Endothelin receptor dimers evaluated by FRET, ligand binding, and calcium mobilization.

ABSTRACT: Endothelin-1 (ET-1) mediates physiological responses via endothelin A (ET(A)) and B (ET(B)) receptors, which may form homo- and heterodimers with unknown function. Here, we investigated ET-receptor dimerization using fluorescence resonance energy transfer (FRET) between receptors tagged with CFP (donor) and receptors tagged with tetracysteine-FlAsH (fluorescein arsenical hairpin) (acceptor) expressed in HEK293 cells. FRET efficiencies were 15%, 22%, and 27% for ET(A)/ET(A), ET(B)/ET(B), and ET(A)/ET(B), respectively, and dimerization was further supported by coimmunoprecipitation. For all dimer pairs, the natural but nonselective ligand ET-1 rapidly (50%, but did not detectably reduce coimmunoprecipitation. ET-1 stimulated a transient increase in intracellular Ca

SUBMITTER: Evans NJ 

PROVIDER: S-EPMC2426627 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature