Figure 5.
EcPltAB disrupts G-protein-coupled signaling. RXFP4 recruits Gi/o α subunits upon ligand activation. PT pretreatment abolishes INSL5-stimulated ERK1/2 phosphorylation, and this is rescued to differing degrees by transfection of individual PT-insensitive Gi/o mutants. a, Chinese hamster ovary-RXFP4 cells were transiently transfected with pcDNA3 vector control, or b–f, Gi/o constructs carrying the C351I mutation (mGαoA, mGαoB, mGαi1, mGαi2, or mGαi3). Blockade of the response to PT but not EcPltAB pretreatment was rescued by transfection of the mutant G-proteins. Cells were stimulated with mouse INSL5 alone (0.1 to 100 nm) or after pretreatment with PT (100 ng/ml) or EcPltAB (100 ng/ml). Data points represent mean ± S.E. of three independent experiments and are expressed as the % response of the positive control (10% v/v FBS). Veh, vehicle.