We previously cloned and characterized the promoter region of the human NeuAcalpha2,3Galbeta1,3GalNAcalpha2,6-sialyltransferase (hST6GalNAc IV) gene [Kim et al. (2003)]. In the present study, we identified a region of 294 bp upstream of exon 1 of the gene that produced maximal transcriptional activity in human Jurkat T cells. Site-directed mutagenesis and transient transfection assays demonstrated that Sp1 and MZF1 elements in this region were required for the promoter activity. Further analysis by electrophoretic mobility shift assays using specific competitors and antibody revealed that Sp1 and MZF1 nuclear proteins interacted with these elements. These results indicate that Sp1 and MZF1 are involved in the transcriptional regulation of the hST6GalNAc IV gene in Jurkat T cells.