Jh. Chung et al., A 5' ELEMENT OF THE CHICKEN BETA-GLOBIN DOMAIN SERVES AS AN INSULATORIN HUMAN ERYTHROID-CELLS AND PROTECTS AGAINST POSITION EFFECT IN DROSOPHILA, Cell, 74(3), 1993, pp. 505-514
We have characterized an element near the 5' boundary of the chicken b
eta-globin domain that insulates a reporter gene from the activating e
ffects of a nearby beta-globin locus control region (5'HS2) when assay
ed in the human erythroid cell line K562. We show that the insulation
mechanism is directional, that it operates at the level of transcripti
on, and that it involves the alteration of chromatin structure over th
e promoter of the gene. The insulator has no significant stimulatory o
r inhibitory effects of its own. In transgenic Drosophila, the insulat
or protects the white minigene from position effects. The action of th
e insulator thus is not restricted to erythroid or mammalian cells, su
ggesting that such elements may serve an important and widely distribu
ted function in the organization of chromatin structure.