Figure 2.

Effects of GRK cotransfection on PTH receptor-mediated [³H]inositol phosphate production. COS-1 cells (100-mm dish) were transiently cotransfected with PTH receptor cDNA (6 μg) and 2 μg of either GRK2, GRK3, or GRK5. Forty-eight hours later, [³H]inositol phosphate production was measured in response to PTH (100 nM) for 60 min at 37°C. The PTH-induced (100 nM) inositol phosphate production in the absence of exogenous GRKs was set to 100%, which corresponds to a 4.0 ± 0.6-fold stimulation. Data are mean ± SE from four independent experiments with duplicate determinations.