Control of commitment steps in mammalian homologous recombination

哺乳动物同源重组中承诺步骤的控制

基本信息

批准号：
9762020
负责人：
Samuel Bunting
金额：
$ 34.1万
依托单位：
RUTGERS, THE STATE UNIV OF N.J.
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-01 至 2020-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9762020
关键词：
Affect Appearance BRCA1 gene BRCA2 gene Biophysics Bone Marrow Brain Cancer Cell Growth Cell Cycle Cell physiology Cells Cellular biology Coiled-Coil Domain Complex Cytotoxic Chemotherapy DNA DNA Damage DNA Double Strand Break DNA Repair DNA Repair Gene DNA Repair Pathway DNA Sequence Alteration Databases Defect Development Double Strand Break Repair EXO1 gene Embryo Environment Excision Frequencies G0 Phase G1 Phase Genes Genetic Genome Genomic Instability Goals Hematopoietic Hematopoietic stem cells Higher Order Chromatin Structure Homodimerization Incidence Individual Interphase Cell Learning Ligation Malignant Neoplasms Mammalian Cell Measures Mediating Methods Mitotic Modeling Molecular Mus Mutation Neurons Nonhomologous DNA End Joining Normal Cell Onset of illness Operating System Outcome Pathologic Pathway interactions Patients Physiological Population Reagent Repression Resources Role Site Site-Directed Mutagenesis Somatic Cell Structural Models Structure System Techniques Testing Transgenic Organisms Work X-Ray Crystallography base cancer cell cancer therapy design experimental study genetic approach genome integrity homologous recombination in vivo p53-binding protein 1 prevent public health relevance reconstitution recruit relating to nervous system repaired response success therapy design three dimensional structure tumor tumorigenesis variant of unknown significance

项目摘要

DESCRIPTION (provided by applicant): Understanding the high mutation frequency of cancer cells is key to finding ways to prevent or delay the onset of disease and subsequent chemoresistance. Errors in repair of DNA double-strand breaks (DSBs) can cause mutations, hence understanding how repair pathways act is of essential importance for the development of new strategies to reduce the frequency of tumors and the appearance of chemoresistance. Mammalian DSB repair is mediated by nonhomologous end-joining (NHEJ) and homologous recombination (HR). Whereas HR uses a homologous template for repair, NHEJ acts by ligation of DSBs. The pathways therefore produce different repair outcomes, and the relative rate of usage of NHEJ and HR is regulated in cells by processes which are poorly understood. Cell cycle appears to be a major determinant of usage of the HR pathway, with HR used infrequently in G1 somatic cells. A second regulator of pathway choice is the DNA damage response factor, 53BP1. 53BP1 limits resection of DSBs, a key step in HR. 53BP1 therefore promotes NHEJ at the expense of HR. Using genetic approaches in primary mouse cells, we propose to measure how 53BP1 interacts with cellular activities including BRCA1, BLM and Exo1 to mediate DSB resection, a key step regulating the use of HR versus NHEJ. We will furthermore test whether the effect of 53BP1 in limiting resection is required for suppressing genomic instability and tumorigenesis arising from defects in DNA repair in non-dividing cells. Finally, we propose to determine how BRCA1 interacts with PALB2, a repair factor that helps recruit BRCA2 to break sites. BRCA1 and PALB2 form a complex through interactions of predicted coiled-coil regions, and we will identify and characterize the exact molecular mechanism of interaction using biophysical and cell biology techniques. Together, these studies will advance our understanding of critical commitment steps to HR in primary mammalian cells, and inform strategies for the design of rational therapies for treatment of individuals with mutations in key DNA repair genes.

描述（由申请人提供）：了解癌细胞的高突变频率是寻找预防或延迟疾病发作和随后的化学抗性的方法的关键。 DNA双链断裂（DSB）修复中的错误可能会导致突变，因此了解修复途径的作用对于开发新策略以减少肿瘤频率和化学抗性的出现至关重要。哺乳动物DSB修复是由非同源末端加入（NHEJ）和同源重组（HR）介导的。 HR使用同源模板进行维修，而NHEJ通过连接DSB来起作用。因此，这些途径会产生不同的修复结果，并且NHEJ和HR使用的相对使用率是通过较少了解的过程在细胞中调节的。细胞周期似乎是HR途径使用的主要决定因素，HR在G1体细胞中很少使用。途径选择的第二个调节剂是DNA损伤响应因子53BP1。 53BP1限制DSB的切除，这是人力资源的关键步骤。因此，53BP1以人力资源为代价促进NHEJ。使用原代小鼠细胞中的遗传方法，我们建议测量53BP1如何与包括BRCA1，BLM和EXO1在内的细胞活性相互作用以介导DSB切除，这是调节HR与NHEJ使用的关键步骤。我们还将测试53BP1在抑制非分裂细胞中DNA修复缺陷引起的基因组不稳定性和肿瘤发生中是否需要限制切除术的作用。最后，我们建议确定BRCA1如何与PALB2相互作用，这是一个修复因子，有助于招募BRCA2破坏站点。 BRCA1和PALB2通过预测的盘绕螺旋区域的相互作用形成了复杂，我们将使用生物物理和细胞生物学技术来确定和表征相互作用的确切分子机制。这些研究将共同提高我们对原代哺乳动物细胞中HR的关键承诺步骤的理解，并为设计有理疗法的策略提供了用于治疗关键DNA修复基因中突变个体的理性疗法。