Roles of Lig3 and XRCC1 Genes in Genome Stability

Lig3 和 XRCC1 基因在基因组稳定性中的作用

• 批准号: 8434118
• 负责人: Alan E Tomkinson
• 金额: $ 29.37万
• 依托单位: UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-22 至 2016-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8434118
• 关键词: Antineoplastic Agents; Apoptosis; Base Excision Repairs; Biological; Cell Cycle Checkpoint; Cell physiology; Cells; Characteristics; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Ligases; DNA Repair; DNA Repair Pathway; DNA Sequence Rearrangement; DNA Single Strand Break; DNA biosynthesis; DNA lesion; DNA ligase III; DNA strand break; DNA-Directed DNA Polymerase; Defect; Development; Enzymes; Eukaryota; Excision; Exposure to; Genes; Genome Stability; Genomic Instability; Genomics; Goals; Homologous Gene; Human; Human Genome; Hypersensitivity; LIG4 gene; Laboratories; Lead; Malignant Neoplasms; Mediating; Metabolism; Mutation; Nonhomologous DNA End Joining; Normal Cell; Nucleotide Excision Repair; Organism; Pathway interactions; Poly(ADP-ribose) Polymerases; Process; Proteins; Reaction; Reagent; Recruitment Activity; Regulation; Role; Series; Single Strand Break Repair; Structure; Therapeutic; Tumor Suppression; Two-Hybrid System Techniques; XRCC1 gene; Yeasts; abstracting; base; cancer cell; inhibitor/antagonist; insight; mutant; neoplastic cell; novel; polypeptide; prevent; protein protein interaction; public health relevance; recombinational repair; repaired; response; small molecule

Abstract The human genome is subject to constant attack by endogenous and environmental DNA damaging agents. If unrepaired, DNA lesions will give rise to mutations that in turn may lead to cancer formation. Fortunately, a complex network of DNA repair pathways operates to remove DNA lesions. To assess the biological significance of exposure to environmental DNA damaging agents, it is necessary to understand the details of the complex cellular response to DNA damage. Unlike the conserved LIG1 and LIG4 genes, lower eukaryotes lack a homolog of the mammalian LIG3 gene, which encodes at least three distinct polypeptides. Interestingly, the DNA ligase III¿-associated proteins, poly (ADP-ribose) polymerase 1 (PARP-1), XRCC1 and DNA polymerase (Pol) ¿, each of which have been implicated in base excision repair and the repair of DNA single strand breaks, are also found only in higher eukaryotes. Using a modified yeast two hybrid assay, we have identified a series of XRCC1 mutants that are defective in specific protein-protein interactions. In Specific Aim 1, we will utilize these mutants to delineate the functional and biological consequences of protein-protein interactions between DNA ligase III¿/XRCC1 and other proteins involved in base excision and single strand break repair. Recent studies have increased the repertoire of DNA repair transactions in which DNA ligase III¿/XRCC1 participates. In Specific Aim 2, we will determine how DNA ligase III¿/XRCC1 is recruited to the DNA nucleotide excision repair machinery and whether this involves an interaction between XRCC1 and PCNA. In preliminary studies, we have identified an interaction between DNA ligase III¿/XRCC1 and hRad50/hMre11/Nbs. In Specific Aim 3, we will determine how DNA damage regulates this interaction and whether these proteins act together in an error- prone non-homologous end-joining sub pathway that repairs DNA double strand breaks. Interestingly, this error-prone pathway is up-regulated in cancer cells and may contribute to their characteristic genomic instability. In Specific Aim 4, we will identify and characterize small molecule inhibitors of DNA ligase III. We envision that that these inhibitors will not only be valuable reagents for elucidating the cellular functions of the LIG3 gene products but also may serve as lead compounds for the development of novel anti-cancer agents.

摘要 人类基因组不断受到内源性和环境dna的攻击。 破坏性因素。如果不修复，DNA损伤将导致突变，进而可能导致 癌症的形成。幸运的是，DNA修复途径的复杂网络可以使 DNA损伤。评估暴露在环境DNA损伤中的生物学意义 药物，有必要了解复杂的细胞对DNA的反应的细节 损坏。与保守的LIG1和LIG4基因不同，低等真核生物缺乏与LIG1和LIG4基因同源的 哺乳动物LIG3基因，编码至少三种不同的多肽。有趣的是， DNA连接酶III？相关蛋白、聚(ADP-核糖)聚合酶1(PARP-1)、XRCC1和 DNA聚合酶(Pol)，每一个都与碱基切除修复和 DNA单链断裂的修复，也只在高等真核生物中发现。使用修改后的 酵母双杂交实验，我们已经鉴定了一系列XRCC1突变体 特定的蛋白质-蛋白质相互作用。在特定的目标1中，我们将利用这些突变体来描绘 DNA连接酶之间蛋白质-蛋白质相互作用的功能和生物学后果 III？/XRCC1等参与碱基切除和单链断裂修复的蛋白质。近期 研究增加了DNA连接酶参与的DNA修复交易的谱系 III？/XRCC1参与。在特定目标2中，我们将确定DNA连接酶III？/XRCC1是如何 被招募到DNA核苷酸切除修复机制，以及这是否涉及 XRCC1与增殖细胞核抗原的相互作用在初步研究中，我们发现了一种相互作用 DNA连接酶Ⅲ/XRCC1和hRad50/hMre11/NBS。在具体目标3中，我们将确定 DNA损伤是如何调节这种相互作用的，以及这些蛋白质是否在错误中共同作用- 修复DNA双链断裂的非同源末端连接子通路。 有趣的是，这种容易出错的途径在癌细胞中上调，并可能有助于其 典型的基因组不稳定性。在具体目标4中，我们将确定和描述小 DNA连接酶III的分子抑制剂。我们预计这些抑制剂不仅将是 用于阐明LIG3基因产物的细胞功能的有价值的试剂，但也可以 作为开发新型抗癌药物的先导化合物。