The human galanin receptor: ligand-binding and functional characteristics in the Bowes melanoma cell line.
The human galanin receptor has been characterized pharmacologically from the Bowes melanoma cell line. Using porcine [125I]galanin as the radioligand, a single population of non-interacting high-affinity binding sites (KD = 0.05 +/- 0.01 nM; Bmax = 135 +/- 7 fmol/mg protein) was demonstrated. Human galanin peptide competitively inhibited the specific binding of [125I]galanin (IC50 = 0.35 +/- 0.13 nM) and decreased the forskolin-stimulated cAMP production (EC50 = 0.46 +/- 0.05 nM) with a maximal inhibition of 63 +/- 2% at 10(-7) M. Rat and porcine galanin peptides and the chimeric peptides M15, M35, M32, M40 and C7 also dose-dependently inhibited the forskolin-stimulated cAMP production, while the fragment porcine galanin-(3-29) and [D-Trp2]galanin were found to be inactive. The specific binding of [125I]galanin was decreased in a dose-dependent manner by GTP and the cAMP response was inhibited by the pertussis toxin, suggesting the activation of a G-protein dependent process. The Bowes cell line thus appears to be a relevant tool for the study of human galanin receptor.
Heuillet
E
E
Department of Biology, Rhone-Poulenc Rorer S.A., CRVA, Vitry/Seine, France.
Bouaiche
Z
Z
Ménager
J
J
Dugay
P
P
Munoz
N
N
Dubois
H
H
Amiranoff
B
B
Crespo
A
A
Lavayre
J
J
Blanchard
J C
JC
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005576:Colforsin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis; D019004:Galanin; D006801:Humans; D007457:Iodine Radioisotopes; D007700:Kinetics; D008024:Ligands; D008546:Melanoma, Experimental / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D037342:Pertussis Toxin; D051381:Rats; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013552:Swine; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D007457:Iodine Radioisotopes; D008024:Ligands; D009479:Neuropeptides; D010455:Peptides; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone; D011993:Recombinant Fusion Proteins; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D019004:Galanin; D000242:Cyclic AMP; D037342:Pertussis Toxin