Identification of a Gs‐protein coupling domain to the β‐aderenoceptor using site‐specific synthetic peptides

Abstract
Competition between Gs-protein and the synthetic peptide, GSA 379-394, derived from the carboxyl-terminal region of the αs-subunit, led to complete inhibition of receptor-mediated adenylate cyclase activation in turkey erythrocyte membranes. Related peptides corresponding to the homologous carboxyl-terminal region of αt-,αil- or αo-subunits did not interfere with β-receptor-Gs coupling. The direct coupling between Gs and adenylate cyclase was not influenced by any of these peptides. These results emphasize the important role of the carboxyl-terminus of G-protein α-subunits for the specific recognition of their corresponding receptors and for signal transduction