Regulation of cell-type-specific interleukin-2 receptor alpha-chain gene expression: potential role of physical interactions between Elf-1, HMG-I(Y), and NF-kappa B family proteins.
The interleukin 2 receptor alpha-chain (IL-2R alpha) gene is rapidly and potently induced in T cells in response to mitogenic stimuli. Previously, an inducible enhancer between nucleotides -299 and -228 that contains NF-kappa B and CArG motifs was identified. We now report the characterization of a second essential positive regulatory element located between nucleotides -137 and -64 that binds Elf-1 and HMG-I(Y). This element had maximal activity in lymphoid cells, paralleling the cell type specificity of Elf-1 expression. Transcription from the IL-2R alpha promoter was inhibited when either the Elf-1 or the HMG-I(Y) binding site was mutated. Coexpression of both proteins activated transcription of the -137 to -64 element in COS-7 cells. Elf-1 physically associated with HMG-I and with NF-kappa B p50 and c-Rel in vitro, suggesting that protein-protein interactions might functionally coordinate the actions of the upstream and downstream positive regulatory elements. This is the first report of a physical interaction between an Ets family member and NF-kappa B family proteins. These findings provide significant new insights into the protein-protein and protein-DNA interactions that regulate cell-type-specific and inducible IL-2R alpha gene expression and also have implications for other genes regulated by Elf-1 and NF-kappa B family proteins.
John
S
S
Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892.
Reeves
R B
RB
Lin
J X
JX
Child
R
R
Leiden
J M
JM
Thompson
C B
CB
Leonard
W J
WJ
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D002522:Chlorocebus aethiops; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D025741:HMGA1a Protein; D006609:High Mobility Group Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000302:isolation & purification / Q000378:metabolism*; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D004268:DNA-Binding Proteins; C512897:ELF1 protein, human; C512896:Elf1 protein, mouse; D006609:High Mobility Group Proteins; D046911:Macromolecular Substances; D016328:NF-kappa B; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D014157:Transcription Factors; D025741:HMGA1a Protein; D015500:Chloramphenicol O-Acetyltransferase; D013755:Tetradecanoylphorbol Acetate