The GTPgammaS exchange assay is a functional model corresponding to the first step of G protein-coupled receptor activation. We provide simple methodologies and controls for setting up GTPgammaS exchange assays in both cell membranes and permeabilized peripheral blood lymphocytes. Specifically, we use guanosine 5'-[35S]triphospate ([35S]GTPgammaS) exchange, in concert with radioligand binding assays, to assess the expression and function of two chemokine receptors important in the trafficking of T lymphocytes: CXCR3 and CCR7. The studies presented here illustrate the utility of GTPgammaS exchange assays in the study of chemokine receptor pharmacology.
Copyright 2002 Elsevier Science B.V.