Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 1995 Feb 28;92(5):1769-73.
doi: 10.1073/pnas.92.5.1769.

Identification of a protein complex that is required for nuclear protein import and mediates docking of import substrate to distinct nucleoporins

A Radu  1 , G Blobel, M S Moore
Affiliations
Comparative Study

Identification of a protein complex that is required for nuclear protein import and mediates docking of import substrate to distinct nucleoporins

A Radu et al. Proc Natl Acad Sci U S A. .

Abstract

We have identified and characterized a 9S protein complex from a Xenopus ovary cytosolic subfraction (fraction A) that constitutes this fraction's activity in recognizing a model nuclear import substrate and docking it at the nuclear pore complex. Because of its function, the complex is termed karyopherin. The 54- and 56-kDa subunits of the complex are termed alpha 1 and alpha 2, respectively, and the 97-kDa subunit is termed beta. In an alternative approach we have identified karyopherin beta from a rat liver cytosolic subfraction A by using immobilized rat nucleoporin Nup98 in a single, affinity-based enrichment step. We have molecularly cloned and sequenced rat karyopherin beta. Comparison with protein sequence data banks showed no significant similarity to other known proteins. Using nitrocellulose-immobilized rat liver nuclear envelope proteins and nuclear import substrate as a ligand, we found Xenopus fraction A-dependent binding to at least three bona fide nucleoporins (Nup214, Nup153, and Nup98) and to a candidate nucleoporin with an estimated molecular mass of 270 kDa. We propose that these nucleoporins function as docking proteins for karyopherin-mediated binding of substrate in a nuclear import/export pathway across the nuclear pore complex.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. J Cell Biol. 1993 Dec;123(6 Pt 1):1333-44 - PubMed
    1. Trends Cell Biol. 1994 Oct;4(10):357-65 - PubMed
    1. Nature. 1993 Dec 9;366(6455):585-7 - PubMed
    1. Cell. 1993 Jan 15;72(1):29-38 - PubMed
    1. J Cell Biol. 1993 Apr;121(1):1-9 - PubMed

Publication types

Substances

Associated data

LinkOut - more resources

  NODES
INTERN 1
twitter 2