Hh-induced Smoothened conformational switch is mediated by differential phosphorylation at its C-terminal tail in a dose- and position-dependent manner

► We examine the levels of Smo phosphorylated in response to Hh threshold. ► Position of Smo phosphorylation is critical in activating Smo. ► Phosphorylation of membrane proximal sites promotes phosphorylation of distal sites. ► Smo phosphorylation by CK1 is regulated by Hh.