title: Exon junction complex proteins bind nascent transcripts independently of pre-mRNA splicing inDrosophila melanogaster.
abstract: Although it is currently understood that the exon junction complex (EJC) is recruited on spliced mRNA by a specific interaction between its central protein, eIF4AIII, and splicing factor CWC22, we found that eIF4AIII and the other EJC core proteins Y14 and MAGO bind the nascent transcripts of not only intron-containing but also intronless genes onDrosophilapolytene chromosomes. Additionally, Y14 ChIP-seq demonstrates that association with transcribed genes is also splicing-independent inDrosophilaS2 cells. The association of the EJC proteins with nascent transcripts does not require CWC22 and that of Y14 and MAGO is independent of eIF4AIII. We also show that eIF4AIII associates with both polysomal and monosomal RNA in S2 cell extracts, whereas Y14 and MAGO fractionate separately. Cumulatively, our data indicate a global role of eIF4AIII in gene expression, which would be independent of Y14 and MAGO, splicing, and of the EJC, as currently understood.
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Subhendu Roy
authors.initials: SR
authors.lastname: Choudhury
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Anand K
authors.initials: AK
authors.lastname: Singh
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Tina
authors.initials: T
authors.lastname: McLeod
authors.affiliation: Stowers Institute for Medical Research, Kansas city, United States.
authors.forename: Marco
authors.initials: M
authors.lastname: Blanchette
authors.affiliation: Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Boyun
authors.initials: B
authors.lastname: Jang
authors.affiliation: Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Badenhorst
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Aditi
authors.initials: A
authors.lastname: Kanhere
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Saverio
authors.identifier: 0000-0001-7063-4381
authors.initials: S
authors.lastname: Brogna
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002478:Cells, Cultured; D002874:Chromosome Mapping; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D039601:Eukaryotic Initiation Factor-4A / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D007438:Introns; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D059007:Polytene Chromosomes / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C107372:Mago protein, Drosophila; D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C440016:tsu protein, Drosophila; D039601:Eukaryotic Initiation Factor-4A
keywords: D. melanogaster; EJC; chromosomes; genes; splicing; translation