Reticulon 4 Receptor - Nogo Pathway: Rho Kinase - NgR Activation of P75

NgR Activation of P75

It was known that NgR, Nogo, and another membrane receptor called p75 were involved in inhibiting neurite outgrowth. Through a variety of experimental procedures Wang et al. were able to identify the biochemical relationship between NgR and p75. First, it was observed that when p75 was knocked out in mice, outgrowth inhibition was no longer seen. Completing binding assays and co-immunoprecipitations revealed that p75 and NgR were not bound to each other through the cellular membrane. Mutating either p75 or NgR, however, resulted in truncated protein that would help reveal the binding interactions. When the extracellular domains of the receptors were removed no outgrowth inhibition was seen. This would suggest that the receptors interact extracellularly. Furthermore, it was reaffirmed that Nogo and myelin-associated gylcoprotein (MAG) bind NgR and not p75. The receptor p75 lacks a binding domain for either of these proteins.