title: Microtubule assembly in meiotic extract requires glycogen.
abstract: The assembly of microtubules during mitosis requires many identified components, such as γ-tubulin ring complex (γ-TuRC), components of the Ran pathway (e.g., TPX2, HuRP, and Rae1), and XMAP215/chTOG. However, it is far from clear how these factors function together or whether more factors exist. In this study, we used biochemistry to attempt to identify active microtubule nucleation protein complexes from Xenopus meiotic egg extracts. Unexpectedly, we found both microtubule assembly and bipolar spindle assembly required glycogen, which acted both as a crowding agent and as metabolic source glucose. By also reconstituting microtubule assembly in clarified extracts, we showed microtubule assembly does not require ribosomes, mitochondria, or membranes. Our clarified extracts will provide a powerful tool for activity-based biochemical fractionations for microtubule assembly.
authors: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA. aaron_groen@hms.harvard.edu
authors: Aaron C
authors: AC
authors: Groen
authors: Margaret
authors: M
authors: Coughlin
authors: Timothy J
authors: TJ
authors: Mitchison
mesh_terms: D000818:Animals; D002457:Cell Extracts; D002474:Cell-Free System; D018385:Centrosome / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D008540:Meiosis; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D020125:Mutation, Missense; D009865:Oocytes / Q000378:metabolism*; D010710:Phosphates / Q000494:pharmacology / Q000502:physiology; D017680:Potassium Compounds / Q000494:pharmacology; D014982:Xenopus laevis; D020931:ran GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D002457:Cell Extracts; D010710:Phosphates; D017680:Potassium Compounds; D006003:Glycogen; C013216:potassium phosphate; D020931:ran GTP-Binding Protein