GENOME STABILITY THROUGH BLOOM SYNDROME HELICASE AND RAD51 COMPLEX FORMATION

通过 Bloom 综合征解旋酶和 RAD51 复合物形成实现基因组稳定性

• 批准号: 7960135
• 负责人: Karen H. Almeida
• 金额: $ 11.2万
• 依托单位: UNIVERSITY OF RHODE ISLAND
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-04 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7960135
• 关键词: Address; Amino Acid Sequence; Amino Acids; BLM gene; Behavioral Research; Biochemical; Bloom Syndrome; Bloom syndrome protein; Cells; Classification; Complex; Computer Retrieval of Information on Scientific Projects Database; DNA; Disease; Event; Exhibits; Funding; Genome; Genome Stability; Genomic Instability; Goals; Grant; Institution; Kinetics; Knowledge; Measures; Mediating; Molecular; Mutagens; Mutation; Pathway interactions; Play; Proteins; Research; Research Personnel; Resources; Role; Sister Chromatid Exchange; Source; United States National Institutes of Health; helicase; neoplastic cell; recombinational repair; research study; response; restoration

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The hallmark feature of tumor cells is a highly unstable genome. Bloom syndrome (BS), an autosomal recessive disorder that results from mutation of the BLM gene, exhibits extraordinarily high levels of sister chromatid exchange (SCE) events, a marker of genomic instability. BLM protein may influence genome stability through 3'-5' DNA helicase activity that can stabilize stalled replication forks caused by damage to the DNA. Since many classes of genotoxic agents have been shown to block replication, this information is essential to the understanding of the cellular responses to genotoxic agents. The homologous recombinational repair (HRR) pathway is required for SCE formation and restoration of a collapsed replication fork. Therefore, HRR is essential in maintaining genomic stability. Rad51, a protein central to the HRR pathway, physically interacts with BLM and thus could play a role in the elevated levels of SCE events seen in BS cells. The goal of this proposal is to define the amino acid residues of BLM physically interacting with Rad51 and to determine the complex's function as a molecular switch through which the cell can govern pathway choice. Knowledge of the physical parameters will assist in the determination of the functional significance of complex formation. The experiments proposed will address the following aims: (1) Refine the BLM amino acid sequence responsible for mediating complex formation with Rad51 through systematic deletion of 25 amino acid increments from the termini; and (2) Measure the biochemical kinetics of BLM-Rad51 complex formation.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 肿瘤细胞的标志性特征是高度不稳定的基因组。布卢姆综合征 (BS) 是一种由 BLM 基因突变引起的常染色体隐性遗传疾病，表现出极高水平的姐妹染色单体交换 (SCE) 事件，这是基因组不稳定的标志。 BLM 蛋白可能通过 3'-5' DNA 解旋酶活性影响基因组稳定性，3'-5' DNA 解旋酶活性可以稳定由 DNA 损伤引起的停滞复制叉。由于许多类别的基因毒性剂已被证明可以阻断复制，因此该信息对于理解细胞对基因毒性剂的反应至关重要。同源重组修复 (HRR) 途径是 SCE 形成和折叠复制叉恢复所必需的。因此，HRR 对于维持基因组稳定性至关重要。 Rad51 是 HRR 通路的核心蛋白，与 BLM 发生物理相互作用，因此可能在 BS 细胞中看到的 SCE 事件水平升高中发挥作用。该提案的目标是定义 BLM 与 Rad51 物理相互作用的氨基酸残基，并确定该复合物作为分子开关的功能，细胞可以通过该分子开关来控制通路选择。了解物理参数将有助于确定复合物形成的功能意义。所提出的实验将实现以下目标：（1）通过从末端系统删除 25 个氨基酸增量，精炼负责介导与 Rad51 形成复合物的 BLM 氨基酸序列； (2)测量BLM-Rad51复合物形成的生化动力学。