Cse1p is required for export of Srp1p/importin-alpha from the nucleus in Saccharomyces cerevisiae.

In metazoan cells, the CAS protein has been shown to function as a recycling factor for the importin-alpha subunit of the classical nuclear localization signal receptor, exporting importin-alpha from the nucleus to allow its participation in multiple rounds of nuclear import. CAS is a member of a family of proteins ...
that bear homology to the larger subunit of the nuclear localization signal receptor, importin-beta, and that are found in all eukaryotes from yeast to humans. Sequence similarity identifies the product of the Saccharomyces cerevisiae CSE1 gene as a potential CAS homologue. Here we present evidence that Cse1p is the functional homologue of CAS: Cse1p is required to prevent accumulation of Srp1p/importin-alpha in the nucleus, it localizes to the nuclear envelope in a pattern typical of nuclear transport receptors, and it associates in vivo with Srp1p in a nucleotide-specific manner. We show further that mutations in CSE1 and SRP1 have specific effects on their association and on the intracellular localization of Cse1p.
Mesh Terms:
Biological Transport, Cell Compartmentation, Cell Nucleus, Cellular Apoptosis Susceptibility Protein, Fungal Proteins, Green Fluorescent Proteins, Karyopherins, Luminescent Proteins, Nuclear Envelope, Nuclear Proteins, Nucleocytoplasmic Transport Proteins, Precipitin Tests, Protein Binding, Proteins, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, alpha Karyopherins
J. Biol. Chem.
Date: Dec. 25, 1998
Download Curated Data For This Publication
15182
Switch View:
  • Interactions 1