Grapes(Chk1) prevents nuclear CDK1 activation by delaying cyclin B nuclear accumulation.
Entry into mitosis is characterized by a dramatic remodeling of nuclear and cytoplasmic compartments. These changes are driven by cyclin-dependent kinase 1 (CDK1) activity, yet how cytoplasmic and nuclear CDK1 activities are coordinated is unclear. We injected cyclin B (CycB) into Drosophila melanogaster embryos during interphase of syncytial cycles and monitored effects on cytoplasmic and nuclear mitotic events. In untreated embryos or embryos arrested in interphase with a protein synthesis inhibitor, injection of CycB accelerates nuclear envelope breakdown and mitotic remodeling of the cytoskeleton. Upon activation of the Grapes(checkpoint kinase 1) (Grp(Chk1))-dependent S-phase checkpoint, increased levels of CycB drives cytoplasmic but not nuclear mitotic events. Grp(Chk1) prevents nuclear CDK1 activation by delaying CycB nuclear accumulation through Wee1-dependent and independent mechanisms.
Royou
Anne
A
Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA. royou@biology.ucsc.edu
McCusker
Derek
D
Kellogg
Douglas R
DR
Sullivan
William
W
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D048750:Cell Nucleus Division / Q000187:drug effects / Q000502:physiology; D000071877:Checkpoint Kinase 1; D019926:Cyclin B / Q000378:metabolism* / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D048749:Cytokinesis / Q000187:drug effects / Q000502:physiology; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects; D009154:Mutation; D009685:Nuclear Envelope / Q000187:drug effects / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011687:Purines / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D000077546:Roscovitine; D008941:Spindle Apparatus / Q000187:drug effects / Q000502:physiology; D013844:Thiazoles / Q000494:pharmacology
D018797:Cell Cycle Proteins; D019926:Cyclin B; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; D011687:Purines; D011804:Quinolines; C512984:RO 3306; D011994:Recombinant Proteins; D013844:Thiazoles; D000077546:Roscovitine; D016590:Aphidicolin; D003513:Cycloheximide; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; C508847:Wee1 protein, Drosophila; D000071877:Checkpoint Kinase 1; C000605877:grp protein, Drosophila; D016203:CDC2 Protein Kinase