WGA binds and immobilizes Sstr3-GFP in cilia. (A) FRAP analysis of Sstr3-GFP mobility in untreated cells and cells treated with 75 µg/ml WGA. The relative (Rel.) Sstr3-GFP intensity is displayed in pseudocolored images before and after bleaching the distal half of the cilium. (B) Averaged fluorescence recovery traces for the bleached half of the cilium are plotted for untreated cells and cells treated with 75 µg/ml WGA. Error bars indicate standard deviations (n ≥ 20). AU, arbitrary unit. (C) The effect of WGA on MBP-GBP progression within cilia was compared for cells expressing GFP fused to Sstr3 (bottom) or the lipidated cytoplasmic tail of Pkhd1 (Pkhd1^ICD; top). GFP and MBP-GBP channels are offset for clarity. Bars, 1 µm.