Saito Shinya, Miura Shigeki, Yamamoto Yuichi, Shindo Heisaburo, Shimizu Mitsuhiro
Department of Chemistry, Meisei University, Hino, Tokyo 191-8506, Japan.
Nucleic Acids Res Suppl. 2002(2):93-4. doi: 10.1093/nass/2.1.93.
In Saccharomyces cerevisiae, alpha 2/Mcm1p represses a-cell specific genes. Previous studies indicated that repression by alpha 2/Mcm1p is associated with organization of positioned nucleosomes in promoters of a-cell specific genes such as STE6 and BAR1. Here, we examined the role of nucleosome positioning in repression of STE6-lacZ by alpha 2/Mcm1p. We showed that insertion of an A34 sequence, which is shown to disrupt an array of positioned nucleosomes, affects STE6-lacZ expression. Furthermore, artificial recruitment of TBP is facilitated by the insertion of A34 to derepress STE6-lacZ expression. These findings support the model that nucleosome positioning plays a regulatory role in repression by alpha 2/Mcm1p.
在酿酒酵母中，α2/Mcm1p抑制a细胞特异性基因。先前的研究表明，α2/Mcm1p的抑制作用与a细胞特异性基因（如STE6和BAR1）启动子中定位核小体的组织有关。在这里，我们研究了核小体定位在α2/Mcm1p对STE6-lacZ抑制中的作用。我们发现，插入A34序列（已证明该序列会破坏定位核小体阵列）会影响STE6-lacZ的表达。此外，通过插入A34促进TBP的人工募集可解除对STE6-lacZ表达的抑制。这些发现支持了核小体定位在α2/Mcm1p抑制中起调节作用的模型。
