title: Sequence-specific interactions of nuclear factors with conserved sequences of human class II major histocompatibility complex genes.
abstract: All class II major histocompatibility complex genes contain two highly conserved sequences, termed X and Y, within the promoter regions(s), which may have a role in regulation of expression. To study trans-acting factors that interact with these sequences, sequence-specific DNA binding activity has been examined by the gel electrophoresis retardation assay using the HLA-DQ2 beta gene 5' flanking DNA and nuclear extracts derived from various cell types. Several specific protein-binding activities were found using a 45-base-pair (bp) HinfI/Sau96I (-142 to -98 bp) and a 38-bp Sau96I/Sau96I (-97 to -60 bp) fragment, which include conserved sequence X (-113 to -100 bp) and conserved sequence Y (-80 to -71 bp), respectively. Competition experiments, methylation interference analysis, and DNase I foot-printing demonstrated that distinct proteins in a nuclear extract of Raji cells (a human B lymphoma line) bind to sequence X, to sequence Y, and to DNA 5' of the X sequence (termed sequence W). The factor binding site in the W sequence is also found to be conserved among beta-chain genes and is suggested to be a gamma-interferon control region.
mesh_terms: D001402:B-Lymphocytes / Q000032:analysis; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D015696:Gene Products, tat; D005802:Genes, MHC Class II; D006681:HLA-D Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics*; D006801:Humans; D008223:Lymphoma; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D015696:Gene Products, tat; D006681:HLA-D Antigens; D006683:HLA-DQ Antigens; C053186:HLA-DQ2 antigen; D014157:Transcription Factors; D004247:DNA