FIGURE 7.

Agonist-induced activation of GHS-R1a in monomers and dimers. Shown is a schematic representation of the proposed mechanism for ghrelin receptor activation in the different assemblies (monomer, homodimer, and heterodimer) considered in this work and its consequence of Gq activation and arrestin (arr.) recruitment. The different shapes represent different conformations of the ghrelin receptor. The assumption that GHS-R1b in the heterodimer does not bind its ligand is made on the basis that the monomeric truncated receptor is totally ligand-incompetent.