The molecular basis for genetic polymorphism of human deoxyribonuclease II (DNase II): a single nucleotide substitution in the promoter region of human DNase II changes the promoter activity

Abstract

Deoxyribonuclease II (DNase II) levels in human vary depending on whether the individual has the DNASE2*H (high) allele or the DNASE2*L (low) allele. We examined the promoter activity of the 5'-flanking region of each of these alleles by transient transfection luciferase assay. DNASE2*H had 5-fold higher promoter activity than DNASE2*L in human hepatoma HepG2 cell. Comparison of the nucleotide sequences of the proximal promoter regions revealed a G to A transition at position -75; G and A residues were assigned to DNASE2*H and *L, respectively. Since no differences were found between the open reading frame sequences of these alleles, it is likely that the A-75G transition causes the allelic difference in the promoter activity of the gene, underlying the genetic polymorphism.