DELETION ANALYSIS OF THE SCHISTOSOMA-MANSONI 28-KDA GLUTATHIONE-S-TRANSFERASE GENE PROMOTER IN MAMMALIAN-CELLS - IMPORTANCE OF A PROXIMAL ACTIVATOR-PROTEIN-1 SITE

The 1241-bp promoter region of the Schistosoma mansoni 28-kDa glutathi one S-transferase gene (Sm28GST) was sequentially deleted and analyzed using the Iuciferase reporter gene system in different cell lines. Th e activator protein-1 (AP-1) site located at -231 seems to be responsi ble for the major part of the promoter activity. The 1241-bp Sm28GST p romoter was not, in transient transfection experiments, activated by r eagents generating reactive oxygen species, such as hydrogen peroxide (H2O2), 3-methyl-cholanthrene, and ter-methylhydroquinone, but was sig nificantly stimulated by phorbol 12-myristate 13-acetate, a potent pro tein kinase C activator. The involvement of the -231 AP-1 site in phor bol 12-myristate 13-acetate stimulation was demonstrated. Moreover, ev idence for in vitro and in vivo binding of the -231 AP-1 site to Jun/F os dimers was obtained using mobility gel shift assays and co-transfec tion of embryonic F9 cells with Jun/Fos expression plasmids, respectiv ely. The presence in S. mansoni nuclear extracts of components with af finity for the AP-1 site suggests conservation of this regulatory path way in the parasite.