Molecular cloning and functional analysis of a novel P2 nucleotide receptor.
The cDNA encoding a novel P2 receptor was isolated from rat aortic smooth muscle cell library and functionally characterized. The cloned P2 receptor exhibits structural features characteristic of the G protein-coupled receptor family and shows 44 and 38% amino acid identity with previously cloned rat P2U and chicken P2Y receptors, respectively. The cloned P2 receptor is functionally coupled to phospholipase C but not to adenylate cyclase in C6 rat glioma cells transfected with the cloned P2 expression vector. The rank order of agonist potency as judged by intracellular Ca2+ mobilization responses is UTP > ADP = 2-methylthioATP > ADP beta S > ATP = ATP gamma S, which is not compatible with any of the previously characterized P2 receptor subtypes. The nonselective P2 antagonists, suramin and reactive blue-2, inhibit nucleotide-induced phospholipase C activation in cells expressing the cloned P2 receptor. The cloned P2 receptor mRNA is abundantly expressed in various rat tissues including lung, stomach, intestine, spleen, mesentery, heart, and, most prominently, aorta. The results indicate that the novel metabotropic P2 receptor has pharmacological characteristics distinct from any of P2 receptor subtypes thus far identified and suggest the existence of a novel regulatory system by extracellular nucleotides of potential significance.
Chang
K
K
Department of Cardiovascular Biology, Faculty of Medicine, University of Tokyo, Japan.
Hanaoka
K
K
Kumada
M
M
Takuwa
Y
Y
D000227:Adenine Nucleotides / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D037361:Adenylate Cyclase Toxin; D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002645:Chickens; D003001:Cloning, Molecular / Q000379:methods; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D018076:DNA, Complementary; D015723:Gene Library; D005910:Glioma; D007295:Inositol Phosphates / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D009928:Organ Specificity; D037342:Pertussis Toxin; D058910:Purinergic P2 Receptor Agonists; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis* / Q000737:chemistry; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000227:Adenine Nucleotides; D037361:Adenylate Cyclase Toxin; D018076:DNA, Complementary; D007295:Inositol Phosphates; D009838:Oligodeoxyribonucleotides; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D000244:Adenosine Diphosphate; D000242:Cyclic AMP; D037342:Pertussis Toxin; D002118:Calcium