Figure 1.

A schematic diagram of the protein components involved in the myelin protein-derived inhibition of neurite growth. The oligodendrocyte derived proteins released from the cell membrane following injury include MAG, Nogo-A (Nogo-66), Oligodendrocyte myelin glycoprotein (OMgp) and Amino-Nogo. The multicomponent cell surface receptor complexes that are localized to the neuronal cell membrane include the Nogo Receptor 1 (NgR1), Lingo-1, p75NTR, and TROY, all of which signal to change the activation of Rho (active Rho is indicated by RhoA-GTP). The PirB receptor also binds the myelin-derived inhibitory molecules but its absolute signaling pathway remains unclear. The C3 transferase enzyme, isolated from Clostridial species, is known to block these Rho activation pathways and to allow for neurite outgrowth in the face of myelin-derived protein inhibition. (Adapted by permission from Macmillan Publishers Ltd: J. Cereb. Blood Flow Metab.; Chaudhry and Filbin; 27(6):1096–107, Copyright 2007).