We have synthesised the β1-subunit of the bovine GABAA receptor in stable, continuous insect (Spodoptera frugiperda) cell lines. A cDNA was integrated randomly into the insect cell genome under control of a baculovirus immediate early (IE-1) gene promoter. Transformed cells were obtained by co-transfection of the insect cells with pIEK 1 .GRβ1, encoding the β1 subunit cDNA, and pIEK1 .neo, encoding the neomycin resistance gene. G-418-resistant clones were selected and expanded into continuous cell lines synthesising functional, GABA-gated, homo-oligomeric chloride channels. These cell lines had significant advantages over the transient baculovirus expression system for the characterisation of receptors using electrophysiological recording techniques.
