Promoter regulatory elements and DNase I-hypersensitive sites involved in serglycin proteoglycan gene expression in human erythroleukemia, CHRF 288-11, and HL-60 cells

We have compared regulation of the serglycin gene in human erythroleukemia (HEL) and CHRF 288-11 cells, which have megakaryocytic characteristics, wit h promyelocytic HL-60 cells, Deletion constructs were prepared from the reg ion -1123/+42 to -20/+42, and putative regulatory sites were mutated. In al l three cell lines, the two major regulatory elements for constitutive expr ession were the (-80)ets site and the cyclic AMP response element (CRE) hal f-site at -70, A protein from HEL and CHRF, but not HL60, nuclear extracts bound to the (-80)ets site. Another protein from ah three cell lines bound to the (-70)CRE. Phorbol 12-myristate 15-acetate (PMA) and dibutyryl cyclic AMP (dbcAMP) increased expression of the reporter in HEL cells 2.5-3- and 4.5-fold, respectively, from all constructs except those with (-70)CRE muta tions. PMA virtually eliminated expression of serglycin mRNA and promoter c onstructs, but dbcAMP increased expression in HL-60 cells. The effects of P MA and dbcAMP on promoter expression correlated with mRNA expression, The s trengths of two DNase hypersensitive sites in the 5 ' -flanking region and the first intron in all three cells correlated with relative endogenous ser glycin mRNA expression, An additional DNase I-hypersensitive site in HL60 D NA in the first intron may be related to the high serglycin expression in H L60 relative to HEL or CHRF cells.