FUNCTIONAL-ANALYSIS OF THE SCHISTOSOMA-MANSONI 28 KDA GLUTATHIONE-S-TRANSFERASE GENE PROMOTER - INVOLVEMENT OF SMNF-Y TRANSCRIPTION FACTOR IN MULTIMERIC COMPLEXES

The ability of the 5' flanking region of the gene encoding the 28 kDa glutathione S-transferase of Schistosoma mansoni gene to promote trans cription, was studied in different mammalian cell lines. Results of tr ansient transfection assays showed a strong activity of the - 277 to 1 nt region of the Sm28GST gene, comparable to that of well-studied p romoters. Deletion analysis indicated that an AP-1 site and two closel y located CCAAT (Y1 and Y2) boxes were the principal motifs responsibl e for the promoter activity. Binding of the NF-Y complex to Y1 and Y2, as well as to a third CCAAT box (Y3) close to the promoter TATA box, was compared in gel shift and super-shift experiments. All of the thre e Y boxes bound protein complexes from S. mansoni nuclear extracts tha t were shown to contain the A subunit of the schistosome NF-Y complex (SMNF-YA). Competition assays revealed a differential affinity of the Y1, Y2 and Y3 sequences for NF-Y. The Y1, Y2 and Y3 regions were also shown to activate transcription when included in an heterologous promo ter and data obtained strongly suggested the involvement of SMNF-Y in multimeric complexes during this process. Copyright (C) 1996 Elsevier Science B.V.