A SP1 BINDING-SITE IN THE GC-RICH REGION IS ESSENTIAL FOR A CORE PROMOTER ACTIVITY OF THE HUMAN ENDOTHELIAL NITRIC-OXIDE SYNTHASE GENE

Endothelial nitric oxide synthase (eNOS) is an important oxygenase whi ch catalyzes the conversion of L-arginine to L-citrulline to form nitr ic oxide (NO), a potent important factor for vasodilation and inhibiti on of platelet aggregation. We have analyzed characteristics of the pr omoter region of the human eNOS gene using the transient expression in human endothelial cells of CAT constructs with a series of 5'-deletio n mutants. The 5'-flanking region between -116 and -98, which contains a putative consensus sequence for binding of transcription factor Spl , is essential to direct a basal promoter activity. Gel mobility shift analysis involving anti-Spl antibody and competitor DNAs disrupted at the binding site for Spl reveals that Spl or its closely related prot ein(s) binds to the consensus sequence located between -104 and -96. T hese results indicate that the Spl site is essential for a core promot er activity of the human eNOS gene. (C) 1995 Press, Inc.