Cloning of a chick A3 adenosine receptor: characterization of ligand binding and receptor-effector coupling of chick A1 and A3 adenosine receptors.
We have reported previously the cloning and partial characterization of a chick A1 adenosine receptor expressed in the heart. We report herein the cloning of a chick A3 adenosine receptor and a comprehensive characterization of both the A1 and A3 receptors expressed in human embryonic kidney 293 cells. [125I]N6-(p-aminobenzyl)adenosine bound to both receptors with similar affinities and was used in competition studies. Although the selectivities of both agonists and antagonists were less than in other species, two antagonists, 3-ethyl-5-benzyl-2-methyl-6-phenyl-4-phenylethynal-(+/-)-dihydropyridine-3,5-dicarboxylate and 3,6-dichloro-2'-(isopropyloxy)-4'-methylflavone), were at least partially selective for A3 receptors while one antagonist [C8-(N-methylisopropyl)amine-N6-(5'endohydroxy)endonorboman-2-yl-9-methyladenine] was selective for A1 receptors. While both receptors coupled to the inhibition of adenylyl cyclase, we were unable to detect coupling of either receptor to phospholipase C or D.
Durand
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Department of Pharmacology, School of Medicine, University of Illinois at Chicago, 60612, USA.
Green
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D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide) / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004274:DNA, Recombinant; D004095:Dihydropyridines / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes / Q000378:metabolism / Q000494:pharmacology; D008024:Ligands; D008969:Molecular Sequence Data; D010739:Phospholipase D / Q000378:metabolism; D011869:Radioligand Assay; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism; D014970:Xanthines / Q000494:pharmacology
D018076:DNA, Complementary; D004274:DNA, Recombinant; D004095:Dihydropyridines; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008024:Ligands; C100736:MRS 1097; D043684:Receptor, Adenosine A3; D018047:Receptors, Purinergic P1; D014970:Xanthines; C056346:BW A1433; D019830:Adenosine-5'-(N-ethylcarboxamide); C044323:3-iodo-N(6)-4-aminobenzyladenosine; D000242:Cyclic AMP; D010738:Type C Phospholipases; D010739:Phospholipase D; D000241:Adenosine