Evidence for a globin promoter-specific silencer element located upstream of the human delta-globin gene.
We describe the negative regulatory activity of a 1.7 kilobase (kb) region (R) in the human beta-globin locus located between 4.0 and 2.3 kb upstream of the delta-globin gene capsite, using a transient assay with the chloramphenicol acetyltransferase (CAT) reporter gene in mouse erythroleukemia (MEL) cells. The R region is deleted in most cases of deletion hereditary persistence of fetal hemoglobin (HPFH), but is unaffected in most delta beta zero-thalassemias. However, no experiments addressing its function in globin gene expression have been reported to date. We show that R inhibits CAT expression of constructs containing a fetal (gamma) or adult (beta) globin gene promoter, but does not affect expression of similar constructs using a non-globin (SV40) promoter. The inhibitory effect on the beta-globin promoter can be localized to a 651 bp sub-region of R. For the gamma-globin promoter, no sub-region of R can reproduce the level of inhibition associated with the entire region.
Vitale
M
M
Unita di Ricerca Piera Cutino, Ospedale V. Cervello, Palermo, Italy.
Di Marzo
R
R
Calzolari
R
R
Acuto
S
S
O'Neill
D
D
Bank
A
A
Maggio
A
A
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D017931:DNA Primers; D005319:Fetal Hemoglobin / Q000235:genetics; D005809:Genes, Regulator; D005914:Globins / Q000235:genetics*; D006441:Hemoglobin A / Q000235:genetics; D006453:Hemoglobinopathies / Q000235:genetics; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D017384:Sequence Deletion; D014162:Transfection; D014407:Tumor Cells, Cultured; D017086:beta-Thalassemia / Q000235:genetics
D017931:DNA Primers; D005914:Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin; D015500:Chloramphenicol O-Acetyltransferase