RNA-binding factor that recruits target transcripts tocytoplasmic protein-RNA complexes (mRNPs). This transcript 'caging'into mRNPs allows mRNA transport and transient storage. It alsomodulates the rate and location at which target transcripts encounterthe translational apparatus and shields them from endonuclease attacksor microRNA-mediated degradation. Preferentially binds to N6-methyladenosine (m6A) -containing mRNAs and increases their stability. Plays a direct role in thetransport and translation of transcripts required for axonalregeneration in adult sensory neurons. Regulateslocalized beta-actin/ACTB mRNA translation, a crucial process for cellpolarity, cell migration and neurite outgrowth. Co-transcriptionallyassociates with the ACTB mRNA in the nucleus. This binding involves aconserved 54-nucleotide element in the ACTB mRNA 3'-UTR, known as the'zipcode'. The RNP thus formed is exported to the cytoplasm, binds to amotor protein and is transported along the cytoskeleton to the cellperiphery. During transport, prevents ACTB mRNA from being translatedinto protein. When the RNP complex reaches its destination near theplasma membrane, IGF2BP1 is phosphorylated. This releases the mRNA, allowing ribosomal 40S and 60S subunits to assemble and initiate ACTBprotein synthesis. Monomeric ACTB then assembles into the subcorticalactin cytoskeleton. During neuronal development, keyregulator of neurite outgrowth, growth cone guidance and neuronal cellmigration, presumably through the spatiotemporal fine tuning of proteinsynthesis, such as that of ACTB. May regulate mRNAtransport to activated synapses. Binds to andstabilizes ABCB1/MDR-1 mRNA. During interstinal woundrepair, interacts with and stabilizes PTGS2 transcript. PTGS2 mRNAstabilization may be crucial for colonic mucosal wound healing. Binds to the 3'-UTR of IGF2 mRNA by a mechanism ofcooperative and sequential dimerization and regulates IGF2 mRNAsubcellular localization and translation. Binds to MYC mRNA, in thecoding region instability determinant (CRD) of the open reading frame (ORF), hence preventing MYC cleavage by endonucleases and possiblymicroRNA targeting to MYC-CRD. Binding to MYC mRNA isenhanced by m6A-modification of the CRD. Binds to the3'-UTR of CD44 mRNA and stabilizes it, hence promotes cell adhesion andinvadopodia formation in cancer cells. Binds to the oncofetal H19transcript and to the neuron-specific TAU mRNA and regulates theirlocalizations. Binds to and stabilizes BTRC/FBW1A mRNA. Binds to theadenine-rich autoregulatory sequence (ARS) located in PABPC1 mRNA andrepresses its translation. PABPC1 mRNA-binding is stimulated by PABPC1protein. Prevents BTRC/FBW1A mRNA degradation by disrupting microRNA-dependent interaction with AGO2. Promotes the directed movement oftumor-derived cells by fine-tuning intracellular signaling networks. Binds to MAPK4 3'-UTR and inhibits its translation. Interacts with PTENtranscript open reading frame (ORF) and prevents mRNA decay. Thiscombined action on MAPK4 (down-regulation) and PTEN (up-regulation) antagonizes HSPB1 phosphorylation, consequently it prevents G-actinsequestration by phosphorylated HSPB1, allowing F-actin polymerization. Hence enhances the velocity of cell migration and stimulates directedcell migration by PTEN-modulated polarization. Interacts with HepatitisC virus (HCV) 5'-UTR and 3'-UTR and specifically enhances translationat the HCV IRES, but not 5'-cap-dependent translation, possibly byrecruiting eIF3. Interacts with HIV-1 GAG protein and blocks theformation of infectious HIV-1 particles. Reduces HIV-1 assembly byinhibiting viral RNA packaging, as well as assembly and processing ofGAG protein on cellular membranes. During cellular stress, such asoxidative stress or heat shock, stabilizes target mRNAs that arerecruited to stress granules, including CD44, IGF2, MAPK4, MYC, PTEN, RAPGEF2 and RPS6KA5 transcripts. [1-15]

MNKLYIGNLNESVTPADLEKVFAEHKISYSGQFLVKSGYAFVDCPDEHWAMKAIETFSGKVELQGKRLEIEHSVPKKQRSRKIQIRNIPPQLRWEVLDSLLAQYGTVENCEQVNTESETAVVNVTYSNREQTRQAIMKLNGHQLENHALKVSYIPDEQIAQGPENGRRGGFGSRGQPRQGSPVAAGAPAKQQQVDIPLRLLVPTQYVGAIIGKEGATIRNITKQTQSKIDVHRKENAGAAEKAISVHSTPEGCSSACKMILEIMHKEAKDTKTADEVPLKILAHNNFVGRLIGKEGRNLKKVEQDTETKITISSLQDLTLYNPERTITVKGAIENCCRAEQEIMKKVREAYENDVAAMSLQSHLIPGLNLAAVGLFPASSSAVPPPPSSVTGAAPYSSFMQAPEQEMVQVFIPAQAVGAIIGKKGQHIKQLSRFASASIKIAPPETPDSKVRMVIITGPPEAQFKAQGRIYGKLKEENFFGPKEEVKLETHIRVPASAAGRVIGKGGKTVNELQNLTAAEVVVPRDQTPDENDQVIVKIIGHFYASQMAQRKIRDILAQVKQQHQKGQSNQAQARRK