Genetic evidence for interactions between yeast importin alpha (Srp1p) and its nuclear export receptor, Cse1p

Mol Gen Genet. 1999 Jun;261(4-5):788-95. doi: 10.1007/s004380050022.


The yeast Srp1p protein functions as an import receptor for proteins bearing basic nuclear localization signals. Cse1p, the yeast homolog of mammalian CAS, recycles Srp1p back to the cytoplasm after import substrates have been released into the nucleoplasm. In this report we describe genetic interactions between SRP1 and CSE1. Results from genetic suppression and synthetic lethality studies demonstrate that these gene products interact to ensure accurate chromosome segregation. We also describe new mutant alleles of CSE1 and analyze a new temperature-sensitive allele of CSE1, cse1-2. This allele causes high levels of chromosome missegregation and cell cycle arrest during mitosis at the nonpermissive temperature.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Genes, Fungal
  • Genes, Lethal
  • Genotype
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Nucleocytoplasmic Transport Proteins
  • Restriction Mapping
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Signal Transduction
  • Suppression, Genetic
  • Temperature
  • alpha Karyopherins


  • CSE1 protein, S cerevisiae
  • Fungal Proteins
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • Saccharomyces cerevisiae Proteins
  • alpha Karyopherins