title: The exon junction core complex is locked onto RNA by inhibition of eIF4AIII ATPase activity.
abstract: The multiprotein exon junction complex (EJC) is assembled on mRNAs as a consequence of splicing. EJC core components maintain a stable grip on mRNAs even as the overall EJC protein composition evolves while mRNAs travel to the cytoplasm. Here we show that recombinant EJC subunits MLN51, MAGOH and Y14, together with the DEAD-box protein eIF4AIII bound to ATP, are necessary and sufficient to form a highly stable complex on single-stranded RNA. Cross-linking and RNase protection studies indicate that this recombinant complex recapitulates the EJC core. The stable association of the recombinant EJC core with RNA is maintained by inhibition of eIF4AIII ATPase activity by MAGOH-Y14. We elucidate the modalities of EJC binding to RNA and provide the first example of how cellular machineries may use RNA helicases to clamp several proteins onto RNA in stable and sequence-independent manners.
authors.affiliation: Equipe Labélisée La Ligue, Centre de Génétique Moléculaire, associé à l'Université Paris 6, CNRS UPR2167, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Ballut
authors.forename: Brice
authors.initials: B
authors.lastname: Marchadier
authors.forename: Aurélie
authors.initials: A
authors.lastname: Baguet
authors.forename: Catherine
authors.initials: C
authors.lastname: Tomasetto
authors.forename: Bertrand
authors.initials: B
authors.lastname: Séraphin
authors.forename: Hervé
authors.initials: H
authors.lastname: Le Hir
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000737:chemistry; D017124:Conserved Sequence; D003593:Cytoplasm / Q000737:chemistry; D039601:Eukaryotic Initiation Factor-4A / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C459802:CASC3 protein, human; C491494:MAGOH protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C406243:RBM8A protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D039601:Eukaryotic Initiation Factor-4A; D000251:Adenosine Triphosphatases