Involved in pre-mRNA splicing as component of the spliceosome (, ). Required for the assembly of the U4/U5/U6 tri-snRNP complex, one of the building blocks of the spliceosome .
Subcellular locations: Nucleus, Nucleus speckle, Nucleus, Cajal body
Predominantly found in speckles and in Cajal bodies.
Ubiquitously expressed.