Role of EMSY protein complexes in the FA DNA repair pathway

EMSY 蛋白复合物在 FA DNA 修复途径中的作用

• 批准号: 9100967
• 负责人: Alexandra Theresia Sobeck
• 金额: $ 19.51万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9100967
• 关键词: Advanced Development; Aphidicolin; BRCA2 Protein; BRCA2 gene; Binding; Bloom Syndrome; Cell Survival; Cells; Chromatin; Chromosomal Stability; Chromosome abnormality; Chromosomes; Cisplatin; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Interstrand Crosslinking; DNA Repair; DNA Repair Gene; DNA Repair Pathway; DNA Replication Damage; DNA lesion; DNA replication fork; DNA-Directed DNA Polymerase; Defect; Disease; Double Strand Break Repair; Event; Excision; Exhibits; FANCD2 protein; Fanconi Anemia pathway; Fanconi anemia protein; Fanconi' s Anemia; Genes; Genetic Models; Genome Stability; Genomic Instability; Human; Hypersensitivity; Individual; Inherited; Knowledge; Laboratories; Lesion; Malignant Neoplasms; Mediating; Mediator of activation protein; Melphalan; Missense Mutation; Mitomycins; Modeling; Molecular; Molecular Target; Mutate; Mutation; Names; Normal Cell; Nuclear; Oncogenes; Ovarian; Pathway interactions; Patients; Perception; Pharmaceutical Preparations; Play; Predisposition; Process; Proteins; Recovery; Recruitment Activity; Research; Resistance; Risk; Role; S Phase; Signal Transduction; Solid Neoplasm; Stress; Syndrome; Testing; Transactivation; Tumor Suppressor Proteins; Work; base; cancer cell; carcinogenesis; chemotherapeutic agent; chemotherapy; crosslink; helicase; homologous recombination; hydroxyurea; interest; leukemia; malignant breast neoplasm; member; novel; prevent; protein complex; protein function; public health relevance; recombinational repair; repaired; response; treatment strategy

 DESCRIPTION (provided by applicant): Genomic instability diseases like Fanconi Anemia (FA) represent rare genetic models for human susceptibility to cancer. FA is a multi-gene disease characterized on the cellular level by chromosomal abnormalities and a hypersensitivity to replication-blocking DNA lesions, particularly DNA interstrand crosslinks (DNA ICLs). A central member of the FA pathway is the FANCD2 protein that is directly recruited to DNA ICLs and stalled replication forks. Accumulating evidence suggests that FANCD2 then recruits other FA and non-FA DNA repair factors that use homologous recombination (HR) repair mechanisms to mediate the removal of replication- blocking lesions such as DNA ICLs, and to promote replication fork recovery. Based on our new results, we predict a protein named EMSY to be a novel functional partner of FANCD2. Whether EMSY functions in any cellular DNA damage responses is not known. We discovered that EMSY is recruited to chromatin in a DNA damage- and strictly FANCD2-dependent manner. Strikingly, EMSY-deficient cells are as hypersensitive to DNA ICLs and to replication stress as FANCD2-deficient cells. Based on our preliminary results, we hypothesize that EMSY and FANCD2 form a novel protein complex that promotes HR- dependent DNA ICL repair and HR-mediated replication fork recovery. We will test this hypothesis as follows: Aim 1: Determine the role of EMSY/FANCD2 in HR-mediated DNA ICL repair. We will test if EMSY and FANCD2 act in concert to promote cellular DNA ICL resistance and to support molecular steps during the HR- repair of DNA ICL-associated DNA double strand breaks (DSBs). Aim 2: Determine the role of EMSY/FANCD2 in HR-mediated replication fork recovery. We will test if EMSY and FANCD2 act in concert to promote cellular resistance to aphidicolin-triggered replication fork stalling and to support molecular steps during HR factor-mediated protection and restart of replication forks. Additionally, we will test if six known FANCD2 patient mutations cause cellular deficiencies in replication fork recovery by interrupting FANCD2/EMSY complex formation. These approaches will elucidate how the currently uncharacterized EMSY protein function in the cellular DNA damage response and reveal a new layer of complexity within the FA pathway-associated DNA repair network. We expect our findings to significantly contribute to an understanding of the FA pathway's role in maintaining genomic stability and in protecting cells from mutagenic events. This in turn will impact research on cancer predisposition and chemotherapeutic treatment strategies.

 描述（由申请人提供）：基因组不稳定性疾病如范可尼贫血（FA）代表了人类对癌症易感性的罕见遗传模型。FA是一种多基因疾病，在细胞水平上以染色体异常和对复制阻断DNA损伤，特别是DNA链间交联（DNA ICL）的超敏反应为特征。FA途径的中心成员是FANCD 2蛋白，其直接募集到DNA ICL和停滞的复制叉。越来越多的证据表明，FANCD 2然后招募其他FA和非FA DNA修复因子，这些因子使用同源重组（HR）修复机制来介导复制阻断性病变（如DNA ICL）的去除，并促进复制叉恢复。基于我们的新结果，我们预测一种名为EMSY的蛋白质是FANCD 2的新功能伴侣。 EMSY是否在任何细胞DNA损伤反应中起作用尚不清楚。我们发现EMSY以DNA损伤和严格的FANCD 2依赖性方式被招募到染色质中。引人注目的是，EMSY缺陷型细胞对DNA ICL和复制应激的敏感性与FANCD 2缺陷型细胞一样。基于我们的初步结果，我们假设EMSY和FANCD 2形成一种新的蛋白质复合物，其促进HR依赖性DNA ICL修复和HR介导的复制叉恢复。我们将测试这个假设如下：目的1：确定EMSY/FANCD 2在HR介导的DNA ICL修复中的作用。我们将测试EMSY和FANCD 2是否协同作用以促进细胞DNA ICL抗性并支持DNA ICL相关DNA双链断裂（DSB）的HR修复期间的分子步骤。目的2：确定EMSY/FANCD 2在HR介导的复制叉恢复中的作用。我们将测试EMSY和FANCD 2是否协同作用，以促进细胞对aphidicolin触发的复制叉停滞的抵抗，并在HR因子介导的保护和复制叉重新启动期间支持分子步骤。此外，我们将测试六种已知的FANCD 2患者突变是否通过中断FANCD 2/EMSY复合物的形成而导致复制叉恢复的细胞缺陷。这些方法将阐明目前未表征的EMSY蛋白如何在细胞DNA损伤反应中发挥作用，并揭示FA途径相关DNA修复网络中新的复杂性。我们希望我们的研究结果显着有助于理解FA途径在维持基因组稳定性和保护细胞免受诱变事件的作用。这反过来将影响对癌症易感性和化疗治疗策略的研究。