Induction of C/EBPε by mutant G-CSF receptor.

(A,B) FDCP1 cells expressing various truncation mutants of G-CSF receptor described in panel A were analyzed for expression of C/EBPε (B). Cells growing in IL-3 were washed twice with PBS and transferred to medium containing 50 ng/mL G-CSF. Cells were harvested at the times indicated and subjected to Northern blot analysis. (C) Relative mRNA induction of C/EBPε. Northern blotting film shown in panel B in the linear exposure was subjected to densitometric analysis. The graph is plotted as the signal ratio of C/EBPε compared with GAPDH. WT indicates wild-type G-CSF receptor; detailed constructions of A, E, and T mutants are described in Fukunaga et al.23