Characterization of the promoter for the human P-selectin gene.

Abstract

P-selectin, an adhesion receptor for leukocytes, is synthesized selectively by megakaryocytes and endothelial cells. We have cloned the 5'-flanking region of the human P-selectin gene and conducted a preliminary analysis of its features. As determined by primer extension, RNase protection, and anchored polymerase chain reaction cloning, there were multiple transcriptional initiation sites from -95 to -25 nucleotides relative to the start of protein-coding sequence. Transfection of bovine aortic endothelial cells with serially truncated segments of the 5'-flanking region linked to luciferase indicated that the sequence from -249 to -13 was sufficient to promote high level gene expression. Deletions to -197, -147, and -128 gradually reduced expression to basal levels, and further deletion to -100 abolished expression. The sequence from -309 to -13 supported only basal luciferase expression in COS-7, 293, or HeLa cells. Putative regulatory elements in the short 5'-flanking sequence included a CACCC sequence, two inverted repeats similar to binding sites for the ETS and NF-kappa B/rel families, a GATA motif, and a sequence related to the GT-IIC element of the SV40 enhancer. The GATA element was functional, as it bound recombinant GATA-2, and mutations in the core sequence impaired both nuclear protein binding and gene expression. These data suggest that the P-selectin gene is regulated by a combination of cis elements and their cognate transcription factors.