Conserved elements containing NF-E2 and tandem GATA binding sites are required for erythroid-specific chromatin structure reorganization within the human beta-globin locus control region

Proper expression of the genes of the human beta-globin gene locus requires the associated locus control region (LCR). Structurally, the LCR is define d by the presence of four domains of erythroid-specific chromatin structure , These domains, which have been characterized as DNase I hypersensitive si tes (HSs), comprise the active elements of the LCR, The major focus of this research is to define the cis-acting elements which are required for the f ormation of these domains of unique chromatin structure, Our previous inves tigations on the formation of LCR HS4 demonstrated that NF-EP and tandem, i nverted GATA binding sites are required for the formation of the native HS, Similarly arranged NF-EP and tandem GATA sites are present within the core regions of the other human LCR HSs and are evolutionarily conserved, Using site-directed mutagenesis of human HSs 2 and 3 we have tested the hypothes is that these NF-E2 and GATA sites are common requirements for the formatio n of all LCR HSs, We find that mutation of these elements, and particularly the GATA elements, results in a decrease or complete loss of DNase I hyper sensitivity. These data imply the presence of common structural elements wi thin the core of each LCR HS which are required far erythroid-specific chro matin structure reorganization.