As a result of the inability to resolve the heterogeneous mixture of G protein beta gamma subunits present in tissues, it has not been possible to compare different beta gamma 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 beta gamma 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 beta 2, gamma 2 and gamma 3 subunits. In addition, we show that the recombinant beta gamma subunits can be readily purified, and can functionally interact with the alpha subunits of the G proteins.
Production, processing and partial purification of functional G protein βγ subunits in baculovirus-infected insect cells