REGULATION OF T-CELL RECEPTOR DELTA-GENE REARRANGEMENT BY C-MYB

Developmental activation of VDJ recombination at the T cell receptor ( TCR) delta locus is controlled by an intronic transcriptional enhancer (E(delta)) Transcriptional activation by E(delta) is dependent on c-M yb. To determine whether c-Myb plays a role in the activation of TCR-d elta gene rearrangement, we compared VDJ recombination in transgenic m ice carrying two versions of a human TCR-delta gene minilocus recombin ation substrate. One includes a wild-type E(delta), whereas the other carries an E(delta) with a mutation that abrogates c-Myb binding. We d emonstrate that an intact Myb binding site is necessary for efficient rearrangement of the minilocus substrate, suggesting that c-Myb plays a crucial role in activating VDJ recombination at the endogenous TCR-d elta locus.