Regulation of G protein-coupled receptor kinase 2

doi:10.1016/S0076-6879(02)43158-8

Methods in Enzymology

Volume 343, 2002, Pages 559-577

https://doi.org/10.1016/S0076-6879(02)43158-8 Get rights and content

Publisher Summary

G protein-coupled receptor kinase 2 (GRK2) was originally termed a “β-adrenergic receptor kinase” (βARK) because it was purified as a kinase of the adrenergic β₂ receptor, and the adrenergic β₂ receptor was the only known substrate of GRK2. GRK2 is now known to phosphorylate different kinds of G protein-coupled receptors (GPCRs), including rhodopsin, muscarinic acetylcholine receptors, and adrenergic β2 receptors when they are stimulated by light absorption or agonist binding. There is no appreciable homology among amino acid sequences around phosphorylation sites in these GPCRs, except that they are flanked by acidic amino acid residues. The substrate specificity of GRK2, however, is strict in a sense that only a few proteins are known to be substrates of GRK2 besides agonist bound GPCRs. One of the reasons why agonist-bound GPCRs are phosphorylated by GRK2 is that GRK2 is activated by agonist-bound receptors. Very recently, tubulin, synuclein, and phosducin have been reported to be phosphorylated by GRK2, but it is not known whether they serve as activators of GRK2 and why they are substrates of GRK2 unless they are activators.

References (36)

K. Haga et al.
FEBS Lett.
(1990)
K. Kameyama et al.
J. Biol. Chem.
(1993)
K. Haga et al.
J. Biol. Chem.
(1994)
A.N. Pronin et al.
J. Biol. Chem.
(1997)
J.A. Pitcher et al.
J. Biol. Chem.
(1998)
C.V. Carman et al.
J. Biol. Chem.
(1998)
A.N. Pronin et al.
J. Biol. Chem.
(2000)
A. Ruiz-Gomez et al.
J. Biol. Chem.
(2000)
K. Haga et al.
J. Biol. Chem.
(1992)
E.M. Parker et al.
J. Biol. Chem.
(1991)

K. Haga et al.

J. Biol. Chem.

(1983)

K. Haga et al.

J. Biol. Chem.

(1985)

K. Haga et al.

J. Biol. Chem.

(1986)

J.K. Northup et al.

J. Biol. Chem.

(1983)

H. Tsuga et al.

J. Biol. Chem.

(1994)

K. Haga et al.

J. Biol. Chem.

(1996)

W.J. Koch et al.

J. Biol. Chem.

(1993)

D. Fushman et al.

J. Biol. Chem.

(1998)

Cited by (5)

β-arrestin-dependent, G protein-independent ERK1/2 activation by the β2 adrenergic receptor
2006, Journal of Biological Chemistry
Citation Excerpt :
At least a decade of research demonstrates that agonist-induced β2AR phosphorylation is carried out by GRK2 and is facilitated by G protein βγ subunits under both in vitro and in vivo conditions. Moreover, membrane targeting of GRK2/3 requires their binding to the G protein βγ subunits (45-50). As seen in Fig. 10, GRK2 coexpression does not augment β2ARTYY phosphorylation, but the membrane targeted GRK2-CAAX does so.
Physiological effects of β adrenergic receptor (β2AR) stimulation have been classically shown to result from G_s-dependent adenylyl cyclase activation. Here we demonstrate a novel signaling mechanism wherein β-arrestins mediate β2AR signaling to extracellular-signal regulated kinases 1/2 (ERK 1/2) independent of G protein activation. Activation of ERK1/2 by the β2AR expressed in HEK-293 cells was resolved into two components dependent, respectively, on G_s-G_i/protein kinase A (PKA) or β-arrestins. G protein-dependent activity was rapid, peaking within 2-5 min, was quite transient, was blocked by pertussis toxin (G_i inhibitor) and H-89 (PKA inhibitor), and was insensitive to depletion of endogenous β-arrestins by siRNA. β-Arrestin-dependent activation was slower in onset (peak 5-10 min), less robust, but more sustained and showed little decrement over 30 min. It was insensitive to pertussis toxin and H-89 and sensitive to depletion of either β-arrestin1 or -2 by small interfering RNA. In G_s knock-out mouse embryonic fibroblasts, wild-type β2AR recruited β-arrestin2-green fluorescent protein and activated pertussis toxin-insensitive ERK1/2. Furthermore, a novel β2AR mutant (β2AR^{T68F,Y132G,Y219A} or β2AR^TYY), rationally designed based on Evolutionary Trace analysis, was incapable of G protein activation but could recruit β-arrestins, undergo β-arrestin-dependent internalization, and activate β-arrestin-dependent ERK. Interestingly, overexpression of GRK5 or -6 increased mutant receptor phosphorylation and β-arrestin recruitment, led to the formation of stable receptor-β-arrestin complexes on endosomes, and increased agonist-stimulated phospho-ERK1/2. In contrast, GRK2, membrane translocation of which requires Gβγ release upon G protein activation, was ineffective unless it was constitutively targeted to the plasma membrane by a prenylation signal (CAAX). These findings demonstrate that the β2AR can signal to ERK via a GRK5/6-β-arrestin-dependent pathway, which is independent of G protein coupling.
The structure of the third intracellular loop of the muscarinic acetylcholine receptor M<inf>2</inf> subtype
2006, FEBS Letters
We have examined whether the long third intracellular loop (i3) of the muscarinic acetylcholine receptor M₂ subtype has a rigid structure. Circular dichroism (CD) and nuclear magnetic resonance spectra of M₂i3 expressed in and purified from Escherichia coli indicated that M₂i3 consists mostly of random coil. In addition, the differential CD spectrum between the M₂ and M₂Δi3 receptors, the latter of which lacks most of i3 except N- and C-terminal ends, gave no indication of secondary structure. These results suggest that the central part of i3 of the M₂ receptor has a flexible structure.
Interaction of the muscarinic acetylcholine receptor M<inf>2</inf> subtype with G protein Gα<inf>i/o</inf> isotypes and Gβγ subunits as studied with the maltose-binding protein-M<inf>2</inf>-Gα<inf>i/o</inf> fusion proteins expressed in Escherichia coli
2014, Journal of Biochemistry
G protein-coupled receptor kinase (GRK)
2010, Folia Pharmacologica Japonica
Involvement of intramolecular interactions in the regulation of G protein-coupled receptor kinase 2
2003, Molecular Pharmacology

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Regulation of G protein-coupled receptor kinase 2

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FEBS Lett.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.