Fig. 5
From: Inhibition of tetrameric Patched1 by Sonic Hedgehog through an asymmetric paradigm
Model for the inhibition of tetrameric Ptch1 by lipid-modified ShhN. The palmitoyl and cholesteryl modified ShhN signaling domain becomes hydrophobic that can be attached to the membrane. Multimerization of the modified ShhN or interaction with lipoprotein particles keep the morphogen soluble. In the absence of Hh ligands, Ptch1 may export the cholesterol, the agonist to Smo, out of the lipid bilayer as a means to suppress Smo. Lipid-modified ShhN inhibits the cholesterol transport activity of Ptch1 using two asymmetric modes, resulting in elevated cholesterol in the membrane that leads to Smo activation
