A myelin-associated neurite growth inhibitory protein (reticulon 4A), expressed by oligodendrocytes but not Schwann cells, involved in diverse processes that include axonal fasciculation and apoptosis. There are three splice variants, nogo-A (1192 aa), nogo-B, and nogo-C, the latter two lacking the axon-inhibiting extracellular domain of 66 aa. Nogo is thought to be one of the molecules responsible for blocking axonal regeneration in the central nervous system and, like MAG and OMgp, can cause growth cone collapse in vitro. Although Nogo, MAG, and OMgp lack sequence homologies, they all bind to the Nogo receptor (NgR, 473 aa), a GPI-linked cell surface molecule widely expressed in brain which, in turn, binds p75 (neurotrophin receptor) and activates rhoA.
Subjects: Medicine and Health.