title: DNA damage-induced mitotic catastrophe is mediated by the Chk1-dependent mitotic exit DNA damage checkpoint.
abstract: Mitotic catastrophe is the response of mammalian cells to mitotic DNA damage. It produces tetraploid cells with a range of different nuclear morphologies from binucleated to multimicronucleated. In response to DNA damage, checkpoints are activated to delay cell cycle progression and to coordinate repair. Cells in different cell cycle phases use different mechanisms to arrest their cell cycle progression. It has remained unclear whether the termination of mitosis in a mitotic catastrophe is regulated by DNA damage checkpoints. Here, we report the presence of a mitotic exit DNA damage checkpoint in mammalian cells. This checkpoint delays mitotic exit and prevents cytokinesis and, thereby, is responsible for mitotic catastrophe. The DNA damage-induced mitotic exit delay correlates with the inhibition of Cdh1 activation and the attenuated degradation of cyclin B1. We demonstrate that the checkpoint is Chk1-dependent.
authors.affiliation: Department of Molecular Physiology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Xingxu
authors.initials: X
authors.lastname: Huang
authors.forename: Thanh
authors.initials: T
authors.lastname: Tran
authors.forename: Lingna
authors.initials: L
authors.lastname: Zhang
authors.forename: Rashieda
authors.initials: R
authors.lastname: Hatcher
authors.forename: Pumin
authors.initials: P
authors.lastname: Zhang
mesh_terms: D019313:BRCA1 Protein / Q000502:physiology; D000071877:Checkpoint Kinase 1; D064447:Checkpoint Kinase 2; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D004249:DNA Damage; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D011494:Protein Kinases / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology
chemical_list: D019313:BRCA1 Protein; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; C000605867:CHEK1 protein, human; C578634:CHEK2 protein, human; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases