Molecular cloning of an unusual bicistronic cholecystokinin receptor mRNA expressed in chicken brain: a structural and functional expression study.
This report describes the molecular cloning and pharmacological characterization of a transiently expressed chicken brain cholecystokinin receptor (CCK-CHR) in COS-7 cells. A polymerase chain reaction (PCR)-based cloning strategy was applied using: (1) an initial PCR with deoxyinosine-containing primers designed to target conserved regions in CCK receptors, followed by (2) rapid amplification of cDNA ends (RACE), and (3) full-length PCR of the CCK-CHR cDNA. The full-length cloned bicistronic CCK-CHR cDNA contained a short upstream open reading frame (uORF) coding for a putative six-amino-acid-long peptide of unknown function, followed by a long open reading frame (lORF) encoding the 436-amino-acid-long CCK-CHR receptor protein. At the amino acid level, the CCK-CHR shared approximately 50% homology with mammalian and Xenopus laevis CCK receptors. The pharmacological profile of CCK-CHR resembled that of CCK-B receptors using agonists (CCK-8, CCK-4, gastrin-17), whereas CCK-CHR showed higher affinity for the CCK-A receptor antagonist, devazepide, than for the CCK-B receptor antagonist, L-365,260. To the best of our knowledge, this is the first description and functional expression study of a cloned chicken CCK receptor cDNA.
Nilsson
Isabelle B M
IB
Strategic Development-LMO, Molecular Biology Laboratory, University Hospital, Linköping S-581 85, Sweden. isani@imv.liu.se
Svensson
Samuel P S
SP
Monstein
Hans-Jürg
HJ
D000595:Amino Acid Sequence; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D019556:COS Cells; D002645:Chickens; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D020109:Devazepide / Q000494:pharmacology; D005755:Gastrins / Q000737:chemistry / Q000494:pharmacology; D007288:Inosine / Q000031:analogs & derivatives / Q000235:genetics; D008969:Molecular Sequence Data; D010671:Phenylurea Compounds / Q000494:pharmacology; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D011869:Radioligand Assay; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012844:Sincalide / Q000494:pharmacology; D013758:Tetragastrin / Q000494:pharmacology
D001570:Benzodiazepinones; D018076:DNA, Complementary; D005755:Gastrins; D010671:Phenylurea Compounds; D012333:RNA, Messenger; D011949:Receptors, Cholecystokinin; D013758:Tetragastrin; C058121:L 365260; D007288:Inosine; C013550:gastrin 17; D020109:Devazepide; D012844:Sincalide