Determining the role of Blm and Marcal1 helicases in replication fork remodeling and progression

描述（由申请人提供）：细胞利用多种途径和信号级联来修复DNA损伤;然而，当DNA活跃复制时，基因组如何修复尚不完全清楚。复制过程中的DNA修复有助于化疗耐药性，而复制过程中受损的修复是许多罕见遗传疾病的原因。复制叉重塑是复制过程中损伤相关修复的关键中间体，然而，哪些蛋白质负责叉回归和随后的回归中间体的解决以促进重新启动仍然未知。该项目将使用经典果蝇遗传学和现代分子技术测试两个候选解旋酶Marcal 1和Blm在复制叉重塑（修复的关键中间体）中的作用和冗余。Blm解旋酶具有同源重组修复双链断裂的功能。初步数据表明，Blm可能在复制相关功能与HR作用中受到差异调节;这可能影响Top3α相互作用， 这是人力资源职能所必需的。将使用标准技术通过表征复制中的Blm-Top3α结合来检验该假设。最后，Blm也参与了通过重复区域促进复制进程。这种新的作用将在果蝇胚胎中结合分子技术进行测试usig创新的检测。该项目的组合方法旨在澄清由修复途径和蛋白质的部分冗余引起的复杂数据解释。该项目将深入了解复制和修复途径如何共同作用以保持基因组稳定性，并有可能影响罕见疾病治疗和化疗设计。

DESCRIPTION (provided by applicant): The cell utilizes a variety of pathways and signaling cascades to repair DNA damage; however, how the genome is repaired when DNA is actively replicating is imperfectly understood. DNA repair during replication contributes to chemotherapeutic resistance while compromised repair during replication is responsible for many rare genetic diseases. Replication fork remodeling is a key intermediate in damage-associated repair during replication, however which proteins are responsible for fork regression and subsequent resolution of regressed intermediates to facilitate restart remains unknown. This project will test the roles and redundancy of two candidate helicases, Marcal1 and Blm, in replication fork remodeling (a key intermediate in repair) using classical Drosophila genetics as well as modern molecular techniques. Blm helicase has functions in homologous recombination repair of double-strand breaks. Preliminary data suggests that Blm may be differentially regulated in replication-related functions vs. HR roles; this may affect Top3α interactions, which are necessary for HR functions. This hypothesis will be tested through characterization of Blm-Top3α binding in replication using standard techniques. Lastly, Blm has also been implicated in facilitating replication progression through repetitive regions. This novel role will be tested usig innovative assays in Drosophila embryos in conjunction with molecular techniques. The combined approach of this project is designed to clarify complex data interpretation resulting from partial redundancy of repair pathways and proteins. This project will provide insight into how replication and repair pathways work together to preserve genomic stability with the potential to impact rare disease treatment as well as chemotherapeutic design.