Cloning and functional characterization of the bovine endothelin-converting enzyme-1a promoter

Endothelin-converting enzyme-1 (ECE-1) mRNA is expressed in three isoforms, termed a, b, and c, originating from alternative promoters. In cultured bo vine aortic endothelial cells, we detected mRNA isoform expression of ECE-1 a and ECE-1b/c, respectively. Investigating transcriptional mechanisms of b ovine endothelial ECE-1a expression in more detail, we identified multiple transcription start sites localized 120-415 nucleotides upstream from the p resumptive translation start codon by RNase protection assay and 5' RACE. U sing luciferase reporter gene assays we found that 1.4 kb of the 5' untrans lated region showed strong promoter activity in endothelial cells. Sequence analysis revealed 71% overall homology of the bovine ECE-1a promoter with its human homologue. The proximal 680 base pair promoter region was shown t o contain cis elements that are sufficient for basal and serum-induced tran scriptional activation. (C) 1999 Elsevier Science B.V. All rights reserved.