期刊
ONCOGENE
卷 23, 期 6, 页码 1206-1213出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/sj.onc.1207199
关键词
checkpoint; genome instability; chromosome replication; ATM pathway; Rad53
资金
- NIGMS NIH HHS [GM61766, GM20056] Funding Source: Medline
The replication checkpoint controls the integrity of replicating chromosomes by stabilizing stalled forks, thus preventing the accumulation of abnormal replication and recombination intermediates that contribute to genome instability. Checkpoint-defective cells are susceptible to rearrangements at chromosome fragile sites when replication pauses, and certain human cancer prone diseases suffer checkpoint abnormalities. It is unclear as to how the checkpoint stabilizes stalled forks and how cells sense replication blocks. We have analysed the checkpoint contribution in controlling replisome-fork association when replication pauses. We show that in yeast wild-type cells, stalled forks exhibit stable replisome complexes and the checkpoint sensors Ddc1 and Ddc2, thus activating Rad53 checkpoint kinase. Ddc1/Ddc2 recruitment on stalled forks and Rad53 activation are influenced by the single-strand-binding protein replication factor A (RFA). rad53 forks exhibit a defective association with DNA polymerases alpha, epsilon and delta. Further, in rad53 mutants, stalled forks progressively generate abnormal structures that turn into checkpoint signals by accumulating RFA, Ddc1 and Ddc2. We suggest that, following replication blocks, checkpoint activation mediated by RFA-ssDNA. laments stabilizes stalled forks by controlling replisome - fork association, thus preventing unscheduled recruitment of recombination enzymes that could otherwise cause the pathological processing of the forks.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据