Roles of ATM and ATR Kinases in DNA Damage Responses

ATM 和 ATR 激酶在 DNA 损伤反应中的作用

• 批准号: 6555197
• 负责人: ROBERT T ABRAHAM
• 金额: $ 39.65万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6555197
• 关键词: DNA damage; DNA repair; brca gene; cell cycle proteins; cell line; enzyme activity; ionizing radiation; neoplasm /cancer genetics; oncoproteins; phosphoproteins; phosphorylation; protein kinase; radiation carcinogen; radiation carcinogenesis; radiation genetics; radiation related neoplasm /cancer; radiation resistance

DESCRIPTION (provided by applicant): Cell-cycle checkpoints are signal transduction pathways that ensure orderly progression of the cell cycle, and that proliferating cells do not attempt to replicate or segregate damaged chromosomes. Recent studies have pinpointed two members of the P1 3-kinase related kinase family, ATM and ATR, as proximal signaling elements in the G1, S, and G2 checkpoint pathways. The emerging view is that ATM function is required for the induction of appropriate checkpoint responses to ionizing radiation-induced DNA double-strand breaks, while ATR plays dominant roles in the responses to ultraviolet light induced DNA damage, as well as to DNA replicative stress induced by drugs or intrinsic errors associated with DNA metabolism. In spite of this progress, the mechanisms underlying the regulation and function of ATR remain unclear, due in large part to the lack of a genetically tractable, ATR-deficient cellular model system. Similarly, although our preliminary studies have identified two important genome surveillance proteins, BRCA1 and hRad17, as substrates for the ATM/ATR kinases in DNA-damaged cells, the functional consequences of these phosphorylation events have not been defined. This project will address these critical issues through implementation of the following specific aims: (1) To complete the generation of a novel ATR-/- cell line, and to characterize the checkpoint signaling defects in these cells, and (2) To determine the impact of ATR-mediated phosphorylation on the genome maintenance functions of BRCA1, through the use of two newly described functional assays for BRCA1, (3) To define the regulatory effects of ATR/ATM-dependent phosphorylation on the checkpoint signaling functions of hRad17, and (4) To identify and functionally characterize novel SIT-Q-containing substrates for ATR and ATM in cells exposed to genotoxic stress.

描述（由申请人提供）： 细胞周期检查点是确保有序的信号转导途径 细胞周期的进展，并且增殖细胞不会尝试 复制或分离受损的染色体。最近的研究指出了两个 P1 3 激酶相关激酶家族 ATM 和 ATR 的成员，作为近端 G1、S 和 G2 检查点通路中的信号元件。新兴观点 是需要 ATM 功能来引入适当的检查点 对电离辐射引起的 DNA 双链断裂的反应，而 ATR 在对紫外线引起的 DNA 损伤的反应中起主导作用， 以及药物或内在错误引起的 DNA 复制应激 与DNA代谢有关。尽管取得了这些进展，但机制 ATR 的调节和功能背后的机制仍不清楚，这在很大程度上是由于 缺乏遗传上易于处理、ATR 缺陷的细胞模型系统。 同样，尽管我们的初步研究已经确定了两个重要的 基因组监视蛋白 BRCA1 和 hRad17，作为 ATM/ATR 的底物 DNA 损伤细胞中的激酶，这些激酶的功能后果 磷酸化事件尚未定义。该项目将解决这些 通过实现以下具体目标来解决关键问题： (1) 完成新型 ATR-/- 细胞系的生成，并表征 这些细胞中的检查点信号传导缺陷，以及 (2) 确定 ATR 介导的 BRCA1 基因组维持功能的磷酸化， 通过使用两种新描述的 BRCA1 功能测定，(3) 定义 ATR/ATM 依赖性磷酸化对 hRad17 的检查点信号传导功能，以及 (4) 识别和功能 表征暴露细胞中 ATR 和 ATM 的新型含 SIT-Q 底物 遗传毒性应激。