Tanaka Yoshiaki, Yoshimura Itsuki, Nakai Kenta
Department of Medical Genome Sciences, University of Tokyo, Minato-ku, Japan.
Chromosoma. 2010 Aug;119(4):391-404. doi: 10.1007/s00412-010-0264-y. Epub 2010 Mar 12.
Although nucleosome remodeling is essential to transcriptional regulation in eukaryotes, little is known about its genome-wide behavior. Since a number of nucleosome positioning maps in vivo have been recently determined, we examined if their comparisons might be used for obtaining a genome-wide profile of nucleosome remodeling. Using seven yeast maps, the local variability of nucleosomes, measured by the entropy, was significantly higher in a set of reported unstable nucleosomes. The binding sites of four transcription factors, known as the remodeling factors, were distinctively high both in entropy and linker ratio, whereas those of Yhp1, their potential inhibitor, showed the lowest values in both of them. Taken together, our map shows the general information of nucleosome dynamics reasonably well. The "nucleosome dynamics" map provides the new significant correlation with the degree of expression variety instead of their intensity. Furthermore, the associations with gene function and histone modification were also discussed here.
尽管核小体重塑对于真核生物的转录调控至关重要,但人们对其全基因组行为知之甚少。由于最近已经确定了一些体内核小体定位图谱,我们研究了对这些图谱进行比较是否可用于获得全基因组的核小体重塑概况。使用七张酵母图谱,通过熵测量的核小体局部变异性在一组已报道的不稳定核小体中显著更高。四种被称为重塑因子的转录因子的结合位点在熵和连接子比率方面都明显较高,而它们的潜在抑制剂Yhp1的结合位点在这两方面都显示出最低值。综合来看,我们的图谱较好地展示了核小体动力学的一般信息。“核小体动力学”图谱与表达多样性程度而非表达强度呈现出新的显著相关性。此外,本文还讨论了与基因功能和组蛋白修饰的关联。