Regulation of Chromosome Cohesion during Cell Cycle Progression

描述(申请人提供)：DNA复制后，每条染色体的两个完全相同的副本被保持在一起，直到细胞通过一种称为姐妹染色单体凝聚的过程进行分裂。姐妹染色单体凝聚力对于准确的染色体分离、DNA损伤的修复、转录程序的维持和正常发育是必不可少的。凝聚力基因的突变会导致出生缺陷，并与某些癌症相关的基因组不稳定有关。凝聚力的丧失被认为是母亲年龄相关的非整倍体卵子增加的基础，非整倍体卵子是出生缺陷和自然流产的主要原因。姐妹染色单体的凝聚力是由一种称为粘附素的大型蛋白质复合体介导的。这个复合体的活性必须受到调节，以确保粘附素被放置在染色质上，并以一种与DNA复制和细胞周期进程相结合的方式被激活。这种调节是通过几种蛋白质的活动来完成的，这些蛋白质相互协作来调节粘附素-染色质相互作用的稳定性。在这里，我们提出了一系列实验，以确定这些蛋白质，我们称之为“粘附素稳定网络”，是如何在DNA复制过程中调节的，并对细胞周期进程做出反应。使用生化和细胞生物学相结合的方法，包括在培养细胞和蛙卵提取物中的分析，我们将定义粘附素复合体和这个调控网络之间的功能相互作用。这些实验的结果将为在脊椎动物系统中建立、维持和重塑凝聚力的机制提供关键的见解。

DESCRIPTION (provided by applicant): Following DNA replication, the two identical copies of each chromosome are held together until cell division by a process referred to as sister chromatid cohesion. Sister chromatid cohesion is essential for accurate chromosome segregation, repair of DNA damage, the maintenance of transcriptional programs, and normal development. Mutations in cohesion genes lead to birth defects and are associated with genomic instability associated with certain cancers. Failures in cohesion are thought to underlie the maternal age-related increase in aneuploid eggs, a major cause of birth defects and spontaneous abortion. Sister chromatid cohesion is mediated by a large protein complex called cohesin. The activity of this complex must be regulated to ensure that cohesin is laid down on chromatin and activated in a way that is integrated with DNA replication and cell cycle progression. This regulation is accomplished by the activities of several proteins that cooperate to regulate the stability of the cohesin-chromatin interaction. Here we propose a series of experiments to define both how these proteins, which we dub the "cohesin stability network", are regulated during DNA replication and in response to cell cycle progression. Using a combination of biochemical and cell biology approaches, including assays in cultured cells and frog egg extracts, we will define the functional interactions between the cohesin complex and this regulatory network. The results of these experiments will provide critical insight into the mechanism by which cohesion is established, maintained, and remodeled in vertebrate systems.