DEK binding to class II MHC Y-box sequences is gene- and allele-specific.
Using electrophoretic mobility shift assays, we examined sequence-specific binding of DEK, a potential autoantigen in juvenile rheumatoid arthritis, to conserved Y-box regulatory sequences in class II MHC gene promoters. Nuclear extracts from several cell lines of different phenotypes contained sequence-specific binding activity recognizing DRA, DQA1*0101, and DQA1*0501 Y-box sequences. Participation of both DEK and NF-Y in the DQA1 Y-box binding complex was confirmed by 'supershifting' with anti-DEK and anti-NF-Y antibodies. Recombinant DEK also bound specifically to the DQA1*0101 Y box and to the polymorphic DQA1*0501 Y box, but not to the consensus DRA Y box. Measurement of the apparent dissociation constants demonstrated a two- to fivefold difference in DEK binding to the DQA1 Y-box sequence in comparison with other class II MHC Y-box sequences. Residues that are crucial for DEK binding to the DQA1*0101 Y box were identified by DNase I footprinting. The specific characteristics of DEK binding to these related sequences suggests a potential role for DEK in differential regulation of class II MHC expression, and thus in the pathogenesis of juvenile rheumatoid arthritis and other autoimmune diseases.
Adams
Barbara S
BS
Department of Pediatrics, Division of Pediatric Rheumatology, University of Michigan School of Medicine, Ann Arbor, MI, USA.
Cha
Hyuk C
HC
Cleary
Joanne
J
Haiying
Tan
T
Wang
Hongling
H
Sitwala
Kajal
K
Markovitz
David M
DM
D000483:Alleles; D001324:Autoantigens / Q000378:metabolism*; D001665:Binding Sites; D023081:CCAAT-Binding Factor / Q000378:metabolism; D002457:Cell Extracts; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D016384:Consensus Sequence; D018983:DNA Footprinting; D024202:Electrophoretic Mobility Shift Assay; D005802:Genes, MHC Class II; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D006801:Humans; D046911:Macromolecular Substances; D015513:Oncogene Proteins / Q000378:metabolism*; D000075223:Poly-ADP-Ribose Binding Proteins; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid
D001324:Autoantigens; D023081:CCAAT-Binding Factor; D002457:Cell Extracts; D002868:Chromosomal Proteins, Non-Histone; C084738:DEK protein, human; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D046911:Macromolecular Substances; D015513:Oncogene Proteins; D000075223:Poly-ADP-Ribose Binding Proteins