Signaling at zero G: G-protein-independent functions for 7-TM receptors

Trends Biochem Sci. 2001 May;26(5):291-7. doi: 10.1016/s0968-0004(01)01804-7.


Eukaryotic cells, whether free-living, single-celled microbes or components of complex metazoa, can sense environmental cues through specialized seven-transmembrane (7-TM) receptors (also called heptahelical or G-protein-coupled receptors). 7-TM receptors detect "inputs" such as light, peptide hormones, neurotransmitters, pheromones, odorants, morphogens and chemoattractants, linking extracellular stimuli to intracellular signaling networks via heterotrimeric G proteins. Recently, this obligatory paradigm has been challenged. A growing body of evidence indicates that 7-TM receptors can also transmit extracellular signals through mechanisms that function independently of G-protein coupling. This review discusses pathways and protein interactions for 7-TM receptors signaling "at zero G" in Dictyostelium and mammalian cells.

Publication types

  • Review

MeSH terms

  • Animals
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Cyclic AMP / metabolism
  • Dictyostelium / metabolism
  • Enzyme Activation
  • Eukaryotic Cells / metabolism
  • GTP-Binding Proteins / metabolism*
  • Membrane Proteins / metabolism*
  • Models, Biological
  • Phosphorylation
  • Protein Structure, Tertiary
  • Signal Transduction*


  • Membrane Proteins
  • Cyclic AMP
  • GTP-Binding Proteins