Hemoglobin subunit gamma 1 gene promoter; Hemoglobin subunit gamma 2 gene promoter (HBG1 promoter; HBG2 promoter)

The hemoglobin subunit gamma 1 and 2 gene promoters are regulatory DNA sequences that control the expression of the HBG1 and HBG2 genes, which encode the gamma chains of fetal hemoglobin (HbF). These promoters play a crucial role in hemoglobin switching during development, being highly active in fetal liver, spleen, and bone marrow to facilitate fetal oxygen transport. In adulthood, promoter activity is usually repressed, but in certain conditions like hereditary persistence of fetal hemoglobin or beta-thalassemia, gamma-globin expression persists, partly due to promoters remaining active. Modulation of transcription factors that bind these promoters is a key therapeutic approach for hemoglobinopathies. This entry describes regulatory DNA sequences, not direct protein or receptor targets, and should be clarified or replaced with specific gene products or transcription factors if a canonical drug target is required.

Other names

gamma-globin gene promotersHBG1 upstream regulatory regionHBG2 upstream regulatory regiongamma-A and gamma-G globin gene promoters

Not direct ligand binding; drugs modulate transcription factor binding to these promoters, leading to increased gamma-globin (fetal hemoglobin) expression