Interaction between NF-kappa B- and serum response factor-binding elements activates an interleukin-2 receptor alpha-chain enhancer specifically in T lymphocytes.
We find that a short enhancer element containing the NF-kappa B binding site from the interleukin-2 receptor alpha-chain gene (IL-2R alpha) is preferentially activated in T cells. The IL-2R alpha enhancer binds NF-kappa B poorly and is only weakly activated by the NF-kappa B site alone. Serum response factor (SRF) binds to a site adjacent to the NF-kappa B site in the IL-2R enhancer, and both sites together have strong transcriptional activity specifically in T cells. Surprisingly, the levels of SRF constitutively expressed in T cells are consistently higher than in other cell types. Overexpression of SRF in B cells causes the IL-2R enhancer to function as well as it does in T cells, suggesting that the high level of SRF binding in T cells is functionally important.
Kuang
A A
AA
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Novak
K D
KD
Kang
S M
SM
Bruhn
K
K
Lenardo
M J
MJ
D001402:B-Lymphocytes / Q000502:physiology; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D015375:Receptors, Interleukin-2 / Q000235:genetics*; D026362:Serum Response Factor; D013601:T-Lymphocytes / Q000502:physiology*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D016328:NF-kappa B; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D026362:Serum Response Factor