Involved in pre-mRNA splicing, specifically in spliceosome disassembly during late-stage splicing events (By similarity). Involved in snRNPs recycling (PubMed:25568310). Required for efficient splicing of genes that act within the plant circadian clock (PubMed:23110899). Part of a transcription elongation checkpoint at alternative exons (PubMed:25568310). Required for correct expression and splicing of DOG1, a regulator of seed dormancy (PubMed:25568310). May induce transient transcriptional pausing of polymerase II at slices sites (PubMed:25568310). Identified in the spliceosome C complex (By similarity). Interacts with ILP1 (PubMed:25568310). Excluded from the nucleolus. Co-localizes with polymerase II. Long circadian-period phenotype under free-running conditions. Physically located at the target splice sites. Belongs to the TFP11/STIP family. Truncated N-terminus. Truncated N-terminus.