title: Stimulation of microtubule aster formation and spindle assembly by the small GTPase Ran.
abstract: Ran, a small guanosine triphosphatase, is suggested to have additional functions beyond its well-characterized role in nuclear trafficking. Guanosine triphosphate-bound Ran, but not guanosine diphosphate-bound Ran, stimulated polymerization of astral microtubules from centrosomes assembled on Xenopus sperm. Moreover, a Ran allele with a mutation in the effector domain (RanL43E) induced the formation of microtubule asters and spindle assembly, in the absence of sperm nuclei, in a gammaTuRC (gamma-tubulin ring complex)- and XMAP215 (Xenopus microtubule associated protein)-dependent manner. Therefore, Ran could be a key signaling molecule regulating microtubule polymerization during mitosis.
authors.affiliation: Carnegie Institution of Washington, Department of Embryology, Baltimore, MD 21210, USA.
authors.forename: A
authors.initials: A
authors.lastname: Wilde
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000818:Animals; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D018385:Centrosome / Q000502:physiology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004398:Dyneins / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D009154:Mutation; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010063:Ovum; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000494:pharmacology; D013077:Sperm Head / Q000502:physiology; D008941:Spindle Apparatus / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D014404:Tubulin / Q000032:analysis / Q000378:metabolism; D014981:Xenopus; D029867:Xenopus Proteins; D020931:ran GTP-Binding Protein
chemical_list: D002457:Cell Extracts; D008869:Microtubule-Associated Proteins; C489079:NUMA1 protein, Xenopus; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D029867:Xenopus Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D004398:Dyneins; D020931:ran GTP-Binding Protein; D004121:Dimethyl Sulfoxide