Western analysis of STAT3 isoform expression and tyrosine phosphorylation kinetics throughout granulocytic differentiation.

(A-D) The changing distribution of STAT3α (▴), β (●), γ (▵), and δ (○) with time, expressed as a percentage of total STAT3, under the indicated culture conditions. (E-H) The corresponding changes in the distribution of tyrosine-phosphorylated STAT3α (▴), β (●), γ (▵), and δ (○) with time, expressed as percentages of total STAT3 pTyr 705. Percentages were calculated by quantifying protein levels of the immunoblots shown in Figure 4A (culture conditions 1-4) and 4B (culture conditions 1-4), respectively. Values on days 5 to 11 represent averages ± SD of 2 separate immunoblots from samples collected during the same experiment.