title: Nuclear transporters in a multinucleated organism: functional and localization analyses in Aspergillus nidulans.
abstract: Nuclear transporters mediate bidirectional macromolecule traffic through the nuclear pore complex (NPC), thus participating in vital processes of eukaryotic cells. A systematic functional analysis in Aspergillus nidulans permitted the identification of 4 essential nuclear transport pathways of a hypothetical number of 14. The absence of phenotypes for most deletants indicates redundant roles for these nuclear receptors. Subcellular distribution studies of these carriers show three main distributions: nuclear, nucleocytoplasmic, and in association with the nuclear envelope. These locations are not specific to predicted roles as exportins or importins but indicate that bidirectional transport may occur coordinately in all nuclei of a syncytium. Coinciding with mitotic NPC rearrangements, transporters dynamically modified their localizations, suggesting supplementary roles to nucleocytoplasmic transport specifically during mitosis. Loss of transportin-SR and Mex/TAP from the nuclear envelope indicates absence of RNA transport during the partially open mitosis of Aspergillus, whereas nucleolar accumulation of Kap121 and Kap123 homologues suggests a role in nucleolar disassembly. This work provides new insight into the roles of nuclear transporters and opens an avenue for future studies of the molecular mechanisms of transport among nuclei within a common cytoplasm, using A. nidulans as a model organism.
authors: Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, National Research Council, 28040 Madrid, Spain.
authors: Ane
authors: A
authors: Markina-Iñarrairaegui
authors: Oier
authors: O
authors: Etxebeste
authors: Erika
authors: E
authors: Herrero-García
authors: Lidia
authors: L
authors: Araújo-Bazán
authors: Javier
authors: J
authors: Fernández-Martínez
authors: Jairo A
authors: JA
authors: Flores
authors: Stephen A
authors: SA
authors: Osmani
authors: Eduardo A
authors: EA
authors: Espeso
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D001233:Aspergillus nidulans / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D015153:Blotting, Western; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D028884:Karyopherins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008938:Mitosis / Q000502:physiology*; D022022:Nuclear Pore / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D012313:RNA / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D014161:Transduction, Genetic; D028961:beta Karyopherins / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D028884:Karyopherins; D028861:Nuclear Pore Complex Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D028961:beta Karyopherins; C119888:transportin SR; D012313:RNA