TAJ/TROY, an orphan TNF receptor family member, binds Nogo-66 receptor 1 and regulates axonal regeneration.
Myelin-associated inhibitory factors (MAIFs) are inhibitors of CNS axonal regeneration following injury. The Nogo receptor complex, composed of the Nogo-66 receptor 1 (NgR1), neurotrophin p75 receptor (p75), and LINGO-1, represses axon regeneration upon binding to these myelin components. The limited expression of p75 to certain types of neurons and its temporal expression during development prompted speculation that other receptors are involved in the NgR1 complex. Here, we show that an orphan receptor in the TNF family called TAJ, broadly expressed in postnatal and adult neurons, binds to NgR1 and can replace p75 in the p75/NgR1/LINGO-1 complex to activate RhoA in the presence of myelin inhibitors. In vitro exogenously added TAJ reversed neurite outgrowth caused by MAIFs. Neurons from Taj-deficient mice were more resistant to the suppressive action of the myelin inhibitors. Given the limited expression of p75, the discovery of TAJ function is an important step for understanding the regulation of axonal regeneration.
Pubmed ID: 15694322 RIS Download
Animals | Axons | Binding Sites | CHO Cells | COS Cells | Cell Differentiation | Cricetinae | GPI-Linked Proteins | Growth Inhibitors | Ligands | Macromolecular Substances | Membrane Proteins | Mice | Mice, Knockout | Myelin Proteins | Myelin Sheath | Myelin-Associated Glycoprotein | Nerve Regeneration | Nerve Tissue Proteins | Neurites | Receptor, Nerve Growth Factor | Receptors, Cell Surface | Receptors, Nerve Growth Factor | Receptors, Tumor Necrosis Factor | rhoA GTP-Binding Protein