Involved in pre-mRNA splicing, specifically in spliceosome disassembly during late-stage splicing events. Intron turnover seems to proceed through reactions in two lariat-intron associated complexes termed Intron Large (IL) and Intron Small (IS). In cooperation with DHX15 seems to mediate the transition of the U2, U5 and U6 snRNP-containing IL complex to the snRNP-free IS complex leading to efficient debranching and turnover of excised introns. May play a role in the differentiation of ameloblasts and odontoblasts or in the forming of the enamel extracellular matrix (By similarity). Identified in the spliceosome C complex. Found in the Intron Large (IL) complex, a post-mRNA release spliceosomal complex containing the excised intron, U2, U5 and U6 snRNPs, and splicing factors. Interacts with TUFT1. Interacts with DHX15; indicative for a recruitment of DHX15 to the IL complex. Interacts with GCFC2 (By similarity). In the nucleus localizes to unique speckle domains in close proximity to nuclear speckles and not identical to paraspeckles. Belongs to the TFP11/STIP family.