Expression of the α1b-Adrenergic Receptor and G Protein Subunits in Mammalian Cell Lines Using the Semliki Forest Virus Expression System

Abstract

Semliki Forest virus (SFV) vectors have been efficiently used for rapid high level expression of several G protein-coupled receptors. Here we describe the use of SFV vectors to express the α_1b-adrenergic receptor (AR) alone or in the presence of the G protein α_q and/or β₂ and γ₂ subunits. Infection of baby hamster kidney (BHK) cells with recombinant SFV-α_1b-AR particles resulted in high specific binding activity of the α_1b-AR (24 pmol receptor/mg protein). Time-course studies indicated that the highest level of receptor expression was obtained 30 hours postinfection. The stimulation of BHK cells, with epinephrine led to a 5-fold increase in inositol phosphate (IP) accumulation, confirming the functional coupling of the receptor to G protein-mediated activation of phospholipase C. The SFV expression system represents a rapid and reproducible system to study the pharmacological properties and interactions of G protein coupled receptors and of G protein subunits.