Cis-and trans-acting determinants of replication timing

复制时间的顺式和反式作用决定因素

基本信息

批准号：
7057820
负责人：
JOEL A HUBERMAN
金额：
$ 38.22万
依托单位：
ROSWELL PARK CANCER INSTITUTE CORP
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-05-01 至 2008-04-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): One of the cellular alterations required for development of cancer is "genomic instability," a term that describes a collection of pathways all leading to increased frequency of gene mutation and altered patterns of gene expression. Among the mechanisms causing genomic instability are chromosome breakage, gene amplification, and changes in levels of gene expression. The latter are frequently associated with changes in gene methylation status. All of these mechanisms have been correlated with changes in replication timing, and it is possible that in some cases changes in replication timing may be the primary cause of these phenomena. So far it has been difficult to evaluate the role of changes in replication timing in cancer development, because so little is known about the mechanisms controlling replication timing. Fortunately previous studies in budding and fission yeasts (Saccharomyces cerevisiae and Schizosaccharomyces pombe), in our laboratory and others, provide entry points into understanding replication timing. In both yeasts we have identified replication origins containing internal cis-acting sequences that determine late replication timing. Here we propose simple strategies that will permit us to precisely localize those sequences and use them to pull out the corresponding trans-acting proteins. In addition, studies in other laboratories and ours have already identified several proteins likely to play roles in replication timing. We intend to investigate the potential roles of all of these proteins in replication timing by studying the effects on timing of mutations in the corresponding genes and by studying the binary interactions between these proteins. The results of the proposed experiments should permit us to develop detailed models of the mechanisms controlling replication timing in both budding and fission yeasts. The conserved aspects of these models are likely to prove applicable to other eukaryotic cells, including human cells. This information may permit the development of drugs that will enhance normal replication timing stability and thus inhibit or reverse the development of cancer.

描述（由申请人提供）：癌症发展所需的细胞改变之一是“基因组不稳定，”一个术语描述了所有导致的途径的集合基因突变的频率增加和基因表达的改变。引起基因组不稳定性的机制包括染色体断裂，基因扩增和基因表达水平的变化。后者是通常与基因甲基化状态变化有关。所有这些机制与复制时机的变化有关，这是在某些情况下，复制时机的变化可能是主要的这些现象的原因。到目前为止，很难评估癌症发展中复制时机的变化，因为很少知道控制复制时间的机制。幸运的是先前关于萌芽和裂变酵母的研究（酿酒酵母和 Schizosaccharomyces pombe）在我们的实验室和其他人中提供入口点理解复制时机。在两种酵母中，我们都已经确定复制起源，包含内部顺式作用序列，以确定晚期复制时机。在这里，我们提出了简单的策略，可以允许我们精确本地将这些序列定位并用它们来拉出相应的跨作用蛋白。此外，在其他实验室和我们的人已经确定了几种可能发挥的蛋白质在复制时机中的角色。我们打算研究所有这些蛋白质都通过研究时间的影响而在复制时间相应基因中的突变，并研究二进制这些蛋白质之间的相互作用。提出的实验的结果应该允许我们开发控制机制的详细模型萌芽和裂变酵母的复制时间。保守的方面这些模型中可能证明适用于其他真核细胞，包括人类细胞。此信息可能允许开发毒品这将增强正常的复制时序稳定性，从而抑制或扭转癌症的发展。