Fig. 10. IEX-1 inhibits apoptosis independently of its ability to potentiate ERK activation. (A, B and E) CHO cells were transfected with the indicated plasmids encoding EGFP-tagged wild-type or mutant forms of IEX-1. After a 7 h treatment with STS in the presence or absence of 30 µM PD98059, cells were either lysed for western blotting analysis (A) or fixed for determination of cell death (B and E). Results of apoptosis are expressed as mean ± SE of four independent experiments. (C and D) CHO cells were transfected with HA-IEX-1 wild type or mutants, with (C) or without (D) HA-ERK1. HA immunoprecipitates were subjected to kinase assay and western blotting, as indicated.