Predicted to enable U2 snRNA binding activity. Predicted to be involved in mRNA splicing, via spliceosome and negative regulation of protein catabolic process. Predicted to be located in nucleolus and nucleoplasm. Predicted to be part of U2 snRNP and spliceosomal complex. Predicted to be active in nucleus. Is expressed in central nervous system and sensory organ. Orthologous to human SF3B3 (splicing factor 3b subunit 3).