A MYC-ASSOCIATED ZINC-FINGER PROTEIN-BINDING SITE IS ONE OF 4 IMPORTANT FUNCTIONAL REGIONS IN THE CD4 PROMOTER

The CD4 promoter plays an important role in the developmental control of CD4 transcription. In this report, we show that the minimal CD4 pro moter has four factor binding sites, each of which is required for ful l function. Using biochemical and mutagenesis analyses, we determined that multiple nuclear factors bind to these independent sites. We dete rmined that an initiator-like sequence present at the cap site and an Ets consensus sequence are required for full promoter function. We als o demonstrate that the Myc-associated zinc finger protein (MAZ) appear s to be the predominant factor binding to one of these sites. This las t site closely resembles the ME1a1 G(3)AG(4)AG(3) motif previously sho wn to be a critical element in the P2 promoter of the c-myc gene. We t herefore believe that the MAZ transcription factor is also likely to p lay an important role in the control of developmental expression of th e CD4 gene.