The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time
The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time
复制标题
DOI：
10.1038/sj.emboj.7601038
复制
发表时间：
2006-04-05
期刊：
影响因子：
11.4
通讯作者：
Donaldson, AD
中科院分区：
文献类型：
--
作者：
Hiraga, S;Robertson, ED;Donaldson, AD
酿酒酵母的染色体末端成簇地位于核边缘。我们报告说，Ctf18，Ctf8和Dcc1，复制因子C（RFC）样复合物的亚基，是必不可少的端粒的核周定位。在酵母和哺乳动物细胞中，G1期染色质的外周核定位与晚期DNA复制相关。我们发现，ctf18细胞的错误定位的端粒仍然复制晚，表明晚期DNA复制不需要在G1期外周定位。Ku和Sir复合物已被证明通过单独的途径来定位端粒，但在缺乏Ctf18的情况下，两种途径都不能完全发挥作用来维持端粒的位置。令人惊讶的是，CTF18不是Ku或Sir4介导的非端粒染色体位点的外周系留所必需的。我们的研究结果表明，Ctf18 RFC样复合物修改端粒染色质，使其能够正常定位到核周围。
Chromosome ends in Saccharomyces cerevisiae are positioned in clusters at the nuclear rim. We report that Ctf18, Ctf8, and Dcc1, the subunits of a Replication Factor C (RFC)-like complex, are essential for the perinuclear positioning of telomeres. In both yeast and mammalian cells, peripheral nuclear positioning of chromatin during G1 phase correlates with late DNA replication. We find that the mislocalized telomeres of ctf18 cells still replicate late, showing that late DNA replication does not require peripheral positioning during G1. The Ku and Sir complexes have been shown to act through separate pathways to position telomeres, but in the absence of Ctf18 neither pathway can act fully to maintain telomere position. Surprisingly CTF18 is not required for Ku or Sir4-mediated peripheral tethering of a nontelomeric chromosome locus. Our results suggest that the Ctf18 RFC-like complex modifies telomeric chromatin to make it competent for normal localization to the nuclear periphery.