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

基本信息

批准号：
8231999
负责人：
Alan E Tomkinson
金额：
$ 29.97万
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：
2004
资助国家：
美国
起止时间：
2004-04-22 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8231999
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

项目摘要

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.

抽象的人类基因组不断受到内源和环境 DNA 的攻击如果不加以修复，DNA损伤将引起突变，进而可能导致幸运的是，有一个复杂的 DNA 修复途径网络可以消除癌症的形成。 DNA 损伤评估暴露于环境 DNA 损伤的生物学意义。剂，有必要了解细胞对 DNA 的复杂反应的细节与保守的 LIG1 和 LIG4 基因不同，低等真核生物缺乏该基因的同源物。哺乳动物LIG3基因，编码至少三种不同的多肽。 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) ¿ ，其中每一个都与碱基切除修复有关，并且 DNA单链断裂的修复也仅在高等真核生物中发现使用修饰的。通过酵母二杂交实验，我们鉴定出了一系列 XRCC1 突变体，这些突变体在在特定目标 1 中，我们将利用这些突变体来描述特定的蛋白质-蛋白质相互作用。 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 和其他参与碱基切除和单链断裂修复的蛋白质。研究增加了 DNA 修复交易的库，其中 DNA 连接酶 III¿ /XRCC1 参与特定目标 2，我们将确定 DNA 连接酶 III 如何进行。 /XRCC1 是被招募到 DNA 核苷酸切除修复机制中，以及这是否涉及 XRCC1 和 PCNA 之间的相互作用在初步研究中，我们已经确定了一种相互作用。 DNA 连接酶 III 之间¿ /XRCC1 和 hRad50/hMre11/Nbs 在具体目标 3 中，我们将确定 DNA 损伤如何调节这种相互作用以及这些蛋白质是否错误地共同作用修复 DNA 双链断裂的易发生的非同源末端连接子通路。模棱两可，这种容易出错的途径在癌细胞中上调，并可能有助于其在特定目标 4 中，我们将识别并表征小的基因组不稳定性。 DNA 连接酶 III 的分子抑制剂我们设想这些抑制剂不仅是是阐明 LIG3 基因产物的细胞功能的有价值的试剂，而且还可能作为开发新型抗癌药物的先导化合物。