FIGURE 1.

A schematic description of progress of Hedgehog protein maturation. In the first step of processing after Hedgehog (HH) protein translation, C-terminal initiates the catalytic action through its processing domain and leads to form an internal thioester between a cysteine and a glycine residue at the cleavage site. The C-terminal domain is then released by nucleophilic attack by the hydroxyl group of cholesterol, resulting in the covalent attachment of cholesterol to the C terminus of the N-terminal domain. Further more, the N terminus of the N-terminal domain is palmitoylated by the acyltransferase Skinny after signal peptide cleavage.