DNA SEQUENCE WHICH ACTS AS A CHROMATIN INSULATOR ELEMENT TO PROTECT EXPRESSED GENES FROM CIS-ACTING REGULATORY SEQUENCES IN MAMMALIAN CELLS

摘要

A newly characterized chromatin insulator element isolated from the DNA of a vertebrate organism and contained in vector constructs is described. The insulator element of the invention comprises a DNA sequence which contains a 5' constitutive hypersensitive site and whose functional activity and biochemical characterization as a pure insulator were previously unknown. Such a DNA molecule having insulating function has been isolated from the β-globin gene locus and from the α-globin gene locus of chicken. A core DNA sequence having strong insulator activity is also described. The insulator elements, including the core sequence, have been demonstrated for the first time in mammalian cells to function to buffer or insulate an expressed gene from the activity of cis-acting regulatory elements, such as enhancers, in the surrounding chromatin or DNA.