Semliki forest virus-based expression of recombinant GPCRs.

Due to their importance as targets for drug development, rapid and consistent high-level production of G protein-coupled receptors (GPCRs) has become an essential part of drug discovery. Alphaviruses, particularly recombinant Semliki Forest virus (SFV) particles, have provided the means for expression of a number of GPCRs in a broad range of mammalian host cell lines for pharmacological characterization by determination of receptor binding activity and functional coupling to G proteins. The rapid high-titer virus particle production has made it possible to study a large number of GPCRs in parallel. Moreover, large-scale production in adherent and suspension cultures of mammalian cells has provided sufficient amounts of GPCRs for purification and subsequent structural studies. Furthermore, the high preference for neuronal delivery of SFV particles has allowed functional and localization studies of recombinant proteins in hippocampal slice cultures, in primary neurons, and in vivo.