Repair of oxidative DNA damage in mammalian cells

修复哺乳动物细胞中的氧化DNA损伤

• 批准号: 7622903
• 负责人: Tadahide Izumi
• 金额: $ 22.69万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-10 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7622903
• 关键词: Adjuvant; Affect; Aging; Alkylation; Apoptosis; Base Excision Repairs; Biochemical; Biological; Cell Death; Cells; DNA Binding; DNA Damage; DNA biosynthesis; DNA chemical synthesis; DNA lesion; Defense Mechanisms; Double Minutes; EP300 gene; Effectiveness; Excision; Functional disorder; Gene Expression Regulation; Generations; Genomics; Genotoxic Stress; Histones; Human; Kinetics; Knowledge; Left; Louisiana; Malignant Neoplasms; Mammalian Cell; Mammals; Modality; Monoubiquitination; Mus; Mutagenesis; Mutation; Organ Preservation; Oxidation-Reduction; Pharmaceutical Preparations; Play; Poly(ADP-ribose) Polymerases; Predisposition; Process; Property; Proteins; Radiation therapy; Radio; Rate; Reagent; Regulation; Regulator Genes; Regulatory Pathway; Resistance; Roentgen Rays; Role; Signal Transduction; TP53 gene; Techniques; Testing; Transducers; Transferase; Ubiquitination; age related; anticancer research; base; cancer cell; cancer therapy; carcinogenesis; cell type; domain mapping; endonuclease; improved; in vivo; insight; metaplastic cell transformation; mouse ubiquitin-protein ligase E3 Mdm2; neoplastic cell; oxidation; oxidative DNA damage; polypeptide; prevent; repair enzyme; repaired; research facility; response; transcription factor

Summary Oxidative DNA damage is continuously generated in cells by both endogenous and exogenous genotoxicants. The damage leads to mutation and cell death and is the cause of cellular transformation and eventual carcinogenesis. DNA base excision repair (BER) is the cell¿s primary defense mechanism to prevent such mutations. The BER enzyme at the center of activity is apurinic/apyrimidinic endonuclease 1 (APE1), which reacts with the DNA lesions to generate 3¿-OH termini that are then processed by the DNA synthesis machineries. Our recent studies indicate that APE1 is essential for cellular viability. Paradoxically, however, APE1 (and BER) may become harmful to the body, since cancer cells can acquire drug- and radio-resistance due to increased APE1 expression, giving the cells a better chance of survival. Therefore, changes in APE1¿s enzymatic properties are crucial not only to cells but also to a whole body. We have found that APE1 is ubiquitinated by the mouse double minute 2 protein, Mdm2, and regulated by p53 upon DNA damage generation. The ubiquitination occurs at specific Lys residues in the APE1 polypeptide. It appears to have significant effects on the functions of APE1 and other cellular factors including XRCC1 and p53 that interact directly with APE1. The central hypothesis of this project is that APE1 ubiquitination, regulated by p53/Mdm2, modulates the cellular APE1 level and activity during the DNA damage response and apoptosis. The Specific Aims of this project are: (1) to determine the effect of APE1 ubiquitination on its functions, (2) to examine the interaction of ubiquitinated APE1 with other BER enzymes and p53/Mdm2, and (3) to determine the regulatory pathways through which APE1 ubiquitination occurs in response to DNA damage. We will use biochemical and cell biological techniques as the primary means of identifying the specific ubiquitination mechanism that regulates APE1 in vivo. Understanding the ubiquitination of APE1 will significantly increase our knowledge of the cellular defense mechanism against carcinogenesis.

概括 氧化DNA损伤是通过两种内源性在细胞中连续产生的 和外源遗传毒性。损害导致突变和细胞死亡，是 细胞转化和最终致癌的原因。 DNA基础惊喜维修 （BER）是预防这种突变的细胞的主要防御机制。 BER酶 在活动的中心是肾上腺素/阿哌丁素核酸内切酶1（APE1），反应 用DNA病变生成3？-OH末端，然后由DNA处理 合成机。我们最近的研究表明，APE1对于细胞活力至关重要。 然而，矛盾的是，APE1（和BER）可能会对身体有害，因为 癌细胞可以由于APE1表达增加而获得药物和放射性， 为细胞提供更好的生存机会。因此，ape1 s酶促的变化 特性不仅对细胞至关重要，而且对整个身体至关重要。我们发现 APE1被小鼠双分钟2蛋白MDM2泛素化，并由 DNA损伤产生的p53。泛素化发生在特定的Lys残差处 APE1多肽。它似乎对APE1的功能有重大影响 以及直接与APE1相互作用的XRCC1和P53在内的其他细胞因子。 该项目的核心假设是APE1泛素化，受 p53/mdm2，调节DNA损伤响应期间的细胞APE1水平和活性 和凋亡。该项目的具体目的是：（1）确定效果 APE1泛素化的功能，（2）检查泛素化的相互作用 APE1与其他BER酶和p53/MDM2和（3）确定调节 APE1泛素化响应DNA损伤而发生的途径。我们 将使用生化和细胞生物学技术作为识别的主要手段 调节体内APE1的特定泛素化机制。了解 APE1的泛素化将大大增加我们对细胞防御的了解 反对致癌的机制。