The allosteric enhancer PD81,723 increases chimaeric A1/A2A adenosine receptor coupling with Gs

PD81,723 {(2-amino-4,5-dimethyl-3-thienyl)-[3-(trifluromethyl)-phenyl]methanone} is a selective allosteric enhancer of the G(i)-coupled A1 AR (adenosine receptor) that is without effect on G(s)-coupled A2A ARs. PD81,723 elicits a decrease in the dissociation kinetics of A1 AR agonist radioligands and an increase in functional agonist potency. In the present study, we sought to determine whether enhancer sensitivity is dependent on coupling domains or G-protein specificity of the A1 AR. Using six chimaeric A1/A2A ARs, we show that the allosteric effect of PD81,723 is maintained in a chimaera in which the predominant G-protein-coupling domain of the A1 receptor, the 3ICL (third intracellular loop), is replaced with A2A sequence. These chimaeric receptors are dually coupled with G(s) and G(i), and PD81,723 increases the potency of N6-cyclopentyladenosine to augment cAMP accumulation with or without pretreatment of cells with pertussis toxin. Thus PD81,723 has similar functional effects on chimaeric receptors with A1 transmembrane sequences that couple with G(i) or G(s). This is the first demonstration that an allosteric regulator can function in the context of a switch in G-protein-coupling specificity. There is no enhancement by PD81,723 of G(i)-coupled A2A chimaeric receptors with A1 sequence replacing A2A sequence in the 3ICL. The results suggest that the recognition site for PD81,723 is on the A1 receptor and that the enhancer acts to directly stabilize the receptor to a conformational state capable of coupling with G(i) or G(s).

Medienart:

E-Artikel

Erscheinungsjahr:

2006

Erschienen:

2006

Enthalten in:

Zur Gesamtaufnahme - volume:396

Enthalten in:

The Biochemical journal - 396(2006), 1 vom: 15. Mai, Seite 139-46

Sprache:

Englisch

Beteiligte Personen:

Bhattacharya, Samita [VerfasserIn]
Youkey, Rebecca L [VerfasserIn]
Ghartey, Kobina [VerfasserIn]
Leonard, Matthew [VerfasserIn]
Linden, Joel [VerfasserIn]
Tucker, Amy L [VerfasserIn]

Themen:

121496-66-0
132861-87-1
161536-31-8
2-(2-(4-amino-3-iodophenyl)ethylamino)adenosine
3-iodo-N(6)-4-aminobenzyladenosine
41552-82-3
95523-14-1
Adenosine
Adrenergic alpha-Agonists
Adrenergic alpha-Antagonists
BW A1433
Cyclic AMP
E0399OZS9N
EC 3.6.5.1
GTP-Binding Protein alpha Subunits, Gi-Go
GTP-Binding Protein alpha Subunits, Gs
Iodobenzenes
Journal Article
K72T3FS567
N(6)-cyclopentyladenosine
PD 81723
Receptor, Adenosine A1
Receptor, Adenosine A2A
Recombinant Fusion Proteins
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Thiophenes
Xanthines

Anmerkungen:

Date Completed 31.05.2006

Date Revised 13.11.2018

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM159897149