RNA-binding protein required for the microtubule-dependent transport of neuronal RNA from the cell body to the dendrite. As protein synthesis occurs within the dendrite, the localization of specific mRNAs to dendrites may be a prerequisite for neurite outgrowth and plasticity at sites distant from the cell body (By similarity). Interacts with microtubules. Isoform 2 and isoform 3 may also interact with ribosomes, and this association is independent of translation (By similarity). Identified in a mRNP complex, at least composed of DHX9, DDX3X, ELAVL1, HNRNPU, IGF2BP1, ILF3, PABPC1, PCBP2, PTBP2, STAU1, STAU2, SYNCRIP and YBX1. Interacts with the exportin XPO5. This requires RNA and RAN bound to GTP. Interacts with TRIM71 (via NHL repeats) in an RNA-dependent manner (By similarity). Shuttles between the nucleolus, nucleus and the cytoplasm. Nuclear export of isoform 1 is independent of XPO1/CRM1 and requires the exportin XPO5. Nuclear export of isoform 2 and isoform 3 can occur by both XPO1/CRM1-dependent and XPO1/CRM1-independent pathways. May also be found in large cytoplasmic ribonucleoprotein (RNP) granules which are present in the actin rich regions of myelinating processes and associated with microtubules, polysomes and the endoplasmic reticulum. Also recruited to stress granules (SGs) upon inhibition of translation or oxidative stress. These structures are thought to harbor housekeeping mRNAs when translation is aborted. Expressed in brain and neurons, where isoform 2 and isoform 3 appear to be the most abundant. Expressed at the neuromuscular junction of the extensor digitorum longus, tibialis anterior and soleus muscles. Expression at neuromuscular junctions is most pronounced in slow-twitch muscle. Also weakly expressed in heart, kidney, ovary and testis. Expression in extrasynaptic regions of muscle is induced by denervation. Expression in myoblasts is induced during differentiation into myotubes and by treatment with nerve derived trophic factors such as AGRN (agrin) and NRG1 (neuregulin). The DRBM 3 domain appears to be the major RNA-binding determinant. This domain also mediates interaction with XPO5 and is required for XPO1/CRM1-independent nuclear export.