SCF and G-CSF induce ser727 phosphorylation of STAT3 through activation of distinct serine/threonine kinases.

MO7e-G cells were factor starved for 18 hours and then either left untreated or treated with SCF (100 ng/mL), G-CSF (10 ng/mL), or both. Where indicated, cells were incubated for 1 hour prior to cytokine treatment with PD98059 (100 μmol/L), wortmannin (500 nmol/L), or H7 (50 μmol/L). Western blots were performed with the indicated antibodies. The same membrane was stripped and reprobed for each blot.