title: GM130 Regulates Golgi-Derived Spindle Assembly by Activating TPX2 and Capturing Microtubules.
abstract: Spindle assembly requires the coordinated action of multiple cellular structures to nucleate and organize microtubules in a precise spatiotemporal manner. Among them, the contributions of centrosomes, chromosomes, and microtubules have been well studied, yet the involvement of membrane-bound organelles remains largely elusive. Here, we provide mechanistic evidence for a membrane-based, Golgi-derived microtubule assembly pathway in mitosis. Upon mitotic entry, the Golgi matrix protein GM130 interacts with importin α via a classical nuclear localization signal that recruits importin α to the Golgi membranes. Sequestration of importin α by GM130 liberates the spindle assembly factor TPX2, which activates Aurora-A kinase and stimulates local microtubule nucleation. Upon filament assembly, nascent microtubules are further captured by GM130, thus linking Golgi membranes to the spindle. Our results reveal an active role for the Golgi in regulating spindle formation to ensure faithful organelle inheritance.
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Electronic address: wei@msg.ucsf.edu.
authors.forename: Jen-Hsuan
authors.initials: JH
authors.lastname: Wei
authors.affiliation: Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Zi Chao
authors.initials: ZC
authors.lastname: Zhang
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: R Max
authors.initials: RM
authors.lastname: Wynn
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Electronic address: joachim.seemann@utsouthwestern.edu.
authors.forename: Joachim
authors.initials: J
authors.lastname: Seemann
mesh_terms: D000818:Animals; D064096:Aurora Kinase A / Q000378:metabolism; D001324:Autoantigens / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D008941:Spindle Apparatus; D014981:Xenopus / Q000378:metabolism; D029867:Xenopus Proteins / Q000378:metabolism
chemical_list: D001324:Autoantigens; D018797:Cell Cycle Proteins; C097741:Golgin subfamily A member 2; D028884:Karyopherins; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C486551:TPX2 protein, Xenopus; C572046:TPX2 protein, mouse; D029867:Xenopus Proteins; D064096:Aurora Kinase A