title: Mechanisms of activation and repression by the alternative splicing factors RBFOX1/2.
abstract: RBFOX1 and RBFOX2 are alternative splicing factors that are predominantly expressed in the brain and skeletal muscle. They specifically bind the RNA element UGCAUG, and regulate alternative splicing positively or negatively in a position-dependent manner. The molecular basis for the position dependence of these and other splicing factors on alternative splicing of their targets is not known. We explored the mechanisms of RBFOX splicing activation and repression using an MS2-tethering assay. We found that the Ala/Tyr/Gly-rich C-terminal domain is sufficient for exon activation when tethered to the downstream intron, whereas both the C-terminal domain and the central RRM are required for exon repression when tethered to the upstream intron. Using immunoprecipitation and mass spectrometry, we identified hnRNP H1, RALY, and TFG as proteins that specifically interact with the C-terminal domain of RBFOX1 and RBFOX2. RNA interference experiments showed that hnRNP H1 and TFG modulate the splicing activity of RBFOX1/2, whereas RALY had no effect. However, TFG is localized in the cytoplasm, and likely modulates alternative splicing indirectly.
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
authors.forename: Shuying
authors.initials: S
authors.lastname: Sun
authors.forename: Zuo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Oliver
authors.initials: O
authors.lastname: Fregoso
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Krainer
mesh_terms: D017398:Alternative Splicing; D001665:Binding Sites; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D005091:Exons; D006367:HeLa Cells; D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C / Q000378:metabolism; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H / Q000378:metabolism; D006801:Humans; D007438:Introns; D009154:Mutation; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism; D034622:RNA Interference; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D033921:Vesicular Transport Proteins
chemical_list: D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D011506:Proteins; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C116747:HNRNPH2 protein, human; C088730:RALY protein, human; C455479:RBFOX1 protein, human; C454924:RBFOX2 protein, human; C096163:TFG protein, human; D033921:Vesicular Transport Proteins