Microtubule assembly in meiotic extract requires glycogen

• Published in: Molecular biology of the cell Vol. 22; no. 17; pp. 3139 - 3151
• Main Authors: Groen, Aaron C, Coughlin, Margaret, Mitchison, Timothy J
• Format: Journal Article
• Language: English
• Published: United States The American Society for Cell Biology 01.09.2011
• Subjects: Animals; Cell Extracts; Cell-Free System; Centrosome - metabolism; Glycogen - metabolism; Glycogen - pharmacology; Glycogen - physiology; Meiosis; Microtubules - metabolism; Mitosis; Mutation, Missense; Oocytes - metabolism; Phosphates - pharmacology; Phosphates - physiology; Potassium Compounds - pharmacology; ran GTP-Binding Protein - genetics; ran GTP-Binding Protein - metabolism; Xenopus laevis
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/mbc.e11-02-0158

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.