Involved in pre-mRNA splicing process. Identified in the spliceosome C complex (PubMed:11991638, PubMed:28502770, PubMed:28076346). Present in a spliceosome complex assembled in vitro containing CRNKL1, HPRP8BP and SNRPB2 (PubMed:12084575). Isoform 2 seems to be predominant in the spliceosome complex (PubMed:12084575). Interacts with PPIL2 (via the PPIase cyclophilin-type domain); they may form a trimeric complex with HSP90 (PubMed:15189447). Colocalizes with core spliceosomal snRNP proteins (PubMed:12084575). Widely expressed (PubMed:11342225). Highly expressed in testis (PubMed:12084575). Not detected in brain and lung (PubMed:12084575). May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the crooked-neck family. Truncated N-terminus. Truncated N-terminus.