A role for Cdc48/p97 and Aurora B in controlling chromatin condensation during exit from mitosis.
During cell division, chromosomes condense so that the replicated chromatids can be segregated by the mitotic spindle. While condensation is governed by cyclin-dependent kinase 1 (Cdk1) during mitotic entry and early mitosis, it is still poorly understood how condensation is maintained during anaphase after Cdk1 inactivation, and how decondensation is triggered in telophase. Here, we review recent reports that point to a novel role of Aurora B kinase in maintaining condensation and preventing premature nuclear envelope formation during exit from mitosis. Timely decondensation and nuclear envelope formation at the end of mitosis may then be triggered by two mechanisms. One is removing Aurora B phosphorylation marks from chromatin by specific phosphatases. The other is removing and inactivating Aurora B kinase itself by the ubiquitin system. We have recently provided evidence that the AAA ATPase Cdc48/p97 plays a central role in the inactivation of Aurora B, as it extracts ubiquitinated Aurora B from chromosomes and thus reduces chromatinassociated Aurora B activity.
Meyer
Hemmo
H
Institute of Biochemistry, ETH Zurich, Zurich 8093, Switzerland. hemmo.meyer@bc.biol.ethz.ch
Drozdowska
Alicja
A
Dobrynin
Grzegorz
G
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism; D005544:Forecasting; D008938:Mitosis / Q000502:physiology*; D008954:Models, Biological; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism; D000074405:Valosin Containing Protein
D018797:Cell Cycle Proteins; D002843:Chromatin; D025801:Ubiquitin; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D000251:Adenosine Triphosphatases; D000074405:Valosin Containing Protein