Francesca Fanelli, Mario Mauri, Valerie Capra, Francesco Raimondi,
Francesca Guzzi, Manuela Ambrosio, G. Enrico Rovati and Marco Parenti
Abstract The structure-based design of a mutant form of the thromboxane A2 prostanoid receptor (TP) was instru- mental in characterizing the structural determinants of the hetero-dimerization process of this G protein coupled receptor (GPCR). The results suggest that the hetero- dimeric complexes between the TPa and b isoforms are characterized by contacts between hydrophobic residues in helix 1 from both monomers. Functional characterization confirms that TPa-TPb hetero-dimerization serves to reg- ulate TPa function through agonist-induced internalization, with important implications in cardiovascular homeostasis. The integrated approach employed in this study can be adopted to gain structural and functional insights into the dimerization/oligomerization process of all GPCRs for which the structural model of the monomer can be achieved at reasonable atomic resolution.