High-resolution analysis of the spatio-temporal control of the DNA replication activation

哺乳动物细胞面临的挑战是每次分裂时复制一次且仅复制一次整个基因组。我们的目标是在单个复制单元水平和整个基因组水平上了解这种中心细胞生物学过程。DNA复制的基本机制已经通过遗传学和体外生物化学的有力结合建立起来。从这项工作中，很明显，DNA复制的基本特征和组成部分在从细菌到哺乳动物的整个进化过程中都得到了很好的保护。一份涉及这一过程及其活动的蛋白质的综合清单已经编制完成，现在有可能在分子水平上对DNA复制机制提供相对详细的描述。然而，真核细胞中的基因组DNA在细胞核内分层排列，基因组复制需要成千上万个个体复制单位的协同努力。因此，了解DNA复制如何在整个基因组和细胞环境中在空间和时间上受到调节是很重要的。我们项目的目标是阐明哺乳动物细胞DNA复制激活机制的时空控制。特别是，我们将解决是否i) DNA高阶结构，ii) DNA修饰和iii) DNA （com）在细胞核中的位置调节DNA复制动力学。我们项目的结果一方面有助于阐明细胞背景下DNA复制过程的结构-功能动力学，另一方面为其激活机制提供证据。

The mammalian cell has the challenge to duplicate its entire genome once and only once every time it divides. Our objective is to understand this central cell biological process at the level of the single replication unit and at the level of the whole genome. The basic mechanisms of DNA replication have been established by a powerful combination of genetics and in vitro biochemistry. From this body of work, it is clear that the fundamental features and components of DNA replication are well conserved throughout evolution from bacteria up to mammals. A comprehensive list of proteins that are involved in the process and their activities has been compiled, and it is now possible to provide a relatively detailed description of the DNA replication machinery on a molecular level. However, genomic DNA in eukaryotic cells is hierarchically packed within the nucleus and genome duplication requires the concerted effort of many thousands of individual replication units over time. As such, it is important to understand how DNA replication is regulated in space and time across the entire genome and within the cellular context.The goal of our project is to elucidate the spatio-temporal control of the activation mechanism of DNA replication in mammalian cells. In particular, we will address whether i) DNA higher order structure, ii) DNA modifications and iii) DNA (com)position in the nucleus regulate DNA replication dynamics. The outcome of our project should contribute to, on the one hand, the elucidation of the structure-functional dynamics of the DNA replication process in the cellular context and, on the other hand, provide evidence for its activation mechanism.