The U1 small nuclear ribonucleoprotein (snRNP) 70K protein is transported independently of U1 snRNP particles via a nuclear localization signal in the RNA-binding domain.

摘要: Expression of the recombinant human U1-70K protein in COS cells resulted its rapid transport to nucleus, even when binding U1 RNA was debilitated. Deletion analysis revealed existence two segments which were independently capable nuclear localization. One localization signal (NLS) mapped within RNA-binding domain and consists typically separated but interdependent elements. The major element this NLS resides structural loop 5 between beta 4 strand alpha 2 helix folded recognition motif. C-terminal half entry contains arginine-rich regions, suggests a second NLS. Site-directed mutagenesis motif demonstrated that can be transported association with small ribonucleoprotein particle occur nucleus.