Measurement of Wnt modulated change in GSK3β activity. (A) HEK293 cells stably expressing the BGCR-WT and S37A mutant reporters were treated with the Wnt-conditioned media for 0.5 h, 1 h, 2 h, and 3 h and BLI activity was measured. The change in BLI activity over control levels was determined and plotted as fold induction. Error bars denote SEM. (B) HEK293 cells stably expressing the BGCR WT reporter were treated with the Wnt-conditioned media for 0.5 h, 1 h, 2 h, and 3 h and western blot analysis was carried out using antibodies to phospho-(S33-S37-T41)-β-catenin, total β-catenin, phospho-(S9)-GSK3β, total GSK3β, luciferase, CK1α and GAPDH.