Characterization of the chicken β-globin insulator

• DOI: 10.1073/pnas.94.2.575
• Publication Date: 2002-07-26T14:31:39Z
• Authors: Jay H. Chung; Adam C. Bell; Gary Felsenfeld
• Keywords: Locus control region; Hypersensitive site; CpG site

Insulators, first identified in Drosophila , are DNA sequence elements that shield a promoter from nearby regulatory elements. We have previously reported at the 5′ end of chicken β-globin locus can function as an insulator. It is capable shielding reporter gene activating effects mouse control region element human erythroleukemic cell line K562. In this report, we show most insulating activity lies 250-bp CpG island (core element), which contains constitutive DNase I-hypersensitive site (5′HS4). binding assays with core reveal complex protein pattern. The multiplied when tandem copies used. Although islands often associated promoters housekeeping genes, find little evidence promoter. Furthermore, insulator differs its ability to block effect directionally.