Cooper J P, Roth S Y, Simpson R T
Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Genes Dev. 1994 Jun 15;8(12):1400-10. doi: 10.1101/gad.8.12.1400.
Repression of a-cell specific gene expression in yeast alpha cells requires MAT alpha 2 and MCM1, as well as two global repressors, SSN6 and TUP1. Previous studies demonstrated that nucleosomes positioned adjacent to the alpha 2/MCM1 operator in alpha cells directly contribute to repression. To investigate the possibility that SSN6 and TUP1 provide a link between MAT alpha 2/MCM1 and neighboring histones, nucleosome locations were examined in ssn6 and tup1 alpha cells. In both cases, nucleosome positions downstream of the operator were disrupted, and the severity of the disruption correlated with the degree of derepression. Nevertheless, the observed changes in chromatin structure were not dependent on transcription. Our data strongly indicate that SSN6 and TUP1 directly organize repressive regions of chromatin.
酵母α细胞中α细胞特异性基因表达的抑制需要MATα2和MCM1，以及两个全局阻遏物SSN6和TUP1。先前的研究表明，α细胞中与α2/MCM1操纵子相邻定位的核小体直接有助于抑制作用。为了研究SSN6和TUP1是否在MATα2/MCM1与相邻组蛋白之间提供联系，我们检测了ssn6和tup1α细胞中的核小体位置。在这两种情况下，操纵子下游的核小体位置都被破坏，并且破坏的严重程度与去抑制程度相关。然而，观察到的染色质结构变化并不依赖于转录。我们的数据强烈表明，SSN6和TUP1直接组织染色质的抑制区域。
