Subtype-specific kinetics of inhibitory adenosine receptor internalization are determined by sensitivity to phosphorylation by G protein-coupled receptor kinases.

G Ferguson, Kenneth R Watterson, Timothy M Palmer

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Despite coupling to the same class of inhibitory G proteins and binding the same physiological ligand, the human A(1) and rat A(3) adenosine receptors (ARs) desensitize at different rates in response to sustained agonist exposure. This is due to the ability of the A(3)AR, but not the A(1)AR, to serve as a substrate for rapid phosphorylation and desensitization by members of the G protein-coupled receptor kinase (GRK) family. The aim of this study was to investigate whether these differences were also manifested in their abilities to undergo agonist-dependent receptor internalization. For the first time, we report that A(3)ARs internalize profoundly in response to short-term exposure to agonist but not activators of second messenger-regulated kinases. The A(3)AR-selective antagonist MRS1523 blocked both A(3)AR phosphorylation and internalization. Moreover, in contrast to the A(1)AR, which internalized quite slowly (t(1/2) = 90 min), A(3)ARs internalized rapidly (t(1/2) = 10 min) over a time frame that followed the onset of receptor phosphorylation. A nonphosphorylated A(3)AR mutant failed to internalize over a 60-min time course, suggesting that receptor phosphorylation was essential for rapid A(3)AR internalization to occur. In addition, fusion onto the A(1)AR of the A(3)AR C-terminal domain containing the sites for phosphorylation by GRKs conferred rapid agonist-induced internalization kinetics (t(1/2) = 10 min) on the resulting chimeric AR. In conclusion, these data suggest that GRK-stimulated phosphorylation of threonine residues within the C-terminal domain of the A(3)AR is obligatory to observe rapid agonist-mediated internalization of the receptor.
Original languageEnglish
Article number10692495
Pages (from-to)546-52
Number of pages12
JournalMolecular Pharmacology
Volume57
Issue number3
Publication statusPublished - 1 Mar 2000

Fingerprint

G-Protein-Coupled Receptor Kinases
Phosphorylation
Purinergic P1 Receptors
Kinetics
Purinergic P1 Receptor Antagonists
Second Messenger Systems
Threonine
GTP-Binding Proteins
Protein Binding

Keywords

  • Genetics

Cite this

@article{23f8124c3a624ecfa0dc277522316bdb,
title = "Subtype-specific kinetics of inhibitory adenosine receptor internalization are determined by sensitivity to phosphorylation by G protein-coupled receptor kinases.",
abstract = "Despite coupling to the same class of inhibitory G proteins and binding the same physiological ligand, the human A(1) and rat A(3) adenosine receptors (ARs) desensitize at different rates in response to sustained agonist exposure. This is due to the ability of the A(3)AR, but not the A(1)AR, to serve as a substrate for rapid phosphorylation and desensitization by members of the G protein-coupled receptor kinase (GRK) family. The aim of this study was to investigate whether these differences were also manifested in their abilities to undergo agonist-dependent receptor internalization. For the first time, we report that A(3)ARs internalize profoundly in response to short-term exposure to agonist but not activators of second messenger-regulated kinases. The A(3)AR-selective antagonist MRS1523 blocked both A(3)AR phosphorylation and internalization. Moreover, in contrast to the A(1)AR, which internalized quite slowly (t(1/2) = 90 min), A(3)ARs internalized rapidly (t(1/2) = 10 min) over a time frame that followed the onset of receptor phosphorylation. A nonphosphorylated A(3)AR mutant failed to internalize over a 60-min time course, suggesting that receptor phosphorylation was essential for rapid A(3)AR internalization to occur. In addition, fusion onto the A(1)AR of the A(3)AR C-terminal domain containing the sites for phosphorylation by GRKs conferred rapid agonist-induced internalization kinetics (t(1/2) = 10 min) on the resulting chimeric AR. In conclusion, these data suggest that GRK-stimulated phosphorylation of threonine residues within the C-terminal domain of the A(3)AR is obligatory to observe rapid agonist-mediated internalization of the receptor.",
keywords = "Genetics",
author = "G Ferguson and Watterson, {Kenneth R} and Palmer, {Timothy M}",
year = "2000",
month = "3",
day = "1",
language = "English",
volume = "57",
pages = "546--52",
journal = "Molecular Pharmacology",
issn = "0026-895X",
publisher = "American Society for Pharmacology and Experimental Therapeutics",
number = "3",

}

Subtype-specific kinetics of inhibitory adenosine receptor internalization are determined by sensitivity to phosphorylation by G protein-coupled receptor kinases. / Ferguson, G; Watterson, Kenneth R; Palmer, Timothy M.

