GLE2, a Saccharomyces cerevisiae homologue of the Schizosaccharomyces pombe export factor RAE1, is required for nuclear pore complex structure and function.
To identify and characterize novel factors required for nuclear transport, a genetic screen was conducted in the yeast Saccharomyces cerevisiae. Mutations that were lethal in combination with a null allele of the gene encoding the nucleoporin Nup100p were isolated using a colony-sectoring assay. Three complementation groups of gle (for GLFG lethal) mutants were identified. In this report, the characterization of GLE2 is detailed. GLE2 encodes a 40.5-kDa polypeptide with striking similarity to that of Schizosaccharomyces pombe RAE1. In indirect immunofluorescence and nuclear pore complex fractionation experiments, Gle2p was associated with nuclear pore complexes. Mutated alleles of GLE2 displayed blockage of polyadenylated RNA export; however, nuclear protein import was not apparently diminished. Immunofluorescence and thin-section electron microscopic analysis revealed that the nuclear pore complex and nuclear envelope structure was grossly perturbed in gle2 mutants. Because the clusters of herniated pore complexes appeared subsequent to the export block, the structural perturbations were likely indirect consequences of the export phenotype. Interestingly, a two-hybrid interaction was detected between Gle2p and Srp1p, the nuclear localization signal receptor, as well as Rip1p, a nuclear export signal-interacting protein. We propose that Gle2p has a novel role in mediating nuclear transport.
Murphy
R
R
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Watkins
J L
JL
Wente
S R
SR
D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000235:genetics*; D020690:GTPase-Activating Proteins; D015966:Gene Expression Regulation, Fungal; D005804:Genes, Lethal; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009685:Nuclear Envelope / Q000378:metabolism; D034521:Nuclear Matrix-Associated Proteins; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins / Q000235:genetics; D029543:Nucleocytoplasmic Transport Proteins; D010455:Peptides / Q000235:genetics; D011061:Poly A / Q000378:metabolism; D011506:Proteins / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D028901:alpha Karyopherins
D005656:Fungal Proteins; C490524:GLE2 protein, S cerevisiae; D020690:GTPase-Activating Proteins; D008565:Membrane Proteins; C077731:NUP100 protein, S cerevisiae; C077730:NUP116 protein, S cerevisiae; C088627:NUP145 protein, S cerevisiae; D034521:Nuclear Matrix-Associated Proteins; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D010455:Peptides; D011506:Proteins; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D028901:alpha Karyopherins; C092953:rae1 protein, S pombe; D011061:Poly A