Transcription alters chromosomal locations of cohesin in Saccharomyces cerevisiae
Transcription alters chromosomal locations of cohesin in Saccharomyces cerevisiae
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DOI：
10.1128/mcb.01007-07
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发表时间：
2007-12-01
影响因子：
5.3
通讯作者：
Gerton, Jennifer L.
中科院分区：
文献类型：
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作者：
Bausch, Christoph;Noone, Seth;Gerton, Jennifer L.
在真核细胞中，姐妹染色单体之间的凝聚力允许染色体在中期板上双定向并将它们保持在一起，直到它们在有丝分裂期间分离成子细胞。内聚由内聚蛋白复合物介导。虽然这种复合物与基因组特定区域的关联是高度可重复的，但尚不清楚是什么区分了染色体区域的粘着蛋白关联。由于cohesin的主要位置之一是聚合转录单位之间的基因间区域，我们探讨了转录和cohesin定位之间的关系。染色质免疫沉淀，然后杂交到一个微阵列（ChIP芯片）表明，转录延长到粘连蛋白协会网站的结果在当地的解离粘连蛋白。一旦转录停止，粘着蛋白可以与其原始位点重新结合，而不依赖于DNA复制和粘着蛋白加载因子Scc 2，尽管粘着蛋白与G（2）/M中染色体的结合对粘着没有功能。开发了一个计算机程序，以系统地识别两个ChIP芯片数据集之间的差异。我们的研究结果是一致的模型，其中（i）一部分的粘附蛋白可以动态加载和卸载，以适应转录和（ii）的粘附蛋白复合物的染色质的特点，是一个反映当地的转录状态的偏好。总之，我们的研究结果表明，凝聚力可能会被转录降解。
In eukaryotic cells, cohesion between sister chromatids allows chromosomes to biorient on the metaphase plate and holds them together until they separate into daughter cells during mitosis. Cohesion is mediated by the cohesin protein complex. Although the association of this complex with particular regions of the genome is highly reproducible, it is unclear what distinguishes a chromosomal region for cohesin association. Since one of the primary locations of cohesin is intergenic regions between converging transcription units, we explored the relationship between transcription and cohesin localization. Chromatin immunoprecipitation followed by hybridization to a microarray (ChIP chip) indicated that transcript elongation into cohesin association sites results in the local disassociation of cohesin. Once transcription is halted, cohesin can reassociate with its original sites, independent of DNA replication and the cohesin loading factor Scc2, although cohesin association with chromosomes in G(2)/M is not functional for cohesion. A computer program was developed to systematically identify differences between two ChIP chip data sets. Our results are consistent with a model for cohesin association in which (i) a portion of cohesin can be dynamically loaded and unloaded to accommodate transcription and (ii) the cohesin complex has preferences for features of chromatin that are a reflection of the local transcriptional status. Taken together, our results suggest that cohesion may be degraded by transcription.