Cloning and pharmacological characterization of a rat kappa opioid receptor.
A full-length cDNA was isolated from a rat striatal library by using low-stringency screening with two PCR fragments, one spanning transmembrane domains 3-6 of the mouse delta opioid receptor and the other unidentified but homologous to the mouse delta receptor from rat brain. The novel cDNA had a long open reading frame encoding a protein of 380 residues with 59% identity to the mouse delta receptor and topography consistent with a seven-helix guanine nucleotide-binding protein-coupled receptor. COS-1 cells transfected with the coding region of this clone showed high-affinity binding to kappa opioid receptor-selective ligands such as dynorphin A and U-50,488 and also nonselective opioid ligands such as bremazocine, ethylketocyclazocine, and naloxone. Not bound at all (or bound with low affinity) were dynorphin A-(2-13), enantiomers of naloxone and levophanol [i.e., (+)-naloxone and dextrorphan], and selective mu and delta opioid receptor ligands. Activation of the expressed receptor by kappa receptor agonists led to inhibition of cAMP. Finally, in situ hybridization revealed a mRNA distribution in rat brain that corresponded well to the distribution of binding sites labeled with kappa-selective ligands. These observations indicate that we have cloned a cDNA encoding a rat kappa receptor of the kappa 1 subtype.
Meng
F
F
Mental Health Research Institute, University of Michigan, Ann Arbor 48109.
Xie
G X
GX
Thompson
R C
RC
Mansour
A
A
Goldstein
A
A
Watson
S J
SJ
Akil
H
H
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000595:Amino Acid Sequence; D000700:Analgesics / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D044482:Benzeneacetamides; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D003342:Corpus Striatum / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D017931:DNA Primers; D018076:DNA, Complementary / Q000378:metabolism; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000378:metabolism / Q000494:pharmacology; D015723:Gene Library; D017403:In Situ Hybridization; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D008969:Molecular Sequence Data; D011759:Pyrrolidines / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017473:Receptors, Opioid, kappa / Q000096:biosynthesis / Q000378:metabolism*; D015183:Restriction Mapping; D014162:Transfection
D000700:Analgesics; D044482:Benzeneacetamides; D017931:DNA Primers; D018076:DNA, Complementary; D004745:Enkephalins; D008024:Ligands; D011759:Pyrrolidines; D012333:RNA, Messenger; D017473:Receptors, Opioid, kappa; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D015544:Inositol 1,4,5-Trisphosphate; D020881:Enkephalin, D-Penicillamine (2,5)-; D000242:Cyclic AMP; C045444:U 69593