Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
J Biol Chem. 2011 Jun 24;286(25):22308-13. doi: 10.1074/jbc.M111.222869. Epub 2011 Apr 18.
RFWD3 has E3 ligase activity in vitro, but its in vivo function remains unknown. In this study we identified RFWD3 as a novel replication protein A (RPA)-associated protein. Using purified proteins, we observed a direct interaction between RPA2 and RFWD3. Further analysis showed that RFWD3 is recruited to stalled replication forks and co-localizes with RPA2 in response to replication stress. Moreover, RFWD3 is important for ATR-dependent Chk1 activation in response to replication stress. Upon replication stress, deletion of RPA2 binding region on RFWD3 impairs its localization to stalled replication forks and decreases Chk1 activation. Taken together, our results suggest that RFWD3 and RPA2 functionally interact and participate in replication checkpoint control.
RFWD3 在体外具有 E3 连接酶活性，但它的体内功能尚不清楚。在这项研究中，我们鉴定 RFWD3 为一种新型复制蛋白 A（RPA）相关蛋白。使用纯化的蛋白质，我们观察到 RPA2 和 RFWD3 之间存在直接相互作用。进一步的分析表明，RFWD3 被募集到停滞的复制叉，并在复制应激时与 RPA2 共定位。此外，RFWD3 对于复制应激时 ATR 依赖性 Chk1 激活是重要的。在复制应激时，RFWD3 上 RPA2 结合区域的缺失会损害其定位到停滞的复制叉，并降低 Chk1 的激活。总之，我们的结果表明，RFWD3 和 RPA2 具有功能相互作用，并参与复制检查点控制。
