Effect of disrupting ets and Sp1 transcription factor–binding sites and an intact RARE on RA induction of the full-length promoter.

RA induction of the full-length promoter is dependent on both functional ets and Sp1 transcription factor–binding sites and an intact RARE. CD18(−918)/luc or the corresponding DNA constructs with ets-site mutations (indicated by X; panel A) or Sp1-site mutations (indicated by X; panel B) were stably transfected into U937 cells, and responsiveness to RA was measured, as described in the legend to Figure 3. All data represent the mean and standard error of at least 3 independent clones, each tested in at least triplicate.