In: Molecular Pharmacology, Vol. 57, No. 3, 10692495, 01.03.2000, p. 546-52.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Subtype-specific kinetics of inhibitory adenosine receptor internalization are determined by sensitivity to phosphorylation by G protein-coupled receptor kinases.

AU - Ferguson, G

AU - Watterson, Kenneth R

AU - Palmer, Timothy M

PY - 2000/3/1

Y1 - 2000/3/1

N2 - Despite coupling to the same class of inhibitory G proteins and binding the same physiological ligand, the human A(1) and rat A(3) adenosine receptors (ARs) desensitize at different rates in response to sustained agonist exposure. This is due to the ability of the A(3)AR, but not the A(1)AR, to serve as a substrate for rapid phosphorylation and desensitization by members of the G protein-coupled receptor kinase (GRK) family. The aim of this study was to investigate whether these differences were also manifested in their abilities to undergo agonist-dependent receptor internalization. For the first time, we report that A(3)ARs internalize profoundly in response to short-term exposure to agonist but not activators of second messenger-regulated kinases. The A(3)AR-selective antagonist MRS1523 blocked both A(3)AR phosphorylation and internalization. Moreover, in contrast to the A(1)AR, which internalized quite slowly (t(1/2) = 90 min), A(3)ARs internalized rapidly (t(1/2) = 10 min) over a time frame that followed the onset of receptor phosphorylation. A nonphosphorylated A(3)AR mutant failed to internalize over a 60-min time course, suggesting that receptor phosphorylation was essential for rapid A(3)AR internalization to occur. In addition, fusion onto the A(1)AR of the A(3)AR C-terminal domain containing the sites for phosphorylation by GRKs conferred rapid agonist-induced internalization kinetics (t(1/2) = 10 min) on the resulting chimeric AR. In conclusion, these data suggest that GRK-stimulated phosphorylation of threonine residues within the C-terminal domain of the A(3)AR is obligatory to observe rapid agonist-mediated internalization of the receptor.

AB - Despite coupling to the same class of inhibitory G proteins and binding the same physiological ligand, the human A(1) and rat A(3) adenosine receptors (ARs) desensitize at different rates in response to sustained agonist exposure. This is due to the ability of the A(3)AR, but not the A(1)AR, to serve as a substrate for rapid phosphorylation and desensitization by members of the G protein-coupled receptor kinase (GRK) family. The aim of this study was to investigate whether these differences were also manifested in their abilities to undergo agonist-dependent receptor internalization. For the first time, we report that A(3)ARs internalize profoundly in response to short-term exposure to agonist but not activators of second messenger-regulated kinases. The A(3)AR-selective antagonist MRS1523 blocked both A(3)AR phosphorylation and internalization. Moreover, in contrast to the A(1)AR, which internalized quite slowly (t(1/2) = 90 min), A(3)ARs internalized rapidly (t(1/2) = 10 min) over a time frame that followed the onset of receptor phosphorylation. A nonphosphorylated A(3)AR mutant failed to internalize over a 60-min time course, suggesting that receptor phosphorylation was essential for rapid A(3)AR internalization to occur. In addition, fusion onto the A(1)AR of the A(3)AR C-terminal domain containing the sites for phosphorylation by GRKs conferred rapid agonist-induced internalization kinetics (t(1/2) = 10 min) on the resulting chimeric AR. In conclusion, these data suggest that GRK-stimulated phosphorylation of threonine residues within the C-terminal domain of the A(3)AR is obligatory to observe rapid agonist-mediated internalization of the receptor.

KW - Genetics

M3 - Article

VL - 57

SP - 546

EP - 552

JO - Molecular Pharmacology

JF - Molecular Pharmacology

SN - 0026-895X

IS - 3

M1 - 10692495

ER -