Involved in pre-mRNA splicing as component of the spliceosome (, ). Combines RNA-binding and PPIase activities ( , ). Binds mRNA and has a preference for single-stranded RNA molecules with poly-A and poly-U stretches, suggesting it binds to the poly(A)-region in the 3'-UTR of mRNA molecules ( ). Catalyzes the cis-trans isomerization of proline imidic peptide bonds in proteins ( , ). Inhibits KMT2A activity; this requires proline isomerase activity ( ).
Subcellular locations: Nucleus
Found in all the examined tissues including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas.