Cdc28 activates exit from mitosis in budding yeast.
The activity of the cyclin-dependent kinase 1 (Cdk1), Cdc28, inhibits the transition from anaphase to G1 in budding yeast. CDC28-T18V, Y19F (CDC28-VF), a mutant that lacks inhibitory phosphorylation sites, delays the exit from mitosis and is hypersensitive to perturbations that arrest cells in mitosis. Surprisingly, this behavior is not due to a lack of inhibitory phosphorylation or increased kinase activity, but reflects reduced activity of the anaphase-promoting complex (APC), a defect shared with other mutants that lower Cdc28/Clb activity in mitosis. CDC28-VF has reduced Cdc20- dependent APC activity in mitosis, but normal Hct1- dependent APC activity in the G1 phase of the cell cycle. The defect in Cdc20-dependent APC activity in CDC28-VF correlates with reduced association of Cdc20 with the APC. The defects of CDC28-VF suggest that Cdc28 activity is required to induce the metaphase to anaphase transition and initiate the transition from anaphase to G1 in budding yeast.
Rudner
A D
AD
Department of Physiology, University of California, San Francisco, California 94143-0444, USA.
Hardwick
K G
KG
Murray
A W
AW
D000705:Anaphase / Q000502:physiology; D042846:CDC2-CDC28 Kinases; D064199:Cdc20 Proteins; D064200:Cdh1 Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase / Q000502:physiology; D018816:Genes, cdc / Q000502:physiology; D008938:Mitosis / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D004718:Saccharomycetales / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
C577495:CDC20 protein, S cerevisiae; C577583:CDH1 protein, S cerevisiae; D064199:Cdc20 Proteins; D064200:Cdh1 Proteins; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases