RNA-binding protein that is involved in the post-transcriptional regulation of mRNAs (PubMed:15764704, PubMed:16554442, PubMed:17035636, PubMed:20064466, PubMed:22387028, PubMed:23383270, PubMed:26305964, PubMed:28111162). Plays a role in the regulation of mRNA stability, alternative splicing and translation (PubMed:15764704, PubMed:23383270, PubMed:26305964, PubMed:28111162). Binds to AU-rich element (ARE) sequences in the 3' untranslated region (3'UTR) of target mRNAs, including GAP43, VEGF, FOS, CDKN1A and ACHE mRNA (By similarity). Many of the target mRNAs are coding for RNA-binding proteins, transcription factors and proteins involved in RNA processing and/or neuronal development and function (PubMed:26305964). By binding to the mRNA 3'UTR, decreases mRNA deadenylation and thereby contributes to the stabilization of mRNA molecules and their protection from decay (By similarity). Also binds to the polyadenylated (poly(A)) tail in the 3'UTR of mRNA, thereby increasing its affinity for mRNA binding (PubMed:20064466). Mainly plays a role in neuron-specific RNA processing by stabilization of mRNAs such as GAP43, ACHE and mRNAs of other neuronal proteins, thereby contributing to the differentiation of neural progenitor cells, nervous system development, learning and memory mechanisms (PubMed:15764704, PubMed:16554442, PubMed:18218628, PubMed:23383270, PubMed:24599466, PubMed:25692578, PubMed:26305964, PubMed:28111162). Involved in the negative regulation of the proliferative activity of neuronal stem cells and in the positive regulation of neuronal differentiation of neural progenitor cells (PubMed:15764704). Promotes neuronal differentiation of neural stem/progenitor cells in the adult subventricular zone of the hippocampus by binding to and stabilizing SATB1 mRNA (PubMed:26305964). Binds and stabilizes MSI1 mRNA in neural stem cells (PubMed:16554442). Exhibits increased binding to ACHE mRNA during neuronal differentiation, thereby stabilizing ACHE mRNA and enhancing its expression (By similarity). Protects CDKN1A mRNA from decay by binding to its 3'-UTR (By similarity). May bind to APP and BACE1 mRNAS and the BACE1AS lncRNA and enhance their stabilization (By similarity). Plays a role in neurite outgrowth and in the establishment and maturation of dendritic arbors, thereby contributing to neocortical and hippocampal circuitry function (PubMed:24599466). Stabilizes GAP43 mRNA and protects it from decay during postembryonic development in the brain (PubMed:28111162). By promoting the stabilization of GAP43 mRNA, plays a role in NGF-mediated neurite outgrowth (By similarity). Binds to BDNF long 3'UTR mRNA, thereby leading to its stabilization and increased dendritic translation after activation of PKC (PubMed:23383270, PubMed:25692578). By increasing translation of BDNF after nerve injury, may contribute to nerve regeneration (PubMed:28111162). Acts as a stabilizing factor by binding to the 3'UTR of NOVA1 mRNA, thereby increasing its translation and enhancing its functional activity in neuron-specific splicing (PubMed:18218628). Stimulates translation of mRNA in a poly(A)- and cap-dependent manner, possibly by associating with the EIF4F cap-binding complex (PubMed:20064466). May also negatively regulate translation by binding to the 5'UTR of Ins2 mRNA, thereby repressing its translation (PubMed:22387028). Upon glucose stimulation, Ins2 mRNA is released from ELAVL4 and translational inhibition is abolished (PubMed:22387028). Also plays a role in the regulation of alternative splicing (PubMed:17035636). May regulate alternative splicing of CALCA pre-mRNA into Calcitonin and Calcitonin gene-related peptide 1 (CGRP) by competing with splicing regulator TIAR for binding to U-rich sequences of CALCA pre-mRNA (PubMed:17035636). Component of a TAU mRNP complex, at least composed of IGF2BP1, ELAVL4 and G3BP (PubMed:15086518). Associates with the EIF4F cap-binding complex, composed of EIF4G, EIF4A, EIF4E and PABP (PubMed:20064466). Within the EIF4F cap-binding complex, interacts with EIF4A (PubMed:20064466). Interacts with SMN (via Tudor domain) in an RNA-independent manner; the interaction is required for localization of ELAVL4 to RNA granules (By similarity). Interacts with MAP1 light chain LC1 (via C-terminus); the interaction contributes to the association of ELAVL4 with microtubules (PubMed:21288476). Interacts with MAP1 light chain LC2 (PubMed:21288476). Co-localizes with ribosomal RNA in polysomes. Expressed in the brain, including the hippocampus, and in pancreatic beta cells (at protein level) (PubMed:22387028, PubMed:18493953, PubMed:15764704, PubMed:24599466). Expressed in pyramidal neurons of the hippocampal CA3 and CA1 region and in the hilus but not in dentate granule cells (at protein level) (PubMed:15519747). Expressed in the dorsal root ganglion and the spinal cord (at protein level) (PubMed:17035636, PubMed:28111162). Expressed in neural stem and progenitor cells (at protein level) (PubMed:16554442). Expressed in radial glia-like cells and in transient amplifying cells in the subventricular zone (SVZ), and in immature neurons both in the SVZ and the rostral migratory stream as well as in mature neurons in the olfactory bulb (at protein level) (PubMed:26305964). Expressed in testis and in the brain, including the hippocampus, the neocortex and the cerebellum (PubMed:8535975, PubMed:11573004, PubMed:24857657). Expressed in lower- but not upper-layer primary neurons of the mature neocortex, in the hippocampal regions CA1-3 and the dentate gyrus (PubMed:24599466, PubMed:9096138). Expressed in the mitral and granule cells of the olfactory bulb, cerebral cortex, entorhinal cortex, thalamus, medial habenula, amygdala, granule cells of the cerebellum, pons, olivary nucleus, dorsal and ventral spinal cord and in dorsal root ganglia (PubMed:9096138). Expressed in motor neurons (PubMed:21389246). Isoform 4: Expressed in the brain (PubMed:9096138, PubMed:22895702). Isoform 5: Expressed in the brain (PubMed:9096138). Isoform 6: Expressed in the brain (PubMed:22895702). Isoform 7: Expressed in the brain (PubMed:22895702). Isoform 8: Expressed in the brain (PubMed:22895702). Isoform 9: Expressed in the brain (PubMed:22895702). Isoform 10: Expressed in the brain (PubMed:22895702). Isoform 11: Expressed in the brain (PubMed:22895702). At 14 dpc, expressed in the intermediate zone of the cortex (PubMed:9096138). At 15 dpc, high expression in the neocortex, with decreased expression at postnatal day 7 and in adulthood (PubMed:24599466). At 16 dpc and at birth, expressed in the retina, thalamus, hypothalamus, midbrain, pons, dorsal and ventral spinal cord, and the dorsal root ganglia (PubMed:9096138). At birth, expressed in the nasal epithelium, olfactory bulb, trigeminal ganglia, cerebral cortex, the pyramidal cells of the hippocampus and the sympathetic ganglia (PubMed:9096138). Widely expressed in the cerebellum at postnatal day 9 (PubMed:9096138). Isoform 4: Highly expressed in the brain at 10 dpc to 14 dpc, with decreased expression at 16 dpc and at postnatal day 8 (PubMed:9096138). Isoform 5: Highly expressed in the brain at 10 dpc, with decreased expression at 16 dpc and at postnatal day 8 (PubMed:9096138). Isoform 6: Expressed in the brain at 14 dpc (PubMed:22895702). Isoform 7: Expressed in the brain at 14 dpc (PubMed:9096138). Isoform 8: Expressed in the brain at 14 dpc (PubMed:9096138). Isoform 9: Expressed in the brain at 14 dpc (PubMed:9096138). Isoform 10: Expressed in the brain at 14 dpc, including the amygdala, hippocampus and cerebral cortex, and strong expression in the olfactory bulb and retina (PubMed:22895702). Isoform 11: Expressed in the brain at 14 dpc (PubMed:9096138). Up-regulated by glucose and by insulin (PubMed:22387028). Up-regulated after memory training in radial arm maze experiments (PubMed:11573004). Up-regulated after sciatic nerve injury (PubMed:28111162). Up-regulated during adult neuronal stem cell differentiation (PubMed:26305964). The RRM 3 domain is required for binding to poly(A) RNA, for the association with polysomes and with the EIF4F cap-binding complex and for the stimulation of translation (PubMed:20064466). The RRM 1 and RRM 2 domains may contribute to polysome association and stimulation of translation (PubMed:20064466). Methylated by CARM1, which leads to reduced RNA-binding activity and enhanced interaction with SMN (By similarity). Methylation at Arg-248 by CARM1 weakens protective binding to the 3'UTR of CDKN1A mRNA and down-regulates CDKN1A protein expression, thereby maintaining cells in a proliferative state (By similarity). Methylation is inhibited by NGF, which facilitates neurite outgrowth (By similarity). Transiently impaired neurite extensions of several cranial nerves, including glossopharyngeal nerve, hypoglossal nerve, trigeminal nerve and acousticofacial nerves in the midembryonic nervous system at 10.5 dpc, however no developmental delays of the nervous system in later-stage embryos at 14 dpc are obvious (PubMed:15764704). By postnatal weeks 4 to 8, 70-80% of the mice exhibit an abnormal clasping reflex of the hind limbs upon being suspended by the tail (PubMed:15764704). Decreased motor coordination, as impaired performance on an accelerating rotarod is observed (PubMed:15764704). Embryonic neural stem cells exhibit enhanced cell renewal capacity and decreased ability to differentiate into neurons (PubMed:15764704). Failure of neural progenitor cells to leave the cell cycle, resulting in increased apoptosis and in reduced production of postmitotic neurons (PubMed:15764704). Increased number of slowly dividing cells in the subventricular zone (PubMed:15764704). High insulin levels in pancreatic beta cells (PubMed:22387028). At 28 dpc, a decreased number of lower layer neocortical neurons is observed and lower layer neocortical neurons and CA3 hippocampal neurons exhibit a decreased dendritic complexity with fewer basal and apical branchpoints, fewer branch endings and shorter basal dendrites (PubMed:24599466). Basal branching deficiency in neocortical lower layer neurons and in hippocampal CA3 neurons persists into adulthood at 90 dpc (PubMed:24599466). Increased time spent in low-energy-expending activities and less in the high-energy activity of locomotion, indicating an anxiety response (PubMed:24599466). Decreased performance in finding a hidden platform in a water bath (Morris water maze test), suggesting difficulty in learning, lack of avoidance of the open arm in a elevated plus maze test, suggesting an aberrant response to anxiety-producing environments, and higher susceptibility to auditory-induced seizures (PubMed:24599466). RNAi-mediated knockdown in the neocortex at 13.5 dpc results in reduced neurite outgrowth (PubMed:24599466). RNAi-mediated knockdown in neural stem/progenitor cells in the adult subventricular zone impairs early neuronal differentiation (PubMed:26305964). Produced by alternative initiation. Produced by alternative splicing of isoform 4. Produced by alternative initiation. Produced by alternative initiation. Produced by alternative initiation. Produced by alternative initiation. Produced by alternative splicing of isoform 1. Produced by alternative initiation. Belongs to the RRM elav family.