The human β-globin gene contains multiple regulatory regions: identification of one promoter and two downstream enhancers.

We have introduced into murine erythroleukaemia (MEL) cells several series of deletion mutants of hybrid genes between the human beta-globin gene and the murine H-2Kb gene. S1 nuclease and transcriptional run-off analysis showed that the human beta-globin gene contains at least three globin specific transcriptional control elements. One is a promoter element and is located 160 bp upstream from the transcription initiation site; it increases the efficiency of the promoter after MEL cells are induced to differentiate. The other two elements are tissue-specific transcriptional enhancers and are located downstream from the transcription initiation site, the first in the structural beta-globin gene and the second in the 3' flanking sequences.