Functional Analysis of the Tip60 Complex

Tip60 复合物的功能分析

基本信息

批准号：
7826594
负责人：
Brendan D Price
金额：
$ 31.18万
依托单位：
DANA-FARBER CANCER INST
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-08-01 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7826594
关键词：
ATM Signaling Pathway ATP phosphohydrolase Ataxia-Telangiectasia-Mutated protein kinase Binding Bleomycin Carcinogens Cell Line Cells Chromatin Chromatin Remodeling Factor Chromatin Structure Complex DNA DNA Damage DNA Double Strand Break DNA Repair DNA Repair Pathway DNA lesion DNA strand break Detection Double Strand Break Repair Environmental Carcinogens Epigenetic Process Event Exposure to Generations Genotoxic Stress Heavy Metals Higher Order Chromatin Structure Histone Acetylation Histones Indium Intervention Link Lysine Malignant Neoplasms Mediating Mediator of activation protein Methylation Mutagens Mutation Phosphotransferases Process Production Property Protein Acetylation Proteins Public Health Recruitment Activity Relaxation Research Risk Role Scaffolding Protein Signal Transduction Signal Transduction Pathway Site Specificity Testing Therapeutic Agents Tobacco smoke Ultraviolet Rays cancer risk cancer therapy carcinogenesis chromatin remodeling cytotoxicity design environmental agent genetic regulatory protein histone acetyltransferase histone methyltransferase improved innovation insight neoplastic cell novel novel therapeutics programs public health relevance repaired response stem

项目摘要

DESCRIPTION (provided by applicant): Cancer arises during the process of carcinogenesis, in which the exposure of cells to genotoxic insults leads to the introduction of permanent genetic changes. The ability of cells to detect this DNA damage and to activate appropriate repair mechanisms is crucial for the cell to suppress carcinogenic events. The Tip60 histone acetyltransferase is a key mediator of the cells ability to detect and repair these DNA lesions. Tip60 is a key component of the NuA4-Tip60 chromatin remodeling complex. Chromatin remodeling is utilized to unpack higher ordered chromatin structures and alter histone-DNA interactions to facilitate access of the DNA repair machinery to DNA lesions. Our results demonstrate that chromatin remodeling by the NuA4-Tip60 complex requires Tip60's HAT activity. Further, Tip60 contains a chromodomain, a conserved domain with the potential to interact with methylated lysine residues on histones, and this domain is required for the activation of Tip60's HAT activity and NuA4-dependent chromatin remodeling. The long term aims are to test the hypothesis that Tip60 is a key component of a novel signal transduction pathway which links the detection of DNA damage to alterations in chromatin structure. We will test the hypothesis that the catalytic components of NuA4, including the p400 ATPase activity and Tip60's HAT activity, are required for chromatin remodeling following DNA damage. Further, we propose that interactions between the chromodomain of Tip60 and exposed methyl-lysine residues on histones at sites of DNA damage mediate this activation of Tip60's HAT activity. Tip60 exists as a trimeric complex containing the Tip60, epc1 and ING3 proteins. In specific aim 1, the role of the ING3 regulatory protein in controlling Tip60's HAT activity will be defined, and the mechanism by which NuA4 is recruited to DNA breaks will be determined. In specific aim 2, the function of the ATPase activity of the p400 sub- unit of NuA4 in chromatin unwinding will be determined, and the contribution of histone acetylation by Tip60 at sites of DNA damage identified. In specific aim 3, the specificity of interaction between the chromodomain of Tip60 and methylated lysine residues on histones will be determined, and the role of histone methylation in the DNA-damage dependent activation of Tip60 examined. An understanding of the signal transduction pathway by which Tip60 detects DNA strand breaks caused by bleomycin and related agents will provide crucial insights into the cytotoxicity and mutagenic properties of these agents. A more complete understanding of how Tip60 regulates the DNA damage response may allow new therapies, including the rational design of novel therapeutic compounds, to be applied to cancer therapy and to clinically beneficial interventions for reducing the risk from genotoxic stress. Finally, Tip60 and its associated proteins are potential targets for developing therapeutic agents which can modify the DNA damage response of tumor cells. PUBLIC HEALTH RELEVANCE: Exposure to carcinogens, including environmental agents such as UV light, tobacco smoke, heavy metals and other genotoxic agents, are the underlying cause of many cancers. An understanding of how Tip60 regulates the repair of this DNA damage is therefore relevant to improving public health, and will allow for the rational design of novel therapeutic compounds which could be applied to cancer therapy, and for clinically beneficial interventions to the cancer risk associated with exposure to carcinogens. In addition, Tip60 is a potential target for developing therapeutic agents which can modify the DNA damage response of tumor cells and sensitize them to anti-cancer therapies.

