Predicting Novel Arsenic Targets in DNA Repair Pathways

预测 DNA 修复途径中的新砷靶标

基本信息

批准号：
8280519
负责人：
LAURIE G HUDSON
金额：
$ 18.88万
依托单位：
UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-03-01 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8280519
关键词：
APTX gene Address Affect Affinity Algorithms Arsenic Arsenites Atlases Automated Annotation Base Sequence Binding Biochemical Bioinformatics C2H2 Zinc Finger Cancer Biology Carcinogens Cell physiology Cells Cellular biology Characteristics Classification Scheme Complex Coupled Cysteine DNA Damage DNA Repair DNA Repair Inhibition DNA Repair Pathway DNA repair protein Data Databases Disease Epidemiology Exposure to Goals Half-Life Health Human Human Genome Individual Knowledge Life Style Literature Malignant Neoplasms Molecular Occupational Outcome Outcome Study Pathway interactions Pattern Recognition Peptides Phylogenetic Analysis Physiological Processes Poly(ADP-ribose) Polymerases Process Proteins Proteome Publishing Relative (related person)Reporting Ring Finger Domain Role SP1 gene Sequence Alignment Structure Testing Toxic effect Validation Water Supply Work Xeroderma Pigmentosum Zinc Zinc Fingers base cancer epidemiology cancer risk carcinogenicity dithiol genotoxicity innovation insight interest novel prevent repaired research study zinc-binding protein

项目摘要

DESCRIPTION (provided by applicant): There is compelling evidence that inhibition of DNA repair contributes to the carcinogenic and co-carcinogenic actions of arsenic. Two DNA repair proteins (PARP-1 and XPA) have been reported as direct arsenic targets based on interference with zinc finger function. To date, identification of arsenic targets in DNA repair pathways has been based solely on empirical evidence and it is unknown whether there are additional direct and highly sensitive DNA repair targets. Our recent work demonstrates preferential interaction of arsenite with zinc finger peptides containing 3 or 4 cysteine residues and arsenite-dependent zinc release from specific DNA repair proteins isolated from exposed cells in C3H1 (e.g. PARP-1) and C4 (e.g. XPA), but not C2H2, zinc finger proteins. These findings provide evidence for target selectivity of zinc finger proteins based on the number of cysteine residues. The objective of this project is to implement an iterative bioinformatic/ experimental approach to identify, test and refine the selection of high-affinity arsenic targets in the DNA repair pathway, in order to gain insights into mechanisms of arsenic co-carcinogenicity and DNA repair inhibition. This work will yield critical information on the relative sensitivities of identified targets, the importanceof number and configuration of cysteine residues in governing observed sensitivities, and the role of distinct zinc finger secondary structures (e.g. ring finger, treble clef, zinc ribbon) in determining vulnerability to arsenic attack. Preliminary results using a bioinformatic approach identified novel candidate DNA repair targets containing zinc finger structures and activities distinct from PARP-1 or XPA, suggesting possible new actions of arsenic in DNA repair inhibition. Based on our published and preliminary findings, we hypothesize that a coupled bioinformatic/ experimental approach can be developed and applied to predict high affinity arsenic targets in DNA repair, based on zinc finger configuration. To test this hypothesis we will: 1) Identify putative arsenic targets in DNA repair using an unbiased zinc finger motif pattern recognition algorithm, correlated with structural bioinformatic data and literature annotations from automated online database searches, and further classified through phylogenetic and pathway analyses. The DNA repair pathway is used as the validation set since it represents a well-established and biologically-relevant focus of direct significance to arsenic cancer biology and epidemiology. 2) Test arsenite interaction with predicted targets using biochemical and cell biology approaches to validate potential targets, establish relative sensitivities to arsenic, and provide information on structural characteristics for iterative refinement of the bioinformatics approach. The outcomes from the proposed studies are expected to advance the field by 1) expanding our understanding of the scope of zinc finger DNA repair protein disruption by arsenic, 2) identifying novel and sensitive targets, and 3) establishing whether specific zinc finger structures represent preferential targets. These results will inform testable hypotheses regarding additional potential arsenic targets in cancer and other arsenic-associated diseases. PUBLIC HEALTH RELEVANCE: Given the widespread public exposure to arsenic in municipal and private water supplies, there is interest and concern in observations that arsenic concentrations at or near the EPA maximum contaminant level greatly enhance the carcinogenic potential of other DNA damaging agents and inhibit DNA repair. Thus, arsenic may contribute to elevated cancer risk when individuals are exposed to other carcinogens through occupational, environmental or lifestyle exposures. This project represents the first effort to computationally predict highly sensitive arsenic targets to better understand the impact of arsenic on DNA repair and inform strategies to reverse or prevent the adverse health effects of arsenic exposure in humans.

