Chromatin Structure of the HLA-DR α Gene in Different Functional States of Major Histocompatibility Complex Class II Gene Expression

Abstract

We utilized DNase I hypersensitivity mapping to study chromatin structure within the HLA-DR alpha gene. We found a single DNase I-hypersensitive site coinciding with the HLA-DR alpha gene promoter in all cells studied. Moreover, in cells that constitutively express HLA-DR, two additional DNase I-hypersensitive sites were observed. These lie within the first intron of the HLA-DR alpha gene and encompass DNA sequences that share homologies with regulatory loci of the immunoglobulin and immune response genes, as well as with core enhancer consensus sequences.