Fig. 4.
ERK expression and activation in GM-CSF–treated TF-1 cells.
TF-1 cells were serum- and factor-starved for 24 hours, and placed in RPMI with BSA 0.5%. Cells were stimulated with rhGM-CSF (1 nmol/L) for 1, 2, 5, 10, and 20 minutes. TPA-stimulated cells represent the positive control and diluent-stimulated, the negative control (15-minute stimulation). The lysate from 2 × 105cells was separated on a 10% SDS-PAGE gel. Antiphosphorylated ERK antibody ([A], 1:20 000) or anti-ERK antibody ([B], 1:5000) was used to probe each blot. The blots represent samples taken from the same experiment loaded on 2 separate gels.