Plays a role in alternative splice site selection during pre-mRNA splicing. Represses the splicing of MAPT/Tau exon 10 (By similarity). Found in a pre-mRNA splicing complex with SRSF4/SFRS4, SRSF5/SFRS5, SNRNP70, SNRPA1, SRRM1 and SRRM2. Interacts with PNN (By similarity). Extensively phosphorylated on serine residues in the RS domain. Belongs to the splicing factor SR family.