Figure 3.

Posttranslational modifications of hedgehog molecules. Posttranslational modification in each of the three HH molecule is similar and highly conserved. The initial HH polypeptide is stepwise cleaved into three domains. After the cleavage of signal sequence (~aa 1–23), the remaining polypeptide is cleaved into a N-terminal signaling domain (~aa 24–197) and a C-terminal autoprocessing domain (~aa 198–424). The Signaling domain undergoes C-terminus cholesterylation and N-terminal palmitoylation before it is secreted in its mature and active form. The autoprocessing domain catalyses the intramolecular chlesterol tranfer reaction necessary for choesterylation of the signaling domain.