A G-protein-coupled receptor, the homologue of the Drosophila protein, that is translocated to the primary cilium when acted upon by patched that has bound the sonic hedgehog ligand. Smoothened (Smo) is then thought to convert the Gli family of transcription factors (see gli oncogenes) from transcriptional repressors to transcriptional activators. The interaction of Smo and the kinesin motor protein KIF3A is regulated by β-*arrestin. Mutations in Smo are associated with some basal cell carcinomas. See cyclopamine; hedgehog signalling complex.
Subjects: Medicine and Health.