Fig. 6

ß-catenin S191D, a Phospho-Mimicking Mutant of ß-catenin, Overcomes GGTI-286-mediated Inhibition in Wnt/ß-catenin Signaling

(A) ß-catenin S191D, a pseudophosphorylated mutant of ß-catenin Ser191, reversed GGTI-286-mediated inhibition of β-catenin nuclear localization. CHO cells were transiently transfected with expression vectors for EGFP-fusion ß-catenin wild-type (WT) or S191D. The cells were treated with 30 µM GGTI-286 for 18 hr and stained with Hoechst33342 and phalloidin. Fluorescent images were observed under a confocal microscope. Scale bars represent 10µm.

(B) ß-catenin S191D reversed GGTI-286-mediated inhibition of ß-catenin/TCF-dependent transcriptional activation. CHO cells were transiently transfected with expression vectors for β-catenin WT or S191D and the reporter plasmids. The cells were treated with 2µm BIO for 18 hr. Luciferase activities were measured. Normalized relative luciferase activities are shown as fold activation to the absence of BIO. Values are ± SEM (n = at least 3).