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G-Quadruplex forming sequence motifs and genome instability

G-四链体形成序列基序和基因组不稳定性

基本信息

批准号：
9889136
负责人：
Nayun Kim
金额：
$ 31.32万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9889136
关键词：
Affect Affinity Chromatography Antibodies Antineoplastic Agents Binding Binding Proteins Biological Assay Cancer Biology Cancer Etiology Cells Characteristics Chemicals Chromatin Chromosome Arm Chromosomes Complex DNA DNA Damage DNA Restriction Enzymes DNA Sequence DNA Structure DNA replication fork Data Development Drug resistance Elements Enzymes Etoposide Eukaryota Event Frequencies G-Quartets Genetic Genetic Recombination Genetic Transcription Genome Genomic Instability Genomics Goals Guanine Human In Vitro Knowledge Lead Left Ligands Link Maintenance Malignant Neoplasms Maps Mass Spectrum Analysis Measurement Measures Methods Mission Modeling Molecular Mutagenesis Mutation Neoplasm Metastasis Pathway interactions Proteins Public Health Repetitive Sequence Reporter Research Resistance Role Running Saccharomyces cerevisiae Saccharomycetales Second Primary Cancers Site Stress Structure Testing Topoisomerase Trans-Activators Transact Transcription Coactivator Type I DNA Topoisomerases United States National Institutes of Health Work Yeasts Zeocin base cancer cell cancer genome cancer therapy chemotherapy chromosome loss design experimental study genetic approach genomic locus grasp in vivo insight mutant novel prevent public health relevance repaired small molecule tumor tumorigenesis tumorigenic yeast genome

项目摘要

DESCRIPTION (provided by applicant): Mutations and chromosome rearrangements are ubiquitous feature of cancer genomes and linked to the anomalous cellular activities associated with oncogenesis. Recombination hotspots, where genome rearrangements initiate at incongruently higher frequencies, are significantly enriched with repetitive sequence elements with the potential to fold into non-helical DNA secondary structures. When left unresolved, such DNA structures can impede transcription and replication leading to genome instability. G-quadruplex or G4 DNA is a tetra-helical structure consisting of runs of guanines and one of the DNA structures that presents a challenge to normal DNA transactions. Comprehensive understanding of how a subset of the guanine run- containing sequences interspersed in the genome becomes genetically unstable, however, is still lacking. Also not understood is how such potential hotspots of genome instability are kept under control. The long-term research goal of the applicant is to better understand how spontaneous mutagenesis and rearrangements occur at disparate rates throughout the genome. The goal of the proposed research is to characterize what potentiates the marked elevation in instability associated with certain guanine-run containing sequences in the model eukaryote, S. cerevisiae. The central hypothesis of this proposal is that genome instability at a G4 motif is contingent on both genomic context and trans-acting factors that modulate the structural transformation of a guanine-run containing sequence into G4 DNA structure. This hypothesis is founded on the preliminary data generated by the applicant that identified two critical factors in modulating instability at a model G4 DNA- forming sequence - the level of transcription and the activity of topoisomerase I. Our specific aims are designed to (1) define the role of topoisomerase I in the G4 DNA-associated genome instability (2) test whether DNA damage cooperatively aggravates the instability of G4 forming sequences and (3) Identify proteins binding specifically to co-transcriptionally formed G4 DNA in vivo. In combination with molecular approaches to detect G4 DNA in vivo, genetic assays developed for quantitative measurement of recombination occurring at a G4 motif in transcription-dependent manner will be employed in AIM 1 and 2 to determine the effect of disruption in Top1 function and accumulation of DNA damage on the stability of co- transcriptionally formed G4 DNA. The genetic assays have proved effective and productive in generating the relevant preliminary data. Under AIM3, novel trans-activating factors with possible roles in suppressing instability at the G4 DNA will be identified by chromatin affinity purification approach. The stability of G4 motifs is particularly relevant to th biology of cancer since there is a significant overlap between genomic loci containing G4 sequences and the sites of translocations observed in various human cancers. The result of the proposed study can ultimately enhance our understanding of the molecular events instigating the tumorigenic rearrangements as well as therapy-related secondary malignancy or drug-resistant tumor development.

描述（由申请人提供）：突变和染色体重排是癌症基因组普遍存在的特征，并与肿瘤发生相关的异常细胞活动相关。重组热点（基因组重排以不一致的较高频率开始）显着富含重复序列元件，有可能折叠成非螺旋 DNA 二级结构。如果不解决，这种 DNA 结构会阻碍转录和复制，导致基因组不稳定。 G-四链体或 G4 DNA 是一种由鸟嘌呤序列组成的四螺旋结构，也是对正常 DNA 交易提出挑战的 DNA 结构之一。然而，仍然缺乏对散布在基因组中的含有鸟嘌呤序列的子集如何变得遗传不稳定的全面理解。同样不明白的是如何控制基因组不稳定的潜在热点。申请人的长期研究目标是更好地了解自发突变和重排如何在整个基因组中以不同的速率发生。拟议研究的目标是表征与模型真核生物酿酒酵母中某些含有鸟嘌呤的序列相关的不稳定性显着升高的原因。该提议的中心假设是，G4 基序的基因组不稳定性取决于基因组背景和反式作用因子，这些因子调节含有鸟嘌呤运行的序列向 G4 DNA 结构的结构转变。该假设基于申请人生成的初步数据，该数据确定了调节模型 G4 DNA 形成序列不稳定性的两个关键因素 - 转录水平和拓扑异构酶 I 的活性。我们的具体目标旨在 (1) 定义拓扑异构酶 I 在 G4 DNA 相关基因组不稳定性中的作用 (2) 测试 DNA 损伤是否协同加剧 G4 的不稳定性 (3) 鉴定与体内共转录形成的 G4 DNA 特异性结合的蛋白质。结合体内检测 G4 DNA 的分子方法，AIM 1 和 2 将采用以转录依赖性方式定量测量 G4 基序上发生的重组而开发的遗传测定法，以确定 Top1 功能破坏和 DNA 损伤累积对共转录形成的 G4 DNA 稳定性的影响。事实证明，遗传测定在生成相关初步数据方面是有效且富有成效的。在 AIM3 下，将通过染色质亲和纯化方法鉴定可能在抑制 G4 DNA 不稳定方面发挥作用的新型反式激活因子。 G4基序的稳定性与癌症生物学特别相关，因为含有G4序列的基因组位点与在各种人类癌症中观察到的易位位点之间存在显着重叠。拟议研究的结果最终可以增强我们对引发致瘤重排以及治疗相关的继发性恶性肿瘤或耐药肿瘤发展的分子事件的理解。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The G-quadruplex DNA stabilizing drug pyridostatin promotes DNA damage and downregulates transcription of Brca1 in neurons.

DOI：
10.18632/aging.101282
发表时间：
2017-09-12
期刊：
Aging
影响因子：
0
作者：
Moruno-Manchon JF;Koellhoffer EC;Gopakumar J;Hambarde S;Kim N;McCullough LD;Tsvetkov AS
通讯作者：
Tsvetkov AS

The etiology of uracil residues in the Saccharomyces cerevisiae genomic DNA.