Figure 3. The ‘PPXY’ motifs regulate the opposing movements of Ptch1 out of and Smo into the primary cilium.
(A) Representative confocal images and (B) distribution of GFP fluorescence showing accumulation of the ‘PPXY’ motif mutants of Ptch1 in primary cilia in the absence or presence of ShhN. Two-tail Student's t test was used for statistical analysis. ***p<0.001, n.s., not significant (p>0.05). (C) Immunofluorescence of GFP as well as endogenous Smo (red) and acetylated tubulin (blue) staining in Ptch1−/− MEFs transfected with Ptch1-GFP or Δ2PY. (D) Quantification of anti-Smo staining and (E) GFP fluorescence as in (C). Only transfected GFP positive cells were counted for the ciliary localization of endogenous Smo. In all of the above experiments, transfected cells were grown to confluence and then serum-starved for 24 hr to allow for ciliogenesis. ShhN-CM treatment was for 24 hr, or as indicated.
Figure 3—figure supplement 1. Inhibition of Lysosomal turnover dampens Shh-induced ciliary exit of Ptch1-GFP.
