A Multi-domain Fragment of Nogo-A Protein Is a Potent Inhibitor of Cortical Axon Regeneration via Nogo Receptor 1

作者:Huebner Eric A; Kim Byung G; Duffy Philip J; Brown Rebecca H; Strittmatter Stephen M*
来源:Journal of Biological Chemistry, 2011, 286(20): 18026-18036.
DOI:10.1074/jbc.M110.208108

摘要

Nogo-A limits axon regeneration and functional recovery after central nervous system injury in adult mammals. Three regions of Nogo-A (Nogo-A-24, Nogo-66, and Nogo-C39) interact with the neuronal Nogo-66 receptor 1 (NgR1). Nogo-66 also interacts with a structurally unrelated cell surface receptor, paired immunoglobulin-like receptor (PirB). We show here that the other two NgR1-interacting domains, Nogo-A-24 and Nogo-C39, also bind to PirB with high affinity. A purified 22-kDa protein containing all three NgR1- and PirB-interacting domains (Nogo-22) is a substantially more potent growth cone-collapsing molecule than Nogo-66 for chick dorsal root ganglion neurons and mature cortical neurons. Moreover, Nogo-22 inhibits axon regeneration of mature cortical neurons in vitro more potently than does Nogo-66. Although all three NgR1-interacting domains of Nogo-A also interact with PirB, expression of PirB in mature cortical cultures is nearly undetectable. Consistent with a relatively minor role for PirB in mature cortical neurons, Nogo-22 inhibition of axon regeneration is abolished by genetic deletion of NgR1. Thus, NgR1 is the predominant receptor for Nogo-22 in regenerating cortical neurons.