Functions as an U snRNP-specific nuclear import adapter. Involved in the trimethylguanosine (m3G)-cap-dependent nuclear import of U snRNPs. Binds specifically to the terminal m3G-cap U snRNAs.
Subcellular locations: Nucleus, Cytoplasm
Nucleoplasmic shuttling protein. Its nuclear import involves the nucleocytoplasmic transport receptor importin beta (, ). It is re-exported to the cytoplasm by the XPO1-dependent nuclear export receptor pathway .