The ATM/E2F1 Pathway in DNA Damage and Growth Control

项目描述（由申请人提供）：本项目的总体目标是研究E2F1稳定性的调控以及E2F1在DNA损伤中的具体作用。虽然E2F在细胞周期进程中的功能已经确立，但我们最近的工作证明了E2F1在DNA损伤反应中的重要作用。ATM/ATR可以磷酸化E2F1，并导致E2F1的稳定。诱导E2F1是DNA损伤诱导的细胞凋亡所必需的。因此，E2F1似乎参与了DNA损伤检查点控制，这在人类癌症中经常丢失。为了进一步了解E2F1如何参与检查点控制，我们确定了三种与E2F1相互作用并可能在DNA损伤期间调节E2F1的蛋白质。我们建议研究这些蛋白如何调节E2F1。

DESCRIPTION (provided by applicant): The overall goal of this project is to study the regulation of E2F1 stability and specific role of E2F1 for DNA damage. While the function of E2F in cell cycle progression is well established, our recent works demonstrate an important role of E2F1 for DNA damage response. ATM/ATR can phosphorylate E2F1 and lead to stabilization of E2F1. The induction of E2F1 is required for DNA damage-induced apoptosis. Thus E2F1 appears to participate in the DNA damage checkpoint control, which is often lost in human cancers. To further understand how E2F1 participates in the checkpoint control, we identified three proteins that interact with E2F1 and may regulate E2F1 during DNA damage. We propose to study how these proteins regulate E2F1. Aim 1: Explore the role of TopBP1/E2F interaction in transcription and replication control. To test the hypothesis: Regulation of E2F1 by TopBP1 is required for proper DNA damage response. Aim 2: Test the role of 14-3-3 in the regulation of E2F stability and activity. To test the hypothesis: Binding of 14-3-3 to E2F1 induces the stability and activity of E2F1. Aim 3: Test the role of hHYD for E2F degradation. To test the hypothesis: hHYD targets E2F1 for ubiquitination and binding of 14-3-3 protects E2F1 from degradation. We will employ biochemical, genetic and fluorescent microscope methodology as well as DNA microarray analysis to address these questions. The knowledge obtained from this study will be important in the understanding of how normal cells respond to genotoxic stress. A loss of the proper response may lead to tumor development.