Fig. 5
C9orf140 negatively regulates Wnt/β-catenin signaling at the destruction complex level by compromising Wnt3A-induced β-catenin accumulation. a Positioning C9orf140 in the Wnt pathway by epistatic analysis. Wnt/β-catenin signaling was induced by transfection of 293T cells with Wnt3A, LRP6ΔN, Dvl2, or pt.β-catenin. TOP luciferase reporter and TK-Renilla reporter, together with C9orf140, Axin1, or empty vector, were co-transfected as indicated. Data were normalized to empty vector-transfected cells and are presented as the mean + SD. b TOPFlash luciferase assays were performed in HepG2 cells transfected with C9orf140, Axin1, or empty vector. Luciferase activities were measured after treatment with L-CM or Wnt3A-CM for 18 h. Data are normalized to empty vector-transfected cells and presented as the mean + SD. c Overexpression of C9orf140 decreases β-catenin accumulation. RKO cells were first transfected with empty vector or C9orf140, treated with Wnt3A-CM, and finally harvested at the indicated times. Cell lysates were subjected to western blot analysis for the indicated proteins (upper panel). The lower panel shows quantitative analysis of active β-catenin levels normalized to GAPDH
