title: Ordered proteolysis in anaphase inactivates Plk1 to contribute to proper mitotic exit in human cells.
abstract: We have found that key mitotic regulators show distinct patterns of degradation during exit from mitosis in human cells. Using a live-cell assay for proteolysis, we show that two of these regulators, polo-like kinase 1 (Plk1) and Aurora A, are degraded at different times after the anaphase-promoting complex/cyclosome (APC/C) switches from binding Cdc20 to Cdh1. Therefore, events in addition to the switch from Cdc20 to Cdh1 control the proteolysis of APC/C(Cdh1) substrates in vivo. We have identified a putative destruction box in Plk1 that is required for degradation of Plk1 in anaphase, and have examined the effect of nondegradable Plk1 on mitotic exit. Our results show that Plk1 proteolysis contributes to the inactivation of Plk1 in anaphase, and that this is required for the proper control of mitotic exit and cytokinesis. Our experiments reveal a role for APC/C-mediated proteolysis in exit from mitosis in human cells.
authors.affiliation: Wellcome Trust/Cancer Research UK Gurdon Institute, Tennis Court Rd., Cambridge CB2 1QR, England, UK. c.lindon@welc.cam.ac.uk
authors.forename: Catherine
authors.initials: C
authors.lastname: Lindon
authors.forename: Jonathon
authors.initials: J
authors.lastname: Pines
mesh_terms: D000705:Anaphase / Q000502:physiology*; D064173:Anaphase-Promoting Complex-Cyclosome; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D064199:Cdc20 Proteins; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D010450:Endopeptidases / Q000378:metabolism*; D017930:Genes, Reporter; D006367:HeLa Cells / Q000166:cytology; D006801:Humans; D007700:Kinetics; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008247:Lysosomes / Q000648:ultrastructure; D008938:Mitosis / Q000502:physiology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D064173:Anaphase-Promoting Complex-Cyclosome; D001426:Bacterial Proteins; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D010450:Endopeptidases; D008164:Luminescent Proteins; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D000097869:Polo-Like Kinase 1; C054562:yellow fluorescent protein, Bacteria; C577488:CDC20 protein, human