title: Identification of mRNA/protein (mRNP) complexes containing Puralpha, mStaufen, fragile X protein, and myosin Va and their association with rough endoplasmic reticulum equipped with a kinesin motor.
abstract: Puralpha, which is involved in diverse aspects of cellular functions, is strongly expressed in neuronal cytoplasm. Previously, we have reported that this protein controls BC1 RNA expression and its subsequent distribution within dendrites and that Puralpha is associated with polyribosomes. Here, we report that, following treatment with EDTA, Puralpha was released from polyribosomes in mRNA/protein complexes (mRNPs), which also contained mStaufen, Fragile X Mental Retardation Protein (FMRP), myosin Va, and other proteins with unknown functions. As the coimmunoprecipitation of these proteins by an anti-Puralpha antibody was abolished by RNase treatment, Puralpha may assist mRNP assembly in an RNA-dependent manner and be involved in targeting mRNPs to polyribosomes in cooperation with other RNA-binding proteins. The immunoprecipitation of mStaufen- and FMRP-containing mRNPs provided additional evidence that the anti-Puralpha detected structurally or functionally related mRNA subsets, which are distributed in the somatodendritic compartment. Furthermore, mRNPs appear to reside on rough endoplasmic reticulum equipped with a kinesin motor. Based on our present findings, we propose that this rough endoplasmic reticulum structure may form the molecular machinery that mediates and regulates multistep transport of polyribosomes along microtubules and actin filaments, as well as localized translation in the somatodendritic compartment.
authors.affiliation: Division of Biochemistry, College of Pharmacy, Nihon University, Chiba 274-8555, Japan.
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Ohashi
authors.forename: Katsuya
authors.initials: K
authors.lastname: Koike
authors.forename: Akira
authors.initials: A
authors.lastname: Omori
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Ichinose
authors.forename: Susumu
authors.initials: S
authors.lastname: Ohara
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Sato
authors.forename: Kaijiro
authors.initials: K
authors.lastname: Anzai
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015153:Blotting, Western; D001921:Brain / Q000502:physiology; D002499:Centrifugation, Density Gradient; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018870:Endoplasmic Reticulum, Rough / Q000502:physiology*; D016547:Kinesins / Q000502:physiology*; D051379:Mice; D018995:Myosin Heavy Chains / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D024701:Myosin Type V / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D009474:Neurons / Q000502:physiology; D011132:Polyribosomes / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D018160:Receptors, Cytoplasmic and Nuclear; D012261:Ribonucleoproteins / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000099150:Receptor, Farnesoid X-Activated
chemical_list: D000906:Antibodies; D017362:Cyclic AMP Response Element-Binding Protein; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D016547:Kinesins; D018995:Myosin Heavy Chains; D024701:Myosin Type V; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D012261:Ribonucleoproteins; D014157:Transcription Factors; D000099150:Receptor, Farnesoid X-Activated; C513082:Myo5a protein, mouse; C121485:Pura protein, mouse; C492185:STAU1 protein, human; C492187:Stau1 protein, mouse; C026452:messenger ribonucleoprotein; C117884:staufen protein, mammalian