U2 Small Nuclear RNA Auxiliary Factor 1 (U2AF1)

U2AF1 belongs to the splicing factor SR family of genes. This gene encodes the small subunit which plays a critical role in both constitutive and enhancer-dependent RNA splicing by directly mediating interactions between the large subunit and proteins bound to the enhancers. Alternatively spliced transcript variants encoding different isoforms have been identified.DEK phosphorylated at serines 19 and 32 associates with U2AF35, facilitates the U2AF35-AG interaction, and prevents binding of U2AF65 to pyrimidine tracts not followed by AG. DEK and its phosphorylation are required for intron removal, but not for splicing complex assembly, which indicates that proofreading of early 3-prime splice site recognition influences catalytic activation of the spliceosome.