title: Mitotic Golgi disassembly is required for bipolar spindle formation and mitotic progression.
abstract: During mitosis, the mammalian Golgi vesiculates and, upon partitioning, reassembles in each daughter cell; however, it is not clear whether the disassembly process per se is important for partitioning or is merely an outcome of mitotic entry. Here, we show that Golgi vesiculation is required for progression to metaphase. To prevent Golgi disassembly, we expressed HRP linked to a Golgi-resident protein and acutely triggered the polymerization of 3,3'-diaminobenzidine (DAB) in the Golgi lumen. The DAB polymer does not affect interphase cell viability, but inhibits Golgi fragmentation by nocodazole and brefeldin A and also halts cells in early mitosis. The arrest is Golgi specific and does not occur when DAB is polymerized in the endosomes. Cells with a DAB polymer in the Golgi enter mitosis normally but arrest with an intact Golgi clustered at a monopolar spindle and an active spindle assembly checkpoint (SAC). Mitotic progression is restored upon centrosome depletion by the Polo-like kinase 4 inhibitor, centrinone, indicating that the link between the Golgi and the centrosomes must be dissolved to reach metaphase. These results demonstrate that Golgi disassembly is required for mitotic progression because failure to vesiculate the Golgi activates the canonical SAC. This requirement suggests that cells actively monitor Golgi integrity in mitosis.
authors: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.
authors: Gianni
authors: G
authors: Guizzunti
authors: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390 joachim.seemann@UTsouthwestern.edu.
authors: Joachim
authors: J
authors: Seemann
mesh_terms: D015100:3,3'-Diaminobenzidine / Q000737:chemistry / Q000494:pharmacology; D020126:Brefeldin A / Q000494:pharmacology; D002461:Cell Line, Transformed; D048749:Cytokinesis; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D015739:Nocodazole / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013450:Sulfones / Q000494:pharmacology
chemical_list: D011743:Pyrimidines; D013450:Sulfones; C000599097:centrinone; D020126:Brefeldin A; D015100:3,3'-Diaminobenzidine; C490219:PLK4 protein, human; D017346:Protein Serine-Threonine Kinases; D015739:Nocodazole
keywords: Golgi disassembly; mitosis; spindle formation