title: The site of RanGTP generation can act as an organizational cue for mitotic microtubules.
abstract: BACKGROUND
  RanGTP, which is generated on chromosomes during mitosis, is required for microtubule spindle assembly. Due to its restricted spatial generation within the cell it has been suggested that RanGTP acts as a spatial cue to organize site-specific spindle assembly within the cell. However, the absence of a detectable sharp gradient of RanGTP in somatic cells has led to suggestions that it may only act as a spatial cue in large cells and that it may operate as a general activator of the mitotic cytosol in somatic cells.
  
  
  RESULTS
  We report that ectopic generation of RanGTP at the plasma membrane stimulates the formation of organized arrays of microtubules at the plasma membrane.
  
  
  CONCLUSIONS
  These results suggest that the site of RanGTP generation in a mitotic somatic cell can generate critical spatial information that specifies where microtubules grow towards and where microtubules are organized. As RanGTP is normally generated on chromosomes, these results suggest that RanGTP may play an important role in specifying that spindle assembly occurs around chromosomes.
authors.affiliation: Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
authors.forename: Julia
authors.initials: J
authors.lastname: Zonis
authors.forename: Andrew
authors.initials: A
authors.lastname: Wilde
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D009687:Nuclear Proteins / Q000378:metabolism*; D021381:Protein Transport; D008941:Spindle Apparatus / Q000378:metabolism; D020931:ran GTP-Binding Protein / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; C470243:KIF11 protein, human; D009687:Nuclear Proteins; C062521:RCC1 protein, human; D016547:Kinesins; D020931:ran GTP-Binding Protein