Opioid receptors from a lower vertebrate (Catostomus commersoni): sequence, pharmacology, coupling to a G-protein-gated inward-rectifying potassium channel (GIRK1), and evolution.

ABSTRACT: The molecular evolution of the opioid receptor family has been studied by isolating cDNAs that encode six distinct opioid receptor-like proteins from a lower vertebrate, the teleost fish Catostomus commersoni. One of these, which has been obtained in full-length form, encodes a 383-amino acid protein that exhibits greatest sequence similarity to mammalian mu-opioid receptors; the corresponding gene is expressed predominantly in brain and pituitary. Transfection of the teleost cDNA into HEK 293 cells resulted in the appearance of a receptor having high affinity for the mu-selective agonist [D-Ala2, MePhe4-Gly-ol5]enkephalin (DAMGO) (Kd = 0.63 +/- 0.15 nM) and for the nonselective antagonist naloxone (Kd = 3.1 +/- 1.3 nM). The receptor had negligible affinity for U50488 and [D-Pen2, D-Pen5]e

SUBMITTER: Darlison MG 

PROVIDER: S-EPMC21583 | biostudies-literature | 1997 Jul

REPOSITORIES: biostudies-literature