Role of ATR in Cell Cycle Checkpoints

ATR 在细胞周期检查点中的作用

• 批准号: 6920654
• 负责人: William G Dunphy
• 金额: $ 45.83万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920654
• 关键词: DNA damage; DNA replication; SDS polyacrylamide gel electrophoresis; Xenopus; cell cycle; cell cycle proteins; chromatin; chromosome aberrations; cyclins; enzyme activity; phosphatidylinositol 3 kinase; phosphorylation; protein binding; protein protein interaction; protein structure function

DESCRIPTION (provided by applicant): In eukaryotic cells, the Cdc2-cyclin B complex regulates the initiation of mitosis. Various checkpoint regulatory mechanisms prevent the entry into mitosis if the genome has not been replicated faithfully or has undergone various types of damage. In vertebrates, a pathway containing ATR, Claspin, and Chkl suppresses the activation of Cdc2-cyclin B when there is incompletely replicated or UV-damaged DNA in the nucleus. ATR is a member of the phosphatidylinositol kinase (PIK)-related family of proteins that also includes ATM and the DNA-dependent protein kinase (DNA-PK). ATR possesses a critical regulatory subunit called ATRIP (ATR-interacting protein). The ATR-dependent regulatory pathway can be studied effectively in cell-free extracts from Xenopus eggs. Xenopus homologues of ATR (Xatr) and ATRIP (Xatrip) have been cloned and characterized. Comprehensive studies of the structure, function, and regulation of Xatr-Xatrip will be conducted. The various functional domains of Xatr and Xatrip will be defined in order to understand how these proteins interact with one another. In addition, the mechanism by which Xatr-Xatrip associates with DNA will be analyzed. The Xatr-Xatrip complex undergoes activation upon binding to certain DNA structures. The mechanistic basis of this activation will be analyzed. For these studies, the role of phosphorylation in the regulation of Xatr-Xatrip will be examined. Moreover, searches for novel proteins that interact with Xatr-Xatrip to control its activation and/or action will be undertaken. To complement these efforts, the roles of known checkpoint proteins and replication proteins in the regulation of Xatr-Xatrip will be assessed. Finally, various screens for novel substrates of Xatr-Xatrip will be carried out. These studies may help to elucidate the range of physiological processes that are controlled by Xatr-Xatrip. It seems very likely that the ATR-ATRIP complex is necessary for the maintenance of genomic integrity in humans. Through the study of Xatr-Xatrip in a vertebrate system that is amenable to intensive functional analysis, important insights may be obtained into the mechanisms by which animal cells prevent the occurrence of chromosomal aberrations.

描述（由申请人提供）：在真核细胞中，Cdc2-细胞周期蛋白B复合物调节有丝分裂的起始。如果基因组未忠实复制或遭受各种类型的损伤，各种检查点调节机制会阻止进入有丝分裂。在脊椎动物中，当细胞核中存在不完全复制或紫外线损伤的 DNA 时，包含 ATR、Claspin 和 Chk1 的通路会抑制 Cdc2-cyclin B 的激活。 ATR 是磷脂酰肌醇激酶 (PIK) 相关蛋白家族的成员，该家族还包括 ATM 和 DNA 依赖性蛋白激酶 (DNA-PK)。 ATR 拥有一个称为 ATRIP（ATR 相互作用蛋白）的关键调节亚基。可以在非洲爪蟾卵的无细胞提取物中有效地研究 ATR 依赖性调节途径。 ATR (Xatr) 和 ATRIP (Xatrip) 的爪蟾同源物已被克隆和表征。对Xatr-Xatrip的结构、功能和调控进行综合研究。将定义 Xatr 和 Xatrip 的各种功能域，以便了解这些蛋白质如何相互作用。此外，还将分析 Xatr-Xatrip 与 DNA 结合的机制。 Xatr-Xatrip 复合物在与某些 DNA 结构结合后会被激活。将分析这种激活的机制基础。对于这些研究，将检查磷酸化在 Xatr-Xatrip 调节中的作用。此外，还将寻找与 Xatr-Xatrip 相互作用的新型蛋白质，以控制其激活和/或作用。为了补充这些努力，我们将评估已知的检查点蛋白和复制蛋白在 Xatr-Xatrip 调节中的作用。最后，将对 Xatr-Xatrip 的新型底物进行各种筛选。这些研究可能有助于阐明 Xatr-Xatrip 控制的生理过程的范围。 ATR-ATRIP 复合物似乎很可能是维持人类基因组完整性所必需的。通过在易于进行深入功能分析的脊椎动物系统中研究 Xatr-Xatrip，可以获得对动物细胞防止染色体畸变发生的机制的重要见解。