Navigating the conformational landscape of G protein-coupled receptor kinases during allosteric activation

J Biol Chem. 2017 Sep 29;292(39):16032-16043. doi: 10.1074/jbc.M117.807461. Epub 2017 Aug 14.


G protein-coupled receptors (GPCRs) are essential for transferring extracellular signals into carefully choreographed intracellular responses controlling diverse aspects of cell physiology. The duration of GPCR-mediated signaling is primarily regulated via GPCR kinase (GRK)-mediated phosphorylation of activated receptors. Although many GRK structures have been reported, the mechanisms underlying GRK activation are not well-understood, in part because it is unknown how these structures map to the conformational landscape available to this enzyme family. Unlike most other AGC kinases, GRKs rely on their interaction with GPCRs for activation and not phosphorylation. Here, we used principal component analysis of available GRK and protein kinase A crystal structures to identify their dominant domain motions and to provide a framework that helps evaluate how close each GRK structure is to being a catalytically competent state. Our results indicated that disruption of an interface formed between the large lobe of the kinase domain and the regulator of G protein signaling homology domain (RHD) is highly correlated with establishment of the active conformation. By introducing point mutations in the GRK5 RHD-kinase domain interface, we show with both in silico and in vitro experiments that perturbation of this interface leads to higher phosphorylation activity. Navigation of the conformational landscape defined by this bioinformatics-based study is likely common to all GPCR-activated GRKs.

Keywords: G protein-coupled receptor (GPCR); Michaelis-Menten; allosteric regulation; molecular dynamics; serine/threonine protein kinase; structure-function.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural

MeSH terms

  • Allosteric Regulation
  • Amino Acid Substitution
  • Animals
  • Cell Line
  • Computational Biology
  • Crystallography, X-Ray
  • Databases, Protein
  • Energy Transfer
  • Enzyme Activation
  • Expert Systems
  • G-Protein-Coupled Receptor Kinase 5 / chemistry
  • G-Protein-Coupled Receptor Kinase 5 / genetics
  • G-Protein-Coupled Receptor Kinase 5 / metabolism*
  • Humans
  • Insecta
  • Kinetics
  • Models, Molecular*
  • Molecular Dynamics Simulation
  • Phosphorylation
  • Point Mutation
  • Principal Component Analysis
  • Protein Interaction Domains and Motifs
  • Protein Processing, Post-Translational*
  • Protein Refolding
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism


  • Recombinant Fusion Proteins
  • G-Protein-Coupled Receptor Kinase 5
  • GRK5 protein, human

Associated data

  • PDB/1L3R
  • PDB/3NYN
  • PDB/4TNB
  • PDB/4TND
  • PDB/1OMW