Truncation of the receptor carboxyl terminus impairs membrane signaling but not ligand binding of human ETB endothelin receptor

Biochem Biophys Res Commun. 1995 Dec 5;217(1):354-62. doi: 10.1006/bbrc.1995.2784.


Human ETB endothelin receptor (hETBR) is a heptahelical G-protein-coupled receptor consisting of 442 amino acids whose carboxyl (C)-intracellular region has four and twelve sites for potential palmitoylation and phosphorylation, respectively. In order to elucidate the functional roles of these modification sites, we constructed a series of C-terminal truncated hETBRs and expressed them in Ltk- cells. All the truncated hETBRs showed ligand-binding profiles similar to those of the wild-type hETBR. The truncated receptors holding Cys-402 retained both normal intracellular calcium ([Ca2+]i) response and its rapid desensitization; however, the deleted receptors lacking Cys-402 failed to induce the [Ca2+]i response. These results showed that Cys-402 of hETBR is necessary for its intracellular calcium signaling and that at least ten of twelve putative phosphorylation sites are irresponsible for the agonist-induced desensitization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites / genetics
  • Calcium / metabolism
  • Cell Line
  • Cell Membrane / metabolism
  • DNA Primers / genetics
  • DNA, Complementary / genetics
  • Endothelins / pharmacology
  • Humans
  • Intracellular Fluid / metabolism
  • Ligands
  • Mice
  • Molecular Sequence Data
  • Palmitic Acids / metabolism
  • Phosphorylation
  • Receptors, Endothelin / classification
  • Receptors, Endothelin / genetics*
  • Receptors, Endothelin / metabolism*
  • Sequence Deletion
  • Signal Transduction
  • Transfection


  • DNA Primers
  • DNA, Complementary
  • Endothelins
  • Ligands
  • Palmitic Acids
  • Receptors, Endothelin
  • Calcium