Buckle R, Balmer M, Yenidunya A, Allan J
Department of Biophysics, Cell and Molecular Biology, King's College, London, UK.
Nucleic Acids Res. 1991 Mar 25;19(6):1219-26. doi: 10.1093/nar/19.6.1219.
Core histone octamers reconstituted in vitro onto DNA fragments containing the chicken beta-globin gene promoter are precisely positioned with respect to the underlying DNA sequence [1]. Here we show that this is also true of the chicken beta-globin gene enhancer. These nucleosome binding sites are also employed within transfected COS cell nuclei, where the chicken beta-globin gene is transcriptionally inactive. Similar results were found in vivo, where positioned nucleosomes were detected over the inactive beta-globin promoter in chicken brain cells and 5-day red blood cells, and over the inactive beta-globin enhancer in brain cells. In contrast, the promoter and enhancer regions were found to be nucleosome-free in 15-day erythrocytes where the beta-globin gene is active. We argue that these results suggest a role for positioned nucleosomes in the regulation of the transcription of the chicken beta-globin gene.
在体外重构成的核心组蛋白八聚体，结合到含有鸡β-珠蛋白基因启动子的DNA片段上时，会相对于其下的DNA序列精确就位[1]。在此我们表明，鸡β-珠蛋白基因增强子的情况也是如此。这些核小体结合位点在转染的COS细胞核内也有使用，在那里鸡β-珠蛋白基因转录失活。在体内也发现了类似结果，在鸡脑细胞和5日龄红细胞中，在失活的β-珠蛋白启动子上检测到定位的核小体，在脑细胞中，在失活的β-珠蛋白增强子上也检测到定位的核小体。相反，在β-珠蛋白基因活跃的15日龄红细胞中，启动子和增强子区域没有核小体。我们认为，这些结果表明定位的核小体在鸡β-珠蛋白基因转录调控中发挥作用。
