title: Auxiliary splice factor U2AF26 and transcription factor Gfi1 cooperate directly in regulating CD45 alternative splicing.
abstract: By alternative splicing, different isoforms of the transmembrane tyrosine phosphatase CD45 are generated that either enhance or limit T cell receptor signaling. We report here that CD45 alternative splicing is regulated by cooperative action of the splice factor U2AF26 and the transcription factor Gfi1. U2AF26 promoted formation of the less-active CD45RO by facilitating exon exclusion. Gfi1 antagonized that process by directly interacting with U2AF26, identifying a previously unknown link between a transcription factor and alternative splicing. The presence of Gfi1 led to formation of the more-active CD45RB, whereas loss of Gfi1 favored CD45RO production. We propose that the relative abundance of U2AF26 and Gfi1 determines the ratio of CD45 isoforms, thereby regulating T cell activation.
authors.affiliation: Institut für Zellbiologie (Tumorforschung), Universitätsklinikum Essen, Virchowstrasse 173, D-45122 Essen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Heyd
authors.forename: Gerdy
authors.initials: G
authors.lastname: ten Dam
authors.forename: Tarik
authors.initials: T
authors.lastname: Möröy
mesh_terms: D016475:3T3 Cells; D017398:Alternative Splicing; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry; D015151:Immunoblotting; D047468:Immunoprecipitation; D017493:Leukocyte Common Antigens / Q000235:genetics*; D008213:Lymphocyte Activation / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*; D014162:Transfection
chemical_list: D004268:DNA-Binding Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; D017493:Leukocyte Common Antigens