RGD Reference Report - Molecular cloning and characterization of an adenosine receptor: the A3 adenosine receptor. - Rat Genome Database

RGD Reference Report - Molecular cloning and characterization of an adenosine receptor: the A3 adenosine receptor. - Rat Genome Database

Submit Data | Help | Video Tutorials | News | Publications | Download | REST API | Citing RGD | Contact

General

Molecular cloning and characterization of an adenosine receptor: the A3 adenosine receptor.
Authors:	Zhou, QY Li, C Olah, ME Johnson, RA Stiles, GL Civelli, O
Citation:	Zhou QY, etal., Proc Natl Acad Sci U S A 1992 Aug 15;89(16):7432-6.
RGD ID:	631705
Pubmed:	PMID:1323836 (View Abstract at PubMed)
PMCID:	PMC49724 (View Article at PubMed Central)
We have previously reported the selective amplification of several rat striatal cDNA sequences that encode guanine nucleotide-binding regulatory protein (G protein)-coupled receptors. One of these sequences (R226) exhibited high sequence identity (58%) with the two previously cloned adenosine receptors. A full-length cDNA clone for R226 has been isolated from a rat brain cDNA library. The cDNA clone encodes a protein of 320 amino acids that can be organized into seven transmembrane stretches. R226 has been expressed in COS-7 and CHO cells and membranes from the transfected cells were screened with adenosine receptor radioligands. R226 could bind the nonselective adenosine agonist tritiated N-ethyladenosine 5'-uronic acid ([3H]NECA) and A1-selective agonist radioiodinated N6-2-(4-amino-3-iodophenyl)-ethyladenosine ([125I]APNEA) but not A1-selective antagonists tritiated 1,3-dipropyl-8-cyclopentylxanthine ([3H]DPCPX) and 8-(4-[([[(2-aminoethyl)amino]carbonyl]methyl)oxy]-phenyl)-1, 3-dipropylxanthine ([3H]XAC) or the A2-selective agonist ligands tritiated 2-[4-(2-carboxyethyl)phenyl]ethyl-amino 5'-N-ethylcarboxamidoadenosine ([3H]CGS21680) and radioiodinated 2-[4-([2-[(4-aminophenyl)methylcarbonylamino] ethylaminocarbonyl]ethyl)phenyl]ethylamino 5'-N-ethylcarboxamidoadenosine. Extensive characterization with [125I]APNEA showed that R226 binds [125I]APNEA with high affinity (Kd = 15.5 +/- 2.4 nM) and the specific [125I]APNEA binding could be inhibited by adenosine ligands with a potency order of (R)-N6-phenyl-2-propyladenosine (R-PIA) = NECA greater than S-PIA greater than adenosine greater than ATP = ADP but not by antagonists XAC, isobutylmethylxanthine, and DPCPX. In R226 stably transfected CHO cells, adenosine agonists R-PIA, NECA, and CGS21680 inhibited by 40-50% the forskolin-stimulated cAMP accumulation through a pertussis toxin-sensitive G protein with an EC50 of 18 +/- 5.6 nM, 23 +/- 3.5 nM, and 144 +/- 34 nM, respectively. Based on these observations we conclude that R226 encodes an adenosine receptor with non-A1 and non-A2 specificity, and we thus name it the A3 adenosine receptor. mRNA analyses revealed that the highest expression of R226 was in the testis and low-level mRNAs were also found in the lung, kidneys, heart, and some parts of the central nervous system such as cortex, striatum, and olfactory bulb. The high-expression level of the A3 receptor in the testis suggests a possible role for adenosine in reproduction.

Gene Ontology Annotations Click to see Annotation Detail View

Molecular Function

Only show annotations with direct experimental evidence (0 objects hidden)

Term	Qualifier	Evidence	With	Reference	Notes	Source	Original Reference(s)
G protein-coupled adenosine receptor activity		IDA		631705		RGD

Objects Annotated

Genes (Rattus norvegicus)

Adora3 (adenosine A3 receptor)

Additional Information