U2AF1L4 is a RNA-binding protein that function as a pre-mRNA splicing factor. It plays a critical role in both constitutive and enhancer-dependent splicing by mediating protein-protein interactions and protein-RNA interactions required for accurate 3'-splice site selection. It acts by enhancing the binding of U2AF2 to weak pyrimidine tracts and also participates in the regulation of alternative pre-mRNA splicing. It activates exon 5 skipping of PTPRC during T-cell activation, an event reversed by GFI1. U2AF1L4 binds to RNA at the AG dinucleotide at the 3'-splice site. Protein Interaction Partner: MDM2, SUZ12, UBC, ELAVL1, GIGYF2, Protein Size: 220