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Peak Mitotic Cyclin Permits Mitotic Exit, Benjamin Drapkin

Student Theses and Dissertations

In eukaryotes, DNA replication, mitosis, and cytokinesis are all regulated by Cyclin-dependent kinase (Cdk). Cyclin/Cdk complexes promote replication origin firing and mitotic entry, and conversely, inhibit pre-replication origin loading and exit from mitosis. Cyclin synthesis and degradation, Cdk phosphorylation and Cdk inhibitors are controlled such that Cdk activity oscillates once per cell cycle. Little is known about the quantitative relationship between the level of Cdk activity and the occurrence, rate, and coordination of cell cycle events. We have addressed this question in Saccharomyces cerevisiae by introducing titrated levels of undegradable mitotic B-cyclin (Clb2kd) in cells prior to release of a …