Studies of the Swi1-Swi3 Replication Fork Protection Complex

Swi1-Swi3 复制叉保护复合体的研究

• 批准号: 8033149
• 负责人: Eishi Noguchi
• 金额: $ 26.19万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8033149
• 关键词: Address; Animal Model; Base Pairing; Biochemical; Biological Models; Biological Preservation; CDC7 gene; Cancer Biology; Cell Cycle; Cell Cycle Arrest; Cell Cycle Regulation; Cells; Complex; Congenital Abnormality; DNA; DNA Binding Domain; DNA Damage; DNA Repair; DNA biosynthesis; DNA replication fork; Defect; Development; Ensure; Environment; Eukaryota; Fission Yeast; Future; Gene Mutation; Genetic; Genome; Genomic Instability; Genomics; Goals; Health; Hereditary Disease; Homologous Gene; Human; Investigation; Knowledge; Lead; Maintenance; Malignant Neoplasms; Mammalian Cell; Mediator of activation protein; Modeling; Molecular; Mutation; Names; Neurologic; Outcome; Phosphorylation; Phosphotransferases; Physiological; Play; Predisposition; Proteins; Quality Control; Regulation; Research; Research Design; Role; Saccharomyces cerevisiae; Saccharomycetales; Signal Transduction; Site; Stress; System; Testing; Therapeutic; Therapeutic Agents; Time; Work; base; coping; insight; interest; novel; prevent; research study; response

DESCRIPTION (provided by applicant): Genomic instability is a major cause of various genetic disease, most notably cancer. To ensure genomic integrity, cell must replicate the millions or billions of DNA base pairs with absolute fidelity every cell cycle. However, cells are constantly under stress of many factors that cause DNA damage or block DNA replication. To circumvent these problems, cells are equipped with a quality control system, termed the DNA replication checkpoint. In humans, defects in this checkpoint cause genetic instability, leading to developmental and neurological defects, and a strong predisposition to cancer. Therefore, the long-term objective of this application is to elucidate how the checkpoints maintain genomic integrity to prevent a variety of genetic disorders. The Swi1-Swi3 complex, which is also known as the Replication Fork Protection Complex (FPC) , plays a central role in activation of the DNA replication checkpoint and stabilization of stalled replication forks in the fission yeast Schizosaccharomyces pombe. The Swi1-Swi3 complex is evolutionally conserved and homologous to Tof1-Csm3 in budding yeast Saccharomyces cerevisiae and Timeless-Tipin in humans. However, how the FPC stabilizes the replication forks, and how it controls the replication checkpoint, are unknown. Therefore, the first aim is to understand the molecular basis of the FPC at the replication forks. We will elucidate how the FPC recognizes the replication forks. The second aims is to establish the functional significance of Swi1 phosphorylation and DDK-FPC interaction. We will investigate the roles a Cdc7-like kinase complex in phosphorylation and regulation of the FPC. The third aim is to understand the roles of Mrc1-FPC interaction in fork stabilization and activation of the replication checkpoint. We will elucidate how the Mrc1 cooperates with FPC to regulate its function to understand the molecular mechanisms of fork stabilization and checkpoint signaling. These studies are designed to test the central hypothesis that FPC coordinates replication fork stabilization and checkpoint signaling through its association with replication forks and interaction with DDK and Mrc1. Genetic and biochemical studies will be carried out in the fission yeast Schizosaccharomyces pombe because it has been shown to be an exceptional model system for studying cell cycle control and genome maintenance mechanisms which are highly conserved amongst eukaryotes, including humans. Successful completion of these experiments should provide a much better framework for guiding investigations of genome maintenance mechanisms in humans. Project Narrative: Cells are constantly under the stress of many factors that arrest DNA replication. These factors often cause genetic alterations, which lead to developmental and neurological defects, and a variety of genetic diseases, most notably cancer. Therefore, elucidating how cells cope with replication arrest is essential for understanding the mechanisms of birth defects and development of cancer, contributing to the development of therapeutic agents.

描述（由申请人提供）：基因组不稳定性是各种遗传疾病的主要原因，尤其是癌症。为了确保基因组完整性，细胞必须在每个细胞周期中绝对保真地复制数百万或数十亿个 DNA 碱基对。然而，细胞不断受到许多因素的压力，导致 DNA 损伤或阻碍 DNA 复制。为了规避这些问题，细胞配备了质量控制系统，称为 DNA 复制检查点。在人类中，这个检查点的缺陷会导致遗传不稳定，导致发育和神经缺陷，以及患癌症的强烈倾向。因此，该应用的长期目标是阐明检查点如何维持基因组完整性以预防各种遗传性疾病。 Swi1-Swi3 复合体，也称为复制叉保护复合体 (FPC)，在裂殖酵母裂殖酵母中 DNA 复制检查点的激活和停滞复制叉的稳定中发挥着核心作用。 Swi1-Swi3 复合体在进化上是保守的，与芽殖酵母酿酒酵母中的 Tof1-Csm3 和人类中的 Timeless-Tipin 同源。然而，FPC 如何稳定复制叉，以及如何控制复制检查点，尚不清楚。因此，首要目标是了解 FPC 复制叉的分子基础。我们将阐明 FPC 如何识别复制叉。第二个目标是确定 Swi1 磷酸化和 DDK-FPC 相互作用的功能意义。我们将研究 Cdc7 样激酶复合物在 FPC 磷酸化和调节中的作用。第三个目标是了解 Mrc1-FPC 相互作用在分叉稳定和复制检查点激活中的作用。我们将阐明Mrc1如何与FPC合作调节其功能，以了解分叉稳定和检查点信号传导的分子机制。这些研究旨在检验以下中心假设：FPC 通过与复制叉的关联以及与 DDK 和 Mrc1 的相互作用来协调复制叉稳定性和检查点信号传导。遗传和生化研究将在裂殖酵母粟酒裂殖酵母中进行，因为它已被证明是研究细胞周期控制和基因组维持机制的特殊模型系统，这些机制在包括人类在内的真核生物中高度保守。这些实验的成功完成应该为指导人类基因组维持机制的研究提供一个更好的框架。项目叙述：细胞经常受到许多阻碍 DNA 复制的因素的压力。这些因素通常会导致基因改变，从而导致发育和神经缺陷以及各种遗传疾病，尤其是癌症。因此，阐明细胞如何应对复制停滞对于了解出生缺陷和癌症发展的机制至关重要，从而有助于治疗药物的开发。