Production, processing and partial purification of functional G protein βγ subunits in baculovirus-infected insect cells

Abstract

As a result of the inability to resolve the heterogeneous mixture of G protein βγ subunits present in tissues, it has not been possible to compare different βγ subunits of the G proteins in terms of their proposed roles in receptor-effector coupling. This study was undertaken to establish the utility of the baculovirus expression system in producing homogeneous βγ subunits of defined composition for the comparative analysis of these subunits in reconstitution systems. In this study we report the expression, and appropriate post-translational processing, of recombinant β2, γ2 and γ3 subunits. In addition, we show that the recombinant βγ subunits can be readily purified, and can functionally interact with the α subunits of the G proteins.