Cell-Cycle-Dependent Chromatin Dynamics at Replication Origins.
Cell-Cycle-Dependent Chromatin Dynamics at Replication Origins.
复制标题
细胞周期依赖于复制起始的染色质动力学。
DOI：
10.3390/genes12121998
复制
发表时间：
2021-12-16
期刊：
影响因子：
3.5
通讯作者：
MacAlpine DM
中科院分区：
文献类型：
--
作者：
Li Y;Hartemink AJ;MacAlpine DM
DNA复制的起源是由复制因子以细胞周期依赖的方式有序募集指定的。G1期复制前复合体的组装和S期激活前的起始前复合体的组装得到了很好的表征；然而，这些复合物的组装与局部染色质环境之间的相互作用尚不清楚。为了研究在复制起点和周围染色质组织的动态变化，我们使用微球菌核酸酶（MNase）通过连续的细胞周期在酿酒酵母中生成核小体、转录因子和复制蛋白的全基因组染色质占用谱。在连续两个细胞周期的每个G1期，我们观察到起源-近端+1核小体的下游重新定位，以及跨越ARS共识序列（ACS）的受保护DNA片段的增加，表明pre-RC组装。我们还发现，ACS染色质占用率与起始效率之间的最强相关性发生在S期早期，这与Cdc45-Mcm2-7-GINS （CMG）复合体的限速形成是起始活性的决定因素相一致。最后，我们观察到核小体的断裂和解体来自复制起点，并在S期随着延长的复制叉穿越基因组，可能分别反映了复制叉前后染色质的拆卸和组装。这些结果为细胞周期调节的染色质动力学以及它们与起源活性调节的关系提供了见解。
Origins of DNA replication are specified by the ordered recruitment of replication factors in a cell-cycle–dependent manner. The assembly of the pre-replicative complex in G1 and the pre-initiation complex prior to activation in S phase are well characterized; however, the interplay between the assembly of these complexes and the local chromatin environment is less well understood. To investigate the dynamic changes in chromatin organization at and surrounding replication origins, we used micrococcal nuclease (MNase) to generate genome-wide chromatin occupancy profiles of nucleosomes, transcription factors, and replication proteins through consecutive cell cycles in Saccharomyces cerevisiae. During each G1 phase of two consecutive cell cycles, we observed the downstream repositioning of the origin-proximal +1 nucleosome and an increase in protected DNA fragments spanning the ARS consensus sequence (ACS) indicative of pre-RC assembly. We also found that the strongest correlation between chromatin occupancy at the ACS and origin efficiency occurred in early S phase, consistent with the rate-limiting formation of the Cdc45–Mcm2-7–GINS (CMG) complex being a determinant of origin activity. Finally, we observed nucleosome disruption and disorganization emanating from replication origins and traveling with the elongating replication forks across the genome in S phase, likely reflecting the disassembly and assembly of chromatin ahead of and behind the replication fork, respectively. These results provide insights into cell-cycle–regulated chromatin dynamics and how they relate to the regulation of origin activity.
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影响因子：
10.5
作者：
Eaton, Matthew L.;Galani, Kyriaki;MacAlpine, David M.
通讯作者：
MacAlpine, David M.
影响因子：
8.8
作者：
Hawkins M;Retkute R;Müller CA;Saner N;Tanaka TU;de Moura AP;Nieduszynski CA
通讯作者：
Nieduszynski CA
影响因子：
4.5
作者：
Dukaj L;Rhind N
通讯作者：
Rhind N
影响因子：
14.9
作者：
Lubelsky, Yoav;Sasaki, Takayo;Gilbert, David M.
通讯作者：
Gilbert, David M.
DOI：
10.1126/science.aan0063
发表时间：
2017-07-21
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Coster G;Diffley JFX
通讯作者：
Diffley JFX