X-box-binding proteins positively and negatively regulate transcription of the HLA-DRA gene through interaction with discrete upstream W and V elements.
Previous reports have identified that the class II box, consisting of the positive regulatory X and Y boxes, is important for expression of all class II major histocompatibility genes. In this paper, we identify additional sequences upstream from the class II box that regulate constitutive transcription of a human class II gene, HLA-DRA, in the B-lymphoblastoid cell line Raji. Using 5' promoter deletions, substitution mutants, and nuclease S1 protection assays, we mapped a positive element, called W, between -135 and -117 base pairs and a negative element, called V, from -193 to -179 base pairs. Sequence comparisons revealed that W and V share homology with the HLA-DRA X box situated downstream. Gel-mobility-shift assays confirmed that the Raji nuclear proteins that bound to W and V elements were competed with by an HLA-DRA X-box oligonucleotide. These results suggest that X-box-binding proteins mediate both positive and negative effects on transcription by means of interaction with multiple elements (W, V, and X) within the same HLA-DRA gene.
Cogswell
J P
JP
Lineberger Cancer Research Center, University of North Carolina, Chapel Hill 27599-7295.
Basta
P V
PV
Ting
J P
JP
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D006684:HLA-DR Antigens; D015719:Single-Strand Specific DNA and RNA Endonucleases