Cloning and characterization of human karyopherin beta3.

Nuclear import of classical nuclear localization sequence-bearing proteins is mediated by karyopherin alpha/beta1 heterodimers. A second nuclear import pathway, mediated by karyopherin beta2 (transportin), recently was described for mRNA-binding proteins. Here we report the cloning and characterization of human karyopherin beta3, which may be involved in a third pathway for ...
nuclear import. Karyopherin beta3 was localized mainly to the cytosol and the nucleus, particularly the nuclear rim. It bound to several of the repeat-containing nucleoporins (Nup358, Nup214, Nup153, Nup98, and p62) in overlay and solution-binding assays and was competed away by karyopherin beta1. For Nup98, we localized this binding to the peptide repeat-containing region. Karyopherin beta3 contains two putative Ran-binding homology regions and bound to Ran-GTP in a solution-binding assay with much higher affinity than to Ran-GDP. Furthermore, it interacted with two ribosomal proteins in an overlay assay. We suggest that karyopherin beta3 is a nuclear transport factor that may mediate the import of some ribosomal proteins into the nucleus.
Mesh Terms:
Amino Acid Sequence, Cell Compartmentation, Cell Nucleus, Cloning, Molecular, Cytoplasm, DNA, Complementary, DNA-Binding Proteins, Escherichia coli, Escherichia coli Proteins, Fluorescent Antibody Technique, Guanosine Triphosphate, Hela Cells, Humans, Membrane Proteins, Molecular Sequence Data, Nuclear Pore Complex Proteins, Nuclear Proteins, Protein Binding, Proteins, Recombinant Proteins, Ribosomal Proteins, Sequence Homology, Amino Acid, beta Karyopherins, ran GTP-Binding Protein
Proc. Natl. Acad. Sci. U.S.A.
Date: Apr. 29, 1997
Download Curated Data For This Publication
1513
Switch View:
  • Interactions 3