Chung J H, Whiteley M, Felsenfeld G
Laboratory of Molecular Biology, National Institutes of Health, Bethesda, Maryland 20892.
Cell. 1993 Aug 13;74(3):505-14. doi: 10.1016/0092-8674(93)80052-g.
We have characterized an element near the 5' boundary of the chicken beta-globin domain that insulates a reporter gene from the activating effects of a nearby beta-globin locus control region (5'HS2) when assayed in the human erythroid cell line K562. We show that the insulation mechanism is directional, that it operates at the level of transcription, and that it involves the alteration of chromatin structure over the promoter of the gene. The insulator has no significant stimulatory or inhibitory effects of its own. In transgenic Drosophila, the insulator protects the white minigene from position effects. The action of the insulator thus is not restricted to erythroid or mammalian cells, suggesting that such elements may serve an important and widely distributed function in the organization of chromatin structure.
我们已经对鸡β-珠蛋白结构域5'边界附近的一个元件进行了表征，当在人红系细胞系K562中进行检测时，该元件可使报告基因免受附近β-珠蛋白基因座控制区（5'HS2）的激活作用。我们表明，绝缘机制是有方向性的，它在转录水平上起作用，并且涉及基因启动子上染色质结构的改变。该绝缘子本身没有明显的刺激或抑制作用。在转基因果蝇中，该绝缘子可保护白色小基因免受位置效应的影响。因此，绝缘子的作用并不局限于红系细胞或哺乳动物细胞，这表明此类元件可能在染色质结构的组织中发挥重要且广泛分布的功能。
