Necessary for the splicing of pre-mRNA. It is required for formation of the earliest ATP-dependent splicing complex and interacts with spliceosomal components bound to both the 5'- and 3'-splice sites during spliceosome assembly. It also is required for ATP-dependent interactions of both U1 and U2 snRNPs with pre-mRNA. Interacts with other spliceosomal components, via the RS domains, to form a bridge between the 5'- and 3'-splice site binding components, U1 snRNP and U2AF. Binds to purine-rich RNA sequences, either 5'-AGSAGAGTA-3' (S=C or G) or 5'-GTTCGAGTA-3'. Can bind to beta-globin mRNA and commit it to the splicing pathway. The phosphorylated form (by SRPK2) is required for cellular apoptosis in response to cisplatin treatment. Interacts with BRDT (By similarity). In vitro, self-associates and binds SRSF1/SFRS1 (ASF/SF2), SNRNP70 and U2AF1 but not U2AF2. Binds SREK1/SFRS12. Interacts with CCNL1 and CCNL2. Interacts with SCAF11. Interacts with ZRSR2/U2AF1-RS2. Interacts with CCDC55 (via C-terminus). Phosphorylation by SRPK2 provokes its redistribution from the nuclear speckle to nucleoplasm. Accumulates in a hypoacetylated/phosphorylated form in response to cisplatin treatment. Extensively phosphorylated on serine residues in the RS domain. Phosphorylated by SRPK2 and this causes its redistribution from the nuclear speckle to nucleoplasm and controls cell fate decision in response to cisplatin treatment. KAT5/TIP60 inhibits its phosphorylation by preventing SRPK2 nuclear translocation. Acetylation on Lys-52 by KAT5/TIP60 promotes its proteasomal degradation. This effect is counterbalanced by HDAC6, which positively controls SRSF2 protein level by deacetylating it and preventing its proteasomal degradation. Belongs to the splicing factor SR family.