Dual role of the Cdc7-regulatory protein Dbf4 during yeast meiosis.
The Dbf4-dependent Cdc7 kinase (DDK) is essential for chromosome duplication in all eukaryotes, but was proposed to be dispensable for yeast pre-meiotic DNA replication. This discrepancy led us to investigate the role of the unstable Cdc7-regulatory protein Dbf4 in meiosis. We show that, when Dbf4 is depleted at the time of meiotic induction, cells enter the meiotic program but do not replicate their chromosomes. Surprisingly when Dbf4 is depleted after the initiation of DNA synthesis, S phase goes to completion, but most cells arrest before anaphase I. Deletion of the cohesin Rec8 suppresses this phenotype, suggesting a distinct role of DDK for meiotic chromosome segregation. As after Cdc5 depletion, a fraction of cells undergo a single equational division suggesting a failure to mono-orient sister kinetochores. Our results demonstrate that Dbf4 is essential for DNA replication during meiosis like in vegetative cells and provide evidence for an additional role in setting up the reductional division of meiosis I.
Valentin
Guillaume
G
Institute of Molecular Genetics and Université Montpellier II, CNRS UMR5535-1919, Route de Mende, F-34293 Montpellier Cedex 5, France.
Schwob
Etienne
E
Della Seta
Flavio
F
D000705:Anaphase; D018797:Cell Cycle Proteins / Q000502:physiology*; D020090:Chromosome Segregation; D002875:Chromosomes; D004261:DNA Replication; D008540:Meiosis / Q000235:genetics*; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D016196:S Phase; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D015003:Yeasts / Q000166:cytology* / Q000502:physiology
D018797:Cell Cycle Proteins; C088096:Dbf4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C081927:CDC5 protein, S cerevisiae