Characterization of GRK2 RH domain-dependent regulation of GPCR coupling to heterotrimeric G proteins

Methods Enzymol. 2004:390:310-36. doi: 10.1016/S0076-6879(04)90020-1.


Heterotrimeric guanine nucleotide (G)-coupled receptors (GPCRs) form the largest family of integral membrane proteins. GPCR activation by an agonist promotes the exchange of GDP for GTP on the Galpha subunit of the heterotrimeric G protein. The dissociated Galpha and Gbetagamma subunits subsequently modulate the activity of a diverse assortment of effector systems. GPCR signaling via heterotrimeric G proteins is attenuated rapidly by the engagement of protein kinases. The canonical model for GPCR desensitization involves G protein-coupled receptor kinase (GRK)-dependent receptor phosphorylation to promote the binding of arrestin proteins that function to sterically block receptor:G-protein interactions. GRK2 and GRK3 have been shown to interact with Galphaq via the regulator of G-protein signaling (RGS) homology (RH) domain localized within their amino-terminal domains. It now appears that the G-protein uncoupling of many GPCRs linked to Galphaq, in particularly metabotropic glutamate receptors, may be mediated by the GRK2 RH domain via a phosphorylation-independent mechanism. This article reviews much of the background and methodology required for the characterization of the GRK2 phosphorylation-independent attenuation of GPCR signaling.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biological Assay / methods
  • Brain Chemistry
  • Cattle
  • Cyclic AMP-Dependent Protein Kinases / chemistry
  • Cyclic AMP-Dependent Protein Kinases / genetics
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism
  • Heterotrimeric GTP-Binding Proteins / metabolism*
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Binding
  • Protein Conformation
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Protein Structure, Tertiary
  • Receptors, G-Protein-Coupled / metabolism*
  • Receptors, Metabotropic Glutamate / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology


  • Receptors, G-Protein-Coupled
  • Receptors, Metabotropic Glutamate
  • Recombinant Fusion Proteins
  • Protein Serine-Threonine Kinases
  • Cyclic AMP-Dependent Protein Kinases
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Heterotrimeric GTP-Binding Proteins