Cloning and expression of an isoform of the rat mu opioid receptor (rMOR1B) which differs in agonist induced desensitization from rMOR1.
A novel rat mu opioid receptor (rMOR1B) has been isolated. It shows identity to the recently published sequence of rMOR1 [Chen, et al., Mol. Pharmacol., 44 (1993) 8-12] up to amino acid 386 and differs only in length and amino acid composition at the very carboxy-terminal tail. Both mu opioid receptor isoforms, when stably expressed in CHO-K1 cells, show similar affinities to opioid compounds and are equally effective in the inhibition of forskolin-induced cAMP formation. Reverse transcription polymerase chain reaction (RT-PCR) revealed that rMOR1B displays a similar distribution as rMOR1 in various rat brain areas. Studies measuring the inhibition of adenylate cyclase in cells that had been pre-exposed to the mu opioid agonist DAMGO indicated that rMOR1B is much more resistant to agonist-induced desensitization than rMOR1.
Zimprich
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Department of Physiology, University of Munich, Germany.
Simon
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Höllt
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000737:chemistry / Q000235:genetics*; D015290:Second Messenger Systems
D017450:Receptors, Opioid, mu; D004247:DNA; D012194:RNA-Directed DNA Polymerase