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  • The EMBO Journal (2007) 26, 2465 - 2476
  • doi:10.1038/sj.emboj.7601686

Published online: 12 April 2007

The Golgi mitotic checkpoint is controlled by BARS-dependent fission of the Golgi ribbon into separate stacks in G2

Antonino Colanzi1, Cristina Hidalgo Carcedoab, Angela Persico, Claudia Cericola, Gabriele Turacchio, Matteo Bonazzi3, Alberto Luini and Daniela Corda

  1. Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy

Correspondence to:

, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Via Nazionale, 8/A, Santa Maria Imbaro, Chieti 66030, Italy. Tel.: +39 0872 570353; Fax: +39 0872 570412; E-mail: colanzi@negrisud.it

Daniela Corda, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Via Nazionale, 8/A, Santa Maria Imbaro, Chieti 66030, Italy. Tel.: +39 0872 570353; Fax: +39 0872 570412; E-mail: corda@negrisud.it

aThese authors contributed equally to this work

bPresent address: Tumour Cell Biology Laboratory, Cancer Research UK London Research Institute, London WC2A 3PX, UK.

cPresent address: Unité des Interactions Bactéries-Cellules, Institut Pasteur, 75015 Paris, France

Received 31 October 2006; Accepted 21 March 2007

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.

  • Keywords:

    • BARS,
    • fission,
    • G2,
    • Golgi complex,
    • mitotic checkpoint