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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1995-7-31
pubmed:abstractText
Drosophila 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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1327-39
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Distinct modes of cyclin E/cdc2c kinase regulation and S-phase control in mitotic and endoreduplication cycles of Drosophila embryogenesis.
pubmed:affiliation
Friedrich-Miescher-Laboratorium der Max-Planck-Gesellschaft, Tübingen, Germany.
pubmed:publicationType
Journal Article