function:Part of pre- and post-splicing multiprotein mRNP complexes. Involved in numerous pre-mRNA processing events. Promotes constitutive and exonic splicing enhancer (ESE)-dependent splicing activation by bridging together sequence-specific (SR family proteins, SFRS4, SFRS5 and TRA2B/SFRS10) and basal snRNP (SNRP70 and SNRPA1) factors of the spliceosome. Stimulates mRNA 3'-end cleavage independently of the formation of an exon junction complex. Binds both pre-mRNA and spliced mRNA 20-25 nt upstream of exon-exon junctions. Binds RNA and DNA with low sequence specificity and has similar preference for either double- or single-stranded nucleic acid substrates.,similarity:Belongs to the splicing factor SR family.,similarity:Contains 1 PWI domain.,subunit:Identified in the spliceosome C complex, at least composed of AQR, ASCC3L1, C19orf29, CDC40, CDC5L, CRNKL1, DDX23, DDX41, DDX48, DDX5, DGCR14, DHX35, DHX38, DHX8, EFTUD2, FRG1, GPATC1, HNRPA1, HNRPA2B1, HNRPA3, HNRPC, HNRPF, HNRPH1, HNRPK, HNRPM, HNRPR, HNRPU, KIAA1160, KIAA1604, LSM2, LSM3, MAGOH, MORG1, PABPC1, PLRG1, PNN, PPIE, PPIL1, PPIL3, PPWD1, PRPF19, PRPF4B, PRPF6, PRPF8, RALY, RBM22, RBM8A, RBMX, SART1, SF3A1, SF3A2, SF3A3, SF3B1, SF3B2, SF3B3, SFRS1, SKIV2L2, SNRPA1, SNRPB, SNRPB2, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF, SNRPG, SNW1, SRRM1, SRRM2, SYF2, SYNCRIP, TFIP11, THOC4, U2AF1, WDR57, XAB2 and ZCCHC8. Found in a pre-mRNA splicing complex with SFRS4, SFRS5, SNRP70, SNRPA1, SRRM1 and SRRM2. Found in a pre-mRNA exonic splicing enhancer (ESE) complex with SNRP70, SNRPA1, SRRM1 and TRA2B/SFRS10. Found in a mRNA splicing-dependent exon junction complex (EJC) with DEK, PRPF8, NCBP1, RBM8A, RNPS1, SRRM1 and THOC4. Interacts with BAT1, CPSF1, RBM8A, RNPS1, and THOC4. Seems to be a compound of RNA export complexes that are released from speckles in a ATP-dependent manner.,