Identification of the Tax-responsive region in theFuc-T VII promoter.

Reporter constructs, full-length, and 5′ deletions of the Fuc-T VII sequence cloned upstream of luciferase reporter gene (pGL2) through +104 nucleotide, were transfected into Jurkat T cells and either not cotransfected (■) or cotransfected with pCGTax (▪). The transcription start site and its location are indicated with an arrow in each construct. Reporter constructs shown are described in “Materials and methods.” The CRE-like element is represented by closed boxes, and the Sp1 consensus element is represented by open boxes. Promoter activity was expressed as the fold induction of the observed reporter activity of the construct cotransfected with pCGTax over that of the negative control, the full-length construct without pCGTax. CRE-mut has a mutation of bases −159 to −155 (from CGTCA to TTTAA) in the half-palindromic CRE motif of the CRE-like element, and Sp1-mut has a mutation of bases −39 to −32 (from GGGGCGGG to GTTTCAGG) in the Sp1 consensus element. Crossed-out boxes depict the site of these mutations. Results are expressed as relative light units normalized for CAT activity. Mean values for 3 independent assays are presented, and the corresponding standard deviation is indicated on the top of each bar.