Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Strasse 47a, 50674 Cologne, Germany.
Mol Cell. 2011 Oct 7;44(1):85-96. doi: 10.1016/j.molcel.2011.08.028.
Faithful transmission of genomic information requires tight spatiotemporal regulation of DNA replication factors. In the licensing step of DNA replication, CDT-1 is loaded onto chromatin to subsequently promote the recruitment of additional replication factors, including CDC-45 and GINS. During the elongation step, the CDC-45/GINS complex moves with the replication fork; however, it is largely unknown how its chromatin association is regulated. Here, we show that the chaperone-like ATPase CDC-48/p97 coordinates degradation of CDT-1 with release of the CDC-45/GINS complex. C. elegans embryos lacking CDC-48 or its cofactors UFD-1/NPL-4 accumulate CDT-1 on mitotic chromatin, indicating a critical role of CDC-48 in CDT-1 turnover. Strikingly, CDC-48(UFD-1/NPL-4)-deficient embryos show persistent chromatin association of CDC-45/GINS, which is a consequence of CDT-1 stabilization. Moreover, our data confirmed a similar regulation in Xenopus egg extracts, emphasizing a conserved coordination of licensing and elongation events during eukaryotic DNA replication by CDC-48/p97.
基因组信息的忠实传递需要严格的时空调节 DNA 复制因子。在 DNA 复制的许可步骤中,CDT-1 加载到染色质上,随后促进其他复制因子的募集,包括 CDC-45 和 GINS。在延伸步骤中,CDC-45/GINS 复合物随复制叉移动;然而,其染色质关联如何被调节很大程度上是未知的。在这里,我们表明伴侣样 ATP 酶 CDC-48/p97 协调 CDT-1 的降解与 CDC-45/GINS 复合物的释放。缺乏 CDC-48 或其辅助因子 UFD-1/NPL-4 的 C. elegans 胚胎在有丝分裂染色质上积累 CDT-1,表明 CDC-48 在 CDT-1 周转中起着关键作用。引人注目的是,CDC-48(UFD-1/NPL-4)缺陷型胚胎显示 CDC-45/GINS 的持续染色质关联,这是 CDT-1 稳定的结果。此外,我们的数据证实了在非洲爪蟾卵提取物中的类似调节,强调了 CDC-48/p97 在真核 DNA 复制过程中对许可和延伸事件的保守协调。