title: Poly(A)-binding protein is associated with neuronal BC1 and BC200 ribonucleoprotein particles.
abstract: BC1 RNA and BC200 RNA are two non-homologous, small non-messenger RNAs (snmRNAs) that were generated, evolutionarily, quite recently by retroposition. This process endowed the RNA polymerase III transcripts with central adenosine-rich regions. Both RNAs are expressed almost exclusively in neurons, where they are transported into dendritic processes as ribonucleoprotein particles (RNPs). Here, we demonstrate with a variety of experimental approaches that poly(A)-binding protein (PABP1), a regulator of translation initiation, binds to both RNAs in vitro and in vivo. We identified the association of PABP with BC200 RNA in a tri-hybrid screen and confirmed this binding in electrophoretic mobility-shift assays and via anti-PABP immunoprecipitation of BC1 and BC200 RNAs from crude extracts, immunodepleted extracts, partially purified RNPs and cells transfected with naked RNA. Furthermore, PABP immunoreactivity was localized to neuronal dendrites. Competition experiments using variants of BC1 and BC200 RNAs demonstrated that the central adenosine-rich region of both RNAs mediates binding to PABP. These findings lend support to the hypothesis that the BC1 and BC200 RNPs are involved in protein translation in neuronal dendrites.
authors.affiliation: Institute of Experimental Pathology, ZMBE, University of Münster, Von-Esmarch-Str. 56, D-48149, Münster, Germany.
authors.forename: Ravi
authors.initials: R
authors.lastname: Muddashetty
authors.forename: Tasneem
authors.initials: T
authors.lastname: Khanam
authors.forename: Alexander
authors.initials: A
authors.lastname: Kondrashov
authors.forename: Marsha
authors.initials: M
authors.lastname: Bundman
authors.forename: Anna
authors.initials: A
authors.lastname: Iacoangeli
authors.forename: Joachim
authors.initials: J
authors.lastname: Kremerskothen
authors.forename: Kerstin
authors.initials: K
authors.lastname: Duning
authors.forename: Angelika
authors.initials: A
authors.lastname: Barnekow
authors.forename: Alexander
authors.initials: A
authors.lastname: Hüttenhofer
authors.forename: Henri
authors.initials: H
authors.lastname: Tiedge
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brosius
mesh_terms: D001483:Base Sequence; D001921:Brain / Q000196:embryology; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins; D011233:Precipitin Tests; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D020736:Ribonucleoproteins, Small Cytoplasmic / Q000235:genetics*; D014162:Transfection
chemical_list: D039102:Poly(A)-Binding Proteins; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D020736:Ribonucleoproteins, Small Cytoplasmic; D012313:RNA