Expression of human preproendothelin-1 cDNA in COS cells results in the production of mature vasoactive endothelin-1.

Transient transfection of simian kidney (COS) cells with a recombinant plasmid encoding human preproendothelin-1 resulted in the production of biologically active endothelin-1. Conditioned medium from human preproendothelin-1 transfected cells demonstrated a significant increase in immunoreactive endothelin and big endothelin which co-eluted, when analyzed by reverse phase HPLC, with synthetic endothelin-1 and big endothelin-1, respectively. In addition, biological activity was confirmed by both inhibition of [125I]endothelin-1 binding to rat cerebellar and renal medullary membrane endothelin receptors and in vitro vasoconstriction of rabbit aorta. This is the first demonstration that human preproendothelin-1 is capable of being processed to a vasoactive form in a heterologous system and suggests that human preproendothelin-1 transfected COS cells may provide a useful model system for the study of endothelin biosynthesis.