Smoothened homolog (SMO)

Smoothened homolog (SMO) is a transmembrane protein that functions as a G protein-coupled receptor (GPCR) in the Frizzled family. It is a key signal transducer in the Hedgehog (Hh) signaling pathway, crucial for embryonic development and tissue homeostasis. Mutations in SMO are implicated in cancer and drug resistance. SMO is a target of several small molecule inhibitors like vismodegib.

Other names

Smoothened frizzled family receptorGx proteinProtein GxFrizzled class receptorSmoothened homolog precursor

SMO transduces Hedgehog signaling by relieving the inhibition of Patched (PTCH) on SMO. Drugs modulate SMO's heptahelical bundle conformation to promote or inhibit downstream signaling activity. Agonists activate SMO, while antagonists like vismodegib inhibit SMO activity.