查点夹具加载器募集型跨性别聚合酶的诱变合成以重新启动停滞的复制叉？ （2）。检查点效应子激酶CDS1如何在防止缺失突变中起作用，检查点夹/夹具加载器是否会促进细胞中的缺失突变以防止复制叉塌陷并重新启动失速复制叉？