A Myc-Associated Zinc Finger Protein Binding Site Is One of Four Important Functional Regions in the CD4 Promoter

Abstract

The CD4 promoter plays an important role in the developmental control of CD4 transcription. In this report, we show that the minimal CD4 promoter has four factor binding sites, each of which is required for full function. Using biochemical and mutagenesis analyses, we determined that multiple nuclear factors bind to these independent sites. We determined that an initiator-like sequence present at the cap site and an Ets consensus sequence are required for full promoter function. We also demonstrate that the Myc-associated zinc finger protein (MAZ) appears to be the predominant factor binding to one of these sites. This last site closely resembles the ME1a1 G₃AG₄AG₃ motif previously shown to be a critical element in the P2 promoter of the c-myc gene. We therefore believe that the MAZ transcription factor is also likely to play an important role in the control of developmental expression of the CD4 gene.