Association with the Plasma Membrane Is Sufficient for Potentiating Catalytic Activity of Regulators of G Protein Signaling (RGS) Proteins of the R7 Subfamily

J Biol Chem. 2016 Mar 25;291(13):7195-204. doi: 10.1074/jbc.M115.713446. Epub 2016 Jan 25.


Regulators of G protein Signaling (RGS) promote deactivation of heterotrimeric G proteins thus controlling the magnitude and kinetics of responses mediated by G protein-coupled receptors (GPCR). In the nervous system, RGS7 and RGS9-2 play essential role in vision, reward processing, and movement control. Both RGS7 and RGS9-2 belong to the R7 subfamily of RGS proteins that form macromolecular complexes with R7-binding protein (R7BP). R7BP targets RGS proteins to the plasma membrane and augments their GTPase-accelerating protein (GAP) activity, ultimately accelerating deactivation of G protein signaling. However, it remains unclear if R7BP serves exclusively as a membrane anchoring subunit or further modulates RGS proteins to increase their GAP activity. To directly answer this question, we utilized a rapidly reversible chemically induced protein dimerization system that enabled us to control RGS localization independent from R7BP in living cells. To monitor kinetics of Gα deactivation, we coupled this strategy with measuring changes in the GAP activity by bioluminescence resonance energy transfer-based assay in a cellular system containing μ-opioid receptor. This approach was used to correlate changes in RGS localization and activity in the presence or absence of R7BP. Strikingly, we observed that RGS activity is augmented by membrane recruitment, in an orientation independent manner with no additional contributions provided by R7BP. These findings argue that the association of R7 RGS proteins with the membrane environment provides a major direct contribution to modulation of their GAP activity.

Keywords: G protein; G protein-coupled receptor (GPCR); GTPase-activating protein (GAP); allosteric regulation; regulator of G protein signaling (RGS); signal transduction.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Biological Assay
  • Bioluminescence Resonance Energy Transfer Techniques
  • Cell Line, Tumor
  • Cell Membrane / metabolism*
  • Gene Expression Regulation
  • Genes, Reporter
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Mice
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Neurons / cytology
  • Neurons / metabolism
  • Protein Multimerization
  • RGS Proteins / genetics*
  • RGS Proteins / metabolism
  • Rats
  • Receptors, Opioid, mu / genetics
  • Receptors, Opioid, mu / metabolism
  • Signal Transduction
  • Tacrolimus Binding Proteins / genetics
  • Tacrolimus Binding Proteins / metabolism


  • Luminescent Proteins
  • Nerve Tissue Proteins
  • R7BP protein, mouse
  • RGS Proteins
  • Receptors, Opioid, mu
  • Rgs7 protein, mouse
  • red fluorescent protein
  • regulator of g-protein signaling 9
  • Tacrolimus Binding Proteins