Splice factor required for alternative splicing of TRA2B/SFRS10 transcripts. May interfere with constitutive 5'-splice site selection (By similarity). Interacts with the C-terminal half of SNRP70/U1-70K, the Arg/Ser-rich domain of AKAP17A as well as with U2AF1 and CLK1. The RanBP2-type zinc fingers mediate binding to RNA. Phosphorylated on Ser-310 upon DNA damage, probably by ATM or ATR. Belongs to the ZRANB2 family.