Isolation and functional analysis of the promoter of the rat CMP-NeuAc:GM3 α 2,8 sialyltransferase gene

A 2.1-kb 5′-flanking fragment of the rat CMP-NeuAc:GM3 α2,8 sialyltransferase (GD3-synthase) gene was cloned by the genomic walking procedure. The promoter activity of the fragment was assessed in F-11 cells by transient transfection and the locations for the basal and maximal promoter activities were defined. Primer extension analysis identified a transcription start site approximately 98 bp upstream of the ATG start codon. DNA sequence analysis of the promoter revealed a number of consensus binding sites for known transcription factors such as SP1, AP1, NFk-B, C/EBP and TFIID, and a repeat GC-GT sequence motif seen for the formation of Z-type DNA. Both TATA and CCAAT boxes were not found in the promoter. Our results from deletion constructs suggested that both positive and negative cis-acting regulatory regions were present in this TATA-less promoter of the rat GD3-synthase gene.