Fine-tuning of GPCR signals by intracellular G protein modulators

Peishen Zhao, Wendy Cladman, Hubert H M Van Tol, Peter Chidiac

Research output: Chapter in Book/Report/Conference proceedingChapter (Book)Researchpeer-review

11 Citations (Scopus)


Heterotrimeric G proteins convey receptor signals to intracellular effectors. Superimposed over the basic GPCR-G protein-effector scheme are three types of auxiliary proteins that also modulate Gα. Regulator of G protein signaling proteins and G protein signaling modifier proteins respectively promote GTPase activity and hinder GTP/GDP exchange to limit Gα activation. There are also diverse proteins that, like GPCRs, can promote nucleotide exchange and thus activation. Here we review the impact of these auxiliary proteins on GPCR signaling. Although their precise physiological functions are not yet clear, all of them can produce significant effects in experimental systems. These signaling changes are generally consistent with established effects on isolated Gα; however, the activation state of Gα is seldom verified and many such changes appear also to reflect the physical disruption of or indirect effects on interactions between Gα and its associated GPCR, Gβγ, and/or effector.

Original languageEnglish
Title of host publicationOligomerization and Allosteric Modulation in G-Protein Coupled Receptors
EditorsTerry Kenakin
Place of PublicationOxford UK
Number of pages33
ISBN (Print)9780123945877
Publication statusPublished - 2013

Publication series

NameProgress in Molecular Biology and Translational Science
ISSN (Print)18771173


  • G protein activation
  • GPCR signaling
  • GPSM protein
  • Keywords
  • Nonreceptor GEF
  • Protein-protein interaction
  • RGS protein

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