GPCR oligomer

A GPCR oligomer is a protein complex that consists of a small number (ὀλίγοι oligoi "a few", μέρος méros "part, piece, component") of G protein-coupled receptors (GPCRs).

[2][3] For a long time it was assumed that receptors transmitted their effects exclusively from their basic functional forms – as monomers.

The first clue to the existence of GPCR oligomers goes back to 1975 when Robert Lefkowitz observed that β-adrenoceptors display negative binding cooperativity.

[11] The first direct evidence that GPCRs functioned as oligomers in vivo came from Overton and Blumer in 2000 by fluorescence resonance energy transfer (FRET) analysis of the α-factor receptor in the yeast Saccharomyces cerevisiae.

[12] In 2005, further evidence was provided that receptor oligomerization plays a functional role in a living organism with regulatory implication.

Crystallographic structure of the human κ-opioid receptor homo dimer ( 4djh ) imbedded in a cartoon representation of a lipid bilayer . Each protomer is individually rainbow colored ( N-terminus = blue, C-terminus = red). The receptor is complexed with the ligand JDTic that is depicted as a space-filling model (carbon = white, oxygen = red, nitrogen = blue). [ 1 ]