Modulation of Gαs and protein kinase A (PKA) causes Smo accumulation in a proximal region of the primary cilium.

<p>(A) Treatment of wild-type MEFs with cholera toxin (CTX) for 24 hours induces Smo (green) translocation to the cilium (red). (B) Quantification of CTX- and FSK-induced Smo ciliary translocation after treatment for the indicated times. Treatment of wild-type MEFs with pertussis toxin (PTX) does not stimulate ciliary translocation of Smo. Error bars indicate +/− SD. (C) Wild-type MEFs were fixed in methanol and stained with antibodies against γ-tubulin (red; label the basal body) and Smo (green). In contrast to the relatively uniform Smo staining on the cilium induced by ShhN, CTX treatment causes Smo accumulation proximal to the basal body. (D) <i>8xGliBS-luciferase</i> Hh reporter activity in wild-type MEFs with the indicated treatment. CTX and FSK do not activate the Hh pathway despite inducing ciliary localization of Smo. Data are representative of three independent experiments. Hh reporter activity was normalized to <i>β-galactosidase</i> activity produced from a constitutive <i>hsp68</i>-lacZ reporter, as alteration of PKA affected <i>Renilla</i> luciferase activity (data not shown). Error bars indicate +/− SD.