Fig. 1.

Screening of STAT3-targeting phosphatases. HEK 293 cells were co-transfected with FLAG-PTPs and HA-STAT3. (A) The interactions between PTPs and STAT3 were assayed by co-immunoprecipitation with anti-FLAG conjugated beads, and STAT3 that interacted with immunoprecipitated FLAG-PTPs was subjected to immunoblotting analysis using an anti-HA specific antibody. (B) After transfection, cells were starved with serum-free medium for 12 h and stimulated with IL-6 (10 ng/mL) for 30 min. Phosphorylation and expression levels of STAT3 and FLAG-PTPs were analyzed by immunoblotting performed using specific antibodies.