MOSMO, also known as Atthog (attenuator of hedgehog) in mouse, acts as a negative regulator of hedgehog (Hh) signaling, probably by promoting internalization and subsequent degradation of Smoothened (SMO). SMO is an oncoprotein that transduces the Hh signal across the membrane. In the absence of Atthog, SMO was stabilized at the cell surface and concentrated in the ciliary membrane [].
