G-quadruplex DNA as a chemical signaling agent

G-四链体 DNA 作为化学信号剂

• 批准号: 9010374
• 负责人: Kevin Douglas Raney
• 金额: $ 29.43万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-21 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9010374
• 关键词: Address; Affect; Aging; Appearance; Area; Binding; Binding Proteins; Biochemical; Biological; Biological Assay; Biological Process; Biology; Cancer Etiology; Cell Nucleus; Cells; Cellular Stress; Chemicals; Cytoplasm; Cytoplasmic Granules; Cytoplasmic Structures; Cytosol; DNA; DNA Damage; DNA Sequence; Data; Development; Diagnostic; Disease; Environment; G-Quartets; Gene Expression; Genetic Transcription; Genetic Translation; Genome; Genomic DNA; Guanine; Human; Human Genome; Hydrogen Bonding; Knowledge; Lead; Link; Location; Malignant Neoplasms; Messenger RNA; Metabolism; Methodology; Mitochondria; Mitochondrial DNA; Molecular; Natural Immunity; Neurodegenerative Disorders; Nuclear; Oligonucleotides; Oxidative Stress; Play; Prevalence; Protein Binding; Proteins; Proteomics; Proto-Oncogenes; RNA; RNA Helicase; Reactive Oxygen Species; Regulation; Reporter; Reporting; Research; Resistance; Role; Signal Transduction; Signaling Molecule; Site; Stress; Structure; Testing; Therapeutic; Transcript; Translations; Work; base; biological adaptation to stress; cancer therapy; in vitro activity; nuclease; prevent; promoter; public health relevance; quadruplex DNA; repaired; response; sensor; small molecule; telomere; transcriptome sequencing; Address; Affect; Aging; Appearance; Area; Binding; Binding Proteins; Biochemical; Biological; Biological Assay; Biological Process; Biology; Cancer Etiology; Cell Nucleus; Cells; Cellular Stress; Chemicals; Cytoplasm; Cytoplasmic Granules; Cytoplasmic Structures; Cytosol; DNA; DNA Damage; DNA Sequence; Data; Development; Diagnostic; Disease; Environment; G-Quartets; Gene Expression; Genetic Transcription; Genetic Translation; Genome; Genomic DNA; Guanine; Human; Human Genome; Hydrogen Bonding; Knowledge; Lead; Link; Location; Malignant Neoplasms; Messenger RNA; Metabolism; Methodology; Mitochondria; Mitochondrial DNA; Molecular; Natural Immunity; Neurodegenerative Disorders; Nuclear; Oligonucleotides; Oxidative Stress; Play; Prevalence; Protein Binding; Proteins; Proteomics; Proto-Oncogenes; RNA; RNA Helicase; Reactive Oxygen Species; Regulation; Reporter; Reporting; Research; Resistance; Role; Signal Transduction; Signaling Molecule; Site; Stress; Structure; Testing; Therapeutic; Transcript; Translations; Work; base; biological adaptation to stress; cancer therapy; in vitro activity; nuclease; prevent; promoter; public health relevance; quadruplex DNA; repaired; response; sensor; small molecule; telomere; transcriptome sequencing

