Plays a role in pre-mRNA splicing as component of the U4/U6-U5 tri-snRNP complex that is involved in spliceosome assembly, and as component of the precatalytic spliceosome (spliceosome B complex).
Subcellular locations: Nucleus, Nucleus speckle
Highly expressed in retina, liver, kidney and blood. Detected at lower levels in heart and brain.