Transcriptional activator. Activates the gene for selenocysteine tRNA (tRNAsec). Binds to the SPH motif of small nuclear RNA (snRNA) gene promoters. Participates in efficient U6 RNA polymerase III transcription via its interaction with CHD8. Interacts with CHD8. Expressed in all tissues tested, with the strongest expression in ovary. Belongs to the GLI C2H2-type zinc-finger protein family.