Identification of two telomere-proximal fission yeast DNA replication origins constrained by nearby cis-acting sequences to replicate in late S phase.
Identification of two telomere-proximal fission yeast DNA replication origins constrained by nearby cis-acting sequences to replicate in late S phase.
复制标题
DOI：
10.12688/f1000research.1-58.v1
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Huberman JA
中科院分区：
文献类型：
--
作者：
Chaudari A;Huberman JA
已知裂殖酵母（裂殖酵母）的端粒在S期晚期复制，但这种晚期复制的原因还不完全清楚。我们已经确定了两个紧密间隔的DNA复制起点，5.5至8 kb的上游端粒本身。这些是裂变酵母基因组中所有复制起点中最接近端粒的。当它们单独位于环状质粒中时，这些起始点在早期S期启动，但是如果环状质粒中包含更接近端粒的侧翼序列，则复制被限制到晚期S期-除了缺乏复制检查点激酶Cds 1的细胞。我们的结论是端粒相关序列的检查点依赖性晚期复制依赖于附近的顺式作用序列，而不是接近线性染色体的物理末端。
Telomeres of the fission yeast, Schizosaccharomyces pombe, are known to replicate in late S phase, but the reasons for this late replication are not fully understood. We have identified two closely-spaced DNA replication origins, 5.5 to 8 kb upstream from the telomere itself. These are the most telomere-proximal of all the replication origins in the fission yeast genome. When located by themselves in circular plasmids, these origins fired in early S phase, but if flanking sequences closer to the telomere were included in the circular plasmid, then replication was restrained to late S phase – except in cells lacking the replication-checkpoint kinase, Cds1. We conclude that checkpoint-dependent late replication of telomere-associated sequences is dependent on nearby cis-acting sequences, not on proximity to the physical end of a linear chromosome.