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DnaA couples DNA replication and the expression of two cell cycle master regulators
Author(s) -
Collier Justine,
Murray Sean Richard,
Shapiro Lucy
Publication year - 2006
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600927
Subject(s) - biology , dna replication , library science , genetics , dna , computer science
Cell cycle progression in Caulobacter is driven by the master transcriptional regulators CtrA and GcrA. The cellular levels of CtrA and GcrA are temporally and spatially out‐of‐phase during the cell cycle, with CtrA repressing gcrA transcription and GcrA activating ctrA transcription. Here, we show that DnaA, a protein required for the initiation of DNA replication, also functions as a transcriptional activator of gcrA , which in turn activates multiple genes, notably those involved in chromosome replication and segregation. The cellular concentration of DnaA is cell cycle‐controlled, peaking at the time of replication initiation and gcrA induction. Regulated proteolysis of GcrA contributes to the cell cycle variations in GcrA abundance. We propose that DnaA couples DNA replication initiation with the expression of the two oscillating regulators GcrA and CtrA and that the DnaA/GcrA/CtrA regulatory cascade drives the forward progression of the Caulobacter cell cycle.