Required for pre-mRNA splicing as component of the activated spliceosome. Involved in the first step of pre-mRNA splicing. Binds directly to the internal stem-loop (ISL) domain of the U6 snRNA and to the pre-mRNA intron near the 5' splice site during the activation and catalytic phases of the spliceosome cycle. Involved in both translocations of the nuclear SLU7 to the cytoplasm and the cytosolic calcium-binding protein PDCD6 to the nucleus upon cellular stress responses. Component of the pre-catalytic and catalytic spliceosome complexes. Component of the postcatalytic spliceosome P complex. Interacts with PDCD6; the interaction induces translocation of PDCD6 in the cytoplasm. Interacts with PPIL1 (By similarity). Nearly exclusively nuclear. Translocated from the nucleus to the cytoplasm after heat shock cell treatment. May be shuttling between the nucleus and the cytosol. The C-terminal RRM domain and the zinc finger motif are necessary for RNA-binding. Belongs to the SLT11 family.