NATURALLY-OCCURRING MUTATIONS IN THE HUMAN 5-LIPOXYGENASE GENE PROMOTER THAT MODIFY TRANSCRIPTION FACTOR-BINDING AND REPORTER GENE-TRANSCRIPTION

Five lipoxygenase (5-LO) is the first committed enzyme in the metaboli c pathway leading to the synthesis of the leukotrienes, We examined ge nomic DNA isolated from 25 normal subjects and 31 patients with asthma (6 of whom had aspirin-sensitive asthma) for mutations in the known t ranscription factor binding regions and the protein encoding region of the 5-LO gene, A family of mutations in the G + C-rich transcription factor binding region was identified consisting of the deletion of one , deletion of two, or addition of one zinc finger (Sp1/Egr-1) binding sites in the region 176 to 147 bp upstream from the ATG translation st art site where there are normally 5 Sp1 binding moths in tandem, Repor ter gene activity directed by any of the mutant forms of the transcrip tion factor binding region was significantly (P < 0.05) less effective than the activity driven by the wild type transcription factor bindin g region. Electrophoretic mobility shift assays (EMSAs) demonstrated t he capacity of wild type and mutant transcription factor binding regio ns to bind nuclear extracts from human umbilical vein endothelial cell s (HUVECs). These data are consistent with a family of mutations in th e 5-LO gene that can modify reporter gene transcription possibly throu gh differences in Sp1 and Egr-1 transactivation.