Translating G protein subunit diversity into functional specificity

Curr Opin Cell Biol. 2004 Apr;16(2):206-9. doi: 10.1016/


Historically, it has been assumed that the functional roles of G proteins in receptor recognition and effector regulation are specified by their diverse alpha subunits. However, the discovery of similarly diverse betagamma subunits that participate in both of these functional processes has called this assumption into question; recent work suggests that G proteins function as heterotrimers whose roles in particular receptor signaling pathways are determined by their specific alphabetagamma subunit combinations. Although much remains to be learned, the assembly of specific alphabetagamma subunit combinations seems to involve both structural and spatial factors.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Cell Compartmentation / physiology
  • GTP-Binding Protein alpha Subunits / genetics
  • GTP-Binding Protein alpha Subunits / metabolism
  • GTP-Binding Protein beta Subunits / genetics
  • GTP-Binding Protein beta Subunits / metabolism
  • GTP-Binding Protein gamma Subunits / genetics
  • GTP-Binding Protein gamma Subunits / metabolism
  • Heterotrimeric GTP-Binding Proteins / genetics
  • Heterotrimeric GTP-Binding Proteins / metabolism*
  • Humans
  • Intracellular Membranes / metabolism
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Signal Transduction / genetics*


  • GTP-Binding Protein alpha Subunits
  • GTP-Binding Protein beta Subunits
  • GTP-Binding Protein gamma Subunits
  • Protein Subunits
  • Heterotrimeric GTP-Binding Proteins