Bring your own G protein

G protein-coupled receptor (GPCR)-G alpha fusion proteins were first characterized more than 10 years ago as a strategy for studying receptor-G protein signaling. A large number of studies have used this approach to characterize receptor coupling to members of the G(s), G(i), and G(q) families of G alpha subunits, but this strategy has not been widely used to study G alpha(12) and G alpha(13). As described in the article by Zhang et al. in this issue of Molecular Pharmacology (p. 1433) characterization of the signaling properties of thromboxane A(2) receptor (TP alpha)-G alpha(12) and -G alpha(13) fusion constructs demonstrates the applicability of this strategy to members of this unique family of G alpha subunits, and how this strategy can be used to resolve otherwise difficult problems of receptor pharmacology associated with these proteins. The general strategy of making receptor-G alpha fusion constructs has wide applicability to a number of research problems, but there are perhaps also hidden messages in how different receptor-G alpha subunit fusion pairs behave.