Smo

Smoothened (SMO) is a crucial component of the Hedgehog (Hh) signaling pathway, acting as a signal transducer. Unlike most signal transducers that are kinases, SMO is a G protein-coupled receptor (GPCR)-like protein. It is activated following the binding of Hedgehog ligands to the Patched1 (PTCH1) receptor, which relieves PTCH1-mediated repression of SMO. Upon activation, SMO initiates a signaling cascade that ultimately regulates the transcription of target genes via the GLI family of transcription factors. Dysregulation of SMO activity has been implicated in various developmental disorders and cancers, making it a target for drugs like vismodegib, which are used to treat conditions like basal cell carcinoma by inhibiting SMO activity.