FIG. 2.
In vitro exchange activity of GRF2 and mutants. Assays were carried out 2 days after transfection of 293T cells with the indicated GRF2 construct. GRF2 was immunoprecipitated and used in an in vitro Ras exchange assay as described in Materials and Methods. Each bar shows the mean exchange activity and standard error of at least three experiments (duplicate readings in each experiment).