Detection of heteromerization of more than two proteins by sequential BRET-FRET

Nat Methods. 2008 Aug;5(8):727-33. doi: 10.1038/nmeth.1229. Epub 2008 Jun 29.


Identification of higher-order oligomers in the plasma membrane is essential to decode the properties of molecular networks controlling intercellular communication. We combined bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET) in a technique called sequential BRET-FRET (SRET) that permits identification of heteromers formed by three different proteins. In SRET, the oxidation of a Renilla luciferase (Rluc) substrate by an Rluc fusion protein triggers acceptor excitation of a second fusion protein by BRET and subsequent FRET to a third fusion protein. We describe two variations of SRET that use different Rluc substrates with appropriately paired acceptor fluorescent proteins. Using SRET, we identified complexes of cannabinoid CB(1), dopamine D(2) and adenosine A(2A) receptors in living cells. SRET is an invaluable technique to identify heteromeric complexes of more than two neurotransmitter receptors, which will allow us to better understand how signals are integrated at the molecular level.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cell Survival
  • Fluorescence Resonance Energy Transfer / methods*
  • Humans
  • Luminescent Proteins / analysis*
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism*
  • Multiprotein Complexes / analysis*
  • Multiprotein Complexes / chemistry*
  • Protein Binding
  • Protein Structure, Quaternary
  • Receptors, Cell Surface / analysis
  • Receptors, Cell Surface / chemistry


  • Luminescent Proteins
  • Multiprotein Complexes
  • Receptors, Cell Surface