Figure 3.

The FZD₄ C-tail distal to the KTXXXW domain requires three additional amino acid residues for substantial activation of Lef/Tcf-dependent transcriptional activation by Norrin. V5mFZD₄ variants were overexpressed in HEK293 cells with hLRP5 and M50 reporter plasmid, stimulated with Norrin. Lef/Tcf-dependent transcriptional activation was measured using a luciferase-based assay, as described in the Materials and Methods section. An experiment comparing the Norrin-induced mFZD₄ WT activation to the Norrin-induced activation of the mFZD₄/C-tailmFZD₁, mFZD₄/C-tailmFZD₃, mFZD₄/C-tailmFZD₇ and mFZD₄ KC506-507AA constructs. Statistically significant differences compared to WT as determined by an ANOVA analysis followed by the Dunnett’s post hoc test are indicated with an asterisk (*).