Ilf3 and NF90 associate with the axonal targeting element of Tau mRNA

• Published in: The FASEB journal Vol. 18; no. 14; p. 1761
• Main Authors: Larcher, Jean-Christophe, Gasmi, Laila, Viranaïcken, Wildriss, Eddé, Bernard, Bernard, Rozenn, Ginzburg, Irith, Denoulet, Philippe
• Format: Journal Article
• Language: English
• Published: United States 01.11.2004
• Subjects: 3' Untranslated Regions; Animals; Antibody Specificity; Axons - metabolism; Biological Transport; DNA-Binding Proteins - analysis; DNA-Binding Proteins - isolation & purification; DNA-Binding Proteins - metabolism; Immunohistochemistry; Mice; Microtubule-Associated Proteins - isolation & purification; Neurons - chemistry; Neurons - metabolism; NFATC Transcription Factors; Nuclear Factor 90 Proteins; Nuclear Proteins - analysis; Nuclear Proteins - isolation & purification; Nuclear Proteins - metabolism; Regulatory Sequences, Ribonucleic Acid; RNA Probes; RNA, Messenger - chemistry; RNA, Messenger - metabolism; RNA-Binding Proteins - analysis; RNA-Binding Proteins - immunology; RNA-Binding Proteins - isolation & purification; Sequence Analysis, Protein; tau Proteins - genetics; tau Proteins - metabolism; Transcription Factors - analysis; Transcription Factors - isolation & purification; Transcription Factors - metabolism
• ISSN: 1530-6860
• DOI: 10.1096/fj.04-1763fje

In neurons, the selective translocation of Tau mRNA toward axons is due to the presence of a nucleotide sequence located in its 3' untranslated region and serving as axonal targeting element. Using this RNA sequence as a probe by a Northwestern approach, we have detected several proteins that interact with the targeting RNA element and could potentially be involved in Tau mRNA translocation, translation halting, and/or stabilization. Among them, two proteins were identified as the interleukin enhancer binding factor 3 (Ilf3) and NF90, two isoforms derived from a single gene product through alternative splicing. Each protein comprises two double-stranded RNA binding motifs that can interact with the predicted stem-loop secondary structure of the axonal targeting element. Specific antibodies raised against common or specific peptide sequences showed that both Ilf3 and NF90 are polymorphic proteins that are detected in neuronal nuclei and cell bodies, as well as in the proximal neuritic segments. This observation favors the idea that Ilf3 and NF90 are part of a protein complex that escorts Tau mRNA toward the axon.