The role of the Cockayne syndrome proetin

科凯恩综合征蛋白的作用

• 批准号: 7964022
• 负责人: Vilhelm Bohr
• 金额: $ 33.89万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7964022
• 关键词: 8-hydroxyadenine; 8-hydroxyguanosine; ATP Hydrolysis; ATP phosphohydrolase; Age; Aging; Aging-Related Process; Base Excision Repairs; Biological; Biological Models; Brain; Cells; Characteristics; Cockayne Syndrome; Complex; Cyclin-Dependent Kinase 4; DNA; DNA Damage; DNA Excision Repair Protein ERCC-6; DNA Repair Pathway; DNA glycosylase; Disease; Drosophila snf protein; Excision; Lesion; Lyase; Maps; Mitochondrial DNA; Mus; Mutation; Nerve Degeneration; Nuclear; Nucleotide Excision Repair; OGG1 gene; Oxidative Stress; Pathology; Pathway interactions; Patients; Play; Post-Translational Protein Processing; Premature aging syndrome; Process; Protein Family; Proteins; Role; Signal Pathway; Single Strand Break Repair; Syndrome; Tissues; Transcription-Coupled Repair; base; brain tissue; early onset; helicase; human TYRP1 protein; in vivo; interest; novel; oxidative DNA damage; protein function; repaired; response

In CS cells, there are deficiencies in the repair of oxidative DNA damage in the nuclear and mitochondrial DNA, and this may be a major underlying cause of the disease. We found that CSB-deficient cells accumulate oxidized bases, 8-hydroxyguanine and 8-hydroxyadenine, after oxidative stress, consistent with the observation that CSB and oxoguanine DNA glycosylase (OGG1), the major DNA glycosylase for 8-oxoG repair, are in a complex in vivo. We also found that the CSB protein physically interacts with the Nei-like DNA glycosylase, NEIL1, which is also involved in the repair of oxidized bases. This interaction significantly stimulates NEIL1 catalytic activities, both the glycosylase as well as the AP-lyase. The observation that CSB-deficient mice accumulate significantly higher levels of several oxidized DNA bases in brain tissue, including fapyadenine and fapyguanine, supports a role for the CSB protein in the removal of oxidized lesions in vivo. It is notewhorty that Fapy lesions are considered canonical substrates for NEIL1, underscoring the biolgical relevance for this protein interaction. We recently demonstrated that the CSB protein also interacts with PARP1, a protein involved in the early steps of single-strand break repair, and that these two proteins cooperate in the cellular responses to oxidative stress. CSB is a substrate for PARP-1 ribosylation and it is likely that these two proteins function together in the process of base excision. Our results indicate that the CSB protein plays an important role in the repair of oxidative DNA damage and that accumulation of unrepaired lesions, particular in target tissues, like the brain, may be relevant to the CS pathology, which is characterized by severe early onset neurodegeneration. Moreover, we have identified a novel catalytic activity of the CSB protein. Despite having 7 conserved helicase domains (characteristic of the SWI/SNF protein family), the only identified catalytic activity of CSB was ATP hydrolysis. We found that CSB efficiently catalyzes the annealing of two complementary strands of DNA. We are now mapping this novel activity to gain a better understanding of its biological relevance. Repair of 8-oxoG is of special interest since this lesion is believed to be highly mutagenic and accumulates with age. We find that OGG1 interacts with and can be phosphorylated by the cyclin-dependent kinase cdk4. This post-translational modification modulates OGG1 catalytic activity, suggesting a role for signaling pathways in the response to oxidative DNA damage.

在CS细胞中，修复核和线粒体DNA中氧化DNA损伤的缺乏，这可能是该疾病的主要根本原因。我们发现，CSB缺乏的细胞在氧化应激之后积累了氧化的碱，8-羟基鸟嘌呤和8-羟基苯胺，这与观察到的观察到CSB和Oxoguanine DNA糖基酶（OGG1）（OGG1），主要的DNA糖基酶的主要DNA糖基酶，用于8-氧化物的主要DNA糖基酶。我们还发现，CSB蛋白与Nei样DNA糖基化酶Neil1物理相互作用，该糖基酶也参与了氧化碱基的修复。这种相互作用显着刺激了Neil1催化活性，包括糖基化酶和AP-乙醇酶。 CSB缺陷型小鼠在脑组织中积累了几种氧化DNA碱的水平显着较高，包括fapaighadenine和fapyguanine，支持CSB蛋白在体生中去除氧化病变中的作用。值得注意的是，Fapy病变被认为是Neil1的规范底物，强调了这种蛋白质相互作用的生物学相关性。 我们最近证明，CSB蛋白还与PARP1相互作用，PARP1是一种参与单链断裂修复的早期步骤的蛋白质，并且这两种蛋白质在细胞对氧化应激的反应中配合。 CSB是PARP-1核糖基化的底物，这两种蛋白可能在碱性切除过程中起作用。我们的结果表明，CSB蛋白在氧化DNA损伤的修复中起着重要作用，并且在靶向组织中，像大脑这样的靶组织中的未经修复病变的积累可能与CS病理有关，CS病理与CS病理有关，该病理的特征是严重的早期发作神经变性。 此外，我们已经确定了CSB蛋白的新型催化活性。尽管具有7个保守的解旋酶结构域（SWI/SNF蛋白家族的特征），但CSB唯一鉴定出的催化活性是ATP水解。我们发现CSB有效地催化了两种互补的DNA链的退火。现在，我们正在绘制这项新型活动，以更好地了解其生物学相关性。 8-oxog的修复是特别感兴趣的，因为这种病变被认为是高度诱变的，并且随着年龄的增长而积聚。我们发现OGG1与细胞周期蛋白依赖性激酶CDK4相互作用并可以磷酸化。这种翻译后的修饰调节OGG1催化活性，这表明信号通路在对氧化DNA损伤响应中的作用。