Nuclear targeting of adenovirus type 2 requires CRM1-mediated nuclear export.
Incoming adenovirus type 2 (Ad2) and Ad5 shuttle bidirectionally along microtubules, biased to the microtubule-organizing center by the dynein/dynactin motor complex. It is unknown how the particles reach the nuclear pore complex, where capsids disassemble and viral DNA enters the nucleus. Here, we identified a novel link between nuclear export and microtubule-mediated transport. Two distinct inhibitors of the nuclear export factor CRM1, leptomycin B (LMB) and ratjadone A (RJA) or CRM1-siRNAs blocked adenovirus infection, arrested cytoplasmic transport of viral particles at the microtubule-organizing center or in the cytoplasm and prevented capsid disassembly and nuclear import of the viral genome. In mitotic cells where CRM1 is in the cytoplasm, adenovirus particles were not associated with microtubules but upon LMB treatment, they enriched at the spindle poles implying that CRM1 inhibited microtubule association of adenovirus. We propose that CRM1, a nuclear factor exported by CRM1 or a protein complex containing CRM1 is part of a sensor mechanism triggering the unloading of the incoming adenovirus particles from microtubules proximal to the nucleus of interphase cells.
Strunze
Sten
S
University of Zürich, Institute of Zoology, CH-8057 Zürich, Switzerland.
Trotman
Lloyd C
LC
Boucke
Karin
K
Greber
Urs F
UF
D021581:Active Transport, Cell Nucleus; D000256:Adenoviridae / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D002522:Chlorocebus aethiops; D004730:Endothelium, Vascular / Q000166:cytology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018613:Microscopy, Confocal; D022101:Microtubule-Organizing Center / Q000187:drug effects / Q000378:metabolism; D008938:Mitosis; D011753:Pyrones / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008941:Spindle Apparatus / Q000821:virology; D014168:Transferrin / Q000493:pharmacokinetics; D014471:Umbilical Veins / Q000166:cytology; D000097606:Exportin 1 Protein
D005231:Fatty Acids, Unsaturated; D049452:Green Fluorescent Proteins; D028884:Karyopherins; D011753:Pyrones; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D014168:Transferrin; D000097606:Exportin 1 Protein; C429103:ratjadone; C038753:leptomycin B