Identification of an endothelial cell-specific regulatory region in the murine endothelin-1 gene

Endothelin-1 is a 21-amino acid peptide first characterized as a potent vasoactive compound synthesized by endothelial cells. Because of its high level cell-restricted pattern of expression, we have employed this gene as a model for investigating the DNA and protein elements that mediate endothelial cell-specific gene expression. In this study we have identified a complex positive regulatory region located at base pairs -364 to -320 in the murine endothelin-1 gene. This region consists of three functionally dependent elements, ETE-C, ETE-D, and ETE-E, which are all required for full activity. When a 43-base pair fragment containing these three elements was employed in heterologous promoter experiments, this sequence was capable of increasing transcriptional activity in an endothelial cell-specific fashion. None of the elements contains a recognized consensus sequence known to bind transcriptional regulatory proteins in higher eukaryotes; however, each element does appear to mediate protein binding. The combination of all three elements promotes binding of a protein complex that is endothelial cell-specific. This is the first evidence for an endothelial cell-specific DNA regulatory element and cognate binding proteins.