描述（由申请人提供）：在癌变过程中出现癌症，其中细胞暴露于遗传毒性损伤会导致引入永久性遗传变化。细胞检测这种DNA损伤并激活适当修复机制的能力对于细胞抑制致癌事件至关重要。 TIP60组蛋白乙酰转移酶是细胞检测和修复这些DNA病变的能力的关键介体。 TIP60是NUA4-TIP60染色质重塑复合物的关键组成部分。染色质重塑用于解开较高有序的染色质结构并改变组蛋白DNA相互作用，以促进DNA修复机械进入DNA病变。我们的结果表明，NUA4-TIP60复合物进行染色质重塑需要TIP60的HAT活动。此外，TIP60包含一个染色体域，一个保守的结构域具有与组蛋白上甲基化的赖氨酸残基相互作用的潜力，并且该结构域是激活TIP60的HAT活性和NUA4依赖性染色质重塑所必需的。长期目的是检验以下假设：TIP60是新型信号转导途径的关键组成部分，该途径将DNA损伤的检测与染色质结构的改变联系起来。我们将测试以下假设：NUA4的催化成分（包括P400 ATPase活性和TIP60的HAT活性）是DNA损伤后染色质重塑所必需的。此外，我们提出，在DNA损伤部位，TIP60染色体域与暴露于组蛋白上暴露的甲基赖氨酸残基之间的相互作用介导了TIP60 HAT活性的激活。 TIP60作为包含TIP60，EPC1和ING3蛋白的三聚体配合物存在。在特定目标1中，将定义ING3调节蛋白在控制TIP60的HAT活性中的作用，并将确定NUA4募集到DNA断裂的机制。在特定的目标2中，将确定NUA4 p400亚单位在染色质中的ATPase活性的功能，并且将确定在鉴定的DNA损伤部位对组蛋白乙酰化的组蛋白乙酰化的贡献。在特定的目标3中，将确定TIP60染色体构和甲基化赖氨酸残基之间相互作用的特异性，并确定组蛋白甲基化在检查的TIP60的DNA破坏依赖性激活中的作用。对TIP60检测到由博来霉素和相关药物引起的DNA链断裂的信号转导途径的理解将提供对这些药物的细胞毒性和诱变特性的关键见解。对TIP60如何调节DNA损伤反应的更全面了解可能允许将新疗法（包括新型治疗化合物的合理设计）应用于癌症治疗，并降低临床上有益的干预措施，以降低遗传毒性应激的风险。最后，TIP60及其相关蛋白是开发可以改变肿瘤细胞DNA损伤反应的治疗剂的潜在靶标。公共卫生相关性：接触致癌物，包括环境药物，例如紫外线，烟草烟雾，重金属和其他遗传毒性剂，是许多癌症的根本原因。因此，了解TIP60如何调节该DNA损伤的修复与改善公共卫生有关，并将允许对可用于癌症治疗的新型治疗化合物的合理设计，以及临床上对与癌症暴露有关的癌症风险的有益干预措施。此外，TIP60是开发治疗剂的潜在靶标，可以改变肿瘤细胞的DNA损伤反应并使它们对抗癌疗法敏感。