RNA-binding protein involved in pre-mRNA splicing. Interacts with the PRP19C/Prp19 complex/NTC/Nineteen complex which is part of the spliceosome. Involved in regulating splice site selection. Binds preferentially RNA with A/C rich sequences and poly-C stretches. Interacts with PRPF19. Isoform 2: Interacts with U2AF65. The C-terminal part is necessary for the interaction with the PRP19C/Prp19 complex/NTC/Nineteen complex. The KH domains mediate RNA-binding. Belongs to the KHDC4 family. Extended N-terminus.