Mre11/Rad50 Structural Biology for DNA Damage Responses

Mre11/Rad50 DNA 损伤反应的结构生物学

• 批准号: 7231663
• 负责人: John A. Tainer
• 金额: $ 34.81万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7231663
• 关键词: ATP phosphohydrolase; Adjuvant; Antibodies; Antibody Affinity; Archaea; Architecture; Ataxia; Ataxia Telangiectasia; Ataxia-Telangiectasia-Mutated protein kinase; Binding; Biochemical Genetics; Biological; Biological Assay; C-terminal; Cancer Etiology; Cell Cycle Checkpoint; Cellular biology; Complex; Coupled; DNA; DNA Binding; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Structure; DNA-Protein Interaction; Defect; Development; Disease; Electron Microscopy; Eukaryota; Eukaryotic Cell; Excision; Figs - dietary; Fission Yeast; Genetic; Human; Ionizing radiation; Ions; Knowledge; Malignant Neoplasms; Meiosis; Modeling; Molecular; Molecular Conformation; Nijmegen Breakage Syndrome; Nucleotides; Phenotype; Play; Predisposition; Process; Proteins; Radiation therapy; Radiation, Other; Research; Resistance; Resolution; Roentgen Rays; Role; Signal Transduction; Site; Solutions; Specificity; Structural Biochemistry; Structure; Synchrotrons; Tail; Techniques; Technology; Telangiectasis; Telomere Maintenance; Testing; Therapeutic; V(D)J Recombination; Yeasts; analog; base; chemotherapy; dimer; genetic analysis; homologous recombination; human CHEK1 protein; human disease; inhibitor/antagonist; insight; member; nuclease; recombinational repair; repaired; research study; response; structural biology

DESCRIPTION (provided by applicant): Cancer predispositions in humans and severe phenotypes in yeast result from defects in the Mre11/ Rad50/Nbs1 (MRN) complex. The Mre11 nuclease complex with the Rad50 ATPase is conserved from archaea to humans and regulated by Nbs1 in S. pombe and higher eukaryotes. MRN plays central and essential roles in repairing DMA double-strand breaks (DSBs) during homologous recombination repair (HRR) as well as acting in meiosis, antibody hypermutation, telomere maintenance, and DMA damage signaling through ATM kinase. Detailed mechanistic insights into these diverse MRN functions are limited. We therefore propose two specific aims to further knowledge of MRN structural biochemistry, interactions, and conformational changes relevant to MRN DNA damage repair and signaling functions. To accomplish these aims, we will apply advanced biophysical techniques, including synchrotron solution x-ray scattering and atomic resolution crystal structure technologies in concert with genetic and mutational analyses in yeast. The expected results will characterize functionally key Mre11 and Rad50 protein:protein and protein:DNA interfaces, conformations, and interaction architectures. The proposed coupled biophysical and genetic studies will test hypotheses regarding Mre11's role in DNA target specificity and processing, RadSO's role in ATP-induced conformational controls and architectural interactions, and the role of the Nbs1 C-terminal domain in modulating Mre11 and RadSO activities. Furthermore, the DNA damage sensitivity observed in the absence of any MRN complex member makes these structures a basis for the development of inhibitors to increase cellular sensitivity to ionizing radiation and other DNA damaging agents as adjuvants in cancer radiotherapy and chemotherapy. Together, the proposed experiments will therefore provide results important for a unified understanding of the molecular mechanisms underlying the roles of MNR complexes in genetic integrity and cancer resistance as well as MRN structures as potential targets for cancer therapeutics.

描述（由申请人提供）：人类的癌症倾向和酵母的严重表型是由 Mre11/Rad50/Nbs1 (MRN) 复合物的缺陷引起的。 Mre11 核酸酶与 Rad50 ATP 酶的复合物从古细菌到人类都是保守的，并在粟酒裂殖酵母和高等真核生物中受 Nbs1 调节。 MRN 在同源重组修复 (HRR) 过程中修复 DMA 双链断裂 (DSB) 以及在减数分裂、抗体超突变、端粒维持和通过 ATM 激酶的 DMA 损伤信号传导中发挥着核心和重要作用。 对这些不同 MRN 功能的详细机制了解是有限的。 因此，我们提出了两个具体目标，以进一步了解 MRN 结构生物化学、相互作用以及与 MRN DNA 损伤修复和信号传导功能相关的构象变化。 为了实现这些目标，我们将应用先进的生物物理技术，包括同步加速器溶液 X 射线散射和原子分辨率晶体结构技术，以及酵母的遗传和突变分析。 预期结果将表征功能关键的 Mre11 和 Rad50 蛋白质：蛋白质和蛋白质：DNA 界面、构象和相互作用架构。 拟议的生物物理和遗传学耦合研究将测试有关 Mre11 在 DNA 靶标特异性和加工中的作用、RadSO 在 ATP 诱导的构象控制和结构相互作用中的作用以及 Nbs1 C 末端结构域在调节 Mre11 和 RadSO 活性中的作用的假设。 此外，在不存在任何 MRN 复合体成员的情况下观察到的 DNA 损伤敏感性使得这些结构成为开发抑制剂的基础，以提高细胞对电离辐射和其他 DNA 损伤剂的敏感性，作为癌症放疗和化疗的佐剂。 因此，所提出的实验将为统一理解 MNR 复合物在遗传完整性和抗癌性中的作用以及 MRN 结构作为癌症治疗潜在靶点的分子机制提供重要的结果。