 DESCRIPTION (provided by applicant): Quadruplex DNA, or G4DNA, is made of four guanines that form Hoogsteen hydrogen bonds in a planar ring which is referred to as a G quartet. Multiple stacks of these G quartets (or tetrads) associate to form highly stable structures. Recently, several methodologies have provided convincing evidence confirming that G4DNA in cells affects DNA metabolism including transcription and replication. Recent work has provided a direct link between formation of G4DNA and G4RNA sequences and some neurodegenerative diseases such as ALS. Intense efforts are underway to develop agents that bind to G4DNA sequences for treatment of various cancers. G4DNA sequences are found throughout the genome, but are localized preferentially to certain regions such as promoters of proto-oncogenes, telomeres, and mitochondrial DNA. Despite the intense research focused on G4DNA, the mechanism(s) through which these structures impart biological function are largely unknown. We have applied a proteomic screen to discover new proteins that bind to G4DNA. The major proteins identified, including DHX36, are known to assemble into cytoplasmic structures termed stress granules under conditions of cellular stress. The location of these proteins and their known roles in regulation of translation leads us to a new hypothesis for the function of G4DNA. We propose that endogenous G4DNA excised from damaged mitochondrial and nuclear genomes can enter the cytosol intact. This excised G4DNA binds to proteins involved in translation to initiate a "stress response" through formation of stress granules. Our hypothesis provides a new mechanism by which cells can respond to the effects of DNA damage during oxidative stress. Hence, excised G4DNA can serve as a chemical signaling agent, alerting the cell to DNA damage. To test this hypothesis, we will determine the quantity and identity of G4DNA in the cytoplasm as a function of oxidative cell stress (Aim 1). In Aim 2, we will determine if G4DNA modulates the translation regulatory activity of DHX36 and if G4DNA and DHX36 co-localize with stress granule proteins. Aim 3 will focus on the consequences of different types of G4DNA on the enzymatic activity of DHX36 to test possible mechanisms by which G4DNA affects the protein. Different G4DNA structures will be evaluated in a biological screen that reports on translation. This work will have a direct impact on our understanding of the mechanisms of small molecules that are targeted to G4DNA and have been proposed as therapies for cancer treatment. Multiple research areas of relevance to cancer etiology will be impacted by this research including DNA damage response, mitochondrial and telomere biology, innate immunity, translation regulation, and cell signaling.

 描述（由适用提供）：四链体DNA或G4DNA由四个鸟嘌呤制成，在平面环中形成hoogsteen氢键，在平面环中被称为g四重奏。这些G四重奏（或四重奏）的多个堆栈相关以形成高度稳定的结构。最近，几种方法提供了令人信服的证据，证实了细胞中的G4DNA会影响DNA代谢，包括转录和复制。最近的工作提供了G4DNA和G4RNA序列与某些神经退行性疾病（例如ALS）之间的直接联系。正在努力开发与G4DNA序列结合以治疗各种癌症的药物。在整个基因组中都发现了G4DNA序列，但更优选地局限于某些区域，例如原始基因，端粒和线粒体DNA的启动子。尽管集中在G4DNA上进行了激烈的研究，但这些结构赋予生物学功能的机制在很大程度上是未知的。我们已经应用了一个蛋白质组学筛选来发现与G4DNA结合的新蛋白质。已知包括DHX36在内的主要蛋白质在细胞应激条件下被称为胁迫颗粒的细胞质结构。这些蛋白质的位置及其在翻译调节中的已知作用使我们提出了G4DNA功能的新假设。我们建议内源性G4DNA受损伤的线粒体和核基因组出色的G4DNA可以完整进入胞质溶胶。这种出色的G4DNA与参与翻译的蛋白质结合，通过形成应力颗粒来引发“应力反应”。我们的假设提供了一种新的机制，可以通过该机制对氧化应激期间DNA损伤的影响做出反应。因此，出色的G4DNA可以用作化学信号剂，从而提醒细胞对DNA损伤。为了检验这一假设，我们将确定细胞质中G4DNA的数量和身份作为氧化细胞应激的函数（AIM 1）。在AIM 2中，我们将确定G4DNA是否调节DHX36的翻译调节活性以及G4DNA和DHX36是否与应力颗粒蛋白共定位。 AIM 3将集中于不同类型的G4DNA对DHX36酶促活性的后果，以测试G4DNA影响蛋白质的可能机制。不同的G4DNA结构将在报告翻译的生物屏幕中进行评估。这项工作将直接影响我们对针对G4DNA的小分子机制的理解，并已被提议作为癌症治疗的疗法。这项研究将受到与癌症病因相关的多个研究领域，包括DNA损伤反应，线粒体和端粒生物学，先天性免疫史，翻译调节和细胞信号传导。