title: Characterization of the human ABO gene promoter in erythroid cell lineage.
abstract: BACKGROUND
  The human ABO blood group system is important in transfusion and organ transplantation. Although the molecular basis of the ABO gene has been established, recent studies have begun to characterize the mechanism of the ABO gene expression.
  
  
  METHODS
  Transient transfection assays were carried out in human erythroleukaemia HEL cells and human gastric cancer KATOIII cells. Electrophoretic mobility shift assays were performed using nuclear extracts derived from both cells.
  
  
  RESULTS
  Our characterization of the 5'-upstream sequence of the ABO genes indicated that the region between -117 and +31 is essential to direct expression of a reporter gene in erythroid cells. We show that a sequence located between positions -22 and -14 of the ABO promoter binds a ubiquitous transcription factor Sp1 or Sp1-like protein(s). Mutation of this site abrogates binding of those factors and reduces the ability of the ABO promoter to function in erythroleukaemia cells and gastric cancer cells.
  
  
  CONCLUSIONS
  The expression of the ABO promoter appears to be influenced by the binding of Sp1 or Sp1-like protein(s) in both erythroid and epithelial cell lineages.
authors.affiliation: Toyama Medical & Pharmaceutical University, Faculty of Medicine, Department of Legal Medicine, Toyama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hata
authors.forename: Y
authors.initials: Y
authors.lastname: Kominato
authors.forename: F-I
authors.initials: FI
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Takizawa
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019070:Cell Lineage; D024202:Electrophoretic Mobility Shift Assay; D004912:Erythrocytes; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D016329:Sp1 Transcription Factor; D014407:Tumor Cells, Cultured
chemical_list: D000017:ABO Blood-Group System; D016329:Sp1 Transcription Factor