DYNAMICS AND FUNCTION OF G4 DNA

G4 DNA 的动力学和功能

• 批准号: 6514000
• 负责人: Nancy Maizels
• 金额: $ 11.37万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6514000
• 关键词: DNA; DNA footprinting; DNA repair; DNA replication; Escherichia coli; Saccharomyces cerevisiae; enzyme activity; genetic crossing over; genetic transcription; guanine; helicase; laboratory mouse; molecular cloning; molecular shape; nucleic acid sequence; nucleic acid structure; polymerase chain reaction; ribosomal DNA; site directed mutagenesis; telomere

DESCRIPTION (provided by applicant): Over the past decade it has become apparent that DNA in the human genome has considerable potential to form structures other than canonical Watson-Crick duplexes. Among the motifs most prone to form structures in vitro are runs of guanines, which readily assemble into structures stabilized by G quartets. G quartets can stabilize a variety of distinct structures, which we refer to collectively as G4 DNA. Our laboratory has identified and characterized activities that recognize G4 DNA with high affinity and specificity and dynamically alter its structure. The affinity and specificity of these factors for G4 DNA substrates argue that G4 DNA forms in vivo, and that it is the target for specific factors involved in DNA metabolism. We now propose (1) to ask directly if G4 DNA forms in vivo; (2) to learn how G4 DNA is recognized by RecQ family helicases; (3) to study how G4 DNA causes or contributes to genomic instability associated with cancer predisposition; (4) to study cleavage of G4 DNA in mammalian cells; (5) and to ask whether repair pathways eliminate G4 DNA. The proposed experiments will provide detailed mechanistic understanding of how DNA sequence impacts chromosome replication and genomic structure. They will elucidate mechanisms of maintenance of critical regions of the human genome, the rDNA and telomeres. They will also have immediate impact on our understanding of human health and disease, because the failure to remove G4 DNA may be associated with genetic instability that leads to malignancy.

描述（由申请人提供）：在过去的十年中，人类基因组中的 DNA 具有形成典型沃森-克里克双链体以外的结构的巨大潜力已经变得显而易见。最容易在体外形成结构的基序之一是鸟嘌呤序列，它们很容易组装成由 G 四联体稳定的结构。 G 四重体可以稳定多种不同的结构，我们统称为 G4 DNA。我们的实验室已经鉴定并表征了以高亲和力和特异性识别 G4 DNA 并动态改变其结构的活动。这些因子对 G4 DNA 底物的亲和力和特异性表明 G4 DNA 在体内形成，并且它是参与 DNA 代谢的特定因子的靶标。我们现在建议（1）直接询问G4 DNA是否在体内形成； (2)了解G4 DNA如何被RecQ家族解旋酶识别； (3) 研究 G4 DNA 如何导致或促成与癌症易感性相关的基因组不稳定性； (4) 研究哺乳动物细胞中G4 DNA的切割； (5)并询问修复途径是否消除G4 DNA。拟议的实验将为 DNA 序列如何影响染色体复制和基因组结构提供详细的机制理解。他们将阐明人类基因组关键区域、rDNA 和端粒的维持机制。它们还将对我们对人类健康和疾病的理解产生直接影响，因为未能去除 G4 DNA 可能与导致恶性肿瘤的遗传不稳定性有关。