SNUPN is a nuclear import adaptor protein which is part of the Snurportin family. SNUPN is Localized to the cytoplasm and nucleus and contains an N-terminal IBB domain and a trimethylguanosine (m3G)-cap binding domain. SNUPN binds specifically the terminal 2,2,7-m3G-cap at the 5 end of U snRNPs and is involved in transport of U snRNPs into the nucleus through an association with Importin beta Synonyms: KPNBL, RNUT1, Snurportin1, SPN1, RNA U transporter 1