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.

Journal Article (Journal Article)

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

Full Text

Duke Authors

Cited Authors

  • Romac, JM; Graff, DH; Keene, JD

Published Date

  • July 1994

Published In

Volume / Issue

  • 14 / 7

Start / End Page

  • 4662 - 4670

PubMed ID

  • 7516470

Pubmed Central ID

  • PMC358839

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/mcb.14.7.4662-4670.1994


  • eng

Conference Location

  • United States