Deciphering activation of olfactory receptors using heterologous expression in saccharomyces cerevisiae and bioluminescence resonance energy transfer

Abstract

Hetero- and homo-oligomerization of G protein-coupled receptors (GPCRs) has been addressed in the past years using various approaches such as co-immunoprecipitation, fl uorescence resonance energy transfer and bioluminescence resonance energy transfer(BRET). Here, we report the methodological detailsfrom a previously published study to investigate the relationships betweenoligomerization and activation states of olfactory receptors (ORs). This methodology combines heterologous expression of ORs in Saccharomyces cerevisiae and BRET assays on membrane fractions, in particular, upon odorant stimulation. We have demonstrated that ORsconstitutively homodimerize at the plasma membrane and that high odorant concentrations promote a conformational change of the dimer, which becomes inactive. We proposed a model in which one odorant molecule binding the dimer would induce activation, while two odorant molecules, each binding one protomer of the dimer, would blunt signaling. © Springer Science+Business Media, LLC 2013.