Mechanisms Linking Genome Stability to RNA Metabolism

将基因组稳定性与 RNA 代谢联系起来的机制

• 批准号: 8238995
• 负责人: Karlene A Cimprich
• 金额: $ 32.49万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8238995
• 关键词: Affect; Biochemical Genetics; Biological; Cells; ChIP-seq; Chromatin; Chromatin Structure; Chromosomal Rearrangement; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA biosynthesis; Data; Defect; Event; Genes; Genetic Transcription; Genome; Genome Stability; Genomic Instability; Genomics; Goals; Hybrids; Individual; Lead; Link; Maintenance; Malignant Neoplasms; Mammalian Cell; Mediator of activation protein; Messenger RNA; Metabolism; Molecular; Nature; Phosphorylation; Play; Prevention; Process; Proteins; RNA; RNA Helicase; RNA Polymerase II; RNA Splicing; Research; Role; Site; Small Interfering RNA; Source; Structure; Susceptibility Gene; Testing; Transcription-Coupled Repair; Work; abstracting; acrosome stabilizing factor; developmental disease; genome-wide; helicase; human disease; insight; knock-down; novel; nuclease; nucleic acid structure; prevent; programs

DESCRIPTION (provided by applicant): Project Summary/Abstract The long-term goal of this application is to understand the molecular mechanisms a cell uses to maintain genome stability. Genome instability is a hallmark of cancer, and defects in genome maintenance genes predispose individuals to cancer. Such defects also cause neurogenerative disorders and developmental problems. Recently, an siRNA screen was completed in mammalian cells to identify genes which, when lost, lead to increased phosphorylation of 3H2AX, a marker for DNA double-strand breaks (DSBs). Enriched among the hits are genes with established roles in RNA metabolism and transcription, and it was shown that for many of these hits, H2AX phosphorylation is dependent on the formation of RNA-DNA hybrids, structures also known as R-loops. It is not clear how R-loops lead to DNA damage in cells, and the basic biological mechanisms that prevent the accumulation of these structures are not known. In the first aim of this application, the molecular mechanisms by which R-loops lead to DNA damage will be examined, using several of the genes identified in the siRNA screen to probe these events. In addition, ChIP-Seq approaches will be used to determine where DNA damage occurs in the genome, and to assess whether the sites of DNA damage are also the same sites where R-loops form. In the second aim, the molecular function of one gene identified in the screen, a DExxQ- type helicase that leads to increased R-loop formation when lost, will be studied. It is hypothesized that this helicase plays a direct role in processing R-loops thereby protecting cells against DNA damage and genome instability. Biochemical and genetic approaches will be used to determine the role of the helicase domain in preventing DNA damage and to assess the types of structures on which the helicase acts. These studies will help us elucidate the function of a novel genome maintenance gene and provide a better understanding of how defects in RNA metabolism can affect genome stability. PUBLIC HEALTH RELEVANCE: Project Narrative Defects in the processes needed to maintain genome stability can cause cancer and neurodegenerative disorders as well as other human syndromes associated with congenital, developmental and neurological defects. In these studies, we will explore how defects in RNA metabolism can affect genome stability. This knowledge could provide insights into the mechanisms by which these different diseases arise, as well as point to new strategies for their treatment and diagnosis.

描述（由申请人提供）： 项目摘要/摘要该应用的长期目标是了解细胞用于维持基因组稳定性的分子机制。基因组不稳定是癌症的一个标志，基因组维护基因的缺陷使个体容易患癌症。这些缺陷还会导致神经生成障碍和发育问题。最近，在哺乳动物细胞中完成了 siRNA 筛选，以鉴定丢失时会导致 3H2AX（DNA 双链断裂 (DSB) 标记）磷酸化增加的基因。这些命中中富含在 RNA 代谢和转录中具有既定作用的基因，研究表明，对于许多这些命中，H2AX 磷酸化依赖于 RNA-DNA 杂合体（也称为 R 环的结构）的形成。目前尚不清楚R环如何导致细胞中的DNA损伤，并且阻止这些结构积累的基本生物学机制也不清楚。在本申请的第一个目标中，将使用 siRNA 筛选中鉴定的几个基因来检查 R 环导致 DNA 损伤的分子机制来探测这些事件。此外，ChIP-Seq 方法将用于确定基因组中发生 DNA 损伤的位置，并评估 DNA 损伤的位点是否也是 R 环形成的位点。第二个目标是对筛选中鉴定出的一个基因（一种 DExxQ 型解旋酶）的分子功能进行研究，该解旋酶在丢失时会导致 R 环形成增加。据推测，该解旋酶在 R 环加工中发挥直接作用，从而保护细胞免受 DNA 损伤和基因组不稳定。生化和遗传学方法将用于确定解旋酶结构域在防止 DNA 损伤中的作用，并评估解旋酶作用的结构类型。这些研究将帮助我们阐明新型基因组维持基因的功能，并更好地了解 RNA 代谢缺陷如何影响基因组稳定性。 公共卫生相关性： 项目叙述维持基因组稳定性所需过程中的缺陷可能导致癌症和神经退行性疾病以及与先天性、发育性和神经性缺陷相关的其他人类综合症。在这些研究中，我们将探讨 RNA 代谢缺陷如何影响基因组稳定性。这些知识可以深入了解这些不同疾病的发生机制，并为其治疗和诊断提供新的策略。