Phosphorylation-independent attenuation of GPCR signalling

Trends Pharmacol Sci. 2007 Apr;28(4):173-9. doi: 10.1016/ Epub 2007 Mar 9.


The uncoupling of G-protein-coupled receptors (GPCRs) from their cognate heterotrimeric G proteins provides an essential physiological 'feedback' mechanism that protects against both acute and chronic overstimulation of receptors. The primary mechanism by which GPCR activity is regulated is the feedback phosphorylation of activated GPCRs by kinases that are dependent on second messengers, GPCR kinases (GRKs) and arrestins. It has recently become apparent, however, that GRK2-mediated regulation of GPCR responsiveness also involves a phosphorylation-independent component that requires both heterotrimeric G-protein alpha-subunit interactions and GPCR binding. Moreover, in addition to GRK2, a growing number of GPCR-interacting proteins might contribute to the phosphorylation-independent G-protein uncoupling of GPCRs. Here, new information about the mechanisms underlying this phosphorylation-independent regulation of receptor and G-protein coupling is reviewed.

Publication types

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

MeSH terms

  • Animals
  • GTP-Binding Proteins / metabolism
  • Humans
  • Phosphorylation
  • Protein Serine-Threonine Kinases / metabolism
  • Receptors, G-Protein-Coupled / metabolism*
  • Signal Transduction


  • Receptors, G-Protein-Coupled
  • Protein Serine-Threonine Kinases
  • GTP-Binding Proteins