GATA-3 REPRESSES GP91(PHOX) GENE-EXPRESSION IN EOSINOPHIL-COMMITTED HL-60-C15 CELLS

To study the regulatory mechanism of gp91(phox) gene expression in eos inophils, we transiently transfected eosinophil-committed HL-60-C15 ce lls with gp91(phox) promoter constructs, and identified a negative ele ment from bp -267 to -246 of the gp91(phox) gene, the deletion of whic h caused an 83% increase in promoter activity. Electrophoresis mobilit y shift assays demonstrated GATA-3 binds to the GATA consensus site fr om bp -256 to -256, An 81% increment in promoter activity was obtained when a mutation was introduced in the GATA-3 binding site of the bp - 267 to +12 construct, which is comparable to that of the bp -245 to +1 2 construct, We therefore conclude that GATA-3 specifically binding to the GATA site negatively regulates the expression of the gene in HL-6 0-C15 cells. (C) 1998 Federation of European Biochemical Societies.