Mre11/Rad50 Structural Biology for DNA Damage Responses

Mre11/Rad50 DNA 损伤反应的结构生物学

• 批准号: 7429769
• 负责人: John A. Tainer
• 金额: $ 35.49万
• 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/7429769
• 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）：人类中的癌症易感性和酵母中严重的表型是由MRE11/ RAD50/ NBS1（MRN）复合物中的缺陷引起的。 与Rad50 ATPase的MRE11核酸酶复合物从古细菌到人类保存，并由S. pombe和较高的真核生物受到NBS1的调节。 MRN在同源重组修复（HRR）期间修复DMA双链断裂（DSB）以及在减数分裂，抗体超突击，维持端粒维持和DMA损伤信号中的作用中起着中心作用。 对这些不同MRN功能的详细机械见解是有限的。 因此，我们提出了两个具体目标，以进一步了解与MRN DNA损伤修复和信号传导功能相关的MRN结构生物化学，相互作用和构象变化。 为了实现这些目标，我们将采用先进的生物物理技术，包括同步溶液X射线散射和原子分辨率晶体结构技术，并与酵母中的遗传和突变分析一起。 预期的结果将在功能上表征关键MRE11和RAD50蛋白：蛋白质和蛋白质：DNA接口，构象和相互作用体系结构。 所提出的耦合生物物理和遗传研究将检验有关MRE11在DNA靶标特异性和加工，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-t末端结构域在调节MRE11和RADSO活性中的作用的假设。 此外，在没有任何MRN复合构件的情况下观察到的DNA损伤敏感性使这些结构成为抑制剂发展对电离辐射的敏感性和其他DNA损害剂作为癌症放射疗法和化学疗法中的辅助剂的基础。 因此，提出的实验将为统一理解MNR复合物在遗传完整性和癌症耐药性中的作用以及MRN结构作为癌症治疗剂的潜在靶标的统一理解而提供重要的结果。