FIGURE 7.

Constitutive activation of Gsk3β bypasses Fap1. A, expression of Y216D-Gsk3β in U937 cells decreases activity of a βcatenin-binding reporter construct more efficiently than WT Gsk3β. U937 cells were cotransfected with the βcatenin-activated TopFlash reporter vector or FopFlash control vector and a dose titration of vectors to overexpress WT or Y216D-Gsk3β (or control vector). Statistically significant differences in reporter expression are indicated by *, **, ***, #, ##, or ###. B, Y216D-Gsk3β blocks Bcr-abl-induced activation of a βcatenin-binding reporter construct in U937 transfectants in a manner that is not influenced by SLV peptide. U937 cells were cotransfected with the TopFlash or control FopFlash reporter vector, a vector to express Bcr-abl (or control vector), and a vector to express WT or Y216D-Gsk3β (or vector control). Transfectants were treated with Fap1-blocking SLV peptide or control VLS peptide, and reporter gene activity was determined. Statistically significant differences are indicated by *, **, ***, or #. NS, not significant.