title: Protein 4.1R Exon 16 3' Splice Site Activation Requires Coordination among TIA1, Pcbp1, and RBM39 during Terminal Erythropoiesis.
abstract: Exon 16 of protein 4.1R encodes a spectrin/actin-binding peptide critical for erythrocyte membrane stability. Its expression during erythroid differentiation is regulated by alternative pre-mRNA splicing. A UUUUCCCCCC motif situated between the branch point and the 3' splice site is crucial for inclusion. We show that the UUUU region and the last three C residues in this motif are necessary for the binding of splicing factors TIA1 and Pcbp1 and that these proteins appear to act in a collaborative manner to enhance exon 16 inclusion. This element also activates an internal exon when placed in a corresponding intronic position in a heterologous reporter. The impact of these two factors is further enhanced by high levels of RBM39, whose expression rises during erythroid differentiation as exon 16 inclusion increases. TIA1 and Pcbp1 associate in a complex containing RBM39, which interacts with U2AF65 and SF3b155 and promotes U2 snRNP recruitment to the branch point. Our results provide a mechanism for exon 16 3' splice site activation in which a coordinated effort among TIA1, Pcbp1, and RBM39 stabilizes or increases U2 snRNP recruitment, enhances spliceosome A complex formation, and facilitates exon definition through RBM39-mediated splicing regulation.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA shu-ching_huang@dfci.harvard.edu.|Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.|Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Shu-Ching
authors.initials: SC
authors.lastname: Huang
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Henry S
authors.initials: HS
authors.lastname: Zhang
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Yu
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: McMahon
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Dan T
authors.initials: DT
authors.lastname: Nguyen
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Faye H
authors.initials: FH
authors.lastname: Yu
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Ou
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors.forename: Jennie Park
authors.initials: JP
authors.lastname: Ou
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.|Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.|Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.|Dana-Farber/Harvard Cancer Center, Boston, Massachusetts, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Benz
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D045744:Cell Line, Tumor; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins; D004920:Erythropoiesis / Q000235:genetics / Q000502:physiology*; D057809:HEK293 Cells; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D039102:Poly(A)-Binding Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D000072260:RNA Splicing Factors / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D017381:Spliceosomes / Q000378:metabolism; D000072668:Splicing Factor U2AF / Q000378:metabolism; D000074019:T-Cell Intracellular Antigen-1
chemical_list: D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C084105:HCC1 autoantigen; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C094604:PCBP1 protein, human; D010750:Phosphoproteins; D039102:Poly(A)-Binding Proteins; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; C112491:SF3B1 protein, human; D000072668:Splicing Factor U2AF; D000074019:T-Cell Intracellular Antigen-1; C071558:TIA1 protein, human; C000607494:U2AF2 protein, human; C028841:erythrocyte membrane band 4.1 protein
keywords: Pcbp1; RBM39; TIA1; alternative splicing; erythropoiesis; protein 4.1R