title: Complex formation of the neuron-specific ELAV-like Hu RNA-binding proteins.
abstract: Hu proteins are RNA-binding proteins that are the vertebrate homologs of Drosophila ELAV, and are implicated in stabilization or enhanced translation of specific mRNAs with AU-rich elements (AREs) in the 3'-untranslated region. Here, using the yeast two-hybrid system, we show that neuron-specific Hu proteins can interact with themselves. Immuno precipitation assays demonstrated that the interaction between Hu proteins occurs in mammalian cells and is strongly enhanced in the presence of cellular RNA. Furthermore, using in situ chemical crosslinking assays, we found that HuD, one of the neuron-specific Hu proteins, multimerizes in cells. The crosslinked HuD multimers retain specific RNA-binding ability and can interact with additional Hu proteins. Consistent with this biochemical property, HuD showed granular distribution in two neurogenic cell lines. These results suggest that the RNA-bound form of HuD multimerizes cooperatively to form a specific granular structure that may serve as a site of post-transcriptional regulation of ARE-containing mRNAs.
authors.affiliation: Department of Biology, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nadaku, Kobe 657-8501, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kasashima
authors.forename: Eiji
authors.initials: E
authors.lastname: Sakashita
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakamoto
mesh_terms: D000818:Animals; D002460:Cell Line; D051959:ELAV Proteins; D000067779:ELAV-Like Protein 4; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000378:metabolism; D009474:Neurons / Q000737:chemistry; D016716:PC12 Cells; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D012261:Ribonucleoproteins / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: D051959:ELAV Proteins; D000067779:ELAV-Like Protein 4; C498010:ELAVL4 protein, human; C498011:Elavl4 protein, mouse; D046911:Macromolecular Substances; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D012313:RNA