Oligomers of D2 dopamine receptors: evidence from ligand binding.
There is increasing evidence that G protein-coupled receptors form oligomers and that this might be important for their function. We have studied this phenomenon for the D2 dopamine receptor and have shown using a variety of biochemical and biophysical techniques that this receptor forms dimers or higher-order oligomers. Using ligand-binding studies, we have also found evidence that this oligomer formation has functional relevance. Thus, for the receptor expressed in either CHO cells or Sf 9 insect cells, the binding properties of several radioligands (in saturation, competition, and dissociation assays) do not conform to those expected for a monomeric receptor with a single binding site. We propose that the receptors exist in oligomers with homotropic and heterotropic negatively cooperative interactions between ligands.
Strange
Philip G
PG
School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, UK. p.g.strange@rdg.ac.uk
D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D019281:Dimerization; D008024:Ligands; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism; D011869:Radioligand Assay; D017448:Receptors, Dopamine D2 / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D018411:Spodoptera
D008024:Ligands; D046911:Macromolecular Substances; D017448:Receptors, Dopamine D2; D011994:Recombinant Proteins