Figure 4.

WNT-3A activates the WNT/β-catenin pathway in Gα-depleted HEK293 cells. Parental HEK293 or Gα-depleted HEK293 cells were stimulated with purified, recombinant WNT-3A (300 ng/ml, 2 h). Autocrine WNT signaling was reduced by porcupine inhibition with C59 (10 nm, overnight). Pathway activation was visualized by detection of LRP6 phosphorylation (P-LRP6 over total LRP6), phosphorylated and shifted DVL2 (unshifted (filled triangle) and shifted (open triangle)), active β-catenin, and total β-catenin stabilization. GAPDH served as a visual loading control. A, a representative immunoblotting experiment from three independent experiments. B–E, immunoblotting experiments were quantified by densitometry and normalized to a control sample (see “Experimental procedures”), and data were summarized in bar graphs. Error bars, S.D. Results were analyzed with unpaired Student's t test. All WNT-3A–induced increases are statistically significant compared with unstimulated conditions (p < 0.05).