Figure 3.

Topflash reporter assay and Western blotting. (a, b) Failure of NDP and FZD4 mutants in the activation of Norrin/β-catenin signaling (72.5% reduction for NDP p.H43N, 70% reduction for NDP p.44del, 71.2% reduction for NDP p.R107Pfs, 70.5% reduction for NDP p.L108Cfs, 73% reduction for NDP p.C126F, and 65% reduction for FZD4 p.M105R). The experiment was carried out in triplicate at the same time and repeated three times. (c, d) Western blotting showed the expression level of β-catenin was decreased, similar to the Topflash reporter assay. Asterisks indicated significant differences from the positive control by pairwise Student's test (P < 0.05).