Quaternary structure predictions and structural communication features of GPCR dimers

In spite of the ever increasing evidence that G protein coupled receptors (GPCR) form dimers/oligomers, the biological role(s) and structural architecture of homologous and heterologous receptor aggregation is/are, however, far from being clarified. This chapter reviews the insights gained so far, at multiscale levels of resolution, on GPCR dimerization/oligomerization from in vitro experiments, structure predictions, and structure determinations. Focus is put on the achievement by the FiPD-based approach, which proved effective in predicting the supramolecular organization of membrane proteins including GPCRs. The combination of FiPD-based quaternary structure predictions with molecular simulations and analyses can be a valuable tool to infer the effects of dimerization on the structural communication features of a receptor dimer/oligomer bound to functionally different ligands. Ultimately, the integration between atomistic and mesoscopic simulations is expected to be a promising tool to unveil functioning mechanisms that involve intricate protein networks.