title: Coupling of mitosis to the completion of S phase through Cdc34-mediated degradation of Wee1.
abstract: The dependence of mitosis on the completion of the period of DNA replication in the cell cycle [synthesis (S) phase] ensures that chromosome segregation occurs only after the genome has been fully duplicated. A key negative regulator of mitosis, the protein kinase Wee1, was degraded in a Cdc34-dependent fashion in Xenopus egg extracts. This proteolysis event was required for a timely entrance into mitosis and was inhibited when DNA replication was blocked. Therefore, the DNA replication checkpoint can prevent mitosis by suppressing the proteolysis of Wee1 during S phase.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla, CA 92093-0347, USA. wmichael@biomail.ucsd.edu
authors.forename: W M
authors.initials: WM
authors.lastname: Michael
authors.forename: J
authors.initials: J
authors.lastname: Newport
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004261:DNA Replication / Q000187:drug effects; D005260:Female; D016195:G2 Phase; D007976:Leupeptins / Q000494:pharmacology; D008025:Ligases / Q000378:metabolism*; D008297:Male; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008938:Mitosis; D009687:Nuclear Proteins; D019319:Okadaic Acid / Q000494:pharmacology; D010063:Ovum; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D016196:S Phase; D013094:Spermatozoa; D025521:Tumor Suppressor Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D014981:Xenopus; D029867:Xenopus Proteins; D020687:cdc25 Phosphatases
chemical_list: D018797:Cell Cycle Proteins; D007976:Leupeptins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D011506:Proteins; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D014452:Ubiquitins; D029867:Xenopus Proteins; C493963:Xicl protein, Xenopus; C063261:acetylleucyl-leucyl-norleucinal; D050760:Cyclin-Dependent Kinase Inhibitor p27; D019319:Okadaic Acid; D016590:Aphidicolin; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D044767:Ubiquitin-Protein Ligases; C095970:MYT1 kinase, Xenopus; C530005:WEE1 protein, Xenopus; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D016200:Maturation-Promoting Factor; D010749:Phosphoprotein Phosphatases; D020687:cdc25 Phosphatases; D008025:Ligases