Dual role of the Cdc7-regulatory protein Dbf4 during yeast meiosis

G. Valentin , E. Schwob (1) , F. Della Seta

1 IGMM - Institut de Génétique Moléculaire de Montpellier

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.

Mots clés: Anaphase Cell Cycle Proteins/*physiology Chromosome Segregation Chromosomes DNA Replication Meiosis/*genetics Protein Kinases S Phase Saccharomyces cerevisiae Proteins/*physiology Yeasts/*cytology/physiology

Domaines: Biochimie, Biologie Moléculaire

G. Valentin, E. Schwob, F. Della Seta. Dual role of the Cdc7-regulatory protein Dbf4 during yeast meiosis. Journal of Biological Chemistry, 2006, 281 (5), pp.2828--34. ⟨10.1074/jbc.M510626200⟩. ⟨hal-02262473⟩