title: The Golgi mitotic checkpoint is controlled by BARS-dependent fission of the Golgi ribbon into separate stacks in G2.
abstract: The Golgi ribbon is a complex structure of many stacks interconnected by tubules that undergo fragmentation during mitosis through a multistage process that allows correct Golgi inheritance. The fissioning protein CtBP1-S/BARS (BARS) is essential for this, and is itself required for mitotic entry: a block in Golgi fragmentation results in cell-cycle arrest in G2, defining the 'Golgi mitotic checkpoint'. Here, we clarify the precise stage of Golgi fragmentation required for mitotic entry and the role of BARS in this process. Thus, during G2, the Golgi ribbon is converted into isolated stacks by fission of interstack connecting tubules. This requires BARS and is sufficient for G2/M transition. Cells without a Golgi ribbon are independent of BARS for Golgi fragmentation and mitotic entrance. Remarkably, fibroblasts from BARS-knockout embryos have their Golgi complex divided into isolated stacks at all cell-cycle stages, bypassing the need for BARS for Golgi fragmentation. This identifies the precise stage of Golgi fragmentation and the role of BARS in the Golgi mitotic checkpoint, setting the stage for molecular analysis of this process.
authors: Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy. colanzi@negrisud.it
authors: Antonino
authors: A
authors: Colanzi
authors: Cristina
authors: C
authors: Hidalgo Carcedo
authors: Angela
authors: A
authors: Persico
authors: Claudia
authors: C
authors: Cericola
authors: Gabriele
authors: G
authors: Turacchio
authors: Matteo
authors: M
authors: Bonazzi
authors: Alberto
authors: A
authors: Luini
authors: Daniela
authors: D
authors: Corda
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D016195:G2 Phase; D006056:Golgi Apparatus / Q000502:physiology* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis
chemical_list: D004268:DNA-Binding Proteins; D049452:Green Fluorescent Proteins; D000429:Alcohol Oxidoreductases; C096794:C-terminal binding protein