The role of dimerisation in the cellular trafficking of G-protein-coupled receptors

The concept that G-protein-coupled receptors can exist as homomeric and/or heteromeric complexes is now well established. Despite this, how dynamic such interactions are and if this may be modulated during receptor trafficking remain topics of debate. Use of endoplasmic reticulum trapping strategies and the generation of asymmetric homomers have started to provide information on the contribution of protein–protein interactions to receptor maturation, cell surface delivery and ligand-mediated endocytosis. Although dimer/oligomer formation appears to be essential for cell surface delivery of class A and class C GPCRs, this may not be the case for class B receptors.