Figure 1
From: Dominant-negative activity of the STAT3-Y705F mutant depends on the N-terminal domain
Dominant-negative activity of STAT3-YF-YFP analyzed by real-time PCR and confocal microscopy. (A) Real-time PCR analysis to examine the influence of STAT3-YF-YFP on the STAT3-induced SOCS3 mRNA expression after IL-6 stimulation. Inducible HEK cells stably transfected with STAT3-YF-YFP were incubated with 20 ng/ml doxycycline for 5 h and stimulated with 20 ng/ml IL-6 and 1 μg/ml sIL-6Rα for 60 minutes or left unstimulated. Non-induced HEK cells (without doxycycline) were treated the same way. RNA was isolated and SOCS3 mRNA expression analyzed by qRT-PCR. The diagram represents the mean of three independent measurements with standard deviations. (B) Nuclear translocation of STAT3-CFP in the presence of STAT3-YF-YFP in living cells after IL-6 stimulation. HEKgp80 cells were cotransfected with STAT3-YF-YFP and STAT3-CFP. Living cells were analyzed at 37°C by confocal microscopy. Pictures were taken from unstimulated cells and after stimulation with 20 ng/ml IL-6 for 60 minutes. The arrow marks the nuclear translocation of STAT3-CFP in a stimulated cell in the absence of STAT3-YF-YFP. Scale bars represent 10 μm.