Axonal localization of neuritin/CPG15 mRNA in neuronal populations through distinct 5' and 3' UTR elements.

Many neuronal mRNAs are actively transported into distal axons. The 3' untranslated regions (UTRs) of axonal mRNAs often contain cues for their localization. The 3' UTR of neuritin mRNA was shown to be sufficient for localization into axons of hippocampal neurons. Here, we show that neuritin mRNA localizes into axons of rat sensory neurons, but this is predominantly driven by the 5' rather than 3' UTR. Neuritin mRNA shifts from cell body to axon predominantly after nerve crush injury, suggesting that it encodes a growth-associated protein. Consistent with this, overexpression of neuritin increases axon growth but only when its mRNA localizes into the axons.