This gene belongs to the family of reticulon encoding genes. Reticulons are associated with the endoplasmic reticulum, and are involved in neuroendocrine secretion or in membrane trafficking in neuroendocrine cells. The product of this gene is a potent neurite outgrowth inhibitor which may also help block the regeneration of the central nervous system in higher vertebrates. Alternatively spliced transcript variants derived both from differential splicing and differential promoter usage and encoding different isoforms have been identified. [provided by RefSeq, Jul 2008],domain:Three regions, residues 59-172, 544-725 and the loop 66 amino acids, between the two transmembrane domains, known as Nogo-66 loop, appear to be responsible for the inhibitory effect on neurite outgrowth and the spreading of neurons. This Nogo-66 loop, mediates also the binding of RTN4 to its receptor.,function:Potent neurite growth inhibitor in vitro and plays a role both in the restriction of axonal regeneration after injury and in structural plasticity in the CNS. Isoform 2 reduces the anti-apoptotic activity of Bcl-xl and Bcl-2. This is likely consecutive to their change in subcellular location, from the mitochondria to the endoplasmic reticulum, after binding and sequestration. Isoform 2 and isoform 3 inhibit BACE1 activity and amyloid precursor protein processing.,online information:Nerve regrowth: nipped by a no-go – Issue 69 of April 2006,online information:The Singapore human mutation and polymorphism database,sequence caution:Translation N-terminally extended.,similarity:Contains 1 reticulon domain.,subcellular location:Anchored to the membrane of the endoplasmic reticulum through 2 putative transmembrane domains.,subunit:Binds to RTN4R. Interacts with Bcl-xl and Bcl-2. Isoform 2 binds to NGBR and RTN3. Isoform 2 and isoform 3 interact with BACE1 and BACE2. Interacts with RTN4IP1.,tissue specificity:Isoform 1 is specifically expressed in brain and testis and weakly in heart and skeletal muscle. Isoform 2 is widely expressed except for the liver. Isoform 3 is expressed in brain, skeletal muscle and adipocytes. Isoform 4 is testis-specific.,