A T-cell-specific transcriptional enhancer element 3' of C alpha in the human T-cell receptor alpha locus.
A transcriptional enhancer element has been identified 4.5 kilobases 3' of C alpha (constant region alpha chain) in the human T-cell receptor (TCR) alpha-chain locus. This enhancer is active on both a TCR V alpha (variable region alpha chain) promoter and the minimal simian virus 40 promotor in TCR alpha/beta Jurkat and EL4 cells but is inactive on a V alpha promoter in human TCR gamma/delta PEER and Molt-13 cells, clone 13 B cells, and HeLa fibroblasts. The enhancer has been localized to a 116-base-pair BstXI/Dra I restriction enzyme fragment, which lacks immunoglobulin octamer and kappa B enhancer motifs but does contain a consensus cAMP-response element (CRE). DNase I footprint analyses demonstrated that the minimal enhancer contains two binding sites for Jurkat nuclear proteins. One of these sites corresponds to the CRE, while the other does not correspond to a known transcriptional enhancer motif. These data support a model in which TCR alpha gene transcription is regulated by a unique set of cis-acting sequences and trans-acting factors, which are differentially active in cells of the TCR alpha/beta lineage. In addition, the TCR alpha enhancer may play a role in activating oncogene expression in T-lymphoblastoid tumors that have previously been shown to display chromosomal translocations into the human TCR alpha locus.
Ho
I C
IC
Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor 48109.
Yang
L H
LH
Morle
G
G
Leiden
J M
JM
D001483:Base Sequence; D003001:Cloning, Molecular; D004742:Enhancer Elements, Genetic; D005803:Genes, Immunoglobulin; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D015183:Restriction Mapping; D013601:T-Lymphocytes / Q000276:immunology*; D014158:Transcription, Genetic; D014162:Transfection
D007127:Immunoglobulin Constant Regions; D007135:Immunoglobulin Variable Region; D011948:Receptors, Antigen, T-Cell