Distinct modes of cyclin E/Cdc2c kinase regulation and S-phase control in mitotic and endoreduplicating cycles of Drosophila embryogenesis

dc.contributor.authorSauer, Karstenen
dc.contributor.authorKnoblich, Jurgen A.en
dc.contributor.authorRichardson, Helena Elizabethen
dc.contributor.authorLehner, Christian F.en
dc.date.issued1995en
dc.description.abstractDrosophila cyclin E (DmcycE) is required in embryos for S phase of mitotic and endoreduplication cycles. Here, we describe regulatory differences characteristic for these two cell cycle types. While DmcycE transcript levels decline in DmcycE mutant cells programmed for mitotic proliferation, they are maintained and no longer restricted to transient pulses in DmcycE mutant cells programmed for endoreduplication. Moreover, DmcycE expression in endoreduplicating cells is down-regulated by ectopic expression of a heat-inducible cyclin E transgene. DmcycE expression in endoreduplicating tissues, therefore, is restricted by a negative feedback to the transient pulse triggering entry into S-phase. Conversely, during mitotic cycles, where S phase entry is not only dependent on cyclin E but also on progression through M phase, cyclin E and associated Dmcdc2c kinase activity are present throughout the cell cycle. Reinitiation of DNA replication during the G2 phase of the mitotic cell cycle, therefore, is prevented by cyclin E/Dmcdc2c kinase-independent regulation. Observations in cyclin A mutants implicate G2 cyclins in this regulation. Our results suggest molecular explanations for the different rules governing S phase during mitotic and endoreduplication cycles.en
dc.description.statementofresponsibilityKarsten Sauer, Jürgen A. Knoblich, Helena Richardson, and Christian F. Lehneren
dc.identifier.citationGenes and Development, 1995; 9(11):1327-1339en
dc.identifier.doi10.1101/gad.9.11.1327en
dc.identifier.issn0890-9369en
dc.identifier.urihttp://hdl.handle.net/2440/11432
dc.language.isoenen
dc.publisherCold Spring Harbor Laboratory Pressen
dc.rights© 1995 by Cold Spring Harbor Laboratory Pressen
dc.subjectCyclin A; cyclin E; Dmcdc2c kinase; S phase; endoreduplication; Drosophilaen
dc.titleDistinct modes of cyclin E/Cdc2c kinase regulation and S-phase control in mitotic and endoreduplicating cycles of Drosophila embryogenesisen
dc.typeJournal articleen

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