How do receptors activate G proteins?

Adv Protein Chem. 2007;74:67-93. doi: 10.1016/S0065-3233(07)74002-0.


Heterotrimeric G proteins couple the activation of heptahelical receptors at the cell surface to the intracellular signaling cascades that mediate the physiological responses to extracellular stimuli. G proteins are molecular switches that are activated by receptor-catalyzed GTP for GDP exchange on the G protein alpha subunit, which is the rate-limiting step in the activation of all downstream signaling. Despite the important biological role of the receptor-G protein interaction, relatively little is known about the structure of the complex and how it leads to nucleotide exchange. This chapter will describe what is known about receptor and G protein structure and outline a strategy for assembling the current data into improved models for the receptor-G protein complex that will hopefully answer the question as to how receptors flip the G protein switch.

Publication types

  • Review

MeSH terms

  • Heterotrimeric GTP-Binding Proteins / chemistry
  • Heterotrimeric GTP-Binding Proteins / metabolism*
  • Protein Binding
  • Protein Conformation
  • Receptors, G-Protein-Coupled / chemistry
  • Receptors, G-Protein-Coupled / metabolism*


  • Receptors, G-Protein-Coupled
  • Heterotrimeric GTP-Binding Proteins