Analysis of the Replication Stress Response

项目摘要 在人类一生中，数十亿个碱基对的DNA必须被复制数万亿次。添加到 困难，复制受到压力的挑战，包括DNA模板损伤，难以复制序列， 并与抄写相冲突。细胞对复制应激采取多种修复和信号反应 取决于问题的类型、持久性和位置。我们运用了蛋白质组学和遗传学 了解细胞如何克服复制压力的方法。这些分析发现了几个新的 复制应激反应蛋白，包括RADX。RADX结合单链DNA并防止 复制分叉被核酸内切酶切割。我们假设它调节复制分叉的过程 通过其单链DNA结合活性进行反转和分叉保护。我们将检验这一假设，并 更普遍地描述了使用生物化学和生物化学来调节叉子反转和保护的机制 遗传方法。由于癌细胞的复制压力水平升高，许多癌症 治疗通过干扰DNA复制发挥作用，这些研究还将产生可能 被转移到癌症诊所。

Project Summary Billions of base pairs of DNA must be replicated trillions of times during a human lifetime. Adding to the difficulty, replication is challenged by stresses including DNA template lesions, difficult to replicate sequences, and conflicts with transcription. Cells employ multiple repair and signaling responses to replication stress depending on the type, persistence, and location of the problem. We have employed proteomic and genetic approaches to understand how cells overcome replication stress. These analyses identified several new replication stress response proteins including RADX. RADX binds single-stranded DNA and prevents replication fork cleavage by endonucleases. We hypothesize that it regulates the processes of replication fork reversal and fork protection through its single-stranded DNA binding activity. We will test this hypothesis and more generally characterize mechanisms that regulate fork reversal and protection using biochemical and genetic approaches. Since cancer cells have elevated levels of replication stress and many cancer therapeutics work by interfering with DNA replication, these studies will also generate discoveries that may be translated into the cancer clinic.