Eukaryotic Chromosome Replication

真核染色体复制

• 批准号: 7161397
• 负责人: BONITA J BREWER
• 金额: $ 47.94万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1976
• 资助国家: 美国
• 起止时间: 1976-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7161397
• 关键词: Alleles; Area; Biological; Biological Assay; Bypass; CDC7 gene; CHEK2 gene; Cells; Centromere; Chromosomes; Cis-Acting Sequence; Class; Cyclin-Dependent Kinases; DNA Sequence Rearrangement; Elements; Fire - disasters; Genome; Hand; Literature; Maintenance; Modeling; Mutate; Mutation; Nucleotides; Peptide Initiation Factors; Phase; Phosphotransferases; Plasmids; Process; Property; Proteins; Rate; Regulatory Element; Replication Origin; Reporting; Resources; Ribonucleotide Reductase Inhibitor; Role; Saccharomyces cerevisiae; Saccharomycetales; Sequence Analysis; Testing; Time; Work; chromosome replication; fascinate; hydroxyurea; mutant; programs; segregation; telomere

DESCRIPTION (provided by applicant): Replication of eukaryotic chromosomes is an ordered process involving the activation of multiple sets of replication origins during S phase. Within S phase, however, not all origins fire at the same time. It is this regulated firing of origins within S phase (the temporal program of origin activation) that has long fascinated us and that we propose to continue to study in budding yeast Saccharomyces cerevisiae. The four areas of proposed work include the following: (1) The S phase activators of Cdk1, Clb5p and Clb6p, are not equivalent with respect to origin firing. Clb6p, unlike Clb5p, is inefficient at activating late origins. We will test models for the mechanistic differences between Clb5p and Clb6p action with regard to late-firing origins. We will also explore the interaction between CDK and the other S phase kinase, Cdc7p. (2) What distinguishes early- from late-firing origins is unknown. We imagine there is an S phase clock that metes out critical initiation factors to different origins at different times during S phase. Reports in the literature suggest that cells treated with hydroxyurea (HU) or mutated in RAD53 show an altered clock with regard to late origins. We propose to explore the role of nucleotide pools and the S-phase checkpoint protein Rad53p in the S phase clock. (3) When an origin fires in S phase is due in large part to the chromosomal context of that origin. Origins near telomeres are late replicating; origins near centromeres are early replicating. We wish to test the idea that this temporal distinction between chromosome domains is important for chromosome maintenance and segregation. (4) The cis-regulatory elements responsible for origin timing only have been vaguely defined. We propose to extend our whole-genome replication studies to characterize late origins as a class in hopes of defining the cis-regulatory sequences and elucidating their mechanism(s) of action.

描述（由申请人提供）：真核细胞染色体的复制是一个有序的过程，涉及在S期激活多组复制起点。然而，在S阶段，并不是所有的起源都同时燃烧。正是这种调节发射的起源在S期（时间程序的起源激活），长期以来一直吸引着我们，我们建议继续研究芽殖酵母酿酒酵母。（1）Cdk 1、Clb 5 p和Clb 6p的S相激活剂在起源点火方面是不等价的。与Clb 5 p不同，Clb 6p在激活晚期起源方面效率低下。我们将测试模型之间的机制差异Clb 5 p和Clb 6p行动方面的迟发起源。我们还将探讨CDK和其他S期激酶Cdc 7 p之间的相互作用。(2)早期和晚期的区别是未知的。我们想象有一个S阶段时钟，它在S阶段的不同时间向不同的起源梅特斯关键的启动因子。文献中的报告表明，用羟基脲（HU）处理或在RAD 53中突变的细胞显示关于晚期起源的改变的时钟。我们建议探讨核苷酸池和S期检查点蛋白Rad 53 p在S期时钟中的作用。(3)当一个起源在S期被激发时，很大程度上是由于该起源的染色体背景。端粒附近的起源是晚期复制;着丝粒附近的起源是早期复制。我们希望测试的想法，这种时间的区别染色体域是重要的染色体的维护和分离。(4)负责起源时间的顺式调控元件仅被模糊地定义。我们建议扩展我们的全基因组复制研究，以表征晚起源作为一个类，希望定义的顺式调控序列，并阐明其作用机制。