Control of Cell Cycle Transitions

描述(申请人提供)：真核细胞的分裂必须以高度忠诚的方式进行。在细胞周期的过程中，细胞必须能够以极高的保真度复制它们的DNA。此外，当复制过程中出现问题时，细胞必须在试图纠正损伤的同时实施检查点介导的细胞周期停滞。最近，我们发现了一种新的蛋白质，称为Treslin，它对脊椎动物细胞中的DNA复制是必不可少的，Treslin在细胞复制的关键调控节点发挥作用。特别是，Treslin是细胞周期蛋白依赖的激酶(CDK)的关键靶点，CDK促进复制起始点的初始激发 始于S阶段。此外，特雷斯林似乎也参与了检查站的监管。对于本提案中的研究，我们将对特雷斯林及其与S期其他关键调控因子的功能关系进行深入分析。我们将在非洲爪哇卵提取液和人类细胞中进行这些研究。卵子提取系统提供了一些目前人类细胞所不具备的技术优势。大量研究表明，这种非洲爪哇系统为人类细胞提供了一个有效的模型。总而言之，我们将试图揭示特雷斯林如何促进脊椎动物基因组的准确复制和维护，以及细胞如何控制特雷斯林的活动。特别是，我们将分析特雷斯林的各种结构域，以阐明其功能结构。我们将研究Treslin与其他复制蛋白的合作如何有助于其功能。我们会研究 此外，磷酸化如何控制Treslin的功能特性。此外，我们还将调查特雷斯林在检查站反应中的作用。最后，我们将尝试寻找Treslin的新合作伙伴，并阐明该蛋白潜在的新功能。总体而言，这些研究有望为细胞如何在其一生中保持基因组完整性提供有价值的见解。这一信息将与人类健康特别相关。由于环境侮辱或遗传突变或两者兼而有之，基因组完整性的混乱可能会导致各种人类病理，最明显的是癌症。因此，彻底了解基因组不稳定的根本原因将是抗击癌症的知情战略所必需的。

DESCRIPTION (provided by applicant): The division of eukaryotic cells must occur in a highly faithful manner. During the course of the cell cycle, cells must be able to replicate their DNA with great fidelity. Furthermore, when problems arise during replication, cells must impose a checkpoint-mediated arrest of the cell cycle while they attempt to rectify lesions. Recently, we identified a novel protein called Treslin that is essential for DNA replication in vertebrate cells Treslin acts at a critical regulatory juncture in cellular duplication. In particular, Treslin is akey target of the cyclin-dependent kinase (CDK) that promotes the initial firing of replication origins at the onset of S-phase. Moreover, Treslin also appears to participate in checkpoint regulation. For the studies in this proposal, we will carry out an intensive analysis of Treslin and its functional relationships with other key regulators of S-phase. We will conduct these investigations in both Xenopus egg extracts and human cells. The egg-extract system offers some technical advantages that are not available currently with human cells. Numerous studies have indicated that this Xenopus system offers a valid model for human cells. Overall, we will attempt to reveal how Treslin promotes accurate replication and maintenance of the genome in vertebrates and how cells control the activity of Treslin. In particular, we will analyze the varios domains of Treslin in order to elucidate its functional architecture. We will examine how the collaboration of Treslin with other replication proteins contributes to its function. We will study further how phosphorylation controls the functional properties of Treslin. Moreover, we will also investigate the role of Treslin in checkpoint responses. Finally, we will attempt to identify new partners of Treslin and elucidate potentially novel functions of this protein. In general, these studies hold the promise to yield valuable insights into how cells maintain genomic integrity throughout their lifetimes. This information would be especially relevant for human health. Derangement of genomic integrity as a consequence of environmental insults or inherited mutations or both can result in various human pathologies, most notably cancer. Thus, a thorough understanding of the root causes for genomic instability will be essential for an informed strategy in combating cancer.