Functional role of the spatial proximity of Asp114(2.50) in TMH 2 and Asn332(7.49) in TMH 7 of the μ opioid receptor
- 26 March 1999
- journal article
- Published by Wiley in FEBS Letters
- Vol. 447 (2-3) , 318-324
- https://doi.org/10.1016/s0014-5793(99)00316-6
Abstract
We examined whether a proposed spatial proximity between Asp114(2.50) and Asn332(7.49) affected the functional properties of the μ opioid receptor. The D114(2.50)N mutant had reduced binding affinities for morphine, DAMGO and CTAP, but not for naloxone and [3H]diprenorphine; this mutation also abolished agonist-induced increase in [35S]GTPγS binding. The N332(7.49)D mutation eliminated detectable binding of either [3H]diprenorphine or [3H]DAMGO. The combined D114(2.50)N-N332(7.49)D mutation restored high affinity binding for [3H]diprenorphine, CTAP and naloxone, and restored partially the binding affinities, potencies and efficacies of morphine and DAMGO. Thus, reciprocal mutations of Asp114(2.50) and Asn332(7.49) compensate for the detrimental effects of the single mutations, indicating that the residues are adjacent in space and that their chemical functionalities are important for ligand binding and receptor activation.Keywords
This publication has 33 references indexed in Scilit:
- G Protein-coupled ReceptorsJournal of Biological Chemistry, 1998
- Molecular biology and pharmacology of cloned opioid receptors 1The FASEB Journal, 1995
- Cloning and expression of an isoform of the rat μ opioid receptor (rMOR1B) which differs in agonist induced desensitization from rMOR1FEBS Letters, 1995
- Expression of two variants of the human μ opioid receptor mRNA in SK‐N‐SH cells and human brainFEBS Letters, 1994
- Locating ligand-binding sites in 7tm receptors by protein engineeringCurrent Opinion in Biotechnology, 1994
- Structure and function of receptors coupled to G proteinsCurrent Opinion in Cell Biology, 1994
- mu opiate receptor: cDNA cloning and expression.Proceedings of the National Academy of Sciences, 1993
- In vitro mutagenesis and the search for structure-function relationships among G protein-coupled receptorsBiochemical Journal, 1992
- Opioid receptor-coupled second messenger systemsLife Sciences, 1991
- Anatomy of CNS opioid receptorsTrends in Neurosciences, 1988