Hedgehog signaling: A tale of two lipids

Hedgehog proteins constitute one of the major classes of intercellular sign als that control inductive interactions during animal development. These pr oteins undergo unusual lipid modifications and signal through an unconventi onal transmembrane protein receptor that is characterized by a sequence mot if implicated in sterol sensing. Recent studies suggest that the lipid addu cts regulate the range and potency of the signals, whereas the sterol-sensi ng domain is essential for receptor activity.