Functions of WRN in Response to DNA Double-Strand Breaks

WRN 响应 DNA 双链断裂的功能

基本信息

批准号：
8433268
负责人：
DAVID J CHEN
金额：
$ 29.7万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2015-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8433268
关键词：
Affect Alanine Aspartic Acid Biochemical Biological Biological Assay Cell Line Cells Chromatin Chromosome abnormality DNA DNA Binding DNA Damage DNA Double Strand Break DNA Repair DNA-PKcs DNA-dependent protein kinase Dominant-Negative Mutation Double Strand Break Repair Event Exonuclease Family Family member Fibroblasts Genome Genomics Human In Vitro Interruption Kinetics Knockout Mice Laboratories Lasers Lead Life Maintenance Malignant Neoplasms Measures Mediating Mesenchymal Cell Neoplasm Mus Mutate Mutation Nonhomologous DNA End Joining Pathway interactions Patients Phosphorylation Phosphorylation Site Phosphotransferases Play Process Protein Family Recruitment Activity Reporter Research Risk Roentgen Rays Role Site Study Section Symptoms System Telomere Maintenance Testing Werner Syndrome XRCC5 gene age related base cellular imaging early onset endodeoxyribonuclease SceI experience helicase homologous recombination human WRN protein in vivo kinase inhibitor mutant polypeptide protein protein interaction repaired research study response sarcoma spatial relationship

项目摘要

DESCRIPTION (provided by applicant): Werner Syndrome (WS) is an autosomal recessive condition characterized by an early onset of age-related symptoms. WS patients also experience an increased risk of rare non-epithelial cancers, especially mesenchymalneoplasms such as sarcomas. Fibroblasts isolated from WS cells senesce prematurely in culture and display increased chromosomal aberrations. WRN, the protein mutated in WS, is unique among the RecQ family proteins possesses on exonuclease activity and 32 to 52 helicase in a single polypeptide. There is accumulating evidence suggesting that WRN contributes to the maintenance of genomic integrity through its involvement in various DNA damage repair pathways and plays a role in telomere maintenance. However, the mechanism by which WRN functions in DNA repair, especially in DNA double-strand break (DSB) repair is still elusive. In vitro and indirect evidence leads to the conclusion that WRN may play a role both in homologous recombination (HR) as well as nonhomologous end joining (NHEJ). Recently, evidence showed that WRN is recruited to DNA damage sites and phosphorylated by PIKK3 kinase family in response to DNA DSB. In this proposal, we will test the hypothesis that WRN is recruited to DNA double-strand breaks (DSB) in vivo, to determine the function of WRN phosphorylation, and its involvement in the process of NHEJ or HR in response to DNA damage. Our specific aims are: (1) To determine the mechanism by which WRN is recruited to the sites of DNA double-strand breaks; (2) To test the hypothesis that WRN is phosphorylated by DNA-PK in response to DNA double-strand breaks and the phosphorylation status of WRN modulates its functions at DNA damage sites; and (3) To verify the hypothesis that WRN plays a role in nonhomologous end joining (NHEJ) and/or homologous recombination (HR) pathways of DNA double-strand break repair. Accomplishment of the proposed research would lead to the understanding of WRN's function in response to DNA damage and help further elucidate the role of WRN in cancer.

描述（由申请人提供）：维尔纳综合征（WS）是一种常染色体隐性遗传病，其特征是早期出现与年龄相关的症状。 WS 患者患罕见非上皮癌的风险也增加，尤其是肉瘤等间质肿瘤。从 WS 细胞中分离出的成纤维细胞在培养物中过早衰老并表现出增加的染色体畸变。 WRN是WS突变的蛋白，是RecQ家族蛋白中独一无二的，它具有核酸外切酶活性，并且在单个多肽中具有32至52个解旋酶。越来越多的证据表明，WRN 通过参与各种 DNA 损伤修复途径有助于维持基因组完整性，并在端粒维护中发挥作用。然而，WRN 在 DNA 修复，尤其是 DNA 双链断裂 (DSB) 修复中发挥作用的机制仍不清楚。体外和间接证据得出这样的结论：WRN 可能在同源重组 (HR) 和非同源末端连接 (NHEJ) 中发挥作用。最近，有证据表明，WRN 被招募到 DNA 损伤位点，并被 PIKK3 激酶家族磷酸化，以响应 DNA DSB。在本提案中，我们将测试 WRN 在体内被招募到 DNA 双链断裂 (DSB) 的假设，以确定 WRN 磷酸化的功能，及其参与 NHEJ 或 HR 响应 DNA 损伤的过程。我们的具体目标是：（1）确定WRN被招募到DNA双链断裂位点的机制； (2) 检验WRN在DNA双链断裂时被DNA-PK磷酸化以及WRN的磷酸化状态调节其在DNA损伤位点的功能的假设； (3)验证WRN在DNA双链断裂修复的非同源末端连接(NHEJ)和/或同源重组(HR)途径中发挥作用的假设。拟议研究的完成将有助于了解 WRN 对 DNA 损伤的反应功能，并有助于进一步阐明 WRN 在癌症中的作用。