IDENTIFICATION OF A T-CELL-SPECIFIC TRANSCRIPTIONAL ENHANCER LOCATED 3' OF C-GAMMA-1 IN THE MURINE T-CELL RECEPTOR GAMMA LOCUS

A transcriptional enhancer element has been localized 3 kilobases 3' of the murine T-cell receptor C-gamma-l locus using a chloramphenicol acetyltransferase reporter gene construct. As a monomer the enhancer functions only in PEER gamma-delta cells and Jurkat alpha-beta cells of the T-cell lines tested. However, a tetramer of the enhancer functions in virtually all T-cell lines tested, including alpha-beta T-cell lines, but not in other cell types. These results suggest that elements other than the enhancer are responsible for the failure of rearranged C-gamma-l genes to be expressed in alpha-beta T cells. The enhancer has been localized to a 200-base-pair Rsa I restriction fragment, which contains sequence motifs similar to those found in the other T-cell receptor enhancers but not in the immunoglobulin enhancers.