Fig. 3.

MK-STYX does not modulate MAPK signaling in response to growth factors or apoptotic stress. (A) HeLa cells were transfected with the indicated siRNAs for 48 h, serum deprived for 6 h, and treated with EGF (100 ng/ml) for the indicated times. Cell extracts were then subjected to immunoblotting with phospho-ERK1/2 and total ERK antibodies. (B) Proliferation rates of control and MK-STYX knockdown cells are similar under basal conditions (10% serum) via a real-time viability assay (xCelligence) and by BrdU incorporation (immunofluorescence). The error bars indicate standard deviations. (C) Similar experiments were performed, but after 6 h, the cells were serum deprived, followed by addition of 10% FBS to the growth medium. (D and E) HeLa cells transfected with the indicated siRNAs were exposed to 100 nM paclitaxel, 50 μM cisplatin, or 80 J/m² of UV for 4 h. The cells were then lysed and immunoblotted with phospho-p38, total p38, phospho-JNK, and total JNK antibodies.