描述（由申请人提供）：有令人信服的证据表明，抑制DNA修复有助于砷的致癌作用和共同致癌作用。基于干扰锌指功能，已经报道了两种DNA修复蛋白（PARP-1和XPA）作为直接砷靶标。迄今为止，DNA修复途径中砷靶标的鉴定仅基于经验证据，尚不清楚是否还有其他直接和高度敏感的DNA修复靶标。我们最近的工作表明，砷矿与含有3或4个半胱氨酸残基的锌指肽和砷依赖的锌从C3H1（例如PARP-1）（例如PARP-1）和C4（例如XPA）（例如XPA）（例如XPA）中的特定DNA修复蛋白（但不是C2H2），但不是C2H2，但不是C2H2，但不是C2H2，但C2H2 Finger Finger Proteins，锌蛋白。这些发现为基于半胱氨酸残基的数量提供了锌指蛋白的靶向选择性的证据。该项目的目的是实施一种迭代生物信息学/实验方法，以识别，测试和完善DNA修复途径中高亲和力砷靶标的选择，以便深入了解砷的共霉素和DNA修复抑制的机制。这项工作将产生有关确定靶标的相对敏感性的关键信息，数字的重要性和半胱氨酸残基在管理观察到的敏感性中的构型，以及确定易于抗鸟类攻击的脆弱性锌指二级结构（例如，环形指，treble clef，Zinc clef，Zinc clef，Zinc clef，Zinc clef，Zinc clef，Zinc clef，ZINC）的作用。使用生物信息学方法的初步结果确定了包含锌指结构和与PARP-1或XPA不同的活性的新型候选DNA修复目标，这表明砷在DNA修复抑制中的新作用可能。根据我们发表的初步发现，我们假设可以开发出一种耦合的生物信息/实验方法，并应用于基于锌指构型的DNA修复中的高亲和力砷靶标。为了检验这一假设，我们将： 1）使用无偏的锌指基序识别算法确定DNA修复中的假定砷靶标，与自动化在线数据库搜索中的结构生物信息学数据和文献注释相关，并通过系统植物剂和途径分析进一步分类。 DNA修复途径被用作验证集，因为它代表了对砷癌症生物学和流行病学具有直接意义的良好且与生物学上的焦点。 2）使用生化和细胞生物学方法测试与预测靶标的砷相互作用，以验证潜在靶标，建立对砷的相对敏感性，并提供有关迭代性生物信息学方法改进的结构特征的信息。预计提出的研究的结果将通过1）扩展我们对锌指DNA修复蛋白蛋白质破坏量的范围的理解，2）确定新颖和敏感的靶标，3）确定特定的锌指结构是否代表优先目标。这些结果将为癌症和其他砷相关疾病中其他潜在的砷靶标提供可检验的假设。公共卫生相关性：鉴于在市政和私人水供应中广泛暴露于砷的广泛接触，人们对EPA最大污染物水平或附近的砷浓度具有兴趣和关注，从而极大地增强了其他DNA损害药物的致癌潜力，并抑制DNA维修。因此，当个人通过职业，环境或生活方式暴露对其他致癌物暴露于其他致癌物时，砷可能会导致癌症风险升高。该项目代表了计算上预测高度敏感的砷靶标的首次努力，以更好地了解砷对DNA修复的影响，并告知策略以逆转或防止砷对人类的不利健康影响。