Ran is required before metaphase for spindle assembly and chromosome alignment and after metaphase for chromosome segregation and spindle midbody organization.
The Ran pathway has been shown to have a role in spindle assembly. However, the extent of the role of the Ran pathway in mitosis in vivo is unclear. We report that perturbation of the Ran pathway disrupted multiple steps of mitosis in syncytial Drosophila embryos and uncovered new mitotic processes that are regulated by Ran. During the onset of mitosis, the Ran pathway is required for the production, organization, and targeting of centrosomally nucleated microtubules to chromosomes. However, the role of Ran is not restricted to microtubule organization, because Ran is also required for the alignment of chromosomes at the metaphase plate. In addition, the Ran pathway is required for postmetaphase events, including chromosome segregation and the assembly of the microtubule midbody. The Ran pathway mediates these mitotic events, in part, by facilitating the correct targeting of the kinase Aurora A and the kinesins KLP61F and KLP3A to spindles.
Department of Medical Genetics and Microbiology, University of Toronto, Toronto M5S 1A8, Ontario, Canada.
Rosalind V
RV
Silverman-Gavrila
Andrew
A
Wilde
D021581:Active Transport, Cell Nucleus; D000818:Animals; D064127:Aurora Kinases; D018385:Centrosome / Q000378:metabolism; D020090:Chromosome Segregation; D002875:Chromosomes / Q000378:metabolism; D029721:Drosophila Proteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D016547:Kinesins / Q000032:analysis / Q000378:metabolism; D008677:Metaphase / Q000235:genetics; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D008941:Spindle Apparatus / Q000201:enzymology / Q000378:metabolism*; D020931:ran GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000502:physiology*
D029721:Drosophila Proteins; C093317:Klp3A protein, Drosophila; C084034:Klp61F protein, Drosophila; D008869:Microtubule-Associated Proteins; D029543:Nucleocytoplasmic Transport Proteins; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins; D020931:ran GTP-Binding Protein