The avian beta-adrenergic receptor: primary structure and membrane topology.

TLDR

The turkey erythrocyte beta‑adrenergic receptor was isolated from partial amino‑acid sequence data, and its sequence predicts a seven‑transmembrane architecture with a long cytoplasmic C‑terminus, an N‑glycosylated extracellular N‑terminus, and weak homology to rhodopsin. Antisera against synthetic peptides cross‑reacted with the purified receptor, confirming the cDNA identity; the receptor is 483 aa long, 54 kDa, and its seven‑transmembrane structure provides a general model for G‑protein‑coupled receptors.

Abstract

Partial amino acid sequence information allowed the isolation of cDNA clones encoding the turkey erythrocyte beta-adrenergic receptor. Antisera raised against synthetic peptides encoded by the cDNA crossreacted with the purified receptor and appropriate tryptic fragments, confirming the identity of the cDNA. The receptor is composed of 483 amino acids and has a molecular mass of 54 kDa. Its sequence suggests that it is arranged predominantly in seven membrane-spanning sequences and a long cytoplasmic carboxyl-terminal domain. The extracellular amino-terminal domain contains a consensus sequence for N-glycosylation. The beta-adrenergic receptor displays overall structural similarity and weak sequence homology with rhodopsin. Because both proteins act by regulating GTP-binding proteins, a compact structure based on seven membrane-spanning regions may be a general model for receptors that act on G proteins.