Role of damaged DNA binding protein (DDB) in checkpoint control & carcinogenesis

受损 DNA 结合蛋白 (DDB) 在检查点控制中的作用

• 批准号: 7269288
• 负责人: Pradip Raychaudhuri
• 金额: $ 25.76万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7269288
• 关键词: 1-Phosphatidylinositol 3-Kinase; ABL1 gene; Apoptosis; Binding; Cell Aging; Cell Cycle; Cell Cycle Checkpoint; Cells; Checkpoint kinase 1; Chromatin; Complex; DDB Chlorinated Hydrocarbons; DNA; DNA Damage; DNA Repair; DNA repair protein; DNA-Binding Proteins; Development; Embryo; Fibroblasts; Frequencies; Funding; Genome; Genomics; Hereditary Disease; Ionizing radiation; Kinetics; Knock-out; Link; Malignant Neoplasms; Molecular; Mouse Strains; Mus; Mutate; Mutation; Nucleotide Excision Repair; Numbers; Oncogenic; Pathway interactions; Phase; Phenotype; Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide; Phosphotransferases; Play; Principal Investigator; Process; Proteins; Recruitment Activity; Role; Signal Pathway; Single-Stranded DNA; Skin Carcinogenesis; Stress; TP53 gene; TREX1 gene; Testing; Tissues; Transcription-Coupled Repair; Tumor Suppression; Tumor Suppressor Proteins; Tumor Tissue; Wild Type Mouse; XPA gene; Xeroderma Pigmentosum; aplidine; base; c-abl Proto-Oncogenes; carcinogenesis; cohort; genetic regulatory protein; human disease; insight; repaired; senescence; sensor; tumor; ultraviolet damage; ultraviolet irradiation; xeroderma pigmentosum group A complementing protein

DESCRIPTION (provided by applicant): DNA damages have been linked to aging, cellular senescence, and development of genetic diseases, including cancer. Cells respond to DNA damage by activating repair and the checkpoint pathways. The checkpoint pathways delay the cell cycle to allow for DNA repair. When the extent of damage is overwhelming, the checkpoint pathways direct the cells to undergo permanent arrest or apoptosis. But the molecular links between the damage recognition, repair and the cell cycle checkpoints, which would be important in determining the fate of a cell, are poorly understood. The checkpoint pathway involves association of the PI3 kinases ATM/ATR with damaged chromatin and subsequent activation of the checkpoint kinases (Chk1 and Chk2) and p53, as well as other regulatory proteins. Despite significant advances, the mechanisms (sensors) that recruit ATM/ATR to damaged-chromatin are not known. Our recent studies revealed that the nucleotide excision repair (NER) protein DDB functions as a sensor in the damage signaling pathway of ATR. The objectives of this proposal are to further investigate the functional link between DDB and ATR. We will test the hypothesis that DDB is a critical partner of ATR in checkpoint activation and genome stabilization. In addition, we will investigate the mechanism by which DDB recruits ATR to the damaged-chromatin and determine whether DDB plays a role in coordinating repair with the checkpoints. DDB is composed to two subunits: DDB1 and DDB2. The DDB2 subunit is mutated in xeroderma pigmentosum (XP-E). We constructed a knockout strain of mice lacking expression of DDB2. These mice recapitulate the key phenotypes of the human disease (XP-E) in that they are highly susceptible to skin carcinogenesis. Moreover, the DDB2-deficient mice develop spontaneous tumors at high frequencies. We will investigate the hypothesis that, in addition to nucleotide excision repair, the tumor suppression function of DDB2 involves the checkpoint pathways related to ATR. The specific aims are: 1. What is the spectrum of spontaneous tumors in DDB2-deficient mice? Are the DDB2 -/- mice deficient in DNA repair and ATR-activated checkpoints? 2. Is DDB required for DNA damage-induced S phase checkpoint? Is DDB required for the genome stabilization function of ATR? 3. How does DDB recruit ATR to damaged-chromatin? Does DDB play any role in coordinating repair with the checkpoints? Does Cop9/signalosome regulate the damage-sensing function of DDB?

描述（由申请人提供）：DNA损伤与衰老、细胞衰老和遗传疾病（包括癌症）的发生有关。细胞通过激活修复和检查点途径对DNA损伤做出反应。检查点通路延迟细胞周期以允许DNA修复。当损伤的程度是压倒性的，检查点途径指导细胞进行永久性逮捕或凋亡。但是，损伤识别、修复和细胞周期检查点之间的分子联系，这对决定细胞命运很重要，却知之甚少。检查点途径涉及PI 3激酶ATM/ATR与受损染色质的结合，以及检查点激酶（Chk 1和Chk 2）和p53以及其他调节蛋白的随后激活。尽管取得了重大进展，但招募ATM/ATR到受损染色质的机制（传感器）尚不清楚。我们最近的研究表明，核苷酸切除修复（NER）蛋白DDB在ATR损伤信号通路中起传感器的作用。本提案的目的是进一步调查DDB和ATR之间的功能联系。我们将测试DDB是ATR在检查点激活和基因组稳定中的关键伙伴的假设。此外，我们将研究DDB招募ATR到受损染色质的机制，并确定DDB是否在与检查点协调修复中发挥作用。DDB由两个子单元组成：DDB 1和DDB 2。DDB 2亚基在着色性干皮病（XP-E）中突变。我们构建了缺失DDB 2表达的敲除小鼠品系。这些小鼠概括了人类疾病（XP-E）的关键表型，因为它们对皮肤致癌作用高度敏感。此外，DDB 2缺陷小鼠以高频率发展自发性肿瘤。我们将研究的假设，除了核苷酸切除修复，DDB 2的肿瘤抑制功能涉及ATR相关的检查点途径。具体目标是： 1. DDB 2缺陷小鼠自发性肿瘤的谱是什么？DDB 2-/-小鼠是否缺乏DNA修复和ATR激活的检查点？ 2. DNA损伤诱导的S期检查点是否需要DDB？ATR的基因组稳定功能是否需要DDB？ 3. DDB如何将ATR募集到受损的染色质？DDB是否在与检查点协调修复方面发挥任何作用？Cop 9/信号体是否调节DDB的损伤感受功能？